+  

 

Alexis Beltran

Nutrition 205

7 November 2012

Eating With Your Senses

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Abstract

Sensory testing involves all five senses: sight, taste, touch, smell, and hearing. These senses affect whether a person will consume a food or beverage or not. This type of testing is a way for food companies to compare their food products and present it in a non-bias environment. It can also be applied to a wide array of situations, including public health, consumer product marketing, and the development of new food and beverage products. By evaluating what company’s customers perceive as desirable can help a company perfect a new product. A series of sensory tests were performed at San Diego State University by a group of 62 untrained Foods and Nutrition Students, in which seven sensory tests were performed: a Beverage Color Association Test, Descriptive Test, Paired Comparison Test, Triangle Test, Duo-Trio Test, Ranking Test, and a Rating Test. Students performed the tests in an orderly fashion, in a non-professional food-sampling environment. The results of this study revealed certain desirable characteristics and undesirable characteristics of foods and beverages. Also, the tests revealed at which level of a characteristics of a food sample is seen as too much or just right. Different aspects of each of the seven tests will be discussed and analyzed further. Assessing the sensory evaluation tests will provide insight as to how tests could be used together to provide the best analytical outcomes, whether color and appearance of food and beverage products affects the consumer, and how sensory evaluation testing has been proven a useful tool in many different studies.

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Introduction

Sensory testing is a way to help commercial food industries produce products that

appeal to their consumers, in order to stay successful in businesses. Industries can

perform sensory tests on food tasters to see what colors are more appealing than others,

and what flavors are preferred and disliked. According to Brown, the author

Understanding Food Principes and Prepartion, sensory tests measure the response of

individuals to food products in accordance with their senses of smell, sight, taste, touch,

and sound (Brown 2011). Usually, sight is the first sense that affects how a person

perceives a food or beverage as good or not and can help a person decide if a product is

ripe or not. There are two types of sensory tests used to evaluate food products: analytical

and affective. Analytical testing is based on differences between food products where as

affective is based on preferences between food products (Brown 2011). The purpose of

sensory testing in the food industry is to be able to differentiate and rank different food

beverage according to people’s sensory parameters. Some of the analytical sensory

testing involves the duo-trio test, triangle test, and the paired comparison test. Another

aspect of analytical sensory evaluation is descriptive testing, which individuals use

specific words to describe flavor or texture profile (Brown 2011). The affective tests are

based on opinion so individuals who perform these tests can be either trained or

untrained. According to Chen, author of Surface Texture of Foods: Perception and

Characterization, whether panelists of sensory tests are trained or untrained, may later

affect the results and accuracy of sensory testing. A combination of affective and

analytical sensory tests were conducted in the nutrition laboratory at San Diego State

Universtiy by untrained students.

In the nutrition laboratory, sensory tests can be conducted on foods which

panelists can subjectively evaluate flavor and texture characteristics. There were seven

different sensory evaluation tests, which were conducted in the nutrition lab and were

used to collect data on the untrained nutrition students. The tests evaluated the student’s

preferences and perceptions on various food and beverage samples. One of the tests

conducted was a descriptive test. Descriptive tests target certain categories a company

wants their product to be evaluated on. Because the panelists were untrained, the specific

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descriptive words were provided to describe the food samples subject to evaluation. The

foods were evaluated in five different categories. A similar study was done by a group of

graduate students at Louisiana State University. The graduate students produced three

different milk chocolate candies. The graduate students wanted the three different kinds

of milk candies, which contained a couple minor changes in ingredients, evaluated by a

panel. The students wanted to see how their panelists described each candy. Later, the

data from the descriptive test would assist the graduate students in improving their

products (Pavon 2003). Descriptive testing is very important in the food industry so that

companies can see how consumers view their product before putting it out on the market.

The descriptive test helps the food producers, evaluate if their onsumers actually describe

their products the way they are meant to be described, and if certain aspects of a product

must be altered to be improved.

Another test conducted, was a beverage analysis test; this test was conducted to

evaluate individual perceptions of color association. The beverage anaylasis test reveals

how certain colors can make a person decide what temperature a food or beverage should

be consumed, or whether a food is perceived as sweet or sour, just by appearance. Also,

just by the color of a food, a person usually makes some kind of judgement whether they

would even consume it or not. Major food companies use appearance to appeal to their

consumers. This type of testing assists the food companies to decide what color to make

new upcoming products in order to appeal to their customers. A similar study, done by

Levitan, author of “An expectationsbased Approach to Explaining the Cross-Modal

Influence of Color on Orthonasal Olfactory Identification”, conducted a beverage

analysis test on artificially colored beverages. Levitan wanted to see how color-generated

assumptions could influence identification of drinks (Levitan and others 2010). Both of

these tests, the one conducted in this sensory testing report and the Levitan study,

demonstrates how association of color greatly influences perception of flavor for

individuals. Also, the beverage analysis test reveals that sight is a very important sense

that helps people determine what foods a person is willing to eat, and even can determine

how much of a food we eat, just like the saying “We eat with our eyes.”

