FoodFoodPreservation Preservation

Chapter 13Chapter 13

Heat TreatmentsHeat Treatments

1.1. Blanching – Heat to deactivate Blanching – Heat to deactivate enzymes enzymes

2.2. Pasteurization – Heat to kill Pasteurization – Heat to kill pathogenic bacteria pathogenic bacteria

3.3. Sterilization – Heat to kill all Sterilization – Heat to kill all bacteria and other organismsbacteria and other organisms

Low TemperatureLow Temperature

1.1. Refrigeration - < 40° FRefrigeration - < 40° F

2.2. FreezingFreezing - 0° F - 0° F

Lowering Water Activity Lowering Water Activity

1.1. Dehydration Dehydration

2.2. Concentration Concentration

3.3. Salt Salt

4.4. Addition of Sugar Addition of Sugar

Chemical Preservation Chemical Preservation

Food AdditivesFood Additives

Food additives are any Food additives are any substitute that becomessubstitute that becomes

part of a food product part of a food product

either directly or indirectly either directly or indirectly during processing, storing during processing, storing

or packaging.or packaging.

Regulations on Food Regulations on Food AdditivesAdditives

1.1. The Food and Drug AdministrationThe Food and Drug Administration

2.2. 1938 Food Drug and Cosmetic Act 1938 Food Drug and Cosmetic Act

3.3. 1958 and 1960 Amendments1958 and 1960 Amendments

1.1. Delaney ClauseDelaney Clause

GRASGRAS

Generally Recognized As Safe Generally Recognized As Safe First established 700 placed on the First established 700 placed on the

list without going through testing list without going through testing Now those substances are being Now those substances are being

reevaluatedreevaluated Foods have been removedFoods have been removed

What It Takes to Become A What It Takes to Become A Food AdditiveFood Additive

1.1. Prove additive is effectiveProve additive is effective

2.2. Prove additive can be detected and Prove additive can be detected and measured in final products measured in final products

3.3. Study the effects of the substance on Study the effects of the substance on animals (in large doses)animals (in large doses)

4.4. Submit results to validate the findingsSubmit results to validate the findings

5.5. Schedule a public hearing Schedule a public hearing

6.6. FDA approves or rejectsFDA approves or rejects

Functions of Food AdditivesFunctions of Food Additives

1. 1. PreservativesPreservatives – Keep food fresh and – Keep food fresh and reduce spoilage. Control bacteria, mold, reduce spoilage. Control bacteria, mold, fungi, and yeast. fungi, and yeast.

Benzoates Benzoates

BHT, BHA (antioxidants) BHT, BHA (antioxidants)

Calcium Propionate (inhibits molds)Calcium Propionate (inhibits molds)

Sodium Bisulfate Sodium Bisulfate

Sodium NitrateSodium Nitrate

Functions of Food AdditivesFunctions of Food Additives

2. 2. Processing AidsProcessing Aids – Improve – Improve consistency, add stability, aid oil and consistency, add stability, aid oil and water mixtures, and retain moisturewater mixtures, and retain moisture

Gums (Algin, Carrageenan, Xanthan)Gums (Algin, Carrageenan, Xanthan)

Aluminum Calcium Silicate Aluminum Calcium Silicate

Benzoyol PeroxideBenzoyol Peroxide

Functions of Food AdditivesFunctions of Food Additives

3. 3. NutrientsNutrients – Maintain or improve the – Maintain or improve the nutritional quality of food. nutritional quality of food.

Alpha- tocopherol Alpha- tocopherol

Ascorbic AcidAscorbic Acid

BiotinBiotin

Beta CaroteneBeta Carotene

Calcium Pantothenate Calcium Pantothenate

Folic AcidFolic Acid

Functions of Food AdditivesFunctions of Food Additives

4. 4. FlavorsFlavors – Complement, magnify or – Complement, magnify or modify the taste of aroma of a food modify the taste of aroma of a food

AspartameAspartame

Corn Syrup Corn Syrup

Ethyl Vanillin Ethyl Vanillin

Mannitol Mannitol

Monosodium Glutamate Monosodium Glutamate

Functions of Food AdditivesFunctions of Food Additives

5. Colors5. Colors –Give foods a desired, –Give foods a desired, appetizing or characteristic color. appetizing or characteristic color.

