snack foods processing - cap16

CHAPTER 16

Rice-Based Snack Foods

SHIN LUTSE-CHIN LIN

1. INTRODUCTION

TWO topics are covered in this chapter: rice milling and an introduction to

rice-based snack foods. Most rice snacks in Taiwan are made from either

normal indica or waxy japonica rice.

Rice growing has had a direct impact on Taiwanese and southern Chinese

culture. As an integral part of their history, rice can be traced back to 4000 BC

when the “Seed in the spring, plow in the summer, harvest in the fall and store

in the winter” proverb originated. In Taiwan, 90% of all rice is consumed as

cooked whole kernels. The rest is milled to produce flour, which is used to make

cakes, desserts and snacks, primarily for special feasts or celebrations [1].

In the United States, rice is usually classified by length of grain: short, medium

and long. In Taiwan, indica rice refers to long grains, while japonica refers to

short grains. The United States produces mostly long-grain and intermediate-

grain rice in Arkansas, Mississippi, Louisiana, Texas and Missouri. California

produces medium or short-grain rice. Taiwan produces mostly japonica rice

with only 10% indica, waxy indica, or waxy japonica varieties. Physical prop-

erties of major rice varieties grown in Taiwan are shown in Table 16.1.

2. RICE MILLING

Rough or paddy rice is shelled usually using rubber rolls and aspiration to

remove the hulls. The brown rice is then milled using abrasive mills (pearlers)

to remove the bran. The milled (polished) rice consists of whole intact starchy

©2001 CRC Press LLC

TABLE 16.1. Physical Properties of Milled Indica, Japonica and Waxy RiceVarieties Grown in Taiwan [2].

1,000 Kernel Kernel Length Kernel Width ShapeRice Varieties Weight (g) (mm) (mm) (Length/Width)

Indica

TNuS 19 22.57 6.64 2.22 2.99

KSS 7 24.48 5.85 2.64 2.22

TCS 10 22.68 6.42 2.40 2.69

TCN 1 21.86 5.35 2.67 2.01

TCS 17 30.28 6.21 2.87 2.16

Japonica

TK 8 23.36 4.75 2.99 1.59

TK 9 22.76 5.02 2.86 1.76

TK 5 22.47 4.69 2.83 1.66

KS 142 22.65 4.76 2.86 1.66

TNa 9 21.60 4.64 2.90 1.60

TC 189 20.99 4.93 2.88 1.71

Waxy

TCSW 1 23.64 6.24 2.46 2.54

TKW 1 22.32 4.44 2.94 1.51

TCW 70 21.12 4.40 3.03 1.45

endosperm (grains) and broken pieces. The milled rice is a light, white color

consisting mainly of starch and protein with low-fat, ash and crude fiber content.

Then the milled rice is further processed by grinding to produce rice flour and

meal depending on the products desired.

Rice is milled (ground to flour or to a coarse meal) in some Asian countries

as part of the process for making traditional baked or steamed products [3–6].

Rice flour is used in processed foods, which include cereals, soup, snacks, candy

and others. Rice flour consumption in 1990/1991 was 12.2 million cwt, which

was over 21% of the total domestic demand for milled rice [7]. Official Taiwan

market statistics indicate that approximately 0.9 million cwt of rice flour are

consumed annually in desserts and snacks. Approximately 30% of total rice

flour production is used in making noodles (bi-tai-ba) which are used in main

dishes.

One thousand years of milling experience has produced three milling pro-

cesses: dry, semidry and wet milling. These processes make different types of

flours depending on the amount of water used (Figure 16.1).

Functional properties of flours are directly related to the amylose content

of their starches [5,6]. Rice starch has more physicochemical interactions than

other cereal starches. The amylose content, which ranges from trace amounts in

waxy types to more than 30% in some non-waxy indica varieties, significantly

affects the use of flour as thickeners and breadings. Because of their higher


Figure 16.1 Flow chart for production of dry-milled, semidry-milled, wet-milled and parched rice

flours.

amylose content (>27%), some indica varieties cause products to thicken and

form a rigid gel during storage. Manufacturers of rice noodles and rice cakes

prefer high-amylose indica varieties such as Taichung Sen 19 and Taichung

Sen 17 [8–10].

Flours milled from medium or short-grain japonica (low amylose) rice are

preferred for puffed rice cakes and rice crackers (arare, sen bei), which are

popular snacks in Japan. The branched chains of amylopectin produce desir-

able, lighter, expanded texture in products. Waxy japonica rice has a stickier

characteristic than waxy indica varieties.

A viscoamylograph, Rapid ViscosityTM Analyzer (RVA), and/or a differential

scanning calorimeter, are used to determine the cooking and pasting properties

of rice. These measurements are used to select rice for production of specific rice

flours [11]. Storage time and conditions, milling methods and pretreatment of

rice kernels significantly affect the physicochemical and functional properties


TABLE 16.2. Composition and Damaged Starch Content of Flours fromTaiwanese Indica, Japonica, and Waxy Rice Varieties.a

Protein Ash Lipid Damaged StarchRice Varieties (%) (%) (%) (%)

Indica

TNuS 19 6.16 0.38 0.38 7.80

KSS 7 6.40 0.56 0.71 4.86

TCS 10 7.16 0.53 0.37 8.78

TCN 1 7.61 0.59 0.77 5.98

TCS 17 6.47 0.51 0.45 4.83

Japonica

TK 8 6.68 0.59 0.95 7.79

TK 9 6.67 0.47 0.64 8.66

TK 5 6.64 0.44 0.69 9.19

KS 142 7.10 0.49 0.70 8.89

TNa 9 6.30 0.61 1.14 7.51

TC 189 7.47 0.54 0.62 8.89

Waxy

TCSW 1 7.77 0.38 0.72 8.40

TKW 1 7.08 0.61 1.39 7.69

TCW 70 7.02 0.52 0.91 8.07

a Means of three replicates on oven-dry weight basis.

of rice flour [12–17]. Additional quality control tests, such as protein, ash, fat

and microbial counts, are used to ensure the flour is an acceptable ingredient in

processed foods (Table 16.2).

3. MILLING EFFECTS

3.1. DRY AND SEMIDRY MILLING

In dry or semidry milling, the type of mill or grinder significantly affects the

functional properties of the flour. Milling with hammer mills results in flours

with fine particles; milling with attrition grinders produces coarse particles.

Genetics and environment affect the kernel hardness of rice varieties, which

produce different particle sizes upon processing (Table 16.3).

Scanning electron microscopic (SEM) examination of the flours shows that

starch granules individually separate or aggregate during dry and semidry

milling, respectively (Figure 16.2). The flours also differ in chemical com-

position and in thermal properties after grinding (Table 16.4).

Differential scanning calorimetry shows relatively similar gelatinization tem-

perature and enthalpy values for the two rice varieties when compared within

each milling process. Lower enthalpy values for some processes indicate rela-

tively high starch damage [15,16].


TA

BLE

16.3

.H

ard

ness

Index,

and

Part

icle

-Siz

eD

istr

ibution

of

Fourt

een

Indic

a,

Japonic

aand

Waxy

Ric

eV

ari

eties

and

Their

Mill

ed

Flo

urs

[18].

Perc

ent

on

CN

SS

cre

en

c

Mill

ing

Ric

eT

hro

ugh

Tem

pera

ture

Vari

eties

BM

HT

aR

tb60

100

150

200

250

250

PS

Id◦C

Ind

ica

TN

uS

19

17.5

142.2

81.3

7.0

3.1

3.2

2.4

3.0

7.3

43.2

KS

S7

31.0

37.2

63.9

16.8

8.9

6.3

2.6

1.6

8.7

36.3

TC

S10

17.1

152.8

82.4

7.7

3.7

3.3

1.8

1.1

7.4

43.4

TC

N1

24.0

67.5

71.9

16.6

7.9

2.6

0.4

0.6

7.8

37.9

TC

S17

24.4

40.5

63.4

19.2

8.5

5.4

2.2

1.3

8.6

36.8

Jap

onic

a

TK

821.9

103.5

80.3

12.2

5.2

1.7

0.4

0.2

7.3

38.6

TK

913.8

132.3

81.1

7.4

7.2

3.1

0.7

0.6

7.5

42.1

TK

510.9

141.7

86.1

6.8

4.1

2.0

0.6

0.4

7.0

44.3

KS

142

12.5

159.2

86.3

6.2

5.3

1.7

0.4

0.2

7.0

46.6

TN

a9

35.7

68.3

74.7

16.8

6.4

1.9

0.1

0.1

7.5

37.5

TC

189

14.7

158.3

84.1

7.2

4.9

2.8

0.8

0.2

7.3

45.7

Waxy

TC

SW

125.3

136.0

82.5

17.1

5.6

3.1

1.0

0.7

7.4

41.7

TK

W1

25.3

101.5

79.4

812.4

5.6

2.0

0.3

0.2

7.3

40.8

TC

W70

31.4

111.7

80.1

410.4

7.1

2.0

0.3

0.1

7.4

43.7

aB

MH

T:B

rab

end

er

mic

ro--

hard

ness

test.

bR

t:R

esis

tance

tim

e.

cC

hin

ese

nationalsta

nd

ard

sie

ves.

dP

art

icle

siz

ein

dex

accord

ing

toW

illia

ms

and

Sob

ering

[19].

©2001

CRC P

ress L

LC

Figure 16.2 SEM micrographs of TCSW1 rice flours: (A) dry turbo-milled; (B) dry cyclone-milled;

(C) dry hammer-milled; (D) semidry ground; (E) semidry hammer-milled; (F) wet stone-milled.

3.2. WET MILLING

The rice kernels are steeped for several hours before stone grinding the wet

slurries into flours with desired textures. The type of abrasive mill, the ratio of

flour to water and speed of the mill affect the functional properties of wet-milled

flour [9].

Flours made by wet milling are highly desirable for most snack foods [2,9].

Optimum steeping is 6 hours at room temperature and more than 10 hours when

the temperature is near 10◦C (50◦F) [20]. Semidry milling is an alternative way


TABLE 16.4. Effects of Milling Methods on Chemical Composition(Dry-Matter Basis) and Pasting Behaviors of TCSW 1 and TCW 70 Waxy

Rice Flours.

Milling Methods

Dry Milling Semi-dry Milling Wet Milling

Rice Varieties Turbo Cyclone Hammer Attrition Hammer Stone

TCSW 1

Protein, % dmb 7.9 7.9 8.0 7.5 7.2 4.9

Ash, % dmb 0.6 0.7 0.6 0.3 0.3 0.2

Fat, % dmb 2.5 2.0 1.9 0.8 0.7 0.3

Thermal Analysis

T0 62.1 62.1 64.2 63.3 62.1 59.3

Tp 72.6 74.4 74.6 72.7 74.0 71.9

�H 10.4 10.5 11.9 4.1 11.6 12.7

TCW 70

Proximate Analysis

Protein, % dmb 7.0 6.9 6.9 6.3 6.29 5.47

Ash, % dmb 0.9 0.8 0.8 0.5 0.5 0.4

Lipid,% dmb 2.2 2.0 1.5 1.2 1.2 0.6

Thermal Analysis

T0 59.8 61.1 62.1 60.1 58.8 58.2

Tp 71.2 72.6 72.9 73.3 71.7 69.6

�H 11.1 10.3 12.4 4.8 12.8 13.1

of producing flour; it decreases the costs of removing excess water and reduces

pollution problems [2,16].

4. SNACK FOODS

Chinese rice snacks are emphasized in this chapter. The reader is referred to

Chapter 17 for rice crackers and products like senbei and arare, which are major

traditional baked snack foods of Japan. Several factors discourage industrial

production of rice snacks. First, snack foods in Taiwan are made by secret

traditional methods. Also, government controls on pricing and distribution of

rice limit new developments in processing rice ingredients for new products.

Snack foods are classified into: (1) products that use whole rice grains, such

as puffed rice items; and (2) products that use flours prepared before and after

cooking of broken or whole milled kernels.

4.1. PRODUCTS USING WHOLE GRAINS

Puffed rice snack products are commonly used in Taiwan. The rice kernel is

expanded several fold by high pressure or by frying [21,22].


Figure 16.3 Process for making gun-puffed rice: (A) puffing gun; (B) rice puffing; (C) boiling

syrup; (D) mixing rice and syrup; (E) pressing; (F) cutting; (G) products.

4.1.1. Gun-Puffed Rice

Gun-puffed rice products are typical Chinese rice snacks. For best results,

japonica varieties with low (<20%) amylose content are chosen for gun puffing

[20]. Waxy-type rice has a higher water absorption index and water solubility

values, resulting in soggy texture and poor eating properties.

The gun (pressure cooker) is preheated for several minutes before it is loaded

with 600 g rice tempered to 14% moisture content. After a short cooking time,

when the pressure has reached 10–12 kg/cm2, the gun is suddenly opened

and the puffed rice kernels are collected in a metal hopper (Figure 16.3). The

puffed rice is mixed with sugar or maltose syrup, and occasionally with peanuts

and flavorings, rolled and cut into small square pieces called “gun-puffed

cake.”

4.1.2. Puffing Rice by Frying (Guo-Ba)

The rice is cooked first using one of two cooking methods: traditional, where

the rice is soaked in water for 30 min and boiled or steamed to obtain whole-

grain cooked rice; or large-scale production, where an equal amount of water

is added to the milled rice, which is soaked at room temperature for two hours

and then steamed at 18 psi pressure for 10 min. Indica waxy rice varieties are

preferred; the water-rice ratio is controlled to prevent the cooked rice from


Figure 16.4 Guo-ba, puffed rice produced by deep-fat frying cooked, dried rice: (A) soaking;

(B) molding/forming; (C) steaming; (D) frying; (E) resulting expansion; (F) finished product.

becoming too soft and sticky. Heating is controlled to ensure gelatinization of

the rice grain to the core without scorching [16]. The cooked rice is compacted,

cut into 5 cm square pieces (10 grams each), dried to 12–15% moisture and

fried in oil at 220◦C (428◦F) for 4–8 seconds in a deep fryer equipped with a

conveyor. Then, the puffed rice is packaged (Figure 16.4).

Another product puffed by frying is mi-hua-tung. Milled or broken rice is

washed, soaked in water and passed through a steaming and drying oven. The

cooked rice is dried to 5–7% moisture using a rotating drum dryer, then fried

at 240–250◦C (464–482◦F) for 10–12 seconds, where puffing occurs [21]. The

puffed rice kernel is mixed with syrup and other ingredients, placed in a mold,

pressed and packaged.

4.2. PRODUCTS USING FLOURS—RICE DESSERTSAND SWEETS

4.2.1. Mochi

Mochi is a popular rice cake made in Southeast Asia including Taiwan. It

is prepared from milled japonica (short-grain) waxy rice by washing, soaking,

wet milling into flour, steaming at 100◦C (212◦F) for 45–60 min, kneading,

cooling, dividing and packaging (Figure 16.5). Traditionally, the dough was


Figure 16.5 Processing glutinous (waxy) rice starch into mochi: (A) waxy rice starch; (B) steaming;

(C) mixing with syrup; (D) addition of fillings; (E) dividing; (F) final product.

pounded using wooden pestles in mortars to remove air from the dough and

obtain rice cakes with a smooth texture. With modern mechanical kneading,

air bubbles are in the dough, which produces mochi with a rough surface and a

whiter appearance. Mochi is usually divided into balls, which are coated with

mashed red beans or peanut grits.

4.2.2. Nien-Kuo (New Year Cake)

Short-grain waxy rice is preferred for making nien-kuo. The rice is soaked

for several hours and ground into a slurry using a stone mill. The excess water

is removed by centrifugation, or by straining the slurry through cotton cloth

bags pressed by heavy stones. The resulting material contains 45% moisture.

Sugar, water and rice flour (8:7:10 ratio) are mixed to obtain a batter (Table

16.5) which is steamed for 4–5 hr, cooled and packaged (Figure 16.6).

4.2.3. Bi-Tai-Ba (Rice Noodle)

Several types of rice noodles, such as mi-fen, bi-tai-ba, and ho-fen, are popular

in Taiwan, Japan, Southeast Asia and in overseas Chinese communities. The


TABLE 16.5. Characteristics of Nien-Kuo Made from DifferentFormulas [23].

Ingredient Ratios (Sucrose:Water:Flour)

Characteristics 11:4:10 10:5:10 9:6:10 8:7:10 7:8:10

Hardnessa 3612 2245 1801 1587 1432

AWb 0.79 0.81 0.86 0.87 0.90

pH 5.66 5.85 5.84 6.01 6.10

Hunter L 26.12 29.37 32.70 33.07 34.82

a 1.01 0.56 0.45 0.31 0.05

b 12.34 --- 9.12 9.25 10.69

a Measured by Fudoh Rheometer.b AW: Water activity.

Figure 16.6 Nien-kuo, a Chinese New Year cake.

449


Figure 16.7 Rice noodle preparation: (A) piston dough extruder; (B) noodle extrusion; (C) cooked

noodles; (D) forming noodles by single-screw extruder; (E) cooked extruder-made noodles; (F) ex-

trusion of green, broad noodles.

popular mi-fen is used in main dishes. Generally, it is processed to the dry state

and is steamed or cooked before serving.

Bi-tai-ba is a short, coarse, wet noodle made by traditional procedures by

soaking high-amylose-milled indica whole and broken rice kernels in water.

The hydrated rice is stone milled in water to produce a slurry, which is divided


Figure 16.8 Fa-kuo (rice muffins).

into two parts. About 75% of the rice slurry is strained through cotton cloth

or sacks to remove the excess water. The other 25% of the ground rice slurry

is heated to gelatinize the rice starch. Time, temperature and conditions vary

with the producer and the rice used. Then the gelatinized slurry is thoroughly

mixed with the ungelatinized ground rice to form a dough, which is forced

through a hand or powered piston forming extruder to produce noodle strands

3 mm in diameter [Figures16.7(A)–(C)]. The extruded noodles are placed

in a boiling water bath or steamed to surface gelatinize the starch, cooled and

packaged. During cooling, the surface of the noodle forms a strong film (of

retrograded starch), which gives proper texture to the product.

Figure 16.9 Flow chart for making bowl rice curd.


Figure 16.10 Preparation of bowl rice curd: (A) washing/steeping; (B) wet milling; (C) rice slurry;

(D) pregelatinized portion; (E) combining; (F) filling; (G) steaming; (H) packing; (I) product.

Bi-tai-ba noodles are consumed fresh; other rice noodles are dried outside

after surface gelatinization using ambient air. Some noodles are deep-fat fried

into crisp snacks and used in major dishes. Bi-tai-ba is mixed with syrup and

ice water in the hot season. It is served with meat, green onion and other

seasonings as a main dish. Indica rice varieties with high amylose content are

preferred for rice noodles because starch retrogradation is necessary for proper

texture.

Recently, Bi-tai-ba has been made using an extruder [Figure 16.7(E)]. Dry-

milled flour, containing 38% moisture, is fed into a single-screw extruder, which

has three barrel sections with temperatures set at 130, 100 and 50◦C (266,

212 and 121◦F) [24,25]. The extruded noodle strands are steamed, cooled and

packaged.


4.2.4. Fa-Kuo (Rice Muffin)

Fa-kuo is a muffin-style rice snack consumed in Southeast Asia. Preferably,

it is made from indica rice. A batter is made from dried or wet-milled rice flour

(100% base), plus 50–80% sugar, 3.5% leavening agent, optional red coloring

and 120% water. The batter is put in bowls, steamed 20 min and cooled (Figure

16.8). The red-colored muffin is mainly used for festivals. Typically, the family

has nien-kuo and fa-kuo on Chinese New Year’s Day.

4.2.5. Bowl Rice Curd

Bowl rice curd is a traditional, popular food consumed at breakfast in southern

Taiwan. Indica rice flour is preferred for its preparation as shown in Figures

16.9 and 16.10. The process is similar to the production of rice noodles, but the

dough is not extruded. Mixing the proper ratio of the raw and gelatinized slurries

is critical to obtain good texture and eating quality in bowl rice curd [26].

4.2.6. Kuo-Tse-Rung (Rice cake)

Parched rice flour is the starting ingredient in making kuo-tse-rung. This

product is seldom served as a snack food in Taiwan, but is used mainly in

religious ceremonies. Precooked or toasted waxy rice flour is mixed with sugar,

oil and other ingredients such as walnuts or almonds until sticky. Then it is

transferred to a wooden mold, pressed tightly, steamed for about 40 minutes,

cooled and packed (Figure 16.11).

Figure 16.11 Different kinds of rice cakes (kao-tse-rung).


5. REFERENCES

1. Unknown, 1998. Taiwan Food Statistics Book. Department of Food, Taiwan Provincial

Government, Republic of China.

2. Chen, J. J., 1998. Effect of Hardness and Milling on Particle Size Distribution and Physic-

ochemical Properties of Rice Flours. Ph.D. dissertation, University Taichung, Chung-Hsing,

Taiwan.

