The Key to A Happy Consumer

Kaila RaygozaFood Science - Nutrition 205

Spring 2014

San Diego State University

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AbstractSensory Testing is widely used in the food and beverage industry to ensure that the best products are being developed for consumers. The objective of this experiment was to teach Food Science students at San Diego State University how to properly administer sensory tests. A color Association/Preference of Beverage test was used to determine the effect color has on preference of beverages. Affective and analytic experiments were used to analyze beverages containing differing concentrations of citric acid. A duo-trio test was used to compare name brand to store brand Vanilla Wafers. Descriptive terms were used to evaluate food products based on their flavor, texture, aroma, consistency and mouthfeel. Results of the Color Association/Perception of Beverages showed that color has a direct effect on the way people perceive beverages. Panelists most preferred the Light Yellow beverage and also perceived it as the most sour as well as natural of all beverages. Emerald was thought to be the most artificial and was also the least preferred beverage. Panelists did not find it challenging to compare high and low amounts of citric acid in beverages. When ranking the sourness of beverages using a scale of one to five, 86% or higher or all panelists (n= 65) correctly placed each beverage. The duo-trio tests revealed that while it may be easy to identify two different brands of Vanilla Wafers, it was difficult to identify the characteristic that set them apart. When evaluating food products using descriptive terms, results varied widely among panelists and a different method may be more successful in achieving consistent results. Data from all tests can be used to develop new products in the food and beverage industry. The purpose of this study was to introduce Nutrition 205 students to subjective sensory testing and its purposes and all objectives were met.

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Introduction

Sensory evaluation is used in many real life situations such as testing new products for

restaurants, marketing of foods, and research. This testing is used to create the most appealing

and desired product a company can develop for the consumer. Sensory evaluation is necessary

when companies are trying to successfully develop the best-selling product, whether it be food or

beverage. These tests can be as simple as whether or not a burger should be made with onion on

it, or as complex as what concentration of a certain ingredient should be added to the product.

They can be used for the introduction of a new product or for the improvement of an old one.

When a company heard about the health benefits of adding bee pollen to the human diet, they

wanted to add it to their marshmallows. In order to determine the amount that could be added

without changing the taste of the marshmallows, they did a sensory test where they made three

different types of marshmallows each with a different concentration of pollen. The results

showed which concentration was most accepted by the consumer and this allowed them to create

a product that consumers would continue to purchase. (Ungure and others 2013) Had they

released a product containing too much bee pollen without doing sensory testing, they risk the

chance of the taste being affected and marshmallow sales decreasing due to the altered taste.  

Sensory evaluations are the study of the chemical and physical properties found in food

that influences the foods quality through components including preparation and type of storage

(Brown 2011). The evaluation of food is done using both objective and subjective testing.

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Objective testing relies on numbers that are generated using tools used in the laboratory such as a

spectrophotometer or viscometer. They are used to evaluate not only the physical properties of

food, but also the chemical differences. Chemical tests can be done using the Benedict and

Fehling tests, enzyme tests, iodine value tests, and many others. They analyze quantitative

measurements that cannot be measured by a sense such as taste or smell. 

Subjective testing is using the sensory characteristics to determine the quality of the food.

The five senses used in sensory testing are sight, taste, touch, smell and hearing. (Brown 2011)

It’s important to understand that all five of these senses contribute to ones opinion of products

and also whether or not they buy them. While one might know that they enjoy the flavor of lunch

meat, they may not purchase a specific brand because the label is not pleasing to the eye. Often

times consumers purchase a name brand item over a store brand item simply because the labeling

is more appealing. (Kemp 2008) In the case of this lab experiment, sensory testing was used to

determine taste, texture, appearance, etc. of beverages and foods. A few specific examples of

subjective testing would be the triangle test, duo-trio test, and ranking test. The triangle test is

done when you have three samples, two of which are the same. You present all three samples

with an arbitrary code and ask the subject to identify which of the three samples is different from

the other two. In a duo-trio test, three samples are presented and one is designated the standard.

The panelist is to identify which sample is most similar to the standard. In the case of the ranking

test you must use two or more samples. The panelist is asked to rank the samples in order of

lowest to highest based on the intensity of a certain characteristic (sourness, sweetness,

bitterness, etc.). These are also examples of tests that were used in this laboratory experiment. 

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Appearance is a major factor that plays a role in the acceptance of food and beverage and

is tested in this experiment. In our testing, the first thing looked at was perception of five

different beverages judging by color only. Four different attributes were considered and had to

be matched to a beverages only by appearance. A study showed that appropriately colored

beverages are more favored because they are easy to identify and don’t confuse the taste buds.

(Zellner 2010) Advertisement of food and drink is a huge business. Commercials are responsible

for consumers trying a new product that they otherwise wouldn’t have known about. Menu’s in

restaurants often times contain pictures that look far better than the actual product. They know

that appearance plays a huge role in deciding what food’s sound good so many restaurants put a

lot pictures into their menus. The second test done in this experiment was evaluating the

appearance of goldfish, raisins, almonds, and marshmallows. Appearance of food is important

because it is considered far before one can judge a food by its taste or flavor. 