Carmel Carmel

Beta-apo-8-Carotenal (Orange)Beta-apo-8-Carotenal (Orange)

Citrus RedCitrus Red

FD&C Blue No 1FD&C Blue No 1

FD&C Red No 3FD&C Red No 3

FD&C Yellow No 5 FD&C Yellow No 5

Other Methods of Other Methods of Preservation Preservation

Controlled or Modified Controlled or Modified Atmosphere Storage and Atmosphere Storage and

PackagingPackaging 1.1. Modified Atmosphere (MA)Modified Atmosphere (MA)

1.1. NitrogenNitrogen

2.2. COCO22

2.2. Controlled AtmosphereControlled Atmosphere (CA) (CA)

1.1. Vacuum PackagingVacuum Packaging

2.2. Shrink Wrapping Shrink Wrapping

Irradiation

1.1. Pasteurization Pasteurization

2.2. SterilizationSterilization

Irradiation

kGykGy Food approved in the USFood approved in the US

PorkPork ChickenChicken BeefBeef Fruits and VegetablesFruits and Vegetables GrainGrain

Many other foods approved in other Many other foods approved in other countriescountries

Irradiation SourceIrradiation Source

--

Irradiated Beef PattiesIrradiated Beef Patties

Purpose Purpose

To evaluate ordor, flavor, To evaluate ordor, flavor, texture, and overall texture, and overall

acceptability of irradiated acceptability of irradiated ground beef patties stored ground beef patties stored

over a six-week period over a six-week period

300-2.8 oz patties were blast frozen300-2.8 oz patties were blast frozenPacked 20 patties per Cryovac bagPacked 20 patties per Cryovac bagVacuum sealed Vacuum sealed Placed in a corrugated box and Placed in a corrugated box and packed in dry ice packed in dry ice Irradiated in Florida Irradiated in Florida Dosimeter placed inside boxesDosimeter placed inside boxesStored at –18°C Stored at –18°C Sampled weekly for 6 weeks Sampled weekly for 6 weeks

Overall acceptability of irradiated ground beef patties

00 1 1 3 5 7 3 5 7 Dose (kGy)Dose (kGy)

Weeks Weeks

00 6.36.3 5.9 6.5 6.8 6.05.9 6.5 6.8 6.0

11 6.6 6.6 6.7 6.3 6.2 6.26.7 6.3 6.2 6.2

22 6.0 6.0 6.3 6.0 6.3 6.6 6.3 6.0 6.3 6.6

33 6.4 6.3 6.2 6.1 6.2 6.4 6.3 6.2 6.1 6.2

44 6.6 6.3 5.7 6.2 5.8 6.6 6.3 5.7 6.2 5.8

55 6.4 5.9 5.5 5.9 5.3 6.4 5.9 5.5 5.9 5.3

66 5.7 6.2 5.4 6.0 5.7 6.2 5.4 6.0 5.15.1 1 (=dislike1 (=dislike

9 (=like)9 (=like)

Irradiated Strawberries

Materials and Methods

Fruit were irradiated at doses of Fruit were irradiated at doses of

0, 0.25, 0.5, 0.75 and 10, 0.25, 0.5, 0.75 and 1 Stored for periods of 0, 1, 3, 5, and 7 Stored for periods of 0, 1, 3, 5, and 7

days at 2days at 2ooCC

ResultsAscorbic Acid

Ascorbic Acid

Day

0 2 4 6

m /

g f

resh

wei

gh

t

24

26

28

30

32

34

36

380kGy1 kGy

ResultsDHA

Dehydroascorbic acid

Day

0 2 4 6

m/g

fre

sh w

eig

ht

0

2

4

6

8

10

12

14

0 kGy 1kGy

Irradiated Strawberries