3. Sakurai, J., 1971. Rice as an industrial raw material for manufacture of processed and ready-to-

eat rice products. (Proceedings) International Seminar on the Industrial Processing of Rice—

Madras, India. United Nations Industrial Development Organization, Vienna, p. 65.

4. Li, C. F. and B. S. Luh, 1980. Rice snack foods. In Rice: Production and Utilization. B. S. Luh,

ed. American Association of Cereal Chemists, St. Paul, Minnesota, pp. 690–711.

5. Juliano, B. O., 1985. Polysaccharides, proteins, and lipids of rice. In Rice: Chemistry and

Technology, 2nd edition. B.O. Juliano, ed. American Association of Cereal Chemists, St. Paul,

Minnesota, pp. 59–141.

6. Chen, J. J. and S. Lu, 1997. Effect on the physicochemical characteristics of rice flours by

milling methods of waxy rice in Taiwan. (Abstr.). Cereal Foods World, 42:629.

7. Setia, P., N. Childs, E. Wailes, and J. Livezey, 1994. The U.S. Rice Industry. U. S. Department

of Agriculture, Washington, D.C.

8. Yeh, A. Y., W. H. Hsiu, and J. S. Shen, 1991. Some characteristics in extrusion cooking of rice

noodle by twin screw extruder. J. Chinese Agricultural Chem., 29:340–351.

9. Lu, S., J. S. Lin, and T. C. Lin, 1995. The effect of physicochemical characteristics at different

soaking and dehydration conditions on wet-milled rice flour. J. Food Science (Chinese), 22:426–

437.

10. Lu, S., W. T. Fang, and C. Y. Lii, 1994. Studies on the effects of different hydrothermal treat-

ments on the physicochemical properties of nonwaxy and waxy rices. J. Chinese Agriculture

Chemical Society, 32:372–383.

11. Lu, S. and W. J. Chen, 1988. Studies on the physicochemical properties of rice with different

milling methods. (Proceedings) Symposium on Rice Quality, 310–326.

12. Nishita, K. D. and M. M. Bean, 1982. Grinding methods: Their impact on rice flour properties.

Cereal Chem., 59:46–49.

13. Bean, M. M. and K. D. Nishita, 1985. Rice flours for baking. In Rice Chemistry and Technology,

2nd edition. B.O. Juliano, ed. American Association of Cereal Chemists, St. Paul, Minnesota,

pp. 539–556.

14. Arisaka, M., K. Nakamura, and Y. Yoshi, 1992. Properties of rice flour prepared by different

methods. Denpun Kagaku, 39:155–163.

15. Jomduang, S. and S. Mohamed, 1994. Effect of amylose/amylopectin content, milling methods,

particle size, sugar, salt, and oil on the puffed product characteristics of a traditional Thai rice-

based snack food (Khao Kriap Waue). J. Sci. Food Agri., 65:85.

16. Yang, J. H., 1994. Studies on Preparation, Processing Properties, and Affecting Factors of

Semi-Dry Milling Rice Flour. Ph.D. dissertation, Taiwan University, Taipei, Taiwan.

17. Chen, J. J., 1995. Effect of Milling Methods on the Physicochemical Properties of Waxy Rice

Flours. Master thesis, Chung-Hsing University, Taichung, Taiwan.

18. Chen, J. J., S. Lu, and C. Y. Lii, 1998. Thermal characteristics and microstructure changes in

waxy rice using different milling methods. J. Food Science (Chinese), 25:314–330.

19. Williams, P. C. and D. C. Sobering, 1986. Attempts at standardization of hardness testing of

wheat. I. The grinding/sieving (particle size index) method. Cereal Foods World, 31:359–364.


20. Su, J. W., 1998. Effect of Steeping and Milling on the Physicochemical Properties of Rice Flours

and the Quality of Rice Curd. Master’s thesis, Chung-Hsing University, Taichung, Taiwan.

21. Chang, S. M. and T. L. Chang, 1995. The characteristics of explosion-puffing rice products

with different amylose contents. J. Food Science (Chinese), 22:465–478.

22. Huang R. M., M. B. Chou, and C. Y. Lii, 1998. Effect of the characteristics of rice and the

processing conditions on the expansion ratio of dry cooked rice. J. Food Science (Chinese),

25:383–393.

23. Lin, J. S., 1993. Studies on the Quality of New-Year Rice Cake at Different Soaking Conditions

and Dehydration Methods, Master thesis, Chung-Hsing University, Taichung, Taiwan.

24. Lu, S. and C. P. Yeh, 1996. Laboratory preparation of Bi-Tai-Ba by a single screw extruder. J.

Food Science (Chinese), 23:650–661.

25. Lu, S., M. S. Lin, T. Z. Lin, and C. Y. Lii, 1993. Studies on the quality of Bi-Tai-Ba and its

frozen stability addition with commercial starches. J. Food Science (Chinese), 20:64–74.

26. Jeang, C. L., S. J. Wu, and T. C. Lin, 1990. Effects of treatments of different additives on the

texture of frozen rice curd. J. Agriculture and Forestry, 39:145–155.


CHAPTER 14

Popcorn Products

CHARLES CRETORS

1. INTRODUCTION

POPCORN is probably the oldest snack food in the world. Although nearly every

one in the United States has popped corn at home in a pot or wire basket, the

average person knows very little about why popcorn pops and what affects the

process other than heat. After a brief orientation to the industry and its history,

this chapter describes why popcorn pops, the different kinds of corn available

and the machinery used to make various products. The important factors and

basic processes common to all popcorn production are discussed. From there,

the three major areas of popcorn use: in-home preparation, commercial (movie

theatre, concession and loose popcorn sales) and industrial (packaged products)

are described.

1.1. SCOPE OF THE INDUSTRY

In calendar 1998, popcorn was the third most popular domestic snack after

tortilla and corn chips and potato chips. Grocery and convenience outlet sales

totaled $1.686 billion, including microwaveable popcorn, $1.136 billion; ready-

to-eat popcorn, $0.465 billion; and unpopped popcorn, $0.085 billion [1]. These

figures do not include sales of freshly popped popcorn, estimated to be about

$1.0 billion at theatres alone and $0.250 billion at various public concessions,

which brought total domestic sales of popcorn products up to approximately

$2.936 billion.

Popcorn, a New World crop, initially was grown exclusively in the United

States. Currently, approximately 30% of the world’s crop is grown in other


countries, including Argentina, Australia, South Africa, Ukraine and many

European countries, for domestic use and export. Popcorn may be grown wher-

ever other hybrids of corn are grown. One of the largest contributors to popcorn

quality is the handling of raw corn after it has been picked. Corn processors in

the United States usually have more experience in these techniques than those

in other parts of the world.

1.2. HISTORY OF POPCORN AND POPPING EQUIPMENT

Corn has been a basic food in South and North America for over 5,000 years.

No one knows when primitive man first discovered that certain varieties of

corn exploded when exposed to intense heat, but it must have been a significant

advancement to a people with only teeth and crude grinding tools. All the native

Americans ate popcorn to some degree.

The ancient Inca and Peruvian civilizations used the colorful popcorn for

both food and ceremonial decorations. The oldest identified corn poppers have

been found along the Northeast coast of Peru and date from about 300 AD.

The oldest written record is from a Spaniard in 1650, who said that the Indians

called the popped product “pisancalla.”

Early American settlers cultivated (flint-type) popcorn, which was used as

a snack and breakfast cereal; dent corn was used for corn flour and corn

bread.

Many families owned corn poppers consisting of wire baskets, with long

wire handles tipped with wood, for holding and shaking popcorn over flames

in fireplaces. As cities grew, street vendors started selling popcorn. A hot-air

process, with wire baskets shaken over a flame, was used (Figure 14.1).

In 1885, Charles Cretors left Decatur, Illinois, for Chicago to become a

street vendor and develop a better peanut roaster. A gasoline-fueled wet (oil)

popping machine, which also had a small compartment for roasting peanuts,

was patented in 1983 and shown at the Columbian Exposition that year. The

exposition was held to celebrate Chicago’s rebuilding from the Great Fire of

1871 and the 400th year of Columbus’ discovery of the New World. Passersby

stopped to watch corn popping and purchase bags of fresh product for a nickel.

These colorful machines were readily accepted by street vendors, circuses and

carnivals, and used for many years (Figure 14.2). They were the forerunners

of corn poppers that eventually would become fixtures in shopping malls and

movie theatres throughout the nation.

Another milestone in popcorn history at the 1893 exposition was the in-

troduction of Cracker JackTM caramel-coated popcorn, the first commercially

successful snack based on popcorn [2]. This product line, with the traditional

small prize in the package, was purchased in 1999 by the nation’s largest snack

foods producer, Frito-Lay Company of Dallas, Texas.


Figure 14.1 Street vendor popping corn over a flame, mid-1800s.

Over the years, C. Cretors & Company continued to innovate popcorn handling

equipment. Developments included:

� 1916—First electric oil popper used commercially in movie theatres� 1936—First electric kettle with a thermostat� 1963—Automatic wet popper� 1965—Cretors Automatic Cooker and MixerTM for cooking

high-temperature candy and low-temperature savory flavors and coating

popcorn, now called the Cretors Caramelizer� 1970—Flo-ThruTM hot-air popper, the first high-volume industrial popcorn

popping machine [2]. A corn metering system, oil measuring system,

microprocessor controls and bag-in-box oil pumps were developed later.

As the popcorn processing industry grew, other innovators contributed their

design skills and a number of equipment manufacturers exist currently. C. Cre-

tors & Company also sold popcorn supplies from 1900 to the late 1930s, but

suspended industrial sales to focus on popcorn processing equipment sold under

the Flo-ThruTM line name.


Figure 14.2 1893 mobile gasoline-fueled corn popper and peanut roaster. (C. Cretors & Company,

Chicago, IL.)

2. RAW POPCORN SELECTION AND PREPARATION

2.1. WHY POPCORN POPS

To meet the objective of presenting a pleasing product to the consumer, it

is important to understand why corn pops before variety selection, harvesting,

cleaning or processing can begin. Unlike most commercial snack foods, the

puffing process occurs naturally in popcorn. A popcorn kernel contains natu-

rally all hard starch, about 14% moisture, and has a very tough pericarp (hull)

and outer layers of the kernel that are capable of withstanding an internal pres-

sure of 135 psi (gauge) or (9.1 atmospheres). When heated, temperature and

pressure in the kernel rise, the internal moisture is turned into superheated steam,

the starch gelatinizes and the endosperm becomes pliable and rubbery-like. At

about 135 psi internal pressure, the kernel ruptures and the superheated steam

expands the starch and proteins to form a foam. As the steam is vented, the in-

ternal temperature drops. At the lower temperature, the starch/protein polymers

retrograde into glassy-like polymers in foam form, which make popcorn crispy

(Figure 14.3).

Optimum popping requires a delicate balance of heating and moisture con-

tent. If the kernel is heated too quickly, the starch at the center is not gelatinized

or softened. Although starch at the outer edge reaches the required temperature


Figure 14.3 Effects of temperature on expansion of popcorn: (A) appearance of kernels popped at

460◦F and 420◦F; (B) cellular structure, popped at 460◦F; (C) cellular structure, popped at 420◦F.

and pressure, causing the pericarp to rupture, the uncooked starch at the core

of the kernel does not expand. If the heating process is too slow, the buildup of

internal pressure cannot keep up with loss of moisture as steam vents from the

tip of the kernel. Although the pericarp of the kernel is hard, non-porous, and

can contain the increasing pressure, the tip, where the kernel was attached to

the cob, is not pressure-tight and will gradually equalize the internal pressure

with its surroundings.

The optimum balance is to heat the kernel at a rate slow enough to cook

the starch to its core before internal pressure ruptures the pericarp, but not so

slow that the available moisture leaks out before the kernel reaches the popping

temperature and pressure [Figure 14.3(C)]. The correct moisture for popcorn


is in the range of 13.5–14.5%; it is not a constant and will vary from hybrid

to hybrid and with the physical condition of the corn. With too little moisture,

the kernels will not pop. With too much moisture, corn may develop a musty,

stored flavor. Optimum popping produces a 40-fold expansion as shown in

Figure 14.4(D).

2.2. METRIC WEIGHT VOLUME AND BULK DENSITYEXPANSION TESTS

Since popcorn quality is generally defined by how large the kernels will

pop or expand, a way is needed for determining whether decisions in breeding

popcorns, selecting planting seed, drying corn after harvest, and adjusting corn

processing machinery, are headed in the right direction. In practice, these are

based on actual expansion tests.

Two factors are important in making popcorn—the expansion of the kernel

and the percentage of kernels that pop. Expansion is the increase in volume

during the popping process. In general, the more the corn expands, the better

the product. From a consumer’s view, highly expanded corn is more tender and

contains fewer partially popped kernels that are hard to chew. From a manu-

facturer’s view, expansion directly affects the profitability of the operation. In

concession stands in movie theaters and at sporting events, the operator buys

popcorn by weight and sells it by volume (a full bag or box). High expan-

sion translates directly into increased profitability. Each percentage point of

increased expansion is a reduction in raw material cost.

The financial reason to favor high expansion is not as pronounced in snack

food plants where the end product is packaged and sold by weight. However,

it does exist. Customers equate highly expanded corn with high quality. For

the manufacturer, high expansion creates a physically larger bag for the same

weight and may be considered a better buy by the customer. Highly expanded

corn usually also indicates a low percentage of unpopped kernels or scrap. In

this case, corn is purchased by weight and sold by weight, and lower scrap

reduces raw material costs.

Two problems are created if expansion of corn supplied to a snack food

manufacturer is not consistent. First, when customers do not find a consistent

product, they will not search for that specific brand. Second, when the expansion

is low, a preprinted bag filled to the correct weight does not appear full to the

consumer.

Commercial raw popcorn processors and large popcorn buyers use the Metric

Weight Volume TesterTM—MWVT (manufactured by C. Cretors & Co., Chicago,

IL)—to determine the potential expansion of a batch of popcorn

[Figure 14.5(A)]. The MWVT is the official measuring instrument of the Pop-

corn Institute, an organization that represents a large percentage of the popcorn

processors in the world.


Figure 14.4 (A) dent corn (l.) and four types of popcorn; (B) environmental scanning electron

microscope (ESEM) micrograph of popcorn hard endosperm, SG = starch granule; (C) ball (l.)

and flake (r.) type popcorns; (D) popcorn expanded 40-fold by popping.


Figure 14.5 (A) Metric Weight Volume Tester—MWVT (C. Cretors & Co., Chicago, IL); (B) poly-

styrene foam box used to measure expansion volume and bulk density.

The MWVT consists of a batch-type oil popper with a cylinder into which

the popped corn falls. The cylinder is calibrated to define the expansion of

the corn in cubic centimeters of popped corn per gram of raw popcorn input.

The MWVT is equipped with instruments for accurately measuring the tem-

perature and energy consumption of the popper and expansion of the popped

corn. This makes it possible to duplicate results from one machine to an-

other and provides a means of comparing different batches and hybrids of

corn.

The MWVT was originally developed for use by popcorn suppliers in their

plants. Before hybrid grains became common, moisture and growing conditions

were the primary factors affecting expansion of popcorn. The popcorn supplier

would take a small sample from a large bin of freshly harvested corn, test it

with the MWVT and record the result. The processor would then begin to dry

small samples of the corn, testing the expansion as the process continued. As

the normal harvest moisture decreased, the expansion increased. When the tests

indicated the expansion was beginning to decrease, the processor knew at what

moisture content the entire batch of popcorn should be dried to get maximum

expansion.


The MWVT is used primarily as a guide to predict the future performance

of popcorn when it is popped. But once corn is popped, another method of

measurement is needed. The most useful is bulk density. While the MWVT

defines the volume of popcorn produced as a function of the amount of raw

corn that was popped, bulk density of the final product gives an indication of

the effectiveness of the popping process itself.

The measuring tube of the MWVT is 4.5 in. (11.4 cm) in diameter and 40 in.

(101 cm) long. This provides good resolution and sensitivity for the laboratory.

In the typical snack food plant, a quick method is needed for determining the

effectiveness of adjustments made to the popcorn machine and the efficiency

of the operation.

When operating a popcorn machine, the bulk density of the popcorn can be

measured with a large open box. The corn that is to be measured should be taken

from the system after the sifter and before the coating or flavoring is applied.

(This is not possible in the case of oil-popped corn.) The box should be approx-

imately 12 in. (0.3 m) on a side for a total volume of 1 cubic foot (0.027 m3)

[Figure 14.5(B)]. The normal weight range of popped corn needed to fill the

box is 1.32–1.60 lb/ft3 (600–725 g), or 21–25g/L for flake corn used to make

salted and savory products. When making caramel corn, the weight is higher

and the density is approximately 1.75–2.00 lb/ft3 (800 to 900 g), or 28–32 g/L.

2.3. VARIETIES, HYBRIDS AND TYPES

Popcorn (Zea mays everta) is a form of flint corn and differs from dent and

other soft commercial corns in two ways [Figure 14.4(A)]. The first is that it

contains almost entirely hard starch [Figure 14.4(B)]. The second is that it has

a very hard pericarp and outer layers of endosperm, which permit the internal

pressure and temperature to rise high enough to pop. Also, see Chapter 3 on

Food Quality of Corn.

The original Indian corn is mainly grown as a curiosity and for decorative

purposes, and the early popcorn varieties have essentially given way to highly

improved hybrids. These are obtained by crossing different strains of popcorn

to emphasize specific physical characteristics, popping expansion, taste and

texture. The characteristics include kernel size, shape and texture. Two groups

of popcorn are commercially available, yellow and white.

White popcorn is a small white grain that appears similar to a grain of rice.

Some specific hybrids use names like: baby rice, Japanese hulless or white

hulless. The pericarp on this grain is thinner than on other hybrids, and after

popping is not as noticeable when eaten. The popped kernels of these hybrids are

very white, small in size and very tender. These hybrids are almost exclusively

used in the home because they are very tender and fragile; breakage typically

is excessive when used in commercial applications.


Yellow popcorn [Figure 14.4(A)] is most commonly used in commercial

operations. The kernels are rounded in shape and have a medium-yellow color.

Several options within this group are available to the raw popcorn buyer. Various

kernel sizes, defined as small, medium, and large, are available. The popped

kernels also differ in shape. Most corn takes on an irregular shape when it pops

and is referred to as flake or butterfly popcorn [Figure 14.4(C)]. Some hybrids

take on a more rounded shape and are referred to as ball or mushroom corn.

When ball-type corn is popped, the kernels expand from a small spherical

shape to a much larger size. The slightly brownish color spots on the surface

are the remaining areas that previously contacted the underside of the pericarp.

The round ball shape should not be confused with heat balls that result from

popping corn too rapidly. When a flake-type kernel pops, it turns inside out,

and pieces of the trapped hull can often be found inside.

Popped flake-shaped kernels are usually more tender and crisp, and are fla-

vored with salt and cheese in relatively gentle tumble drums. The ball/mushroom-

shaped kernels have fewer small protrusions to break off and are used in more

vigorous flavor application systems such as the caramel-coating process.

2.4. POST-HARVEST HANDLING AND PREPARATION

Essentially all popcorn is grown under contract, in some cases by third-

generation farmers supplying the same corn processor or industrial user. Hybrid

selection, production, harvesting, storage and handling are carefully controlled.

Popcorn quality starts in the field. Although popcorn grows on a stalk like

other corns and can be harvested by the same processes, several precautions

must be taken to get a top-quality product. The popcorn plants and ears are

not as large as those of the more commonly grown field corn. Adjustments and

modifications must be made to the machinery to ensure the popcorn kernels

are not damaged in the picking and shelling processes. Damage, in the form

of scratches or cracks in the pericarp, reduces expansion of the kernels during

popping. In the past, to avoid this problem some growers/suppliers would pick

and husk the corn, and keep it on the ear until shelled at a central plant with the

equipment adjusted to handle the smaller ears. This resulted in higher costs, but

the corn was promoted as very high quality.

After air and gravity separators, and precision sizers, most popcorn processors

also use computerized color sorters. Virtually every kernel is inspected by an

optical system that identifies discolored kernels, weed seeds, stones and foreign

matter, and removes them with a jet of air.

After the corn is cleaned, sorted, and inspected, it is slowly dried to the

optimum moisture content for maximum expansion during popping. Dried corn

may be stored almost indefinitely as long as the moisture level is not allowed

to change. Kernels of popcorn over 4,000 years old, found in caves in New

Mexico, have been successfully popped.


2.5. PACKAGING FOR HOME, COMMERCIALAND INDUSTRIAL POPPING

2.5.1. Home-Use Popcorn

Popcorn purchased in grocery stores has the greatest variation in quality and

packaging methods. Raw popcorn is often sold in flexible laminated packaging.