A paired comparison test was conducted in the nutrition laboratory, as well. The

paired comparison test utilizes two different samples of the same type of product. For

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example, in this sensory report the paired comparison test utilized citric acid juice but the

two samples each had a different percentage of citric acid. A taster is asked to taste and

evaluate both products and determine which has more of a certain attribute such as

sweetness, sourness, or spiciness (Brown 2011). An article in the Journal of Food

Science by Colyar explained a similar study. The paired comparison test was conducted

on various food products and evaluated on certain characteristics one at a time. . One

difference in the study conducted by Colyar test, was that the panelists were called back

twice to evaluate the products The food products were given to the panelists in a slightly

different order (Colyar and others 2009). This type of testing reveals to the conductors

which products contain more of a desired characteristic and which do not, and which

product contains more of a certain flavor or other type of characterstic than another

similar product.

The triangle test and the duo trio test both utilize three samples- one of which is

different than the other two. When a triangle test is conducted, the evaluators are simply

asked to determine which sample differs from the others. A very identical study was done

by Rhee, Myers, and Waldron, a triangle test was done on two different types of meat.

Rhee and others conducted a triangle test to evaluate if people could determine the odd

sample of meat, when provided with two identical meats, and one being from a different

animal (Rhee and others). For the duo trio test, tasters are asked to determine the sample

that differs from the designated standard product, and further explain what exactly is

most different about it. This type of testing can be useful for food companies to see if a

certain amount of an ingredient in products will make all the difference in making their

product a good seller.

Another test performed is the ranking test, which is similar to the triangle and duo

trio test. For the ranking test, more than two samples must be utilized and presented to a

panel (Brown 2011). Evaluators are asked to rank a certain food or beverage product

from the lowest to highest for a certain specified characteristic. Also, many times

evaluators are asked to rank the product in order of preference. One similar ranking test

was conducted, by Aykut, on five different cheese products, ripened for different

amounts of time. The producers put together a ranking test to evaluate their products. The

ranking tests would help Akyut and others to reveal what products were ranked highest

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and lowest by their evaluators(Aykut and others 2011). As shown in this study, food

producers can use the ranking test for a new upcoming product. They can make the same

product but with minor changes in each product and perform a ranking test on a group of

panelists. The test will help the food producers to better their upcoming products or even

better a product already on the market.

A scoring or rating test is a sensory test which requires more than two samples. A

reference sample is given an arbitrary ranking, while the other two samples are to be

rated higher or lower according to the intensity of a certain characteristic. A scoring test

was performed in the nutrition lab on two different juices which each contained a

different percentage of citric acid compared to the standard juice, which also had a

different percent of citric acid in it. A test similar to this was conducted on debittered

grapefruit juice. An article published in the International Journal of Food Sciences and

Nutrition describes a scoring test done with varying degrees of bittered grapefruit juices.

Because too much bitterness in a juice isn’t always desired by consumers, the producers

wanted to perform a rating test on the juices to see how the evaluators ranked each

juice.The evaluators were given a ranking scale of zero to nine, zero having no bitterness

and nine having the most bitterness. The panel consisted of both trained and untrained

individuals and the testing room was controlled with red light. (Frank and others 1997).

Sensory testing is an important tool when it comes to food science or nutrition.

The overall objective for this laboratory is to teach students, who are Foods and Nutrition

majors, how to properly conduct different sensory tests. While conducting the tests,

students are able to learn the different errors in certain sensory tests, and how these errors

will effect the end results. Students are also able to learn which sensory tests are most

practical for certain food products, and other possible reasons a test should be used or

not. Also, this sensory laboratory gives the students the knowledge of how important

senses are to the way we may feel towards a certain food, whether a person will consume

a food or not, and how a food is perceived even before consuming it.

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Methods

Panelist Demographics

The panelists involved in the sensory evaluation tests consisted of sixty-two

untrained Nutrition 205 students at San Diego State University (N=62). Each of the

panelists were given a piece of paper labeled “Demographic Questionnaire.” It consisted

of eight questions like panelist’s name, living situation, age, major, gender, smoking

habits, food allergies, and student status. The students were given a few minutes to

answer the questions. The students either circled or filled in the answer that corresponded

to them for each question. Once the students finished filling out the questionnaire, Linda

Copp asked each question out loud. The students would raise their hands when Linda said

the answer that they marked. The lab assistant, Brandy Hunter, entered the information as

the students raised their hand into the computer.

The panelists’ ages ranged from 19 to 45 years old. The mean age among the

panelists was about 27 with a standard deviation of 6.63. Of the panelists 87.1% of the

students were female and 12.9% of them were male. One hundred percent of the panelists

were Foods and Nutrition majors with 95.2% of the panel being undergraduate students

and 4.8% as graduate students. There were 90.3% of the panels that were single, 8.1%

that were married, and 1.6% of the panel was divorced. The panel consisted of 67.7% of

participants living with two or more roommates, 22.6% living with one roommate, and

9.7% of the panel living alone. The majority of the panelists were non-smokers, which

consisted of 95.2%, and 4.8% were smokers. Out of the 62 panelists, 90.3% of them did

not have a food allergy and 9.7% did have food allergies.

Environment

The experiment took place in the Nutrition Lab at San Diego State University.

The classroom was white with plain walls and had rows of desks in the center of the

classroom. There were five rows of desks with five desks in each row, each spaced

approximately two feet apart from each other. In the front of the classroom, there was a

large table with a stovetop and a computer. There was a white large refrigerator behind

the table in the front of the classroom and a white freezer on the left side of the

classroom. There were six metal stations in the room; three on the right and three on the

left, each had two stovetops and a box full of cooking supplies Also, there were hand

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washing station on each side of the room and one in the very front of the room. There

were two stainless steal dishwashing stations that each had three compartment sinks, one

on the left side of the classroom and the other on the right. The room was very well lit

and quiet. On the right side of the class room there were silver cabinets arranged along

the walls which had different cooking utensils like pots, cutting boards, knives, colanders,

and much more stored in them. Both of the doors of the classroom were shut so that

outside noise in the hallway would not disturb the panelists. The only things on the

students’ desks were the sensory evaluation papers, pen or pencil, and a white Styrofoam

cup filled with water. The students would use the water to cleanse their palates in

between samples of food or drinks given to them.