The primary requirement of this packaging is that it contain a barrier to eliminate

the possible loss of moisture, which is critical to successful popping.

High-profile brands, such as Orville ReddenbackerTM, are packaged in screw-

top plastic or glass jars. Reddenbacker had a major influence in improving the

quality of popcorn for home use. He developed very tender flavorful hybrids

that were adapted to popping in the home and packaged them in glass jars,

which kept the moisture at the correct level. Before Reddenbacker, popcorn

was usually packed in inexpensive flexible films and had a tendency to dry out

on the grocery store shelf. Orville Redenbacher made “theatre popcorn” quality

available to the average person popping corn at home.

Today, microwave popcorn is the most common form of packaging found in

grocery stores. The packages are the result of much research, and many patents

have been issued to manufacturers of these products. The typical microwave

package contains popcorn, popping oil and salt for flavor. When the package

is placed in a microwave and cooked, the corn pops and the package expands

to become a serving bag. Although these products are fast and easy to prepare,

they are somewhat different from traditional oil-popped products.

2.5.2. Vendor-Use Popcorn

Commercial processors, such as concession stands and movie theaters, buy

their raw popcorn packed in two ways. The most common is a 50 lb (22.68 kg)

plastic-lined paper bag. This package will keep corn fresh for at least six months

if not exposed to excessive heat.

Additionally, popcorn is sold in a 50-lb case of four 12 1/2 lb (5.67 kg)

polypropylene bags. These small bags are useful in small concession stands

where an open 50-lb bag would not be consumed for a long time.

2.5.3. Industrial-Use Popcorn

Industrial processors start off where the commercial end; 50-lb bags are

commonly used. However, automatic popcorn machines capable of consuming

one bag a minute require larger units of measure for their raw corn supply.

Bulk totes, with a capacity of 2,500 lb (1,134 kg) are available to the large

industrial user. The totes are expensive and are recycled between the corn


supplier and processor. They are usually used in conjunction with a long-term

contract.

Bulk shipping of popcorn is possible for processors using large volumes and

equipped with a high level of automation. In this system, corn is loaded in bulk

into a tank truck, and the plant that receives the popcorn is equipped with a large

metal bulk tank to hold it. A typical load might be 40,000 lb (18,144 kg). When

the truck arrives, it is emptied into a receiving pit or collector and pneumatically

transferred to the storage tank. Corn is then fed from these tanks directly to the

popper. Gentle handling of corn to avoid breakage is critically important.

3. POPPING METHODS

3.1. OIL POPPING

3.1.1. Popping Process

The oil or wet popping process, patented by Charles Cretors in 1893, is

most commonly used in point-of-purchase concession stands and was the most

common in homes before the advent of the microwave.

Corn and oil are placed in a container in a ratio of three parts corn and

one part oil by volume. The corn begins to pop when the corn and oil reach

the proper temperature. Enough heat (450◦F, 232◦C) needs to be applied to

the bottom of the pan for a normal popping cycle of 2.5–3.0 minutes. At that

time, the corn expands to its greatest volume. The time cycle may be adjusted by

either changing the heating rate or, if the rate is fixed, by changing the amount

of raw material put in the cooking pan. The corn and oil must be agitated during

the process to obtain even transfer of heat. In commercial machinery, a motor

turns an agitator on the bottom of the popper kettle. In the home, the pot in

which the corn is being popped is shaken over a burner on a stove.

Popping corn in oil is probably the simplest snack-production process avail-

able and permits making the end product at the point of purchase. The aroma,

animation, and the obvious freshness of the product, make the process ideal for

concession stands where the consuming public can see and smell the product

being made.

3.1.2. Oils Used

Oil serves two purposes. The first is the transfer of heat from the bottom of

the popping pan or kettle to the popcorn kernels. The second is to add flavor to

the finished product.

Generally, any shelf-stable oil that will tolerate the high temperature of the

popping process can be used; see Chapter 6, Oils and Industrial Frying. Several


factors should be considered when choosing popping oil. The first is melting

point. If the melting point is above body temperature, the finished product can

leave a waxy coating inside the consumer’s mouth. Popcorn is often eaten in

conjunction with cold drinks, which can accentuate the waxy sensation and

make the product undesirable.

Popular popping oils in the United States are coconut, corn, peanut, sun-

flower, canola, soybean and commercial blends. All have melting points be-

low body temperature, and some are liquid at most room temperatures. The

primary differences are their flavors and how they perform in the popping

kettle.

The temperature in a popping kettle usually exceeds 450◦F, a temperature

that will carbonize and burn the residual oil left in the kettle. Some oils are

more inclined to create a carbon buildup in the kettles, and a direct relationship

to the amount of unsaturated fatty acids in the oil exists.

For many years, coconut oil was the most popular popping oil. Initially, it was

relatively inexpensive. It melts at 76◦F, is very stable and has a good flavor. This

oil is also desirable from the manufacturing point of view because it creates a

minimum of carbon in the popping kettle. The only negative is that it is highly

saturated and is considered by some consumers to be unhealthy.

3.2. DRY POPPING

This process is found in home, commercial and industrial applications. The

first hot-air poppers were wire baskets, holding a small amount of popcorn,

that were held over a fire. The baskets were shaken rapidly to agitate the corn

and keep it from burning. Today, commercial versions of this process use a

motorized rotating wire drum over an open flame or electric heat elements.

This type of corn popper was used in retail locations in the United States for

many years before development of the oil pop method.

3.3. MICROWAVE POPPING

The same process that warms a cup of coffee will pop corn. Microwave ovens

can rapidly heat the water and starch throughout a corn kernel to the temperature

of popping. Due to high energy costs of operation, this method of popping

corn is found almost exclusively in the home, where microwave ovens are

common.

3.4. INCOMPLETE POPPING

Not every kernel in a popper charged with raw corn will pop. Additionally,

some kernels will not pop completely, resulting in heat balls and hard or tough

pieces. Being more dense than fully popped corn, these kernels normally settle


to the bottom of the bowl or bag as consumers help themselves to the fresh

product. However, they are undesirable in industrially made popcorn, especially

in products like caramel corn where they may be stuck to fully puffed kernels

by the coating and create dental pain and damage during mastication. Typically,

screens are used to remove the smaller unpuffed kernels when making puffed

corn products. These are further described under Sifting and Scrap in the next

major section of this chapter.

4. HOME PREPARATION OF POPCORN AND EQUIPMENT

4.1. OIL POPPING

Traditional salted popcorn is made by putting corn in a pot with oil and salt,

and heating and shaking until popping is completed. Some experimentation is

necessary to be successful. The level of heat applied to the pot must be controlled

so that the popping process takes about 2.5 minutes from a cold start with oil

and corn. If the oil is preheated, as some operators prefer, the popping time will

be only about 1.5 minutes. Extreme caution must be exercised when preheating

the oil. If the process is left unattended, the oil may become overheated and

begin to burn.

4.2. DRY POPPING

Hot-air poppers are popular in homes where consumers are concerned about

fats and oils in their diet. Also, many people like them because they require

little cleanup. Small hot-air home poppers operate on the principle of forcing

heated air up through a bed of popcorn to heat it until it pops. The popped corn

may then be seasoned with salt, butter or other flavors as desired.

4.3. MICROWAVE POPPING

Microwaving is probably the easiest way to prepare popcorn, requires the

least cleanup, but is the most expensive in cost per serving. Raw popcorn and

oil are packed in a specially designed package that is placed in a microwave

oven and heated. Directions are printed on microwave popcorn packages. The

packages are disposable serving containers for the finished product.

4.4. FLAVORINGS

Salt is the most popular flavoring for popcorn in the United States. When the

corn is oil-popped, salt is added to the popping kettle with the raw corn and oil.


The best type of salt to use is the finest size grade available. This is often called

popcorn salt or flour salt and is more like a powder than a fine grain.

Cheese and other flavors can be added easily in powder form by shaking onto

the corn after it is popped.

Caramel corn is often made at home. Sugar, water and glucose (corn syrup) are

brought to a boil and cooked to hard-crack temperature, about 300◦F (149◦C).

After the sugar is cooked, a small amount of baking soda may be added to the

mixture to cause it to foam. This foaming action increases the volume by four

to five times. It is important that the kettle in which the sugar is cooked be

large enough to contain the expanded volume. Popped corn is then mixed into

the foaming caramel. While the popcorn is still warm, it may be formed into

shapes such as balls or bars. If loose caramel corn is desired, a mixture of liquid

lecithin and vegetable oil is sprayed on the caramel corn as it is worked on a

flat surface while cooling.

5. COMMERCIAL PROCESSES FOR FRESH POPCORN

5.1. OIL POPPING

Popcorn machines for concession stands are available in a broad range of

sizes. Small countertop machines, 14 in. (35 cm) deep by 20 in. (51 cm) wide,

have a processing capacity of 7 lb (3 kg) of popped corn per hour. Large ma-

chines, 6 ft (1.8 m) long and nearly 7 ft (2.1 m) tall, are capable of producing

100 lb (45 kg) per hour of popped corn and are often found in movie theaters

(Figure 14.6). The most prominent feature of these machines is the popper pan.

This is a steel or aluminum pan with heating elements on the underside and

a thermostat to control the temperature. In addition to heating elements, the

pans are equipped with a motorized stirring mechanism to keep the corn from

burning during the popping process. The larger machines are equipped with a

pump and timer to pump the correct amount of popping oil into the kettle at the

beginning of each cycle.

The cabinets of larger machines may have many features. Enclosed models

have exhaust fans and grease filters to trap any smoke or oil vapor produced

in the popping process. The lower part of the cabinet usually has a perforated

screen with circulating hot air to keep the popped corn warm and crisp. This

perforated screen also has a section with a sieve to separate the unpopped and

undersized kernels from the rest of the corn.

The basic process is to add corn, oil and salt to the kettle and turn on the

heat and agitator. When starting with a cold kettle, the first cycle can take

6–8 minutes. The following cycles should take no more than 2.5–3.5 minutes.

In most of these machines, the oil is supplied by a pump equipped with a timer

to provide the correct amount to the kettle.


Figure 14.6 Oil popper for large concession stands and movie theaters, 100 lb/hr (45 kg) capacity.

(C. Cretors & Company, Chicago, IL.)

5.1.1. Salted Popcorn

Salt can be added to the corn oil mixture at the beginning of the process. Salt

is normally used in North America; sugar is more common in much of Europe.

5.1.2. Sugar Popcorn

The sugar corn process is slightly different than that for salted corn and

requires more attention from the operator. The basic problem is that popcorn

pops at temperatures over 400◦F (200◦C), and sugar begins to carbonize badly

above 310◦F (155◦C). This requires that thermostats on the popcorn kettle be

set slightly lower than when popping salted corn, and the operators must be

more attentive and empty the popping kettle as soon as the popping process


is complete. The popping kettles also require more cleaning to remove carbon

buildup from the residual sugar or from savory flavors if used.

While there are different recipes, typically the corn-to-oil ratio is reduced

from 3:1 to 4:1, and the overall volume by 20 to 30%. The reduced volume is

replaced with white granulated sugar. The sugar-to-corn ratio is usually 0.7–1.0

sugar to 1 of corn. The sugar is usually added to the kettle with the corn and

oil, but some operators prefer to add the sugar just as the corn begins to pop.

Adding the sugar later produces a whiter popcorn because sugar added at the

beginning of the cycle has a greater tendency to burn and add a slight brown

color to the corn.

5.2. DRY POPPING

Batch-type dry poppers are rotating wire drums that are suspended over a

flame or electric heater. Corn is placed in the popper and the heat is turned on.

As the corn pops, a screen made from coarse wire scoops the popped corn out

of the rotating drum. This type of popper is often found in shops that specialize

in caramel and other flavored corns.

Automatic dry poppers operate on the same principle as home poppers in

that hot air is blown up through a bed of corn to heat it to popping temperature.

With this machine, there is an option of producing dry corn for sale or letting

the corn fall onto a pan with an agitator that stirs it while oil is added.

After the corn is dry popped and screened, it may be flavored with many

different toppings. Popcorn has a pleasant neutral flavor and just about any

other flavor can be added. The most common are oil and salt, cheddar cheese,

sugar and caramel with nuts.

6. INDUSTRIAL PROCESSES FOR PACKAGED POPCORN

6.1. OIL POPPING

Industrial oil popcorn production lines consist of one or more banks of the

largest oil poppers set up over a conveyor belt (Figure 14.7). Typically, six

poppers are set side by side and one operator adds corn, oil and salt to the

machines. Operating on a typical 3-min cycle, the operators will dump, empty

and refill a popper every 30 seconds. Corn is usually fed by hand using sized

measuring cups.

Oil may be added to the kettle in several ways. In one option, oil is circulated

from a large central oil storage tank to volumetric measuring points above each

popper. When it is time to recharge a popper, the dry ingredients are added to

the kettle and the oil measure is emptied into the kettle. Another approach is

to have a timed metering pump at each popper. The dedicated pump may draw


Figure 14.7 (A) industrial 200 lb/hr oil popper. (B) industrial oil-popping line consisting of smaller

units mounted above takeaway conveyor and sifter to remove unpopped corn. (C. Cretors & Com-

pany, Chicago, IL.)


oil from a manifold that circulates from a central tank, or from individual 50-lb

(22.68 kg) pails. In an additional option, the pumps are immersed in the pails

themselves and are equipped with thermostatically controlled heating elements

to melt frying shortening or oils that are solid at room temperature.

6.2. DRY POPPING

Currently, hot-air popping of corn is used mainly in industrial applications.

The commercial hot-air corn popper is essentially a continuously fed, fluidized-

bed oven. While it is primarily a popcorn machine, it is also used to puff third-

generation snacks and roast peanuts and will process any type of snack that

requires precise temperature and time control and a continuous process.

The extremely high air velocity can transfer heat almost as quickly as oil

popping processes. Continuous dry poppers recirculate 90% of the air used in

the process and require a short time to reach a stable atmosphere once popping

begins. This is due to the fact that almost 10% of the weight of the corn is lost as

moisture inside the cabinet during the popping process. Within five minutes, the

atmosphere in the cabinet is stable and a very consistent product is produced.

6.2.1. Dry Popper Design

The basic design of a Cretors Flo-ThruTM Dry Popper is used as an exam-

ple. The machine consists of an horizontal auger with nine complete flights

wrapped around the shaft. The auger has a 16 in. diameter and is wrapped with

a perforated steel sheet with 3/32 in. holes. About 33% of the steel is open holes

and 67% is metal. The combined auger and perforated steel wrap is called a

popping drum and revolves as one unit [Figure 14.8(A)]. The entire assembly

is installed in an oven [Figure 14.8(B)], which is held at a temperature of 430◦F

(221◦C). A fan at the bottom of the oven blows hot air up through the bottom

of the perforated rotating drum. Raw popcorn or any product to be processed is

introduced into one end of the cylinder, and heated air is forced up through the

perforations in the cylinder with enough pressure to fluidize the material lying

on the bottom surface of the drum. The high velocity of the air agitates the corn

and provides for very rapid and uniform heat transfer. As the drum revolves,

the heated product is propelled toward the popping and discharge end of the

machine.

Adjustable controls built into the machine provide full control of the process.

The feed rate is usually adjustable and appropriate for the size of machine. The

variable-speed drum permits control of the residence time from 15 seconds to as

long as 5 minutes. When popping corn, the residence time is about 80 seconds

at 420–445◦F (215–230◦C). The recirculating atmosphere makes it possible

to control the temperature to within 2◦F (1◦C) once the process is stable. The

volume of airflow that fluidizes the product is controlled by the rpm of the


Figure 14.8 (A) popping drum; (B) hot-air popping oven for industrial popper. (C. Cretors &

Company, Chicago,IL.)


Figure 14.9 (A) reel-type sifter used to remove unpopped and partially popped kernels and frag-

ments of hot-air-popped pop corn; (B) closeup of sifter screen; (C) effects of popping temperature

on popcorn bulk density and scrap. (C. Cretors & Company, Chicago, IL.)

blower. For popcorn, the best airflow is that which just provides fluidizatioin

and agitation. Excess air usually damages the popped kernels. The popped corn

next enters a sifter [Figure 14.9(A) and (B)] to remove unpopped kernels and

then proceeds to a coating drum where flavorings are applied.

6.2.2. Operating Adjustment Options

Popcorn kernels are a raw grain. The only prior processing they have been

exposed to is cleaning, sizing, and drying to the appropriate moisture level

for maximum expansion. The variability of a natural product requires that the

popcorn machine operator be able to adjust the machine to compensate for

variation in kernel size, shape, hybrid type and moisture content.


The temperature is critically important [Figure 14.9(C)]. The typical dry

popper has four variables that can be used to control the output of the machine.

These variables are: feed rate, residence time, temperature and air circulation

rate. Before a popper can be adjusted successfully, it is important to start from

a neutral point.

� Feed Rate. When tuning up a machine, the first step is to check the feed rate

of raw popcorn to determine if it is within the capabilities of the machine. A

200 lb/hr machine has a maximum feed rate of 200 lb/hr. If there is a

question, it is best to check this out with the manufacturer. All Cretors’

machines use the model number as a designation of the maximum feed rate.

This is the amount of raw corn fed into the machine, and not the output of

the machine. Once the size of the machine has been determined, the

calibration of the feeder must be checked to determine if the input is within

the normal operating range of the machine. If difficulties in successfully

controlling the output of the machine have been experienced, it is best to

start at a feed rate of about 80% of the recommended maximum.� Residence Time. Once the feed rate is determined, the residence time of the

corn in the popper must be checked. The ideal starting point is a residence

time of 75–80 seconds.

It is controlled by the rotational speed of the popping drum, which should

turn at about 7 rpm to obtain the desired time.� Temperature. Temperature of the final product is the most prominent

variable and is dependent on the residence time (drum speed), size and

hybrid of individual corn kernels, and moisture content of the corn. A good

starting temperature for the popper is 435◦F (224◦C).� Air Circulation. Air circulation is controlled by the speed of the fan. The

rpm required depends on many factors. The design of the particular machine

and the internal clearances will affect the rpm needed for correct operation.

It is best to check the manual supplied with the machine to determine the

correct rpm. Adjustment of the blower rpm is extremely important for

correct operation of the machine.

It is important to understand the theory and function of air circulation in order

to properly adjust the blower. A layer of corn lies on the bottom of a perforated

drum in a continuous fluidized bed popcorn machine. Heated air is forced up

through the perforations with enough force to agitate the corn and cause it to act

like a fluid mass. The agitation and high velocity of air achieve a high rate of heat

transfer between air and the corn. When the air pressure is too low, the air will

not pass through the layer of corn and will not circulate within the cabinet. If

the pressure is too high, the corn can be damaged by the violence of the airflow.

The feed rate can be adjusted to provide the amount of corn required for

any given process. It should be remembered that the quality of popcorn pro-

duced may deteriorate as the maximum rating of the machine is approached or


exceeded. An increase in feed rate will increase the thickness of the corn bed

on the bottom of the popping drum and may also require an increase in blower

rpm. If the feed rate is already near maximum, the temperature also may need

to be increased. Once the desired feed rate has been established by adjustment,

the remaining three variables are used to control the character of the corn that

is produced. It is important to adjust poppers in small increments:

temperature, 2◦F (1◦C); drum speed, 0.1 RPM; and

blower speed, 50 RPM

and wait long enough for the change to take effect. If the drum speed is set to

produce a residence time of 75 seconds, the results of any change to blower or

drum speed require at least 75–80 seconds before the effects are seen. In the

case of a temperature change, the time required for the cabinet to adjust to the

new setting must be added to the residence time.

When popped corn fills the drum above the center line, the drum’s rotation

does not move all of it forward. Some spills over the center into the preceding

space in the auger and moves backwards in the drum, eventually plugging the

drum. Periodic plugging and clearing is called surging, and usually is caused

by too high a feed rate. Surging can also be caused by too high a temperature,

which causes the corn to pop in the first half of the drum.

A popper usually is considered to be operating correctly if the corn is heard

to be popping at the discharge end of the popping drum. If the corn is popping

in the sifter after it leaves the machine, the temperature is too low or some other

variable is not correct.

6.2.3. Adjusting for Variability in Popcorn

Referring to the two types of popcorn described earlier, flake type (high

volume, low density) and ball type (low volume, high density), the following

adjustments may further optimize the popping operation:

� Flake type—Characteristics:

—Kernels are irregular—Kernels are fragile and crispy—Scrap rate is higher

—Machine adjustments:—Lower the popping temperature—Slow the drum speed for longer residence time—Lower the feed rate

� Ball type—Characteristics:

—Kernels are more spherical


—Kernels are stronger and tougher—Scrap rate is lower

—Machine adjustments:—Raise the popping temperature—Increase the drum speed for shorter residence time—Increase the feed rate

A wet (oil) popper heats the corn at anywhere from 420◦F to 500◦F (215–

260◦F) in 0–180 seconds during the popping cycle. In contrast, a dry popper

heats the corn at 430◦F for 80 seconds and has a very narrow range of operating

conditions. It requires a very uniform corn. Major variations in raw popcorn

are moisture, kernel size, high-expansion corn, hybrid uniformity and changes

in corn stored in the user’s warehouse or bins.