Color Association/Perception of Beverages

The Beverage Color and Associations with Other Parameters

At the front of the testing room there were five beakers, each filled with equal

amount of a different colored liquid in each. The liquid beakers were placed in order from

left to right by the lab technician. The order of the beverage colors went light yellow,

dark yellow, chartreuse, dark chartreuse, and emerald green. The colors represented five

different kinds of beverages which were not revealed to the panelists until after the

experiment, these beverages were Mountain Dairy Lemonade, Xtremo Citrico Vibrante

Gatorade, 350 mls Lemon Lime Gatorade plus 150 mls. Green Sqall Powerade, Green

Squall Powerade, and Watermelon Gatorade. Linda asked each participant to observe the

color of each liquid and associate it with different parameters. The parameters consisted

of sweetness, sourness, artificiality, naturalness, preference and dislike. The participants

were asked to give one ranking from one to five (one being the least and five being the

most) to each beverage based on the six parameters. The panelists then went on ahead to

rank each of the five beverages, giving each beverage only one ranking so that it had its

own specifying ranking number per parameter. Once the panelists recorded their answers

on the sheet of paper where there was a chart marked with each parameter down the left

side of the chart, and the drink colors labeled across the top, Linda asked each student

what parameter they marked for each beverage while Brandi recorded the numbers on the

computer. In addition to ranking the different colored liquids, the panelists were also

asked at what temperature they would drink each liquid. The choices consisted of hot,

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warm, tepid, and cold. The last question asked by the instructors was whether the

participants would drink each liquid or not, only yes or no could be used to answer the

question. The lab assistant recorded on the worksheet as well as on the computer all the

choices.

Descriptive Test

Experiment: Evaluation of Food Products Using Descriptive Terms

The instructors provided enough 2-oz white sample cups of four different foods

for each participant. The four different foods were raisins, marshmallows, almonds, and

goldfish. The first person in each row of desks was asked to grab enough of the four food

cup samples and distribute them evenly to each person in their row. The participants were

asked to evaluate each of the four samples under the categories of appearance, flavor,

texture, aroma, consistency, and mouthfeel. The participants were provided with a chart

for each sample of food, with each category the food would be evaluated on and words

the panelists would be able to choose from. For Almonds under the category of

appearance the descriptive terms the panelists could choose from were rounded, dry,

golden-brown, light brown, rough, smooth, dull, asymmetrical, symmetrical, grainy, and

sticky. The texture descriptive terms provided were rubbery, velvety, chewy, crisp,

rough, hard, firm, crunchy, gritty, mealy, and tender. The terms given for the category of

aroma for almonds were spicy, burnt, sweet, sour, flowery, fruity, none, and flavery.

Consistency was the second to the last category with descriptive terms like butter, chewy,

thin, rubbery, viscous, thick, and gummy. Mouthfeel was the last category, which would

be evaluated for the almond. The terms provided for this category were crisp, sticky,

slimy, gritty, slick, crunchy, and smooth. The descriptive terms given for flavor were flat,

nutty, bitter, salty, stale, rancid, and sweet. The panelists were instructed to circle one

word for each category for each food sample. A list of categories and terms for each food

sample was provided similar to the one for the almond sample. The terms provided are

located in the appendices. After recording the results in the lab manual using the terms

provided for one given sample food, the panelists were asked to take a drink of water and

continue with the next sample and so on until all four food samples were evaluated. All

the results were recorded by the panelists n their own lab manual then recorded on the

computer by the lab assistant.

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Difference tests

Experiment: Paired Comparison Test

The chose two similar beverage products and gave each sample a code. One was a

0% citric acid juice (635T1) and the other was a juice with 1% citric acid (573T2). The

first person in each row placed 1-oz samples of the liquid into 2-oz sample cups marked

with each code. The person in the front row provided enough samples so that each

panelist in their row received one. Water was also provided so that each panelist could

take a sip of water in between samples to cleanse their pallets. The participants each

tasted both samples with a sip of water in-between. They were asked to determine which

sample was less sour and which was sourer. Their decisions were recorded in their own

lab manual under the “Paired Comparison Test” chart.

Experiment: Triangle Test

For the Triangle Test, the panelists were given three 1-oz samples of beverage

products in a 2-oz white paper sample cup. Two of the beverages were going to be

identical, and one would be different. The first person in each row was asked to get

enough samples of each beverage product for each panelist in their row, so that everyone

could taste all three. Each beverage was given a different sample code; the first beverage

was labeled a 0% citric acid juice (777C1), another was also 0% citric acid (542E2,) and

the third was a 1% citric acid beverage (112H9). The participants were asked to taste

each beverage sample with a sip of water in-between each taster. They were asked to

evaluate the samples and determine which two samples were identical and which one was

different. The panelists fill out their chart labeled Triangle Test In their lab manual. In the

chart, they would write down each sample could and identify all three as either

“different” or the “same.” The lab assistant then entered the panelists’ decisions into the

computer.