6.2.3.1. Moisture

High-moisture corn pops at a low-temperature; low-moisture corn pops at a

high temperature. If two bags of popcorn, one at 14% and one at 13%, are mixed

completely and the moisture is checked, the assay will be 13.5% moisture. If put

in a dry popper, with the temperature set to pop the high-moisture corn, most

of the low-moisture corn will leave the machine unpopped and be discarded as

scrap. If the temperature is increased to properly pop the low-moisture corn,

the high-moisture corn will begin to pop early when the core starch has not yet

been gelatinized, and small, tough, hard heat balls will be created and become

even tougher in the hot-air popper. All the corn kernels must be equilibrated to

the same moisture content.

6.2.3.2. Kernel Size

Large kernels heat more slowly than small kernels. With a blend of large

and small kernels, it is impossible to optimize hot-air popper conditions. The

machine can only pop one size kernel satisfactorily.

6.2.3.3. High-Expansion Corn

High-expansion corn is usually more desirable because it takes less weight

to fill a given bag than low-expansion corn. However, expansion of the corn

affects the operation of the popper because the popping drum cannot be filled

more than half way with popped corn. Often, the operator erroneously thinks

the feed rate is too high. Prior popping of new corn samples helps to prewarn

the operator. When a consistently high expansion corn is encountered, as with

a newly introduced hybrid, reducing the dry popper feed rate reduces raw ma-

terials costs and does not reduce popped corn production. This is a distinct


operating benefit, provided the high-expansion corn still fits into packaging

materials with preprinted weights.

6.2.3.4. Hybrid Uniformity

High-quality popcorn hybrids provide uniform grain with excellent potential

for expansion and taste. However, environmental conditions significantly affect

popping quality. Popcorn suppliers have their corn grown in carefully selected

environments that are consistently stable and provide good consistent corn

quality for popping.

6.2.3.5. Corn Changes in Storage

Reputable raw corn suppliers control their grain carefully to minimize varia-

tions in popping properties from shipment to shipment. However, changes oc-

cur in grain stored in the user’s warehouse or tanks. Repetitive major changes

may require review of current packaging or operation of storage facilities. Ac-

cumulated adjustments that have been made while using the same shipment

of corn over a long period may make the new shipment appear like an en-

tirely different corn and therefore require major resetting of the hot-air popping

equipment.

6.3. SIFTING AND SCRAP

After the corn is popped, it must be cleaned to remove unpopped and un-

dersized kernels. It is best to do this immediately after the corn has left the

popper while the corn is still flexible before cooling and drying. If the sifting

process is delayed, popped corn becomes increasingly crisp, brittle and fragile,

and unnecessary breakage occurs.

The sifter is a stainless steel wire mesh drum that rotates on a horizontal axis.

Unpopped, undersized and broken kernels pass through the 7/16 in. (1.1 cm)

square opening between the wires and are separated from the rest of the corn

(Figure 14.9). When small-grain, white popcorn is used, it is advisable to reduce

the screen size to avoid discarding too much good corn.

6.4. POPPED CORN YIELD

Popcorn is a natural product, and variations in the grain affect yield, even

with sophisticated processing. For example, not all kernels will pop to the

volume needed for commercial distribution, some kernels won’t pop at all and

should never be packaged and sold. It is necessary to clean the popped corn

with a rotary sifter before it is coated with flavors or sold. A typical materials


balance is:

100. kg Load of raw popcorn containing approximately 14% moisture

−12. kg Moisture and corn oil vapor loss during the popping

process 88. kg

−8. kg Sifted out as unpopped or partially popped corn

80. kg Popped corn yield produced from 100 kg raw popcorn,

using a 7/16 in. (1.1 cm) wire-mesh sifting screen.

7. COMMERCIAL AND INDUSTRIAL FLAVORINGS

AND APPLICATORS

One or more flavoring and color agents, like oil, salt, cheese or sugar, typically

are added to corn after popping. Coating processes for popcorn are similar to

those of other expanded snacks. They can be divided into two basic systems,

batch and continuous.

7.1. BATCH APPLICATORS

Batch coaters for salt and savory popcorn typically are coating pans that turn

on an axis, inclined 30 degrees from horizontal [Figure 14.10(A)]. The popcorn

to be coated is placed in the pan, and the oil coating and flavor are introduced

as the pan turns. The coating is either poured from a measuring pan or pumped

in by a pump with a timer control. The pan is allowed to turn until the coatings

are evenly distributed on the surface of the corn. At this point, the coating pan

is stopped, emptied and refilled for another batch.

Figure 14.10 (A) batch coating pan; (B) continuous horizontal coating drum. (C. Cretors & Com-

pany, Chicago, IL.)


7.2. CONTINUOUS APPLICATORS

Continuous coaters typically are horizontal stainless steel drums, 24–36 in.

(60–90 cm) in. diameter, that turn on their axis [Figure 14.10(B)]. The coater

may be depressed or inclined slightly to promote or retard product flow. In

principle, the popcorn and coating are introduced at one end of the rotating

drum, and the coating is evenly distributed over the popcorn by the time the

product exits from the other end of the drum. The continuous coater is usually

equipped with a variable-speed drum drive to control residence time, a variable-

speed pump so that the coating ratio may be varied and a dry applicator to apply

salt or other dry seasonings.

7.3. SALT AND CHEESE FLAVORS

Salt and cheese flavors are usually applied with oil, which acts as a vehicle

to carry the flavor to the corn and help it stick. In the case of salted corn, the oil

is sprayed on the corn with almost any type of spray nozzle at concentrations

from 20 to 30% of the finished weight of the product. Color or flavorings may

be added to the oil to produce different products. Salt is blown or metered into

the coater at a steady rate to produce the desired flavor.

To begin a cheese coating process, a slurry is prepared by mixing coconut

oil or another shelf-stable oil with powdered cheese. Cheese content is usually

30%–50% by weight. This mixture is then heated to 120◦F–130◦F (49◦–54◦C)

to melt the cheese. Melting the cheese is important because the coating sprays

much more easily and is less likely to plug the pump, oil lines or spray nozzle.

Additionally, the liquid cheese is better absorbed by the popcorn and is less likely

to come off in the bag or on the customer’s hands. Care must be taken to not

heat the oil and cheese mix too rapidly. If the surface temperature of the mixing

kettle becomes too hot, the cheese will be darkened and the flavor changed.

Typically, cheese begins to break down above 130◦F (54◦C). An agitator must

be in the tank to keep the oil and cheese blended.

Cheese-flavored popcorn can also be made by adding powdered cheese to

either oil- or dry-popped popcorn. Although used in some plants, these products

are not commonly seen because the powdery coating comes off on consumers’

hands, even though some manufacturers feel they have better flavor. A typ-

ical continuous system for producing salty and savory popcorn is shown in

Figure 14.11(A).

7.4. BATCH SYSTEM FOR SWEET/CARAMEL COATINGS

The preparation of sweet-coated snacks is more complex than for salted

and savory popcorn because the sugar coating must be mixed and cooked


Figure 14.11 Systems for continuous production of: (A)savory flavor-coated popcorn; (B) caramel-

coated popcorn. (C. Cretors & Company, Chicago, IL.)


Figure 14.12 Basic equipment for batch production of sweet caramel popcorn: (A) steam-jacketed

kettle for preheating syrup; (B) copper kettle for cooking caramel; (C) mixing auger for coat-

ing popped corn; (D) working and cooling table for coated popcorn. (C. Cretors & Company,

Chicago, IL.)

before application. The batch process for making sweet-coated popcorn begins

by boiling a sugar solution in a stainless steel or copper kettle to make hard

candy or caramel [(Figure 14.12(B)]. The boiling solution is then poured over

the popped corn in a mixer, consisting of a drum rotating in a vertical axis with

an internal vertical rotating auger along the side of the drum wall [Figure 12(C)].

The resulting action lifts and mixes the puffed product and sugar to distribute

coating over the popcorn.

Sugar or caramel is made in the batch system by adding sugar, water and

glucose (dextrose) to the cooking kettle and heating to 300◦F (149◦C). This

is called hard-crack candy. The recipe may include varying amounts of white

sugar, brown sugar, butter and various other flavorings or colorings as may be

desired. If butter is used in the mix, it is added at the end of cooking so the


flavor won’t be lost. Just before the sugar mix is poured onto the product, a

small amount of baking soda may be added to the mix to make it foam. Foam-

ing doubles or triples the mix’s volume. The light frothy mixture does a better

job of coating than the heavy sugar produced at the end of the cooking cycle.

The amount of soda used must be watched very carefully. Too much causes a

bitter taste in the finished product.

It should be noted that copper catalyzes development of flavor in the coating.

Therefore, reformulation may be necessary if a copper cooking kettle is replaced

with stainless steel or aluminum equipment.

In larger systems, steam-jacketed cooking kettles [Figure 14.12(A)] are used

to premix and preheat all the ingredients to 180◦F (82◦C) before they are added

to the cooking kettle[Figure 14.12(B)]. This substantially speeds up the cooking

process in the kettles. The maximum practical holding temperature for the

premix is 180◦F. If held above this temperature for more than approximately an

hour, the premix color darkens and flavors begin to change. As a result, caramel

coating made from the same batch of premix will not be consistent from the

beginning to the end.

After the sugar and popcorn are well coated, a small amount of an oil/lecithin

mixture is sprayed into the coating drum. The lecithin mix causes the product

to separate into individual particles. The typical ratio is one part liquid lecithin

to 10 parts oil.

Hot caramel or candy-coated product from the coater is next placed on a

cooling table [Figure 14.12(D)] and stirred with hand tools while it cools. Con-

tinuous agitation and lecithin are necessary to produce a free-flowing product. If

a large amount of product is to be made, a horizontal continuous cooling tumbler

may be used. A cooling tumbler is a large drum about 4 ft (120 cm) in diameter

and 8 ft (240 cm) long, made of perforated metal. The tumbling action provides

the agitation necessary to separate the product, and the perforations allow air

to circulate and cool the product to a temperature where it is no longer sticky.

Air conditioning must be used with caution when cooling caramel corn.

Popcorn and hot sugar are very hygroscopic and absorb moisture from the air

quickly. Air-conditioning systems often produce cold air at very high moisture

levels. It is important to temper the air to reduce its relative humidity.

7.5. AUTOMATED BATCH SYSTEMS FORSWEET/CARAMEL COATINGS

Automated batch sweet products coaters are different from the manual batch

coaters in several ways:

� The amount of sugar coating cooked is significantly larger.� Cooking and mixing take place in the same piece of equipment.


Figure 14.13 Cooker/coater for automated batch popcorn sweet coatings. (C. Cretors & Company,

Chicago, IL.)

� Hydraulic or pneumatic power, rather than manual labor, is used to empty

the batch from the machine.

Automated batch cooker/coaters generally have a batch size of 90 lb (40 kg)

of sugar coating. All ingredients may be mixed and cooked in the kettle/coater

[Figure 14.13]. The cycle time and the hourly production rate may be in-

creased by premixing and heating the ingredients in a steam-jacketed kettle

[Figure 14.12(A)]. Once the coating is fully cooked, the popcorn is added to

the kettle and the internal mixing system is turned on to blend the products.

When the corn is completely coated, a small amount of an oil/lecithin mixture

is sprayed on the product to facilitate its separation into individual pieces as it

cools. When the process is complete, the kettle/coater drum is dumped with the

help of pneumatic or hydraulic cylinders.

From the coater, the hot sugar-coated popcorn goes to a continuous cooler

where it is cooled and agitated. This agitation, with help from the lecithin

sprayed on earlier, causes the popcorn to separate into individual pieces. The

popcorn is ready for packaging after it leaves the separating and cooling

tumbler.


7.6. AUTOMATIC CONTINUOUS SYSTEMSFOR SWEET/CARAMEL COATINGS

The fully automatic continuous system [Figure 14.11(B)] uses premix kettles

to hold all sugar ingredients at a high temperature. The premix is pumped to a

thin film concentrator, where the syrup is cooked to a hard-crack temperature

(300◦F, 148◦C) in about five seconds. The caramel then flows to a steam-heated,

stainless steel trough with a steam-heated auger that blends the continuous flow

of popcorn and hot sugar into a finished product. At a point, about one third

of the way through the coating process, a small amount of lecithin-oil mixture

is sprayed into the coater to promote separation of the product into individual

particles. From the coater, the hot sugar-coated snack goes to a continuous cooler

where it is cooled and separated. After the caramel corn leaves the cooling and

separating tumbler, it is ready for packaging.

7.7. FLAVORED POPCORN RECIPES

The flavor is very important to the finished popcorn product and often is the

first item in the snack name—cheese corn, caramel corn, or salt and vinegar.

It is important that the amount of flavor not be reduced in an effort to reduce

costs, since usually it cheapens the product and makes it difficult to sell.

� Salted Popcorn—Oil Pop Popcorn

3 volumes raw corn

1 volume popping oil

Salt to taste (flour or fine salt)—Dry Pop Popcorn

80% popcorn (weight)

20 to 22% coating oil (weight)

Salt to taste� Cheese-Flavor Popcorn

15–25 % cheese (weight)

28% oil (weight)

57% popcorn (weight)� Sweet Popcorn, Sugar Corn

3.0 volumes raw corn

0.75 volume popping oil

1.5–2.0 volume sugar depending on taste� Caramel Corn

—Batch

70% light brown sugar

21% glucose


9% water

Flavorings as desired—Continuous

65% light brown sugar

25% glucose

10% water

Flavorings as desired—Finished Product

70%–90% Sugar Coating

30%–10% Popcorn100% 100%

When working with artificial fruit color and flavors, begin with white sugar,

which does not add flavor of its own.

8. POPCORN PACKAGING

8.1. RELATIVE HUMIDITY AND HYGROSCOPICITY

Popcorn is the most hygroscopic of the crispy snacks. The following prin-

ciples to keep popcorn fresh and crisp apply to all crispy snacks. Tough and

chewy popcorn is most frequently caused by weather-related excessive humid-

ity. In an oil-popping operation, the problem usually occurs during days when

the relative humidity (RH) is over 50%. In the midst of the summer or a rainy

season, 70–90% RH is a major challenge to handling popcorn. The desired

moisture content for salted, cheese-flavored, or other savory flavors of snacks

is 1.0–1.5% or less. A very crisp product at 1–2% moisture content turns into

an increasingly chewy product at 4–5% moisture content. Some customers,

especially fond of popcorn, object to moisture contents above 2.5%.

The literature indicates that popcorn, initially at about 1.5% moisture, equi-

librates to approximately 2.5% moisture at 20% RH in 15 minutes when com-

pletely exposed to the environment, 3.5% moisture at 30% RH, 4.5% moisture

at 40% RH, 5.5% moisture at 50% RH, 6.5% moisture at 60% RH, and 7.5 %

moisture at 70% RH [3].

Moisture absorption is slower in oil-popped corn. Nevertheless, minutes

count when getting fresh popcorn into suitable packages, or at least into a

protected temporary environment or tote.

8.2. SUGGESTIONS FOR KEEPING POPCORN CRISP

� Burning natural gas and popping corn release large amounts of water into

the air. The popping room needs ample outside air intake and exhaust of


steam and vapors directly from the poppers, whether oil or dry poppers. A

hood is best for collecting the humid air. Air conditioning and humidity

control usually are too costly for effective use in the popping room, and

packaging is better done in a separate area.� Popcorn coming out of a dry popper is very hot and usually contains 3–4%

moisture. The sifter and tumbler allow the corn to cool and dry to 1–2%

moisture by exposure to the ambient air. If the corn is kept at least 20◦F

(11◦C) above the room temperature, it will remain dry and crisp.� The best approach is to quickly package the product while it is more than

20◦F (11◦C) over the temperature of ambient room air. Popcorn should not

be stored before packaging unless it has already dried and can be protected

and kept dry by suitable enclosure.� Whenever the relative humidity is over 50%, the packaging area should

have humidity control equipment. In the absence of environmental controls,

maintaining the popcorn at 20◦F (11◦C) above room temperature keeps it

dry and crisp. Popcorn and other snacks pick up moisture at over 50%

relative humidity. The problem is critical at over 70% relative humidity. A

30%–45% relative humidity, which is normal in winter-heated areas, allows

long-term storage of puffed snack products without packaging protection;

45% is borderline, while 20%–30% is safe over a long period of storage.

8.3. PACKAGING MATERIALS AND EQUIPMENT

Protection of the packaged popcorn against gaining moisture must be con-

tinued to the sales outlet by appropriate packaging materials, and then for

a reasonable time until the consumer opens the package. Seasoned products

also need oxygen barriers to protect against oxidation of the oils. Internally

enameled metal containers, sealed with appropriate tapes and containing small

pouches of desiccant, offer excellent protection but are expensive. Their use is

mainly limited to gifts or holiday parties. Where coloring agents are used in

snack products, it is desirable to provide light-barrier protection, which can be

accomplished by using metallized film. Although not as effective as foil lami-

nates, metallized polypropylene packaging films are increasingly used because

they are more economical. The pouches can be flushed with nitrogen to remove

oxygen, and sealed with a pillow headspace to help cushion fragile products

against breakage. The reader is referred to Chapter 22 on packaging materials,

and Chapter 23 on snack foods filling and packaging for further details.

9. RELATIVE NUTRITION

Popcorn has not borne as much accusation of junk food as some of the

other snacks. In fact, it is often considered a healthy snack. Dentists have


endorsed salted popcorn as an alternative to a sweet snack. The American

Dietetic Association permits popcorn as a bread exchange in weight control

diets. In addition, the National Cancer Institute includes popcorn in its list of

moderately high sources of fiber to help reduce the risk of colon cancer.

Dry-popped corn has the same protein, fat, carbohydrate and mineral con-

tent per unit weight as natural whole popcorn, except in greater concentra-

tion because of moisture loss during popping. Air-popped corn contains about

30 calories per cup, oil-popped corn about 55 calories and lightly buttered

popcorn about 90–120 calories. On a volume basis, popped popcorn is low in

calories, and a high quality source of complex carbohydrates (fiber) compared

to other snack foods [4].

10. MARKETING OF POPCORN

While North America and most parts of Europe can be considered mature

markets, many other parts of the world are only now discovering popcorn.

Taste preferences vary from country to country, but caramel corn continues to

be a strong seller in most areas. Caramel corn enjoys an image as a healthy

food that satisfies the consumer’s craving for sweetness, is filling and is a fun

product. With savory popcorns, a particular flavor is often popular for a while,

and consumers then change to a newer flavor. Considerable potential exists for

continued innovations in flavor development and marketing.

Starting in the 1980s, movie theaters in the United States began to divide

their large auditoriums into several smaller rooms. This was done to give the

moviegoer more choices in movies and to enable the concession stand to serve

more customers. The average movie theater patron spends as much on snacks at

the concession counter as at the ticket booth. Profit dollars from the concession

stand exceed those of ticket sales, with 80% of a movie theater’s profit coming

from cold drinks and popcorn, popcorn being the sales and profit leader. Cur-

rently, movie theater attendance is at its highest in 40 years, and the growing

number of megaplexes continue to provide fresh popcorn products to the public.

Opportunities for selling new high-quality popcorn products through grocery

and convenience stores have been demonstrated in recent years by introduction

of products like white cheddar cheese popcorn, fat-free caramel popcorn, and

gourmet caramel popcorn. Popcorn excels in the gift market relative to other

snack foods. Some of the largest manufacturers of popcorn in the United States.

fill large decorated gift cans with divided sections of salted popcorn, cheese corn

and caramel-coated popcorn.

An innovative product example is (compressed) popcorn cakes, patterned

after the earlier success of rice cakes as a low-fat snack food. Supermarket

sales of popcorn cakes reached $200 million in the United States in 1997.

These products offer the advantages of a fixed number of calories per cake for


consumers who count calories, and no shedding of fines as often occurs when

handling popped corn. More recently, chocolate, caramel, savory and other

flavored corn cakes have been introduced, as well as mini-cakes specifically

promoted as snacks.

Improved flavor systems, especially for no-fat or low-fat products, and im-

proved packaging systems already shared with the rest of the snack food indus-

try, indicate that increased sales of high-quality ready-to-eat popcorn products

is limited only by individual abilities to innovate new products and creative

marketing.

11. REFERENCES

1. SF&WB, (June) 1999. State of the industry. Snack Food & Wholesale Bakery, 88(6):SI-1-SI-82.

2. SFA, 1987. 50 Years: A Foundation for the Future. Snack Food Association, 1711 King St, Suite

One, Alexandria, VA 22314.