Experiment: Rating Test

The panelists were given three different beverages ranging in sourness. The

reference sample was a 2.5% citric acid juice (0110), which was given an arbitrary score

of 4 on a scale of 1 to 7, one being the most sour and seven being less sour. The two other

beverages were 5% (S723) and 1% citric acid juice (420M). The first person at the first

desk in the row was asked to get enough of each sample for every person in the row and

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distribute the samples. The panelists were asked to taste the reference sample first. Then

they were asked to taste the other two samples and evaluate each one on intensity of

sourness compared to the reference sample. On a scale of one to seven, the panelists were

asked to rank the two samples relative to the reference one. So were the samples more

sour than the reference sample or less sour. The decisions of the panelists were recorded

themselves on the table provided on the worksheet, then recorded on the computer.

Experiment: Duo-Trio Test

The participants were given worksheets with codes that pertained to samples of

cookies. The standard cookie was a Nabisco Villa Wafer (8175). One sample cookie was

a First Street (Smart and Final) Vanilla Wafer (6104) and the second sample cookie was a

Nabisco Nilla Wafer as well (1108). First the lab technician and the lab assistant went

around to each panelist and provided him or her with a standard cookie. They were asked

to taste the cookie and then take a drink of water to cleanse their pallets. Then, the

instructors went around to each panelist’s desk to provide each of them with the other

two samples and the panelists were asked to taste the other two cookies. The panelists

were asked to determine which sample they thought differed from the standard cookie.

Once they chose which sample differed, the panelists were asked to write down what they

believed the major difference was. The panelists recorded their decision on the sheet of

paper provided and in their lab manual. Also, the lab assistant recorded the decision of

each panelist on the computer.

Experiment: Ranking Test

The instructors chose five different beverage products with different intensities of

sourness. Each panelist was given a 1-oz sample of each beverage in a 2-oz sample cup,

so that each sensory panelist could try all the beverage products. All five of the beverage

products were given a different sample code. One beverage was a 10% citric acid juice

(555D7), another was 2.5% citric acid (695F8), another was 1% citric acid (543K8),

another was 5% citric acid (192L3) and the last juice contained 0% citric acid (495P2).

Each sample was given out to the panelists by the first person seated in each row. Once

the samples were handed out to everyone, the panelists were asked to try each one with a

sip of water in-between each beverage product. They were instructed to rate each sample

on a scale of one to five, one being the most sour and five being the least sour. Also, they

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were asked to rate each sample according to their preference on a scale of one to five, one

being the most preferred and five being the least preferred. Each ranking could only be

used once. The panelists recorded their decisions themselves in their lab manual, then the

lab assistant recorded the panelists’ ratings on the computer.

Results

Color Association/Perception of Beverages

Figure 1, demonstrates the percentage of students who perceived certain

beverages as the sweetest. The majority of the students, 28% perceived dark yellow as the

sweetest beverages while only 8% of the students perceived chartreuse as being the

sweetest. The rest of the beverages ranged in the middle for sweetness, 26% of the

students perceived emerald as the sweetest, 19% thought light yellow and dark chartreuse

as being the sweetest beverage. Refer to Figure 1.

Figure 1 (n=62)

Figure 2, illustrates the percentage of panelists who perceived a certain beverage

as the sourest. The light yellow beverage was perceived as the sourest by 47% of the

panel and the emerald was perceived as the sourest by only 3% of the panelists. The rest

of the beverages were perceived somewhere between those two percentages, 21% of the

panelists believed dark yellow would be the most sour, 25% thought chartreuse would be

the most sour, 4% thought dark chartreuse would be those most sour. Refer to Figure 2.

19%  

28%  8%  

19%  

26%  

Rating  of  Sweetness  for  Light  Yellow,  Dark  Yellow,  Chartreuse,  Dark  

Chartreuse,  and  Emerald  Beverages  

Light  Yellow  

Dark  Yellow  

Chartreuse  

Dark  Chartreuse  

Emerald  

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Figure 2 (n=62)

Figure 3 represents the percentages of participants who perceived a beverage as

the most artificial. According to most participants, 48% saw the emerald colored

beverage as the most artificial and only 2% perceived light yellow as being the most

artificial. Also, 5% of the panelists though dark yellow would be the most artificial, 8%

believed chartreuse was the most artificial, and 19% perceived dark chartreuse as being

the most artificial. Refer to Figure 3.

Figure 3 (n=32)

47%  

21%  

25%  

4%   3%  

Rating  of  Sourness  for  Light  Yellow,  Dark  Yellow,  Chartreuse,  Dark  Chartreuse,  and  Emerald      

Light  Yellow  

Dark  Yellow  

Chartreuse  

Dark  Chartreuse  

Emerald  

2%   5%  

8%  

19%  

66%  

Rating  of  ArtiIiciality  of  Light  Yellow,  Dark  Yellow,  Chartreuse,  Dark  Chartreuse,  and  

Emerald  Colored  Beverages  

Light  Yellow  

Dark  Yellow  

Chartreuse  

Dark  Chartreuse  

Emerald  

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The percentages of students that perceived a beverage as being the most natural is

presented by Figure 4. The majority of students chose light yellow as the most natural,

which accounted for 90% of the students. None of the students perceived dark yellow as

being the most natural. Dark Chartreuse and emerald were seen as most natural by 2% of

the students. Also, chartreuse was seen by 6% of the students as being the most natural.

Refer to Figure 4.

Figure 4 (n=62)

Of the five beverage choices, the drink perceived as the most preferred was the

light yellow colored drink. 68% of the panelists voted for light yellow as being the most

preferred and only 3% of the panelists preferred emerald. Also, 6% of the participants

preferred dark chartreuse, 5% preferred dark yellow, and 18% of them preferred

chartreuse. Refer to Figure 5.

90%  

0%  6%  

2%  2%  

Rating  of  Naturalness  of  Beverages  that  are  Light  Yellow,  Dark  Yellow,  Chartreuse,  

Dark  Chartreuse,  and  Emerald    

Light  Yellow  

Dark  Yellow  

Chartreuse  

Dark  Chartreuse  

Emerald  

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Figure 5 (n=62)

Graph 6, shown below, illustrates the beverage perceived as the most disliked.

The majority of panelists perceived the light yellow as the most disliked beverage, which

accounted for 63% of the participants. The emerald colored liquid only had 1% of

panelists perceive it as the most disliked. The dark yellow was perceived as most disliked

by 18%, 8% perceived chartreuse as the most disliked, and 10% of the panelists believed

dark chartreuse would be the most disliked. Refer to Figure 6.

Figure 6 (n=62)

Graph 7 displays the percentages of panelists that would drink each beverage or

not. Almost all the panelists, 88.7%, said that they would drink the light yellow beverage,

68%  

5%  

18%  

6%   3%  

The  Most  Preferred  Beverage:  Light  Yellow,  Dark  Yellow,  Chartreuse,  Dark  Chartreuse,  and  Emerald  

Light  Yellow  Dark  Yellow  Chartreuse  Dark  Chartreuse  Emerald  

1%  

18%  

8%  

10%  63%  

The  Most  Disliked  Beverage:  Light  Yellow,  Dark  Yellow,  Chartreuse,  Dark  Chartreuse,  and  Emerald  

Light  Yellow  

Dark  Yellow  

Chartreuse  

Dark  Chartreuse  

Emerald  

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and only 11.3% would not drink it. For the dark yellow beverage, 50% of the participants

said they would drink it and 50% would not drink the dark yellow beverage. The

chartreuse colored beverage would most likely be consumed by 71% of the panelists, and

29% would not consume it. 51.6% of the panelists said that they would drink the dark

chartreuse beverage and 48.4% of them said they would not drink it. Lastly, the emerald

colored beverage received 74.2% of panelists would drink the beverage and 25.8% would

not. Refer to Figure 7.

Figure 7 (n=62)

Table 1 represents the temperature at which the panelists would drink each

beverage. Most of the panelists preferred to drink each beverage cold. The light yellow

beverage was preferred to be drank cold by 93.5% of panelists, the dark yellow was

preferred cold by 95.2% of participants, 93.5% for the chartreuse colored beverage, and

91.9% preferred the emerald beverage cold. Very few of the participants preferred to

drink any of the beverages at a warm or tepid temperature. The dark yellow, chartreuse,

and dark chartreuse beverages were preferred to not by drunk by 0% of the participants.

The light yellow beverage was preferred hot and warm by 1.6% of the panelists for both

of the temperatures. Emerald was preferred hot by 3.2% of the evaluators and 1.6%

preferred the emerald beverage warm. The tepid temperature was the second most

preferred temperature for each colored beverage. The light yellow, dark chartreuse, and

emerald beverages were most likely to be consumed tepid by 3.2% of the evaluators.

88.70%  

50%  

71%  

48.40%  

25.80%  

11.30%  

50%  

29%  

51.60%  

74.20%  

0.00%   20.00%   40.00%   60.00%   80.00%  100.00%  120.00%  

light  yellow  

dark  yellow  

chartreuse    

dark  chartreuse  

emerald  

Percentage  of  Students  

Beverage  Color  

Would  the  panelists  drink  the  different  colored  beverage  or  not?  

yes    

no  

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4.8% of the participants said they would drink the dark yellow beverage tepid and 6.5%

said they would drink the chartreuse colored beverage tepid. Refer to Table 1.

Table 1

Light Yellow Dark Yellow Chartreuse Dark Chartreuse

Emerald

Cold 93.5% 95.2% 93.5% 96.8% 91.9%

Hot 1.6% 0% 0% 0% 3.2%

Warm 1.6% 0% 0% 0% 1.6%

Tepid 3.2% 4.8% 6.5% 3.2% 3.2%

Evaluation of Food Products Using Descriptive Terms:

There were 62 participants, who participated in this test for each food sample,

except for the goldfish sample, only 61 panelists participated. The descriptive test

resulted in a wide variety of percentages of descriptions. The mouth feel and texture

category for each food sample varied the most in votes. The top results for each category

for each food sample are represented in Table 2.