3. Matz, S. A., 1993. Snack Food Technology, 3rd edition. AVI Van Nostrand, Reinhold, New York.

4. www.popcorn.org, June 22, 2000, Popcorn Board, Chicago, Illinium.


CHAPTER 15

Snack Foods of Animal Origin

PETER J. BECHTEL

1. INTRODUCTION

FOR the purpose of this chapter, a snack is a food product that is predominantly

consumed between meals. It is not clear when the practice of eating meals at

prescribed times originated, but snacking between meals appears to have been

institutionalized in recent times, resulting in a multibillion dollar domestic and

international snack food industry. This chapter reviews snacks of animal origin

including meat, fish, dairy and egg products. Meat snacks have their origin in

meat- and fish-drying practices that were innovated to prevent rapid spoilage.

Consumption of meat snack foods has received increased attention as the result

of several popular diets that encourage consumption of increased amounts of

protein and less carbohydrate.

Raw meat consists of approximately 75% water,18% protein,varying amounts

of fat (2–20%), less than 1% minerals and less than 1% carbohydrate. With a pH

usually between 5.5–6.5, raw meat is an ideal substrate for microbial growth.

In general, the place of meat in the human diet has been well established as

an excellent nutritional source of high-quality protein, B vitamins including

vitamin B12, zinc, bioavailable iron and many micronutrients. A large variety

of distinctive dried meat products exists, some of which are listed in Table 15.1.

Most meat snacks fit into the low-moisture category (water activity below

0.6) or intermediate-moisture category (water activity of 0.9–0.65) [1]. Low-

moisture meat-like snacks include jerky, dried fish and seafood products, which

are stable at room temperature for long periods of time. Intermediate-moisture

meat products usually are partially dehydrated to l5–50% moisture, and con-

tain salt, sugar, or humectants added to further reduce water activity, and mold


TABLE 15.1. Intermediate- and Low-Moisture Meat Products.1

Name Region or Country

Beef jerky North America

Biltong South Africa

Bunderfleisch Europe

Carne de sol South America

Charqui South America

Dendeng giling Indonesia

Fermented sausages Europe

Khundi Africa

Pastirma Turkey

Pemmican North America

Prosciuto ham (raw) Europe

Sou song China

Spreck wurst Europe

Quanta Africa

1 Partially taken from Reference [3].

inhibitors to prolong shelf life. These products are packaged to reduce devel-

opment of oxidative rancidity and other flavor problems. Generally, they can

be stored at room temperature for long periods of time and are eaten without

rehydration.

1.1. WATER ACTIVITY

Knowledge of the percent moisture content in a meat product is useful for

categorizing its potential for microbial and chemical degradation. However,

water activity (AW ) measures availability of water for microbial growth and is

a better predictive tool. Some water is bound very tightly to macromolecules

in the food and is not available to support microbial growth. Typically, the

additional water is loosely bound or free within the food and can be used by

microorganisms. Free or loosely bound water vaporizes easily, whereas tightly

bound water vaporizes with difficulty.

Water activity is the ratio of the vapor pressure of the water in the food to

that of water alone at the same temperature. Various instruments are available

for measuring AW as the relative humidity in the air space of a small con-

tainer in which a test sample has been allowed to equilibrate. The relationship

between the moisture content of a food and water activity is described by a

sorption isotherm as shown in Figure 15.1. Sorption isotherms for different

foods often have common features; however, each food has a distinctive sorp-

tion isotherm for a given temperature. Temperature effects include changes in

the physical properties of the product as well as in co-solubilities of the ingredi-

ents. Thus, the sorption isotherm for cooked beef is different from cooked beef


Figure 15.1 Representation of sorption isotherm for cooked meat at 70◦F (21◦C).

containing salt [2]. It can be affected by many factors, including the product’s

composition, process treatments, and by addition of salt, sugar or humectants

[3]. Humectants bind to water very tightly and reduce its vaporization and

availability to microorganisms for growth.

In most meat and fish snack foods, the water content has been greatly reduced

so microbial growth is not supported. However, removing moisture is expen-

sive and leads to flavor and texture changes. Therefore, it is usually desirable

to remove the least amount of water possible while still inhibiting microbial

growth. The creation of a shelf-stable meat snack requires the product to be

free of bacterial, yeast and mold growth and to have minimal lipid oxidation,

non-enzymatic browning and enzyme-catalyzed degradations. Water activity

plays an important role in all these processes. The amount of moisture that

must be removed from the product to obtain a desired AW can be determined

from the appropriate sorption isotherm. Conversely, the water activity of a food

product can be measured and used to predict potential problems that may be

encountered [4].

Water activities of pure solutions can be estimated mathematically and are

related to the percent mole weights of solvent (water) and solutes (dissoci-

ated ingredients) present in the mixture, rather than percent ingredient weights.


Because of complete dissociation in solution, a mole of salt, with a molar weight

of 58.44 g, theoretically provides twice the competition for water than a mole of

glucose (180.16 g). Similarly, 3 carbon compounds (glycerin and propylene gly-

col) are more effective per unit weight in reducing AW than monose (6 carbon)

sugars like glucose, which, in turn, is more effective than dioses like sucrose with

12 carbons. Prediction becomes more complex when macromolecules like pro-

tein in meat and cooked starch from cereal additives are encountered in foods [4].

Strategies for reducing water activity in a meat product include removal of wa-

ter by dehydration and addition of compounds to bind water tightly in the meat

product. The preparation of some meat products includes use of both strategies

by adding salts and/or sugars and drying the meat product. Humectants such as

glycerol and propylene glycol and other polyhydric alcohols have become com-

mon components in intermediate-moisture foods. These compounds reduce the

water activity and often improve texture and other properties. Addition of large

amounts of salt can create sensory problems, and addition of large amounts of

humectants can introduce distinctive sweet flavors.

The water activity of fresh meat is above 0.99 [5]. Most intermediate-moisture

meat products have water activities between 0.65 to 0.90 and contain less that

50% moisture. Low-moisture foods have water activities below 0.60, which cor-

responds to moisture contents below 15% for many meat products. Safety of

intermediate-moisture meat products for human consumption requires that wa-

ter activity be reduced below that necessary for growth of food-borne pathogens.

In general, the water activity of intermediate foods should be reduced below

0.85 to inhibit most pathogenic bacteria, as shown in Table 15.2. However,

many molds and yeasts continue to grow at an AW of 0.85 [6,7]. These can be

further controlled by the addition of antimycotic compounds such as sorbic acid

and potassium sorbate. The general topic of water activity and microbiology of

meat drying has been well reviewed by Gailani and Fung [8].

TABLE 15.2. Approximate Minimum Water Activity (Aw) forMicrobial Growth.1

Organism Minimum Aw

Most bacteria 0.90

Most yeasts 0.88

Most molds 0.80

Most halophilic bacteria2 0.75

Most xerophilic molds3 0.70

Extreme limit of osmophilic yeasts 0.60

and xerophilic molds4

1 From References [1, 5, 8, and 21].2 Halophilic means high salt tolerant.3 Xerophilic means low moisture tolerant.4 Osmophilic means high osmotic pressure tolerant.


Factors that can alter the shelf life of meat snacks include: heating or cooking

steps in the process, reduction of water activity, reduction of pH, addition of

preservatives and reduction of the redox potential in the product [3]. Often the

pH is lowered using organic acids or glucono-delta-lactone. A heating step can

also be a low-temperature pasteurization process. Packaging can reduce the

redox potential to inhibit the growth of bacilli and oxidation problems. The

addition of nitrite (curing agent) to the product may have some positive effects

including stabilization of color and flavor components, and some inhibition of

microbes. Mold growth can be reduced by smoke treatment of the product,

dipping the product in a potassium sorbate solution and vacuum packaging [3].

2. JERKY PRODUCTS

Preserving strips of meat by drying is one of the earliest food preservation

methods and has survived for centuries because it preserves meat while main-

taining its nutritional qualities, and desirable flavor and texture properties.

A publication of the Food and Agriculture Organization of the United Nations

outlines some common meat preservation techniques [9]. Meat drying is often

accompanied by other preservation methodologies like addition of salt and

smoke treatment.

Jerky includes a variety of products, ranging from intact strips of dried muscle

to dried ground and comminuted products. It is expensive compared to other

snack foods due to the high cost of meat before drying. Lean raw meat has

a water content of approximately 70–75%, and the cost per pound of product

increases dramatically as water content is reduced during drying. Meat with a

high fat content is normally not used for jerky because rendering of fat interferes

during the drying process, and also due to sensory and texture problems of the

finished product.

The USDA Food Standards and Labeling Policy Book [10] states that all jerky

products must have a moisture-to-protein ratio (MPR) of 0.75:1 or less, and the

meat species or kind must be in the product’s name. Jerky has a MPR lower than

other common meat products such as pepperoni (1.6:1) or dry salami (1.9:1).

Jerky products can be cured or uncured, smoked or non-smoked and dried using

air or oven drying methods. Additional labeling possibilities exist. For example,

a jerky produced from a large piece of beef may be called “natural-style beef

jerky” provided an accompanying explanatory statement such as “made from

solid pieces of beef” is used.

A classic method for making beef jerky is to take 50 kg of beef and cut it

along the direction of the grain in long strips that are 2–3 mm thick and 2.5 cm

wide. Salt (4%), pepper (0.5%) and other minor ingredients such as soy sauce,

garlic and lemon juice are mixed and used to coat the meat strips, which then

are placed on wire racks. The meat strips are dried at 175◦F (80◦C) for about


25 hours until brittle. The strips are then wrapped in a cloth and stored in a cool

place for several days before transferring them to an airtight container at room

temperature [11]. Other procedures include immersing cut strips of meat in a

cold marinade containing salt, spices and cure agents for several hours. The

marinated strips are then rinsed with water and dried in a smoke house at 131◦F

(55◦C) or higher [12].

There are many variations on production of jerky from whole pieces of mus-

cle. Most procedures cut the muscle with the grain and place the meat in a

marinade prior to drying. Different spice mixes, cutting geometry, curing and

smoking options, and packaging increase the variety of products made. The pro-

cessing is simple enough that small meat processing plants can produce very dis-

tinctive products. Selling shredded jerky in a small round can, similar to that used

for some tobacco products, is only one of the interesting packaging practices.

2.1. FORMED JERKY PRODUCTS

Chunked and formed jerky products are made by mixing and massaging

chunks of meat, spices and salt, and placing the mixture in a mold for heat

treatment. The resulting solid piece of molded meat is then cut into strips and

dried to the same 0.75:1 moisture-to-protein ratio.

Jerky can be labeled “ground and formed” or “chopped and formed” when

made from meat that has been ground or (bowl) chopped as shown in Figure 15.2.

The ground or chopped meat is mixed with spices and salt and placed in molds

that are heated. After firming, the meat is removed from the mold, cut to the

desired shape and dried to the same MPR. Another product, labeled as “jerky

Figure 15.2 Flow sheet-ground and formed jerky processing.


sausage,” can be made by mixing ground or chopped meat with spices and salt

and stuffing it into small-diameter casings. The same MPR of 0.75:1 is required;

however, the product may be dried at any stage in the process [10].

Another procedure used to make ground or chopped jerky products involves

mixing ground or flaked meat with curing agents, spices, salt and phosphates,

and placing the mixture in casings that are tempered to 28.5 to 23◦F (−2 to

−5◦C). Then, the firmed product is sliced, spread on racks and dried at 55◦C

or higher to the desired MPR [12].

2.2. JERKY INGREDIENTS AND SAFETY CONCERNS

Ingredients used for formed and sausage jerky products include different

species and kinds of meats, salt, spices, curing agents and sometimes binders.

If the level of binder (e.g., soy protein concentrate) used is less that 3.5%, the

label must list the binder in a qualifying statement. If levels of binder exceed

3.5%, the binder must be reflected in the product’s name. Regulations limit

amounts of nitrite and other additives that can be used.

Types of meat used to make jerky have included skeletal muscle from do-

mestic and wild animals. A recent study found that jerky made from beef top

round had more desirable sensory properties than jerky made from beef hearts

or beef tongue [13]. In another study of highly spiced jerky-like products made

from beef top round, turkey breast or emu cuts, the naturally lean emu product

came out well in comparison [14].

Dried meat products, such as jerky, owe their existence in large part to the

fact that, due to low AW , they do not support growth of most microorganisms.

However, products can be contaminated with pathogenic microorganisms, in-

troduced by ingredients or during processing, that multiply during the drying

process. Although a specified heat treatment is not required in the production

of jerky [10], it is recommended that the meat be heated above 160◦F (71◦C)

prior to drying at 131◦F (55◦C). Many of the safety concerns for jerky products

came from home manufacture, where problems may occur in monitoring and

maintaining the temperature during drying [15].

Microbiological safety of shelf-stable meat products has been the topic of

many reviews [8, 16]. Faith et al. [17] evaluated drying time, temperature and fat

content on viability of E. coli 0157:H7 in ground and formed turkey jerky. They

identified conditions that would result in a 5-log cycle reduction. Holly [18]

inoculated product with Staphylococcus aureus, Clostridium perfringens, Bacil-

lus subtilis and Salmonella strains, and reported that drying at 131–140◦F

(55–60◦C) provided a margin of safety against the initial low numbers of

pathogens naturally occurring on meat slices. Microbial problems with dried

meat products are often the result of organism growth during the drying process.

Usually, rod-shaped bacteria are more sensitive to dehydration than cocci, and

endospores are largely unaffected.


3. SHELF-STABLE SAUSAGE STICK SNACKS

Many sausage or imitation-sausage stick products are marketed using pro-

prietary names. The name sausage implies that the meat has been chopped.

Long shelf lives of these products are obtained by strategies that can include

reducing water activity, lowering pH, adding chemical preservatives and using

mild heat steps. Dry-sausage stick products must have MPRs of 1.9:1 or less.

The common non-refrigerated, semidry shelf-stable stick products must have

MPRs of 3.1:1 or less and pH of 5.0 or less [10]. Other rules apply to other

products in this diverse classification of non-refrigerated, semidry shelf-stable

sausages [10]. Dry or semidry stick products that do not meet USDA-FSIS def-

initions for sausages must include ingredient listings on the label. Formulation

of a beef stick snack sausage product could include 100 kg beef (lean beef, beef

trimmings, flank), 2.5 kg salt, 1.25 kg dextrose, commercial spice blend, nitrite,

sodium erythorbate and a commercial lactic acid starter culture. The process

shown in Figure 15.3 includes grinding the meat, mixing the ingredients, and

stuffing into small-diameter edible casings [19]. The product is put in a smoke

house for a time and temperature that allows the lactic acid starter culture to

reduce the pH to 5.0 or lower before drying the product. The final step includes

heating the product to an internal temperature above 137◦F (58 ◦C). Depending

on the ingredients and processing, the above product would have a moisture

content of less than 50%, a protein content of 24% for a MPR of 2.1, and a pH

of less that 5.0.

The microbiology of intermediate-moisture meat products is complex. The

margins of safety often are not large, and breakdowns in the antimycotic

Figure 15.3 Flow sheet-beef stick snack sausage product processing.


protection system result in mold growth. Other problems include migration

of moisture into the package resulting in spotty areas of mold growth. To a

large extent, intermediate-moisture meat products are relatively stable at nor-

mal storage temperatures. However, a variety of deleterious chemical reactions

can occur, especially at elevated storage temperatures [7]. The first is oxida-

tion of the unsaturated lipids, which results in rancidity, aggregation of protein,

cleavage of protein chains and destruction of vitamins and amino acids. A

second common chemical reaction is non-enzymatic browning, which results

in formation of dark insoluble products. A third type of reaction can occur when

glycerin is used as an ingredient. It can react with many compounds, resulting

in protein cross-linking (including collagen) and changes in the myoglobin (red

color) spectrum.

4. OTHER DRIED MEAT PRODUCTS

A large variety of freeze-dried meats and seafoods is used in shelf-stable

products like soup mixes, and so on. Most are not snacks, and are usually

rehydrated before consumption. The process for making freeze-dried meat is

to first freeze the meat and then remove the ice as vapor in a vacuum chamber.

Dried beef slices are produced by first curing beef in a solution of salt, sugar

and nitrite until the cure solution has completely penetrated the meat. The slices

are then rinsed and dried in a smoke house for several days at 90–100◦F. Dried

beef is not cooked and may or may not be smoked [20].

4.1. MEAT BARS

Dehydrated meat bar products are used as components of military and survival

rations. A process for making this type of product is to first reduce the moisture

content of the meat by about 90% by freeze drying. The meat is then compressed

into bars at pressures about 10,000 psi (69,000 kPa). Then the bar is dried further

with radiant heat in a vacuum chamber and packaged in a water-impermeable

pouch with an inert atmosphere. Shelf lives of five years at room temperature

have been reported [21].

4.2. SOUTH AFRICAN BILTONG

Biltong is an uncooked dried meat delicacy made in South Africa and else-

where. It is purchased in sticks or slices, and portions are cut or broken off and

eaten as a snack. In making the product, fresh meat is cut in long strips with the

grain and placed in brine or dry salted. Besides sodium chloride, other brine

components may include spices, sugar, vinegar, nitrate-nitrite cures and preser-

vatives such as potassium sorbate (0.1%) or boric acid. The meat is left in the


brine for several hours, then dipped in a hot water-vinegar solution and finally

air dried at room temperature for 1–2 weeks. The final product has a pH of

about 5.5, moisture content of approximately 25%, water activity of 0.65–0.85

and salt content of about 6%.

A recipe for making biltong is to slice 100 kg of lean meat and rub in 4 kg

salt and spices (0.06 kg nitrite, 0.12 kg chilies, 0.38 kg pepper), refrigerate, let

the cure develop for 18 hours and then dry in a low-moisture atmosphere [11].

Biltong, like other low-moisture dried meat products, is stable at room tem-

perature. The major problem with biltong is that salmonella can survive for a

long time in uncooked meat products. Therefore, it is important to use meat

with a low initial microbial load, sanitary manufacturing practices and to rapidly

reduce water activity during the drying procedure.

4.3. TURKISH PASTIRMA

Pastirma is a salted dried beef product enjoyed in Turkey and other Mideastern

countries. Meat from the hind quarters of older beef animals is cut into 50–60 cm

long strips with a diameter less than 5 cm. Salt containing 0.02% potassium

nitrate is used to cover the strips, which are then placed in a pile at room

temperature for a day. The strips are then turned, salted and stored for another

day. Then they are washed and dried for days at room temperature. After drying,

the strips are put in a pile and pressed with heavy weights for 12 hr. The meat

strips are then dried, piled and pressed again with heavy weights before being

dried for 5–10 days at room temperature. The dried meat is covered with a paste

that contains ground fresh garlic and other spices. Then the paste-covered strips

are stored in a pile for a day, and hung and dried for an additional 5–12 days

before distribution. The finished product has a pH of about 5.5, salt content

of approximately 6%, water activity of approximately 0.88 and water content

close to 35% [3].

4.4. CHINESE DRIED MEAT PRODUCTS

The category of Chinese dried meat products includes some produced by

several techniques [3]. One type of product consists of meat cubes or strips.

To prepare it, chunks of beef, pork or chicken are cooked with addition of

water until tender and cut into strips or cubes. Sugar, soy sauce, monosodium

glutamate and spices are added to the liquid in which the meat was cooked, and

the meat-sauce mixture heated over low heat until almost dry. The meat pieces

are then placed on racks for several hours at 122–140◦F (50–60◦C) until about

50% of the original meat weight has been lost. The product can be stored at

room temperature for several months and has a water activity of about 0.7. The

product has a pH about 6.0 and contains 3–5% salt, 10–15% water and sugar

in excess of 20%.


A slightly different type of Chinese product is referred to as “shredded pork,”

“pork floss,” or Sou Song. Lean pork tissue is cut with the grain and cooked

in an equal amount of water until soft. After the meat is removed, the cooking

liquid is evaporated to 10% of its volume, and sugar, salt, soy sauce, wine,

monosodium glutamate and spices are added to the liquid. The meat pieces

are mashed, separated into fibers and added to the prepared liquid. Low heat

is applied until the liquid has evaporated, and the stirring continued for an

additional hour at about 85◦C until dry (AW ∼ 0.6). If a crisp product (AW of

about 0.4) is desired, 20% vegetable oil is added and the product stirred over

low heat until a golden brown color is obtained [3].

4.5. PEMMICAN

Pemmican is a dried meat and fat product that was initially produced by

American Indians [22]. Its taste is not outstanding, but the product has a very

high caloric density, provides all nutritional advantages of meat and is a method

of preserving meat. Pemmican was made by first heat drying meat (often buffalo)

and then pounding it into small fragments. The fragmented meat was then mixed

with animal fat and flavor agents. The dried meat-fat mixture was originally

stored in animal skin bags until eaten. There was a commercial market for

pemmican as late as the 1870s. Since that time, it has been a specialty item used

as survival rations by explorers, and was included in some military rations.