Table 2 (n=62)

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Food Sample

Appearance Flavor Texture Aroma Consistency

Mouth feel

Goldfish

(n=61)

Dry: 32.3% Golden Brown: 24.2% Puffy: 16.2%

Salty: 90.2% Sharp: 6.6% Flowery: 1.6%

Crisp: 65.6% Crunchy: 23% Flaky: 4.9%

Flavory: 39.3% Burnt: 24.6% Spicy: 23%

Brittle: 62.3% Cheezy: 26.2% Thin: 4.9%

Crunchy: 49.2% Crisp: 40.9% Sticky: 3.3% Gritty: 3.3%

Raisin Sunken: 38.7% Dry: 22.6% Dark: 11.3%

Sweet: 53.2% Fruity: 40.3% Bitter: 3.2%

Gummy: 24.2% Chewy: 24.2% Rubbery: 21% Lumpy: 8.1%

Fruity: 53.2% Sweet: 35.5% Flowery: 4.8% None: 4.8%

Chewy: 58.1% Gummy: 27.4% Rubbery: 11.3%

Sticky: 38.7% Smooth: 21% Slimy: 12.9% Gritty: 12.9% Slick: 12.9%

Almond Light Brown: 32.2% Golden Brown: 21.0% Dry: 19.2%

Nutty: 80.6% Flat: 11.3% Bitter: 3.2% Sweet: 3.2%

Hard: 33.9% Firm: 21% Crunchy: 17.7%

None: 90.3% Burnt: 4.8% Flavory 3.3%

Thick: 64.5% Chewy: 29.3% Rubbery: 3.2%

Crunchy: 62.9% Gritty: 19.4% Smooth: 9.7%

Marshmallow Puffy: 90.3% Smooth: 4.8% Dull: 3.2%

Sweet: 74.2% Floury: 14.5% Pasty: 11.3%

Springy: 27.4% Gummy: 25.8% Velvety:

14.5%

Sweet: 59% Nothing 3%

Gummy: 60% Chewy: 25.8% Rubbery: 12.9%

Smooth: 58.1% Slimy: 19.4% Sticky: 11.3%

Paired Comparison Test

The results for the paired comparison test resulted in 100% of the participants

choosing 1% citric acid apple juice solution (573T2) as more sour than the 0% citric acid

apple juice solution (635T1).

Triangle Test

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The Triangle Test resulted in 100% of the panelists identifying the 1% citric acid

solution as different while the other two samples, both of which were 0% citric acid as

the same.

Ranking Test

Illustrated by Figure 8, the majority of the panelists accurately described the

degree of sourness of the five beverages. Sixty-one (98%) of the students believed that

the 10% citric acid sample was the most sour; the one (2%) remaining panelist selected

the 5% citric acid to be the beverage with the greatest intensity of sourness. Fifty-five of

the panelists chose the 5% citric acid, as the second most sour, 4 (6%) chose the sample

of 2.5% citric acid, 2 (3%) selected the 10% citric acid sample, and zero selected the 0%

beverage sample. Of the sixty-two panelists, fifty-seven (92%) of them ranked the 2.5%

citric acid beverage as the most sour. Three (5%) selected the sample of 1% citric acid, 2

(3%) chose 5% citric acid and zero selected the 10% and 0% citric acid. Fifty-six (90%)

of the participants accurately selected the 1% citric acid beverage as being the drink with

the sourness being the most intense. The 0%, 2,5%, 5%, and 10% juices were chosen by

2 (3%) as being ranked third. The juices that had the lowest intensity of sourness was the

third sample tasted by the participants. The 0% citric acid juice was the least sour and

was chosen by 58 (94%) of the participants. Three (4.8%) of the students chose the 1%

citric acid juice as being the lease sour and one (1.6%) person chose the 5% beverage as

being the least sour. Refer to Figure 8.

Figure 8 (n=62)

61  

57  

56  

58  

55  

52   54   56   58   60   62  

10%  Citric  Acid  2.5%  Citric  Acid  1%  Citric  Acid  0%  Citric  Acid  5%  Citric  Acid  

Number  of  Votes  

Concentration  of  Citric  Acid  in  

Apple  Juide  

The  Number  of  Correct  Rankings  of  Citric  Acid  Concentration  of  0%,  1%,  2.5%,  5%,  and  10%  in  Apple  Juice,  as  Rated  by  Nutr.  205  Students  

Beltran    20  

Illustrated in Figures 9 and 10, the percentages of the panelists that preferred the

0% and 1% citric acid juices are shown, as well as, the percentages of students who least

preferred the 5% and 10% citric acid beverages are shown. In regards to preference of

beverages 42 (68%) of participants gave the 0% citric acid sample as their top choice, 10

(32%) chose the sample of 1% citric acid as their top choice. 0%. 2.5%, and 5% citric

acid juices received zero votes by the participants as being their top choice. The second

favorite beverage among the panelists was 1% citric acid with 40 (65%), then 17 (27%)

for 0% citric acid, 3 (5%) citric acid for 2.5% citric acid, 2 (3%) citric acid, 2 (3%) for

5% citric acid, and zero for 10% citric acid. The third juice preferred was 2.5% citric acid

juice, with 52 (84%) panelists voting for it, then 1% and 5% citric acid had 17 (27%), and

10% and 0% citric acid had 2 (3%). Ranking fourth in preference was 5% citric acid with

52 (84%) participants then 7 (11%) selected 2.5% citric acid, 2 (3%) selected 0% citric

acid, 1 (2%) chose 10% citric acid juice, and zero votes for the 1% citric juice. Fifty-eight

students (94%) ranked the 10% citric acid as being their very least preferred flavor, then

4 (6%) selecting the 5% citric acid sample, and zero for 0%, 1%, and 2.5%. Refer to

Figures 9 and 10.

Figure 9 (n=62) Figure 10 (n=62)

68%  

32%  

Percentage  of  Nutr.  205  Student  Who  Ranked  Citric  Acid  Concentrations  0%  and  1%  as  Top  Choice  of  Flavor  

0%  citric  acid  

1%  citric  acid    

6%  

94%  

The  Number  of  Nutr.  205  Students  That  Ranked  the  Citric  Acid  Concentrations  of  

5%  and  10%  as  Last  in  Flavor  

5%  citric  acid  

10%  citric  acid  

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Duo-Trio Test

Figure 11 represents the 56 (90.3%) panelists that accurately chose the First Street

Vanilla Wafer from Smart and Final (6104) as being the sample that differed from the

standard cookie, which was a Nabisco Nilla Wafer (8175). The remaining 6 (9.7%) of

panelists selected the sample Nabisco Nilla Wafer as the differing cookie. Refer to Figure

11.

Figure 11 (n=62)

Illustrated by Figure 12, 62 panelists, 15 (24.2%) described the differing sample

as being drier, 19 (30.6%) said it was crunchier, and 28 (45.2%) described the wafer as

having less vanilla than the standard wafer. Refer to Figure 12.

Figure 12 (n=62)

90%  

10%  

Percentage  of  Students  Who  Accurately  Chose  the  Smart  &Final  Cookie  as  the  differing  

Sample  

S&F  

Nabisco  

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Scoring or Rating Test

Figure 13 represents the percentage of students who ranked the citric acid juices

with 5% and 1% being less or more sour than the reference sample, which had 2.5% citric

acid. For the sample of 1% citric acid juice 1 (2%) panelist ranked it at the highest sour

intensity of 1, 2 (3%) ranked it at 2, 0% ranked the beverage at 3, 1 (2%) ranked the juice

at 4, 9 (15%) ranked it at 5, 43 (69%) ranked it at a low sour intensity of 6, and 6 (10%)

ranked it at the lowest intensity of sourness at 7. The sample with 5% citric acid had 37

(605) of the participants rank the juice at the highest intensity of 1, 21 (34%) ranked it at

2, 2 (3%) ranked it at 3, 1 (2%) ranked it at 4, non of the participants ranked the juice at 5

or 7, and only 1 (2%) ranked it at a low sour intensity of 6. Refer to Figure 13 below.

Figure 13 (n=62)

24%  

31%  

45%  

Percent  of  Panelists  that  Described  the  Differing  Cookie  as  Being  Drier,  Less  Crunchy,  and  Having  

Less  Vanilla  

dryness  

crunchiness  

less  vanilla  

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Discussion

1.6129  3.2258  

0  1.6129  

14.516  69.353  

9.677  

59.677  33.871  

3.226  1.6129  0  0  0  

0   20   40   60   80  

1  2  3  4  5  6  7  

Percentage  

Rankings  

The  Rating  of  Sour  Intensity  on  a  Scale  of  1  to  7  of  the  Concentrations  of  1%  and  5%  Citric  Acid  Compared  to  the  Reference  Sample  of  2.5%  Citric  Acid  Rated  By  the  Nutr.  

205  Students  

5%  Citric  Acid  

1%  Citric  acid  

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The results from the sensory tests done in this lab report compared very closely to

the results in the research, although there were a few contradictions. While looking at the

data from the sensory tests, certain points of errors should be addressed. The environment

in which the sensory tests were given to the Nutrition 205 students, was not considered a

controlled or professional environment for sensory testing. The Nutrition 205 students

may have been disturbed by outside noises, facial expressions made by classmates could

have influenced a student’s opinion, or by students rustling around in their seats. One

factor to be considered in the sensory tests conducted is that one student is gluten

intolerant and unable to participate in one of the tests.

Color Association/Beverage Analysis

The goal of the beverage analysis test was to evaluate if people perceive colors

differently. The tests evaluate the appearance of color, and how it corresponds to the way

a food is perceived to taste. The results for the beverage analysis test were interesting, in

that, the majority of people perceived the emerald colored beverage as being most

artificial, as well as being the most disliked drink. Also, the majority of the panelists

perceived the light yellow beverage as being the most natural and the most preferred. In

the similar study done by Levitan, the results of that test corresponded to the beverage

analysis test done in the lab. Levitan found that color was perceived somewhat similar

among his panelists. Although, the majority of the panelists perceived color the same

way, his results showed that panelists perceived beverages with the least artificial

coloring as having the least flavor, and were the most disliked (Levitan and others). A

factor that could contribute to the relationship of the artifical color of the beverage

corresponding to dislike or like of the beverage in the nutrion lab is that the students

performing the test are Foods and Nutrition students who have knowleds of artificiality of

foods. The demographics of the panelists in the Levitan test are a group of trained

panelists which eliminates bias.

Descriptive Test

The results of the descriptive test done on the five different samples of food were

vary scattered. When panelists described the appearance of a raisin, 38.7% described it as

sunken, 22.6% said the raisin was dry, and 11.3% of the panelists said it looked dark. In a

similar test conducted by Louisiana State University graduate students, a group of

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untrained panelists were asked to use descriptive terms to describe their three different

milk chocolate candies. The results of their descriptive test were similar to the one

conducted in the nutrition laboratory. The graduate students found that the descriptions

varied and were scattered. They found that older panelists described the candies

differently, than some of the younger panelists. Everyone’s tastes buds are different,

therefore people describe foods and beverages differently.

Paired Comparison Test

The results of the paired comparison test on the two different concentration of

citric acid in apple juice, resulted in 100% of the panelists choosing the 1% citric apple

juice (573T2) as being more sour than the 0% citric acid juice. In the paired comparison

test by Coylar, the results were identical to the results of the apple juice. Generally,

Coylar’s results revealed that the panelists were in agreement with each other as to

identifying the food sample with the stronger characteristic (Coylar and other 2009). One

error that can occur in this type of sensory testing is someone not submitting their

opinion. Overall, this type of testing is very simple and easily done on food or beverage

products which have very drastic characteristics.