(Armour and Company made pemmican from 1906 to 1954.) There was much

variation in pemmican recipes, but a product could contain 64% dried meat,

35% fat and 1% salt [22].

5. PORK RIND PRODUCTS AND EXPANDED PRODUCTS

Pork rinds have been a small niche market in the U.S. snack food indus-

try, but are showing surprising growth. Sales grew by 16% in the year ending

December 31, 1998 [23,24]. Pork rinds are sold in small bags in convenience

stores and a variety of other locations, including grocery stores, vending ma-

chines, and so on. There are two parts to the industry: (1) making pork rind

pellets; and (2) making pork rinds from the pellets.

Pork rind pellets are made from raw pork skins, with often only the belly and

fat back portion skins used. Other competing uses for pork skins include the

gelatin and the leather industries. After the skin is removed from the carcass,

it can be dipped for 30 seconds in a brine at 212◦F [25]. The skin is then cut

into small squares and rendered for 1–2 hours at approximately 230–240◦F in

vats of lard to remove fat and water. The squares of skin are agitated and kept

submersed during the rendering process. After rendering, the pieces of skin will

have decreased in size about 50%. The resulting defatted, dehydrated pieces of


skin (pellets) are bagged and stored frozen. The quality of the pellets can be

monitored by watching changes in the peroxide value of the fat.

Pork rinds are made by first rehydrating the pellets in a flavored aqueous

solution, followed by cooking with agitation for approximately 1 minute in fat

at 400–425◦F. During this frying step, the pellets expand (“pop”) to form a

light-density product that can float. Rendered pork fat is often used for frying.

The rinds are then separated from the oil, and flavorings such as barbecue,

hot pepper or cheese may be added. The expanded snack can be air-dried to a

brittle-hard texture. Packaging is important to avoid crushing of the product.

Fat stability can be lengthened by using antioxidants and modified atmosphere

in the package. Quality issues include a lack of size uniformity, texture and

color uniformity, degree of expansion and variation in composition. A typical

pork rind product contains approximately 70% protein and 30% fat [25].

Pork cracklings are shelf-stable products made from rendered fatty tissues.

The process involves frying out (rendering) the fat from pieces of pork fat. The

protein-connective tissue matrix left after the fat is removed are the cracklings.

The pork skin must be removed before rendering the fatty tissue or the presence

of the skin descriptively noted on the label [10]. Cracklings are consumed as a

snack food or used as a condiment.

5.1. EXTRUDED STARCH SNACK PRODUCTSCONTAINING MEAT

Meat can be used as an ingredient to make cereal-based extruded snacks,

although it is not an ideal ingredient because of its high moisture and fat content.

Studies to optimize conditions and formulas have been conducted using a starch

source, soy isolate, salt, hydrolyzed vegetable protein and a pork or beef slurry

at the 20% level [26]. Acceptable products, with a bland flavor and light color,

were produced. The use of lower-cost meat sources, including beef heart and

pork shank trimmings, have also been evaluated. Other studies have examined

the properties of extruded raw beef blended with defatted soy flour and amylose

cornstarch [27], and properties of extruded meat and potato flour products [28].

A patent for an interesting expanded meat chip product has been described

[29]. Ground or chopped meat is mixed with water, heated to 212◦F (100◦C)

and combined with a mix of corn and potato starch to form a dough. The dough

is cooked under pressure, cooled, and held for 8–12 hours before slicing. The

slices are fried in hot oil at 400◦F (220◦C), resulting in an expanded chip.

5.2. EXPANDED FISH AND SHRIMP CHIPS

Small amounts of fish, shrimp and other shellfish mince have been mixed

with starch and used to produce crisp expanded snacks. The first step in most

processes is to form a dough from starch, water, fish mince and salt. The dough


is heated to gelatinize the starch, sliced and dried. The dried slices are expanded

in an oven or by frying [30]. Fat rancidity is a problem for these products, and

use of antioxidants is common. Large varieties of these snacks are common in

Asian markets.

6. PICKLED SNACK FOODS

Marination of meat has been used to improve meat tenderness and impart

desirable flavor characteristics. Several types of marinades exist, with acidic

formulations common. After meat is kept in an acidic marinade for sufficient

time, the marinade penetrates to the center of the product, resulting in a lowering

of meat pH [31]. The product can become shelf stable if the pH drop is sufficient.

Different types of cooked sausages have been packed in hot vinegar solutions

of approximately 5% acetic acid plus salt and spices. The sausages come to an

equilibrium with the vinegar solution in several days, resulting in lowering

the pH inside the sausage and a weight gain of approximately 25%. Sausage

types used for pickling include small individual frankfurter-like sausages, pieces

of coarse-ground sausages and artificially colored (often red) small sausages.

These products have good shelf life in the vinegar solutions. USDA regulations

regarding sausages in vinegar require a minimum of 4 g of acetic acid per

100 cubic cm of product [10]. The vinegar pickle must completely cover the

sausages, and pH maximum is 4.5. Pickled sausages and meat products are

available in sealed glass and metal containers and consumed as snacks and as

appetizers. Another pickled product consumed as a snack is pickled pigs feet.

Several processes for pickling pigs feed are described in Matz [25].

7. DAIRY- AND EGG-BASED SNACK FOODS

Some cheeses, with low moisture and very high salt content, are shelf stable

but are not commonly used as snacks. Some small snack packages of cheddar,

processed, and mozzarella (string cheese) are intended for eating as snacks,

but usually require refrigeration. Other shelf-stable cheese-like products and

spreads are packaged with or between crackers. Some puddings and dessert

products contain significant quantities of dairy components and are packaged

in individual shelf-stable portions utilizing sterile processing and packaging

procedure. Small dried balls of yogurt, stable at room temperature, are used as

snacks in Central Asia and other parts of the world.

The snack food industry uses dairy products mostly as ingredients. They

include: skim milk powder, milk solids, casein, dried whey, spray-dried yogurt,

cheese powders and enzyme-modified derivatives of cream and cheese [32].

Powdered cheese is a common snack food ingredient and coating for a large


variety of snacks. Dehydrated and ground cheese products are available for these

purposes, but use of spray-dried products consisting of some cheese plus dried

buttermilk, powdered whey, color and flavor components is more common [25].

Eggs are not common domestic snack foods. An egg snack that has lost

popularity is pickled eggs. The process for making pickled eggs is to hard boil

chicken or quail eggs, which are then covered with a vinegar solution containing

spices. The low pH results in a shelf-stable product.

8. DRIED AND MARINATED FISH AND SHELLFISH SNACKS

There are many dried and smoked fish and seafood snack products throughout

the world. Many of these are salted for periods ranging from minutes to weeks

[33]. Three primary salting methods are used: (1) a solid salt rub that extracts the

moisture, which is drained away from the product; (2) a salt pickle, where

the fish remains in contact with the extracted moisture; and (3) brining, where

the fish is soaked in a concentrated salt solution for specified length of time.

Smoking of fish and seafood is used to impart flavor, provide antioxidant

properties and inhibit microbes. Three general methods are used for smoking

fish and seafood products: (1) cold smoking, where the temperature is approx-

imately 86◦F (30◦C); (2) hot smoking, where the fish is cooked during the

smoking operation and the temperature often is in the 131–167◦F (55–75◦C)

range; and (3) smoke drying, where the fish is cooked and dried. Usually, prod-

ucts originating in Europe are brined before smoking, while products from

Africa often are not brined but sometimes air dried prior to smoking [33]. Fish

can be dried using many procedures, from hanging and drying in the air to using

commercial drying equipment. Air drying at ambient temperature usually can

be accomplished within 3 to 10 days, provided temperature and humidity con-

ditions are appropriate. Care must be taken to avoid a crusting (case hardening)

on the surface of the flesh which will inhibit moisture escape from the interior

flesh.

8.1. DRIED FISH AND SHELLFISH PRODUCTS

Dried fish consumed as snacks include: anchovies, sardines, herring, mack-

erel, saury, sand eel, pout and pieces of the fillet from larger fish. Lean fish

are usually used to reduce oxidative rancidity problems. Dried shellfish snacks

include: shrimp, clams, mollusks and squid [30]. The largest variety of small

dried fish products is found in Japan. The small fish are dried whole, split dried

or pierce dried, and can be salted or nonsalted. The salting of fish can be done us-

ing the dry salting procedure (20 to 30% salt overnight) or soaking in a 10–15%

brine for 4 to 8 hours. Drying procedures include drying at high temperature,

or partial drying to 44–48% moisture, plus salt curing and smoking.


A well-known specialty from India is Bombay duck, which is dried small

bumnaloe fish. During drying, the bumnaloe loses its fish flavor and develops a

unique roasted oil flavor. The production of flavored dried fish, which are made

from small and medium-size sardines, saury, mackerel, flat fish and sea bream

is a Japanese specialty. The fish are gutted and seasoned for several hours with

a combination of soy sauce, sugar, sake and monosodium glutamate, and then

dried. Clams and squid are also seasoned and dried [30]. A dried “fish floss”

or shredded fish product is consumed in parts of Asia as a snack food. This

product is made by soaking fish in a brine, followed by cooking and deboning.

The deboned fish is pressed to remove moisture and heated to further reduce the

moisture content to approximately 25%. The dried fish muscle is then shredded

into fibers that are mixed with oil and spices and roasted. Another snack, found

at times in North America and Europe, is minced white fish that has been roller

dried. Dried cod that has been mechanically softened is available in small snack

packages in Nordic countries.

Dried shrimp and squid snacks are common in many parts of Asia. In Japan

and Southeast Asia, a shrimp snack product is made by boiling shrimp in a

2% brine for 30 minutes, followed by peeling and drying. Other snack items

include dried squid, dried herring, gray mullet roe and fried fish bladders [30].

8.2. MARINATED AND/OR CANNED FISH ANDSHELLFISH PRODUCTS

Pickled herring is a common snack and appetizer, with a 17 to 25% fat

content, made from herring. The classic processes involve aging salted herring

in barrels for 6 to 24 months at 39.2–53.6◦F (4–12◦C). Small pieces of fillet are

then put in glass jars with vinegar and spices. Faster processes delete the aging

and marinate the herring in the jar. Shelf-life concerns may occur, depending

on the procedure used, and the product is usually refrigerated.

Anchovies are made from spat in the Nordic countries and anchovy in the

Mediterranean countries. Whole fish are packed in containers with salt, sugar

and spices and stored at 15 to 20◦C for ripening. After ripening, the fish are

filleted and packed in cans with an acidified brine marinade. Other marinated

snack products include shrimp, eel, and oysters [30]. The process for making

a canned oyster product is to mix raw oysters with 3 to 6% salt and boil. They

are then steamed and smoked for 20 to 40 minutes and put in an oil before the

canning process. Canned smoked clams are made by a similar process.

9. REFERENCES

1. Cassens R. G., 1994. Meat Preservation. Food and Nutrition Press, Trumbull, Connecticut,

pp. 68–71.


2. Iglesias, H. A. and J. Chirife, 1982. Handbook of Food Isotherms: Water Sorption Parameters

for Food and Food Components. Academic Press, New York, pp. 31–35.

3. Leistner, L., 1987. Shelf-stable products and intermediate moisture foods based on meat. In

Water Activity: Theory and Applications to Food. L. B. Rockland and L. R. Beuchat eds. Marcel

Dekker, Inc., New York, pp. 295–327.

4. Bone, D. P., 1987. Practical applications of water activity and moisture relations in food. In

Water Activity: Theory and Applications to Food. L. B. Rockland and L. R. Beuchat, eds.

Marcel Dekker, Inc., New York, pp. 369–395.

5. Romans, J. R., W. J. Costello, C. W. Carlson, M. L. Greaser, and K. W. Jones, 1994. The Meat

We Eat. 13th edition. Interstate Publishers, Danville, Illinois, pp. 710–765.

6. Ledward, D. A., 1981. Intermediate moisture meats. In Developments in Meat Science—2.

R. Lawrie, ed. Applied Science Publishers, London, pp. 159–194.

7. Ledward, D. A., 1983. Novel intermediate moisture meat products. In Properties of Water

in Food. D. Simatos and J. L. Multon, eds. Martinus Nijhoff Publishers, Dordrecht, The

Netherlands, pp. 447–463.

8. Gailani, M. B. and D. Y. C. Fung, 1986. Critical review of water activity and microbiology of

dried meats. CRC Crit. Rev. Food Sci. Nutr., 25:159–183.

9. FAO, 1990. Manual of Simple Methods of Meat Preservation. FAO Animal Production and

Health Paper, No. 79. Food and Agriculture Organization, Rome.

10. USDA, 1996. Food Standards and Labeling Policy Book. United States Department of Agri-

culture, Washington, D.C. (August), pp. 107–175.

11. Ocherman, H. W., 1989. Sausage and Processed Meat Formulations. AVI-Van Nostrand,

Reinhold, New York, pp. 27–28, 265–266.

12. Davis, J. M., 1990. Meat based snack foods. In Snack Foods. R. G. Booth, ed. AVI-Van Nostrand

Reinhold, New York, pp. 205–224.

13. Miller, M. F., J. T. Keeton, H. R. Cross, R. Leu, F. Gomez, and J. J. Wilson, 1988. Evaluation of

physical and sensory properties of jerky processed from beef, heart and tongue. J. Food Qual.,

11:63–70.

14. Carr, M. A., M. F. Miller, D. R. Daniel, C. E. Yarbrough, J. D. Petrosky, and L. D. Thompson,

1997. Evaluation of the physical, chemical and sensory properties of jerky processed from

emu, beef and turkey. J. Food Qual., 20:419–425.

15. Buege, D. and J. Luchansky, 1999. Ensuring the safety of home-prepared jerky. Meat and

Poultry, 25(2):56–57.

16. Tompkin, R. B., 1986. Microbiology of ready-to-eat meat and poultry products. Advances in

Meat Research, 2:89–121.

17. Faith, N. G., N. S. Le-Coutour, M. B. Alvarenga, M. Calicioglu, D. R. Buege, and J. B.

Luchansky, 1998, Viability of Escherichia coli 0157:H7 in ground and formed beef jerky

prepared at levels of 5 and 20% fat and dried at 53, 57, 63 or 68 degree C in a home-style

dehydrator. Int. J. Food Microbiol., 41:213–221.

18. Holly, R. A., 1985. Beef jerky: Viability of food-poisoning microorganisms on jerky during its

manufacturing and storage. Journal of Food Protection, 48:100–106.

19. Long, L., S. L. Komarik, and D. K. Tressler, 1981. Food Product Formulary, Volume 1: Meat,

Poultry, Fish, Shellfish. AVI Publishing Co., Westport, Connecticut, pp. 37–58.

20. Pearson, A. M. and T. A. Gillet, 1996. Processed Meats. 3rd edition. Chapman Hall, New York,

pp. 351–353.

21. Varnam, A. H. and J. P. Sutherland, 1995. Meat and Meat Products. Chapman Hall, London,

pp. 387–41.


22. Binkert, E. F., O. E. Kolari, and C. Tracy, 1976. Pemmican. In 29th Annual Reciprocal Meat

Conference of the American Meat Science Association, pp. 37–53.

23. McMabon, T., 1997. Living high off the hog. Snackworld, 54(11):12–14.

24. Snack Food Association, 1999. Salted snacks: Pork rinds. Snack Food & Wholesale Bakery,

June, pp. S1–52.

25. Matz, S. A., 1993. Snack Food Technology. 3rd edition. Avi-Van Nostrand, New York, pp. 39–50

and 225–234.

26. Thomas, L., P. Bechtel, and R.Villota, 1989. Effects of Composition and Process Parameters

on Twin-Screw Extrusion of Expanded Meat-Based Products. 1989 Annual Meeting of the

Institute of Food Technologists. Abstract No. 118.

27. Park, J., K. S. Rhee, B. K. Kim, and K. C. Rhee, 1993. Single-screw extrusion of defatted soy

flour, corn starch and raw beef blends. J. Food Sci., 58:9–20.

28. McKee, L. H., E. E. Ray, M. Remmenga, and J. Christopher, 1995. Quality evaluation of chile-

flavored, jerky-type extruded products from meat and potato flour. J. Food Sci., 60:587–591.

29. Karmas, E., 1976. Processed Meat Technology. Noyes Data Corporation, Park Ridge, New

Jersey, pp. 275–276, 308–324.

30. Nielsen, J. and A. Bruun, 1990. Fish snacks and shellfish snacks. In Snack Food. R. G. Booth,

ed. Avi-Van Nostrand Reinhold, New York, pp. 183–203.

31. Gault, N. F. S., 1991. Marinated meat. In Meat Science—5. Applied Science Publishers, Lon-

don, pp. 191–246.

32. Robinson, R. K., 1990. Snack foods of dairy origin. In Snack Food. R. G. Booth, ed. AVI-Van

Nostrand Reinhold, New York, pp. 159–182.

33. Poulter, R. G., 1988. Processing and storage of traditional dried and smoked fish products. In

Fish Smoking and Drying. J. R. Burt, ed. Elsevier Science Publishers, London, pp. 85–90.


SECTION IV

OPERATIONS AFTER SHAPING

AND DRYING


CHAPTER 19

Snack Food Seasonings

JON SEIGHMAN

1. INTRODUCTION

CONSUMERS buy more than $6.5 billion worth of flavored salty snacks in the

United States annually. This is an incredibly competitive business where

small regional chippers and national snack food giants go toe to toe in competing

for a share of the snacking consumer’s money. Americans are snacking more

than ever before. From 1993 to 1998, the percentage of adults who eat three

meals a day without snacking between meals decreased from 33% to 24%.

Today, more than 50% of Americans eat less than three meals per day and snack

once or twice between meals. There is a growing population of Americans who

snack throughout the day with no sitdown meals at all. It should be no surprise

that this translates into big opportunities for snack companies. However, snack

consumers are demanding. They want variety and many options. It is up to the

snack food companies to provide new seasonings for chips to keep snackers

interested and coming back for more.

From cheese to barbecue (BBQ) to sour cream and onion, the average person

consumes 8 pounds of flavored chips, pretzels, popcorn, nuts and meat snacks

per year. Since the mid-1980s, flavor line extensions have fueled growth for

many snack food producers. A reason for this is the huge expense associated

with development, commercialization and marketing of new snack food brands.

Developing a new snack brand is difficult. Manufacturers must identify how the

new brand will be different from current brands. Shapes must be identified and

tested. Texture and thickness must be evaluated. New equipment and ingredients

may have to be purchased. In addition, advertising budgets must be increased

to inform consumers about the new brand and persuade them to buy it.


On the other hand, a flavor extension of a line uses the same production

equipment and brand name as existing products. Development time is shortened

to the time spent formulating and testing the new seasoning. Consumers are

already familiar with the brand and its benefits. A new flavor is easier to try and

accept than a new brand. Line extensions allow the snack manufacturer to have

a portfolio of products that appeal to a broad range of consumers at lower cost.

Each flavor can be used to extend the reach of the brand. Snack food companies

may launch a new brand once every five years, but launch new flavors each

year.

Historically, the most popular flavors for salty snack seasonings have been

Cheese, BBQ, Sour Cream and Onion, and Ranch. These four seasonings form

the basis for the flavor portfolios of most snack food brands. As a result, con-

sumers are very familiar with the taste profiles of these seasonings and readily

accept them on almost any snack product. A Nacho Cheese seasoning devel-

oped for tortilla chips may taste just as good on potato chips, or a Sour Cream

and Onion developed for potato chips may be a great new flavor for corn chips.

Many snack food companies include two or more of these flavor profiles in each

new brand they introduce.

The challenge for many snack food companies is deciding on the seasoning

to develop after the “Big Four.” Since flavor line extensions are a major source

of growth, snack companies are always looking for the next great-selling new

snack flavor. The new flavor may be a replacement for BBQ, Cheese, Sour

Cream and Onion or Ranch, but is just as likely to be a reformulation of the

current flavor with enhancements to make the seasoning more in accord with

current taste trends. For example, BBQ seasonings developed in the mid-1960s

were typically hickory smoke type with high levels of torula yeast, paprika and

spices. In the late 1980s, many companies reformulated their BBQ seasonings

to switch from hickory smoke to mesquite smoke and made the flavor much

sweeter by introducing sugar, dextrose, or honey. In the 1990s, many BBQ

formulas were adjusted to be spicier with more red pepper and more acidity.

Similar evolutions have occurred for each of the classic seasoning types over the

last 20 years, with each profile changing slightly to match the changing tastes of

the snack consumer. Although the classical seasonings have evolved gradually

over time, at least one new flavor is introduced each year as a contestant for the

next classic snack flavor that will withstand the test of time.