Triangle Test

The results from the the triangle test expressed that 100% of the participants

selected 1% citric acid apple juice (112H9) as most sour compared to the two samples

both having 0% citric acid (77C1 and 542E2). These results show that very drastic

flavors can be determined by the majority of people, if not all. A similar test on goat and

beef meat contradicted the results done in the nutrition lab. Rhee, Myers, and Waldron

didn’t get a very close results from their panelists after presenting them with the meat

samples. A possible reason for not getting similar results, stated by Rhee, Myers, and

Waldron, was that the way they had presented the samples to their panelitsts may have

affected the results. There’s a possibility if the standard sample is presented too early,

panelists may have forgotten what the standard sample tasted like (Rhee and others). The

order of samples given to the students in the nutrition lab did not seem to impose any

errors in the Triangle test with the different concentration of apple juice. This may be

because citric acid is such a drastic flavor, and maybe if the concentration in the citric

Beltran    26  

acid juices were more subtle then the panelists wouldn’t have been able to tell the

difference so easily.

Ranking Test

Results from the ranking test showed that 61 out of the 62 people ranked the 10%

citric acid juice correctly as being the most sour. At the same time, the majority of the

people ranked the 10% citric acid juice as being the least liked. The rest of the juices with

different percentages of citric acid varie in votes. In the ranking test conducted by

Beathard, cheeses with various ripenings were presented to the panel. Beathard’s results

differed from the one conducted on the citric acid juices. His results revealed that the

cheese ripened for the longest period of time, which had the strongest flavor was not

ranked the lowest. The cheese was ranked somewhere in the middle of the ranking scale.

These two tests show that in certain foods the extreme characteristic meant for that

specific food can be an advantage or disadvantage (Beathard 2008). Also, some people

may like stronger flavors than others, and some people’s taste buds may be a lot more

sensitive than others and certain groups of populations. A source of error in a ranking test

can be that some flavors may be too similar for people to be able to rank, or they simply

may not be able to tell the difference. Also, a trained panelist may be a lot better at

ranking tests compared to untrained panalist. Another source of error may be that the

panelist may not have cleansed their palate with water before trying each sample.

Duo-Trio Test

The results of the duo-trio test on the vanilla wafers resulted in 56 (90.3%) of the

panelists identifying the sample identical to the standard sample wafer. The remaining

participants identified the First Street Vanilla Wafer from Smart and Final as the identical

sample to the standard sample. Although, the majority of the panelists identified the

correct sample as the identical wafer there may have been reasons why not everyone

identified the right sample. One source of error may have been that panelists did not take

a sip of water in-between tasting each cookie, so that flavor from the previous cookie

tasted remained. Another error could be that the standard sample was tasted too early, in

which the panelists forgot what the first sample tasted like. Also, because people are

more sensitive to certain flavors than others, it could have been difficult for a person to

identify the difference in the wafers.

Beltran    27  

Scoring and Rating Test

The results for the rating test showed that the majority of the panelists ranked the

1% citric acid apple juice as being the more sour than the arbitrary sample. Also, most of

the participants ranked the 5% citric acid juice less sour than the arbitrary one. In the

similar study done on grapefruit juice with different bitterness, the results corresponded

to the ones done in the nutrition lab on the three different sample of apple juice

containing different percents of citric acid. One difference in Frank’s study was that his

panelists consisted of trained and untrained individuals. The results from the grapefruit

juice rating test resulted in the panelists ranking the grapefruit juice correctly. Although,

the percentages of the exact ranking scale for the two grapefruit juices varied, the

panelists were able to rank the two juices bitterness compared to the arbitrary sample

correctly (Frank 1997). Trained panelists for this type of testing can be very helpful for a

rating test. This type of testing results in very scattered results because people are more

sensitive to certain tastes than others. Some people might not think something is that sour

when others may think it’s too sour, therefore giving a very different rating on a scale.

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References

Aykut u, Tarakcil, Temiz H, Turhan S. 2011. Influence of wild garlic on color, free fatty acids and chemical and sensory properties of herby pickled cheese. International Journal of Food Properties. 14:287-299.

Beathard K. 2008. Lab Manual for Brown’s Understanding Food Principles and Preparations. 3rd Edition. Carlifornia:Wadsworth 304

Brown A. 2011. Understanding food principles of preparation 4th ed. California Wadsworth. pp. 23-25.

Chen J. 2007. Surface texture of foods: Perception and characterization. Critical Reviews in Food Science and Nutrition. 47: 583-598.

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Coylar JM, Dunn ML, Eggett DL, Ogden LV, Steele FM. 2009. Sensitivity comparison of sequential monadic and side –by-side presentation protocols in affective consumer testing. Journal of Food Science. 74:7.

Frank GC, Nelson DB, Sami PS, Toma RB. 1997. Effects of debittering on grapefruit juice acceptance. International Journal of Food Sciences and Nutrition. 48. 237-242.

Levitan CA, McClure S, Shankar M, Shiv B, Simons C, Spence C. 2010. An Expectationsbased approach to explaining the cross-modal influence of color on orthonasal olfactory identification: The influence of the degree of discrepancy. Attention Perception and Psychophysics 72: 1981-1993.

Pavon N. 2003. Sensory characteristics of flavored milk candies 10-16.

Appendices