Successful new snack seasonings often use familiar flavors and combine

them in creative ways. A review of the top-selling flavored snack food products

shows that many of the same ingredients are used. Cheese powder, tomato

powder, onion and garlic appear in almost every ingredients statement. These

ingredients appear in seasoning formulas like BBQ, nacho cheese, pizza, taco,

chili cheese, or ranch. The key to successful seasoning development is creating

variety in new seasonings by combining well-known ingredients in unique

ways.


2. INGREDIENTS

Before discussing the formulation of seasonings, it is necessary to develop an

understanding of the ingredients and their functions. As an example, one top-

selling snack has the following long ingredients statement, arranged in order of

diminishing content:

Salt, sugar, maltodextrin, dextrose, monosodium glutamate, onion powder, tomato

powder, brown sugar, sour cream powder, molasses, cheddar cheese powder,

Monterey Jack cheese powder, garlic powder, spices, sodium diacetate, natural

and artificial flavors, whey, artificial colors, natural hickory smoke flavor, worces-

tershire sauce powder, dehydrated bell pepper, hydrolyzed proteins, beef stock,

autolyzed yeast, lactic acid, citric acid, vinegar, tamarind, disodium inosinate,

disodium guanylate, and yeast extract.

Seasoning manufacturers do not construct complicated ingredient declara-

tions to confuse the competition, but rather to create great-tasting snacks with

well-balanced flavor and appetizing visual appeal. To accomplish this, season-

ing formulators develop complex blends of ingredients that provide multiple

flavor sensations. Each ingredient in the formula serves a specific function to

help achieve flavor and appearance characteristics that attract consumers.

Some ingredients provide the characterizing flavor of the seasoning. The

smoke, worcestershire, and natural and artificial flavors are the primary char-

acterizing flavors in the seasoning, and part of the initial flavor burst. They are

tasted first as the top note of the seasoning and also are part of the aftertaste.

Other ingredients affect the mouth feel or texture of the seasoning. Sour

cream powder, cheddar cheese powder, or Monterey Jack cheese powder are

not present to introduce characterizing dairy flavors that the consumer will

taste and recognize, but to give a pleasant fatty mouth feel to the seasoning. The

fattiness of these ingredients helps blend the harshness of the hickory smoke

and meaty flavors with the background flavors of onion, garlic and tomato to

provide a smooth transition from taste to taste.

Numerous flavor enhancers, including monosodium glutamate (MSG), dis-

odium inosinate, disodium guanylate, autolyzed yeast and salt, are in the for-

mula. These enhance the overall flavor impact of the seasoning and give a

mouth-watering sensation that attracts the consumer to eat more. Some snack

producers avoid use of flavor enhancers like these to meet consumer demands

for so-called clean labels. But for seasoning formulators, this class of ingredi-

ents is very important in the development of great-tasting salty snack products.

In addition to enhancing flavor, ingredients are present to stimulate the basic

taste sensations of sweet, salty, bitter and sour. For example, dextrose, brown

sugar and molasses provide rich, sweet brown flavors to the seasoning. Mo-

lasses, tamarind, some spices and yeasts, provide a subtle bitterness to the

formula. A complex acid profile results from the addition of sodium diacetate,


lactic acid, vinegar and/or citric acid. The acid complex enhances the sweet

brown flavors described previously.

The selected ingredients determine how the flavor releases, what the after-

taste will be, and whether the seasoning can be applied evenly. Grouping the

ingredients of a seasoning into salt, fillers, spray-dried dairy and vegetable pow-

ders, spices, compounded flavors, flavor enhancers, sweeteners, acids, colors

and processing aids helps to develop an understanding of how seasonings are

formulated for salty snacks.

2.1. SALT

Salt is a key ingredient in salty snack seasonings. The main purpose of salt

is to potentiate the overall flavor of the seasoning. Without salt, it would have

a bland flavor and lack intensity. The most common salt used in formulating

seasonings is flour salt, a fine granular material with a particle-size distribution

of 96% minimum through a U.S. 80 mesh (178 micron) screen. Granulated

salt, fine flake salt, or pretzel salt may be used for snacks where only salt is

added, but are not recommended for seasoning blends. The relatively larger

salt particles have a tendency to adhere to the snack base differently than the

other fine-particle-size ingredients in the blend, and often result in excessive

salt falloff or uneven distribution of the seasoning

Salt typically is used in formulas at 15–25%, if the seasoning is applied to

the finished product at 5–8%. The exact salt level for a seasoning should be

determined through consumer testing. It is important to remember that salt also

is present in many spray-dried dairy powders, hydrolyzed vegetable proteins

(HVP), autolyzed yeast extracts and in some compounded flavors. Also, salt

perception is enhanced by the use of monosodium glutamate, disodium in-

osinate, disodium guanylate and some organic acids. These factors should be

considered when adjustments are made to the salt level.

2.2. FILLERS

The fillers used in seasoning blends typically are low-cost, commodity prod-

ucts, bland in flavor. The most common fillers are: maltodextrin, corn syrup

solids, wheat flour, corn flour and whey. Fillers are used in seasonings at

20–40%, depending on the type of seasoning and its level of application to

the product.

Most seasoning blends are used on snacks at 5–8%. Formulators use fillers

to adjust the application level of the seasoning to ensure desired coverage and

flavor impact. For example, if the overall flavor impact of the seasoning is too

strong, additional filler may be added to dilute it. If the appearance of the blend

on the snack is uneven, one solution may be to increase its application level.

But if the seasoning use level is increased, the filler should also be increased to

maintain an equivalent flavor impact.


This can be shown for a seasoning which contains, among other things, 20%

maltodextrin, 20% added salt and 1% compounded flavor.

Maltodextrin 20.00%

Salt 20.00%

Compounded flavor 1.00%

Other ingredients 59.00%

100.00%

The blend was intended to be used at 5% on a snack base but, when applied

to chips, although the flavor of the seasoning is acceptable, its coverage of the

product is uneven. An increase in seasoning application level to correct this

is indicated. But if the blend is applied at 7%, the flavor will be too strong.

Therefore, the filler should be increased to dilute the seasoning.

Referring again to the example formula, at 5% use level seasoning, the mal-

todextrin, salt and compounded flavor on the finished product is 1%, 1% and

0.05%, respectively. If increased to 7% without adjustment of fillers, the salt

content would be 1.4% and the compounded flavor 0.07%, a 40% increase of

each:

At 7% Use Level At 5% Use LevelIngredient Formula on 100 g Chips on 100 g Chips

Maltodextrin 20.0% 1.00 g 1.40 g

Salt 20.0% 1.00 g 1.40 g

Compounded flavor 1.0% 0.05 g 0.07 g

Other ingredients 59.0% 2.95 g 4.13 g

Total 100.0% 5.00 g 7.00 g

The objective is to keep the flavor impact of the seasoning when used at 7%

equal to the flavor impact at 5%, and salt and flavor in the formula are reduced.

The new levels are 14.30% for the salt and 0.70% for the compounded flavor.

The difference in the formula is added to the maltodextrin.

At 7% Use LevelIngredient Formula on 100 g Chips

Maltodextrin 26.00% 1.00 g

Salt 14.30% 1.00 g

Compounded flavor 0.70% 0.05 g

Other ingredients 59.00% 2.95 g

Total 100.00% 5.00 g

Referring to the previous chart, we see that the levels of flavor and salt in the

first formula applied at 5% are now equal to the salt and flavor applied at 7%.


The changes in bland filler will have little impact on the overall flavor of the

seasoning when applied at 7%.

2.3. SPRAY-DRIED DAIRY POWDERS

Cheese powders, sour cream powders, butter powder and buttermilk powder

are key ingredients in formulating blends for salty snacks. Their function is to

provide mouth feel and flavor to the seasoning. Dairy powders are manufactured

by spray drying a slurry of cheese, butter, sour cream, or buttermilk, water,

starch, emulsifier, salt, and sometimes compounded flavors. The relatively high

level of butterfat in the powders, typically 15–50%, makes them valuable to the

seasoning formulator.

The need for dairy powders in seasonings like Nacho Cheese or Sour Cream

and Onion is obvious because the named ingredients, cheese and sour cream,

are required for labeling and for flavor. However, the use of dairy powders is not

as clear in the case of BBQ seasoning. Formulators use dairy powders in this

application to provide mouth feel and to help blend all the flavors contained in

the seasoning. Seasonings without any fat tend to “clean up” very quickly; even

well-formulated flavor profiles, lacking fat, have this problem. Dairy fat, with a

melting point below 100◦F (37.8◦C), readily melts and coats the mouth during

eating. As the fat melts, lipophilic flavor chemicals solubilize in the fat, creating

a longer-lasting flavor sensation in the mouth. The aftertaste of the seasoning can

be affected by manipulating the fat-soluble flavor components of the formula.

This is useful in BBQ seasonings, which have a tendency to be harsh due to the

smoky, meaty and vinegary notes present in their formulas. Spray-dried dairy

powders should be used in most applications and not just dairy seasonings.

Many types of dairy powders are produced for use in the snack industry, and

the product for the seasoning should be selected carefully. The dairy powder

should have a clean taste without significant cooked notes. Dairy powders are

relatively expensive and are priced according to cost of the starting material

used, the level of butterfat in the finished powder, and whether the product is

kosher or not.

Dairy powders are used in seasonings at levels of 5–20%. At low levels, they

help smooth out the flavor, especially if the seasoning has a high level of flavors

and spices. At high levels, they make a significant contribution to the mouth

feel and flavor of the seasoning.

2.4. DEHYDRATED VEGETABLE POWDERS

Onion powder, garlic powder and chili pepper are the most common vegetable

powders used in seasonings. They are produced by drying a slurry of the veg-

etable, usually by heat and vacuum, to a moisture content of less than 5%. The

resulting powders are relatively inexpensive and concentrated in flavor. Toasted


or roasted versions of onion or garlic powders offer distinctively different flavor

profiles.

Onion or garlic appears in almost every snack seasoning currently sold. They

bring depth to the middle part of the seasoning’s flavor profile. The initial flavor

of a seasoning comes from compounded flavors that dissolve rapidly and release

flavor quickly. After the initial burst of flavor, the next flavor perceived comes

from ingredients that solubilize slower. Onion and garlic powders release flavor

slower than spray-dried flavors and therefore are used to fill the middle of the

taste experience. The initial flavor release can be intense in seasonings using

only compounded flavors, but the flavor dissipates quickly. Addition of onion or

garlic powder to the formula makes the taste profile more complex and prolongs

the taste experience. Both ingredients are versatile in most applications, and can

also be used at low levels to help sustain the flavor impact in cheese seasonings.

However, these powders are generally higher in yeast, mold and standard

plate count than most other ingredients used in seasonings, a factor to consider

if the blend is used in microbially sensitive applications.

Onion powder is typically used at 1–10% in seasonings, and garlic powder

at lower levels, usually 0.5–5%.

2.5. SPICES

Herbs and spices were the primary source of added flavor in seasonings for

many years. The first snack seasoning depended on flavors contributed by spices

such as black pepper, chili powder, mustard flour, oregano, basil and cumin. In

some cases, the spices were ground to fine powders to blend easily with the salt,

garlic and onion powders. Some spices, like parsley, oregano and basil, were

used whole to contribute to the appearance of the seasoning as well as the flavor.

Spices have always been an important part of seasonings, and familiarity

with flavor and appearance of common products is essential for any seasoning

formulator. Formulators should be able to recognize by taste and appearance:

anise, basil, black pepper, celery seed, chili pepper, cinnamon, clove, coriander,

cumin, dill, fennel, marjoram, mace, nutmeg, oregano, parsley, rosemary, sage,

savory, thyme and turmeric. All are commonly used in seasonings for snacks.

Spices, like onion and garlic, add depth to the flavor profile of a seasoning.

Ground spices are concentrated in flavor, which releases slowly during the

eating experience and lasts a long time, like onion and garlic. Whole spices are

additionally visually appetizing.

More recently, spice extracts (essential oils or oleoresins), were added to

seasonings for more flavor impact. Essential oils or oleoresin generally are

spray dried, which accelerates the flavor release to be more like compounded

flavors. Encapsulation increases shelf stability.

Generally, ground spices are used at 0.25–2.00% in seasonings. Spice extracts,

spray-dried essential oil, or encapsulated spices are generally sold as 5×, 10×


or 25× replacers for ground or whole spices. Spices are expensive ingredients

on a per pound basis, ranging from $2.00 to $5.00 per pound, but their strength

makes them cost effective for use in seasonings in most applications.

Like onion and garlic powders, spices have higher yeast, mold and standard

plate counts than most other seasoning ingredients. Spices are generally treated

with ethylene oxide or irradiation to reduce microbiological risk. The use of

essential oils or oleoresins in place of whole or ground spices is a sound alter-

native because of the extremely low microbial risk after the extraction process.

2.6. COMPOUNDED FLAVORS

In the last 10 years, compounded flavors have replaced spices as the primary

contributors to taste in seasonings. The need for a wider range of flavor pro-

files, and stronger-flavored seasonings, has led to the shift. Ground spices were

not sufficiently stable over the shelf life of snacks, and some natural sources

became too expensive for widespread use. Consumer testing indicated the need

for stronger cheese flavors and more authentic dairy flavors, but spray-dried

dairy powders no longer met the requirements. Consequently, formulators be-

gan incorporating compounded flavors into seasonings to satisfy the changing

marketplace.

Advances in flavor technology enabled the development of a wide range of

shelf-stable, high-impact flavors that are cost-effective for use in seasonings.

Spray-dried or encapsulated flavors are used in most blends. Compounded fla-

vors are used in seasoning formulas at 0.1–5.00%, depending on the application.

Costs are $3.00–10.00 per pound and are highly dependent on whether the com-

ponents are natural or artificial.

Flavor selection has become the most important step in developing a sea-

soning. The potential compounded flavor should be screened in the application

when considered. Smelling the bottle and finger tasting are not acceptable alter-

natives. Each potential flavor should be evaluated at two use levels, for example,

the high and low levels of the usage range suggested on the container. This is

necessary to see the effect of flavor level on the overall flavor of the seasoning. A

range of flavor profiles should be considered before making the final selection.

If the flavor is a butter flavor, then natural, natural and artificial, and artificial

versions should be evaluated as well as flavors high in diacetyl and without

diacetyl. Fresh butter profiles should be screened versus melted butter profiles.

It is best to understand all possible source options for the flavor in question and

how they interact with other seasoning ingredients and the base before making

the final selection.

2.7. FLAVOR ENHANCERS

Like salt, flavor enhancers are key ingredients in seasoning. The most com-

mon flavor enhancers are monosodium glutamate, autolyzed yeast, disodium


inosinate, disodium guanylate and hydrolyzed vegetable protein. Each contains

a high level of 3′ and 5′ nucleotides, which are known to potentiate savory

flavors in seasonings.

Flavor potentiation is important to the overall taste of the seasoning. Without

one or more of these ingredients, the seasoning may have a bland or flat taste.

A mouth-watering response, resulting from the addition of nucleotides to the

seasoning, will benefit all aspects of the flavor profile.

Use levels for flavor enhancers vary according to the seasoning profile, but

starting levels are: monosodium glutamate, 1–5%, autolyzed yeast extract,

1–5%, disodium inosinate and disodium guanylate, 0.01–0.05% and hydro-

lyzed vegetable protein, 1–5%. Costs vary for these ingredients with MSG and

HVP the lowest cost at $1.00–$3.00 per pound, to disodium inosinate and dis-

odium guanylate at about $13.00 per pound. Autolyzed yeast extract is priced at

$2.00–$6.00 per pound.

2.8. SWEETENERS

Sugar, brown sugar, dehydrated honey solids, spray-dried molasses, dextrose

and fructose are the most common sweeteners used in seasonings. As with

all seasoning ingredients, the formulator should select sweeteners with small

particle sizes to be compatible with the other ingredients in the blend.

Each of the sweeteners gives a slightly different flavor to the formulation.

Sugar, brown sugar and molasses give similar sweetness perceptions. Honey

solids and fructose are similar in sweetness profile. Dextrose, when added to

the formula, has a mouth-cooling effect and is effectively used in many BBQ

formulations.

Most sweeteners are inexpensive additions for seasonings. Prices range from

$0.25 per pound for sugar up to $0.70 per pound for honey.

Sweeteners should be added to seasonings with care because most are hy-

groscopic and may cause flowability problems during the hot summer months.

Typically, additional free-flow agents are necessary.

2.9. ACIDS

Citric, lactic, malic and acetic acids are the most common acids used in

seasoning formulations. Additionally, the sodium salt of acetic acid, sodium

diacetate, may also be used as an acidulant to mimic the flavor of vinegar.

2.10. COLORS

Color is added to most seasonings by use of artificial colors. The most com-

mon colors are FD&C alumina lakes including Yellow #5, Yellow #6, Red #40,

and Blue #1. Alumina lakes are preferred in seasoning applications because of

stability and non-reactivity. The use of pure dyes is not recommended in topical


seasoning systems. The color dye transfers readily to hands and clothing in the

presence of a small amount of moisture and becomes a nuisance in production

and final use by consumers. The lakes are used alone or as blends in seasoning

formulations.

Almost any color may be made from combinations of these colors. Manu-

facturers of seasonings have two options for adding colors to formulas:

� Add directly to the seasoning blend following the addition of all granular

material and any liquids. A blending step usually follows to begin

dispersing the color; or� Purchase spray-dried ingredients where colors have been added to the slurry

prior to drying. An example is spray-dried cheddar cheese powders with

FD&C Yellow #4 and FD&C Yellow #5 added. Cheese powder

manufacturers generally offer a “normal color” version for applications

where high levels of the cheese are used and a “triple color” version for use

if lower levels of cheese are added to the seasoning but a significant level of

orange color is desired.

The major advantage of adding color directly to the seasoning blend is flex-

ibility in customizing. Seasoning manufacturers can quickly adjust color to

meet customer needs for reformulation. Advantages of adding colors via spray-

dried ingredients is uniformity, ease of handling and weighing and avoidance of

flashing of individual non-lake colors in the seasoning. Both methods of adding

artificial colors to seasonings are used.

Extractives of paprika and turmeric may also be used for adding color to

seasonings. These spice extractives are oil-soluble and must be plated onto salt,

sugar or maltodextrin to distribute the color throughout the blend. Annatto can

also be used to contribute a yellow or orange color to a seasoning. Caramel

color is used to add brown to seasonings.

All the colors, with the exception of caramel color, are relatively expen-

sive, priced at $8.00–$13.00 per pound. However, use levels are relatively low,

resulting in a low-cost contribution to the total price of the seasoning.

The FD&C colors are the most stable of the colors and contribute no flavor.

Extractives of paprika can be light-sensitive and will fade if a stabilized ver-

sion is not used. Turmeric oleoresin can change color with varying pH ranges.

Caramel colors usually contain sulfites, which may require declaration on the

snack product label.

2.11. PROCESSING AIDS

With the exception of fillers and colors, all of the ingredients described thus

far contribute to the flavor and flavor release of the seasoning. An equally

important set of ingredients affects processing of the blend. These ingredients

are added at different times during blending of the seasoning.


Once the seasoning is formulated, consideration must be given to the method

of its application to the snack product. Often, a tumbler coater is used in which

a curtain of seasoning is spread over the snack base, allowing it to adhere to the

base.

The seasoning must flow freely and not contain agglomerated particles; other-

wise, the snack product will appear unevenly coated. Problems from ineffective

use of processing aids include excessive seasoning fall-off, or clogging of the

equipment and frequent shutdown for cleaning.

The most common processing aids are vegetable oil and silicon dioxide.

Vegetable oil is used to coat ingredients that are hydrophilic, thus reducing the

tendency of these ingredients to absorb moisture. This prevents the ingredients

from agglomerating or causing lumps in the blend, which makes even applica-

tion of the seasoning difficult. The best practice is to add the vegetable oil close

after the hydrophilic ingredients in blending order, followed by a blending step

of sufficient duration, which allows the oil to coat the material as completely

as possible.

Vegetable oil is also important if the seasoning blend contains ingredients

with large differences in particle-size distribution. Although it is advisable to

keep the particles of seasoning formulations small and uniform in size and shape,

sometimes larger particles are needed to improve the appearance of the snack,

for example, dried parsley in sour cream and onion seasoning. In this case, it

is important to have vegetable oil in the blend to facilitate agglomeration of

the parsley with the other ingredients. The vegetable oil acts like a glue to hold

the parsley in position throughout preparation of the seasoning and prevents

its stratification. Once the hydrophilic ingredients are coated with oil, it is

necessary to adjust the flowability of the seasoning back to its normal operating

characteristics. This entails adding a free-flow agent such as silicon dioxide or

tricalcium phosphate to the blend. These ingredients have the opposite effect of

vegetable oil. They act by coating all particles in the blend with fine powders

that resist agglomeration, effectively making the seasoning free flowing.

2.12. ANTIOXIDANTS

Direct addition of antioxidants to a seasoning formulation is not widely prac-

ticed. Incidental addition of antioxidants to oil-soluble ingredients, for exam-

ple, paprika oleoresin, is more common. Such antioxidants typically are used

to protect the raw material during storage, but usually are non-functional in the

seasoning. Vitamin E, alpha-tocopherols, extractives of rosemary, and butylated

hydroxyanisole (BHA) and/or butylated hydroxy toluene (BHT) were once used

in formulations in attempts to preserve seasonings. Now, alternative processing

techniques for sensitive materials are often used in place of adding preserva-

tives. Many snack manufacturers advertise their products as preservative-free

and seasoning suppliers have responded by omitting addition of antioxidants.


High-barrier packaging films and gas flushing of packaged snacks have also

eliminated much of the need for antioxidants in seasoning blends.

3. SEASONING FORMULATION

Seasonings for salty snacks are blends of salt, dairy powders, vegetable pow-

ders, flavor enhancers, spices, compounded flavors, colors and processing aids.

When the blend is applied to potato chips, corn chips, tortilla chips or other

snack bases, flavors in the seasoning, frying oil and the base start to intermin-

gle. Partitioning of flavors occur and prevent some from being tasted. Other

flavors are potentiated over time. With time, the flavors smooth together to

form the overall flavor of the snack food. Allowing seasonings to equilibrate

after blending, and allowing the seasoned snack to equilibrate after application,

are important steps in evaluating seasonings during development.

When starting to develop a seasoning formulation, it is useful to think in terms

of building a pyramid. The characterizing flavors of the seasoning are at the top

of the pyramid. This is the part of the seasoning that is tasted first, like the sour

cream flavor in Sour Cream and Onion potato chips, or the robust smoke flavor

in a mesquite BBQ seasoning for corn chips. The origin of this flavor portion is

typically compounded flavors or spices. These flavors are supported by the next

level, a foundation of basic commodity materials. In the case of the sour cream

flavor, the supporting commodity material is generally sour cream powder, but

could be non-fat dry milk, buttermilk powder, or cheese powder. In the third

level of the pyramid, the commodity materials and flavors are enhanced by salt,

sweeteners, flavor enhancers and acids. The bottom of the pyramid consists of

fillers, colors and processing aids to complete the seasoning blend.

3.1. TARGET SELECTION

The first step is identifying the direction of flavor development by asking the

following questions:

� Who is the target consumer?—Male or female?—Children, teens, adults, or seniors?

� What type of flavor does this consumer prefer?—High impact or subtle?

� What is needed to make this flavor interesting to the target consumer?—Is an existing flavor to be duplicated, or a new flavor profile created?

By answering these questions, the formulator reduces the development time

by focusing on the most highly acceptable ideas about the targeted consumer.


The questions should not be answerable by too many categories. It is easy to

say the product should appeal to everyone. Since this is impossible, it is best

practice to focus on a specific segment of total population. Obviously, in all

seasoning development projects it is best to target consumers who like to eat

salty snacks with flavors applied to them. If the seasoning is going to be a BBQ,

the product should be tested with consumers who buy BBQ-flavored products.

Finally, the age group to be targeted should be considered. Many companies

target consumers between ages 13–35. But snack seasonings that appeal to teens

do not necessarily appeal to seniors.

3.2. SEASONING DEVELOPMENT EXAMPLE

A few basic concepts apply to formulating snack food seasonings:

� The process is trial and error. The formula should begin with typical usage

levels of salt, fillers and enhancers, and then be adjusted as needed to suit

the snack base and consumer expectations.� A usage level of 6% can be assumed for the seasoning initially, with the

final level to be decided after the formula has been tested at several higher

and lower levels with consumers.� The existence of a product that fits the flavor profile under development

should be determined. Different products that resemble the flavor being

developed should be screened. If a match exists, the ingredients listing of

the product should be reviewed for ideas for duplicating the overall flavor

profile of the snack seasoning.� Formulation should begin with a cost target in mind, but with enough room

left in the cost allowance for subsequent changes in the formula.� All the formula constraints should be considered before actual formulation

is begun. Does the seasoning need to be kosher? Consist of natural flavors?

Is MSG allowed?

The best way to describe seasoning formulation techniques is by using an

example like development of a sour cream and onion seasoning for potato chips.

It is assumed that consumer research has identified the following characteristics

about the target customer:

� The target is teens and young adults, male and female.� The target customer prefers strong, bold flavors.� The target customer eats many of the existing sour cream and onion snacks

on the market, but would prefer a new flavor profile because current

offerings are “tired and old fashioned.”� The expected usage level for the seasoning is 7%.

From the flavor profile target, the formulator knows that salt, sour cream

and onion are necessary ingredients in the formula. Simply making a blend of


33% salt, 33% onion and 33% sour cream powder could be the beginning of

a seasoning, but the formula would not be balanced. It lacks complexity and

would be cost-prohibitive. The formulator must next think about the ingredients

needed to balance the flavor profile, enhance the flavor system and provide visual

appeal to the finished product.

Initially, several adjustments can be made to the formula based on information

available at the beginning of the project. Since the application level for the

seasoning will be 7%, the formulator can begin by reducing the level of salt in

the formula to 22%. This results in a salt content of 0.07 × 22, or 1.54% in the

finished product. The salt content for most snacks is 1.50–1.90%. This formula

can start on the low side of the range because salt-enhancing ingredients will be

added later. Sour cream powder is expensive, selling for $1.50–$2.00 per pound,

so the formulator reduces the sour cream powder to 20%. At this level, the sour

cream powder provides adequate mouth feel and flavor to the seasoning blend.

The onion powder is very high at 33% in the formula. Keeping in mind that

the target consumer prefers high-impact flavors, it is still advisable to reduce

the level of onion in the seasoning, so the level is changed to 10% for the first

revision. Maltodextrin is added at 48% to return to a 100% formula. The first

seasoning formula looks like the following:

Maltodextrin 48.00%

Salt 22.00%

Sour cream powder 20.00%

Onion powder 10.00%

100.00%

Applying the blend to the potato chip base at 7% use level, the formulator

observes good compatibility with the base, but it is still not a complete sea-

soning. The sour cream impact is too low. The overall flavor impact is low,

except for the onion. The next step in formulating is to begin increasing the

level of sour cream flavor without adversely affecting the overall cost of the

seasoning.

The sour cream flavor impact can be enhanced by several methods besides

increasing the dehydrated sour cream powder in the formula. Acidity is a key

component in delivering impact to dairy seasonings. The formulator can add

citric acid and lactic acid to give the impression of more sour cream. The

formulator adds 0.5% citric acid and 1.00% lactic acid to increase the overall

dairy impact of the seasoning. Another method is to add compounded sour

cream flavors to the seasoning. Numerous flavors are available to fit the needed

profile. The formulator selects one and adds it to the formula at 0.50%. In the

case of sour cream, added sweetness sometimes helps increase the dairy impact.

The formulator adds 5% dextrose and 5% non-fat dry milk to the seasoning in

an attempt to round out the sour cream flavor. The first revised formula is:


Maltodextrin 36.00%

Salt 22.00%


Onion powder 10.00%

Dextrose 5.00%

Non-fat dry milk 5.00%

Lactic acid 1.00%

Citric acid 0.50%


100.00%

Applying the seasoning to chips, the formulator can now taste elements of the

appropriate sour cream flavor and impact, but the seasoning lacks depth and the

flavor disappears too quickly. Next, the formulator adds 1.00% monosodium

glutamate to the seasoning to help potentiate the overall flavor profile of the

formula. Also, the formulator wants to make the onion part of the profile more

complex. One way to do this is to change to toasted onion powder instead of

white onion powder, or to add hydrolyzed vegetable protein to make the overall

flavor meatier in character. The second revised formula is:

Maltodextrin 33.00%

Salt 22.00%


Toasted onion powder 10.00%

Dextrose 5.00%


Hydrolyzed vegetable protein 2.00%

Lactic acid 1.00%

Monosodium glutamate 1.00%

Citric acid 0.50%


100.00%

At this point, the formula is nearly completed. Only a few variables in the

flavor profile remain to be optimized in this sour cream and onion seasoning. The

formulator now adjusts the key variables up and down to get to the optimized

formula.

The first step is to look at the sour cream level of the seasoning. In most con-

sumer tests, responses indicate a need for more sour cream impact. Consumers

almost always say they want more dairy impact in the flavors used for salty

snack seasonings. In this formula, the sour cream impact is affected by the level

of the compounded flavor, the sour cream powder level, the acid and the level

of dextrose. At this stage, changes to the formulation should be bold moves,

eliciting a definite response on impact. The revision should clearly be stronger

than the previous formula. When impact in a formula is an issue, it is better


to begin adjusting the flavor and acid rather than the sour cream powder level

or sweetness. The current levels of sour cream and dextrose in the formula are

adequate. A significant increase in the dehydrated sour cream powder would

make the seasoning too expensive, and an increase in the dextrose would not

significantly increase the overall sour cream flavor perception. The formulator

starts by increasing the level of sour cream flavor from 0.5% to 1.00%. The

level of acid is also raised by increasing the citric acid to 0.75% and the lactic

acid to 2.00%. The third revised formula is:

Maltodextrin 30.25%

Salt 22.00%



Dextrose 5.00%



Lactic acid 2.00%


Citric acid 0.75%


100.00%

The onion flavor level is rebalanced in the next step. After adjusting the

sour cream flavor and acid system, the overall onion impact is weaker. Also,

the toasted onion powder has slightly less impact than the white onion powder

initially used in the formula. The level of toasted onion powder is increased to

15%, and 5% white onion powder is added to the formula. More depth is added

to the onion flavor by increasing the MSG slightly to 2.00% and increasing the

HVP to 3.00%. The fourth revised formula is:

Maltodextrin 19.25%

Salt 22.00%



Onion powder 5.00%

Dextrose 5.00%



Lactic acid 2.00%


Citric acid 0.75%


100.00%

From a flavor standpoint, formulation of the seasoning is complete. However,

consumers also “eat” with their eyes. So the visual appeal of the seasoning blend


is just as important as the taste. The current seasoning blend has an off-white

to beige color and becomes virtually invisible when applied to the potato chips.

Consumers generally need a visual signal that the snack food is seasoned and

contains added flavor. As a result, the next step is to focus on appearance of the

seasoning blend.

Sour cream and onion seasonings historically have included a green leafy

material to give a visual signal that a seasoning has been added to the chips.

Looking at other similar food items, like ready-to-eat sour cream dip products,

can give assistance in deciding the type of appearance characteristics to be

added. In this case, dehydrated green onion, dehydrated parsley, or a fabricated

soy particulate with added FD&C colors could be used to improve the appear-

ance of the seasoning. The formulator should evaluate each possibility for use

in the formula. For most snack items, dehydrated parsley is the best choice.

It is bright green in color and is available in a range of sizes and prices. But

parsley or green onion would not be acceptable choices if the finished product

were to be exposed to light for prolonged periods. Photo-oxidation is a concern

in cases where plant material containing chlorophyll can oxidize the oils to

cause off-flavors in the seasoning and finished product. In cases where light

sensitivity is an issue (like see-through bags), the bits containing color would

be the preferred material. Parsley flakes are added at 3.00% for visual appeal

for the fifth revised formula:

Maltodextrin 16.25%

Salt 22.00%



Onion powder 5.00%

Dextrose 5.00%


Parsley flakes 3.00%


Lactic acid 2.00%


Citric acid 0.75%


100.00%

The final phase in seasoning development is to adjust the formula to facil-

itate problem-free application to the snack base. There are two parts in this

step, protecting hygroscopic materials from excessive water absorption and

adding free-flow agent. To protect the formula from excessive water absorp-

tion, a liquid vegetable oil is added to the formula. In the sour cream and onion

formula being developed, 0.5% vegetable oil is added. Partially hydrogenated

soybean oil is commonly used for this purpose. The vegetable oil typically is

added in the plating stage of manufacturing the seasoning, usually after the


addition of salt, MSG, maltodextrin and any other granulated ingredients. A

blending step follows the addition of the vegetable oil to adequately spread the

oil across the ingredients in the blend. Any hygroscopic materials should be

added to the seasoning blend following the vegetable oil. An additional blending

step completely coats the hygroscopic materials, forming an effective barrier

against moisture absorption. After addition of all the remaining ingredients and

a blending step, the free-flow agent is added as the last ingredient.

The free-flow agent of choice in most seasoning applications is silicon diox-

ide, although tricalcium phosphate also is popular. Silicon dioxide is a small-

particle-size, powdery material with a large surface area. When applied to sea-

soning blends, silicon dioxide coats the ingredients and reduces the tendency for

agglomeration. A free-flowing seasoning is necessary for even application of

the seasoning to the snack base. To complete the sour cream and onion formula,

1.00% silicon dioxide is added:

Maltodextrin 14.75%

Salt 22.00%



Onion powder 5.00%

Dextrose 5.00%


Parsley flakes 3.00%


Lactic acid 2.00%


Citric acid 0.75%

Vegetable oil 0.50%

Silicon dioxide 1.00%


100.00%

At this point, the basic seasoning formulation work is complete. Additional

consumer testing on the use level is an important final step. The seasoning may

be good at 7% use level, but have a higher acceptability with consumers at 8%

use level. This is a final checkpoint with consumers for overall acceptability of

the seasoning formulation.

Once the formulation work and consumer testing are complete, the formula

should be checked for shelf stability. Studies on the seasoning in its packaging

material, and on the finished, seasoned, packaged snack product are recom-

mended. These tests will indicate any ingredient interaction or stability prob-

lems with the seasoning blend. All shelf life test products should be compared

to frozen control, held at 0◦F (−18◦C) or lower for the duration of the test. It

is good practice to collect analytical data on the control before starting the test

and also on each shelf life sample evaluated. After successful completion of

shelf life testing, the new formula is ready for the marketplace.


The process for developing a seasoning is similar whether it is Sour Cream

and Onion, BBQ or Nacho Cheese. The same basic steps are followed:

� Start with demographic information about the target audience and ask

questions about the type of seasoning these consumers prefer.� Identify the ingredients and flavors that must be in the formula.� Add the basic elements of the seasoning and begin building each part of the

flavor profile by adjusting levels.� Check the appearance of the seasoning on the snack product.� Make sure the seasoning has the correct flowability to ensure problem-free

application and adhesion.� Consumer test the seasoning at several points during the development

process

4. SEASONING OF MAJOR SNACK FOODS

The development of seasonings requires trial and error and repeated consumer

testing. Another consideration in the development of formulation seasonings is

the effects of base interaction on flavor perception.

4.1. EFFECTS OF APPLICATION METHODON FLAVOR SELECTION

The method of applying the seasoning blend will affect the formulation. The

most common method for applying seasonings to snacks is to use an inclined

drum tumbler. The seasoning is metered into the tumbler and introduced as a

curtain of powder across the tumbling snack chips. In some cases, oil is sprayed

into the tumbler to help the seasoning adhere to the chips. It is important to keep

the seasoning free flowing when applied in this manner. Appropriate attention

to the level of free-flow agent added to the formula is essential. The formula

must be free-flowing in the snack manufacturer’s processing facility, not just in

the seasoning blender’s facility.

Selection of ingredients for seasonings applied as a dry powder in a tumbler

usually is limited to spray-dried and encapsulated flavors. Plated flavors and

liquid flavors may flash off during the application process if the flavors are

volatile and the temperature of the snack chip at the time of application is too

high. Spray-dried and encapsulated flavors usually have a longer shelf life than

plated or liquid flavors.

Another method for applying seasonings to snacks is to spray on a slurry of

oil and seasoning. In this case, the seasoning is added at levels up to 40% to

vegetable oil and then sprayed on the snack base. The seasoning-oil mixture

is kept agitated to prevent the slurry from separating. Slurries are applied to

snack bases at levels of 10–20%. Ingredients selected for seasonings applied


by this method typically also are spray-dried or encapsulated for the same

reason described for the dry powder method. Some flavor suppliers produce

seasonings in a paste form that is primarily oil-soluble and may be used in

this type of application. The pastes contain flavors, acid, colors and flavor

enhancers. They usually do not contain fillers, and sometimes are referred to as

flavor concentrates. The slurry would consist of oil, flavor paste and salt. The

use of a flavor paste in this manner is not common.

The slurry concept is also used with water as the carrier. In this case, sea-

sonings are formulated for mixing with water, maltodextrin and starches into

a slurry that is sprayed on a snack base. The moisture is removed from the

finished product in a final drying step. The resulting product is lower in oil

content than the oil slurry application method. This method is primarily used in

low-fat snack products where oil spray is not permitted. The downside of this

type of application is heat abuse of the seasoning flavor system. The heat used

to quickly dry the snack also volatilizes the flavor components of the seasoning

blend, resulting in an unbalanced flavor or loss of impact. Encapsulated flavors

that are insoluble in water, and do not melt, are the best choice for formulating

seasonings for this application method.

4.2. POTATO CHIPS

Development of seasoning blends for potato chips is straightforward. Not

many corrections are needed for this type of base. Potato chips generally are

bland, carrying only the flavor of the frying oil. The overall surface area of

the chip may require additional consideration for use level. For example, a

seasoning developed for a flat, thin potato chip requires a lower use level to

deliver the same flavor impact than seasoning required to deliver flavor on a

thicker, ripple-cut potato chip.

Large potato chip operations may use two-stage seasoning. All chips are

salted directly out of the fryer, then split into two or more streams. Some chips go

directly to packaging, others may go to a tumbler where seasoning is applied dry

if used, and then on to separate packaging line. Seasoning blends for potato chips

have reduced salt content compared to blends developed for tortilla chips or

extruded snacks because some salt is already on the base. Two-stage seasoning

is not done with tortilla chips, corn chips or corn puffs, and the rate of seasoning

application on these products is typically monitored by rapid salt analysis.

Seasonings are usually applied at use levels of 6–8% on salted potato chips.

4.3. TORTILLA CHIPS

Yellow corn and white corn tortilla chips need additional flavor impact in

seasonings to overcome the taste of the corn base. When the tortilla base is

made from dehydrated masa, the flavor system in the seasoning needs to be

much stronger to overcome the reduced flavor of the corn.


If only salt is applied, this is done downstream from the fryer. The salt contents

of tortilla chip seasonings will be 22–25% and higher than for potato chips, to

compensate for lack of salt on the base.

Use levels for tortilla chip seasonings generally are 8–10%. In addition, 3%–

4% spray oil is added to help adhere the seasoning to the base.

4.4. CORN CHIPS

Corn chips have very high fried corn flavor, which overwhelms most attempts

at seasoning. Stronger flavors must be used in formulating seasonings for this

type of base. Corn chips are generally salted in a tumbler away from the fryer.

If used, the level of seasonings for corn chips generally is 8–10%.

4.5. PRETZELS

Pretzels are a difficult base to flavor. Seasonings will not adhere to the smooth

crusty surface. Manufacturers of flavored pretzels must either break open the

pretzels to expose the porous internal structure or apply the seasoning using a

sticky adhesive that dries on the surface of the pretzel. Flavors may be added to

pretzels internally, but the flavor release is not as immediate as the seasoning

applied to the surface of the pretzel.

Pretzels generally are formulated to be low- or no-fat. This presents flavoring

problems because of the need for fat to help carry and sustain flavors throughout

eating of the snack. Low-fat bases with applied seasonings tend to have a strong

initial impact, but the flavor quickly disappears and the taste of the base takes

over.

4.6. EXTRUDED SNACKS

Extruded snacks, whether fried or baked, usually are flavored using a slurry of

oil and seasoning. The extremely porous surfaces of snacks absorb oil readily.

This causes the flavor to be masked somewhat making additional seasoning

necessary. All the salt is in the seasoning, which typically has a salt content of

10–15%.

The use level for seasonings applied to extruded snacks is typically 10–15%.

5. SUGGESTED READING

Ashrust, P. R., ed., 1995. Food Flavorings. 2nd edition. Blackie Academic & Professional, London.

Burdock, G. A., ed., 1995. Fenaroli’s Handbook of Flavor Ingredients, Vols. I and II. 3rd edition.

CRC Press, Boca Raton, Florida.

Heath, H. B. and G. A. Reineccius, 1986. Flavor and Technology. Avi-Van Nostrand Reinhold,

New York


Reineccius, G., ed., 1994. Source Book of Flavors, 2nd edition. Chapman and Hall, New York.

Risch, S. J. and G. A. Reineccius, eds., 1988. Flavor Encapsulation; ACS Symposium Series: 370.

American Chemical Society, Washington, D.C.

Schay, R., 1975. Natural flavors. In Fenaroli’s Handbook of Flavor Ingredients, Vol. 1. T. E. Furia

and N. Bellanca, eds. CRC Press, Inc., Palo Alto, California, pp. 271–495.

Tainter, D. R. and A. T. Grenis 1993. Spices and Seasonings: A Food Technology Handbook.

Wiley-VCH, New York.


snack foods processing - cap16

Documents