Taste is another component of sensory evaluation. Taste is one of the most influential

characteristics when selecting food. There are five taste stimuli; sweetness (from different

sugars), sourness which comes from acids, bitterness which comes from foods such as caffeine

(found in coffee and teas) and theobromine (found in chocolate), salty from ionized salts, and

lastly, savory (or umami) which is glutamate. The impression of flavor is actually 75% aroma,

but overall flavor is composed of taste, aroma and texture. This is something that goes unrealized

until something is eaten while a cold is present. Not being able to smell that food affects the way

it tastes. (Brown 2011) A study was conducted that compared the difference between regular

sodium vegetable soup (0.93% NaCl) and low-sodium vegetable soup (0.45% NaCl). They found

that the flavor profile of the two soups were completely different. The full sodium soup had a

“salty flavor”, “carrot aroma”, “yellow color”, and “overall flavor complexity.” The reduced

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sodium soup had a “green color”, “pepper flavor”, sweet flavor.” (Mitchell 2011) This highly

affects the way foods taste and also affects the way consumers feel about certain food, which in

turn determines the foods they buy. If the low-sodium soup has a lower overall sensory profile,

it’s more than likely going to have lower sales and affect the company that makes it.

Texture is another important factor to consider when doing sensory evaluations. Texture

is described as the a response of the tactile senses that is brought on by the physical

characteristics of foods. It is a major determinant of food acceptance. Our evaluation of the

texture of food is influenced by the structure of the food as well as its resistance to forces such as

the mouth, teeth, knife, or roof of the mouth. (Brown 2011) Texture is the reason that many

people don’t eat certain foods such as sushi or cottage cheese and is also the reason many people

like certain foods. A study done on olives showed that texture and flavor play a huge role in the

acceptance of table olives. They used olives from California, Egypt, Spain, Morocco, Portugal

and flavor and texture were the two main determinants in consumer preference. (Lee and others

2012). The purpose of their study was to determine the preference patterns of Californians using

both domestic and imported black ripe olives to improve their sensory quality. Their goal was to

better the experience for the consumer by providing the producers and importers with

information regarding what factors are most important to the consumer. 

Another important sensory characteristic is aroma. It’s another one of the senses that

causes people to determine whether or not they accept or reject a product before it has been

tasted. Researchers have classified odors into six categories; spicy, fruity, resinous, foul, burt,

and flowery. Volatile molecules from the product are what allow us to smell it. It only takes a

few molecules traveling into the olfactory epithelium located in the upper nasal cavity for odors

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can be distinguished. Temperature plays a major role in aroma, the higher the temperature, the

greater volatility and the greater flavor perception. (Brown 2011) In a study, “Characteristic

Aroma Compounds of Cooked and Fermented Soybean (Chungkook-Jang) Inoculated with

Various Bacilli,” researches extracted volatile compounds from their products and detected them

using laboratory equipment. They found that the Bacillus species that had a nutty initial top note

along with nutty, cheesy long-lasting note aroma was positivity correlated with the most overall

acceptance among panelists. The species containing chemical, fatty aromas was negatively

correlated with overall acceptance. The analysis revealed that consumers prefer a nutty, cheesy

aroma over a fatty one. (Yoon and others 2013)

Sensory testing is highly important in developing successful products that will make the

consumer, as well as the business owner, happy. Without the use of these tests, companies would

create products that would potentially never be a success, so these tests provide a much greater

chance of releasing a successful product. In this experiment, many subjective tests are used to

evaluate food and beverages. The panelists were untrained Nutrition 205 students at San Diego

State University so a major objective of the experiment was to expose them to sensory

evaluation. 

Materials and Methods 

Panelists

The panel was made up of a total of 65 students in three different classes. All panelists

were students in a Food Science (Nutr 205) class at San Diego State University. A total of 66

students were used for the study and were split up into three classes. Ninety-one precent (91%)

were undergrad students and nine percent were enrolled in a graduate program. Ninety-eight

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percent (98%) of the students were between the ages of 19 and 44 with only one student being

over the age of 45. Eighty-two percent (82%) of the classes combined was female with the

remaining 18% being males. The living situations of these individuals included 10 living alone,

19 living with one roommate and 36 living with two or more roommates. Only one of the 65

students was a smoker. Eight students had food allergies such as nuts, soy, dairy, wheat, melon,

bleu cheese and gluten. The remaining 57 students did not have any food allergies that they were

aware of. 

Environment 

Testing was held in a food science laboratory located in the West Commons building at

San Diego State. The room does not contain any windows and is lit up by fluorescent lighting.

The room was very open and the air was cool. The room was very organized and all desks were

clear from clutter. A total of 30 desks are located in the center of the room with a large counter

top and projection screen directly in front of them. One professor along with 2 teachers assistants

were located behind the counter top to count votes for each test conducted. Some students were

using laptops as a way to keep track of their data but were also surfing the internet while votes

were being taken. This appeared to be a distraction to students around them. 

Color Association/Perception of Beverages 

The objective of this test was to determine how people perceive beverages based purely

on their appearance. For this test, there were five clear beakers placed at the front of the

classroom. Each beaker was labeled; light yellow, dark yellow, chartreuse, dark chartreuse, and

emerald. The beakers sat about four inches apart from each other and were each wrapped with

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plastic wrap. Testing began and in the very quiet classroom students were to be judging the

beverages based on characteristics such as sweetest, sourest, most artificial, and most natural.

Next, they had to choose which one they preferred, and which they disliked. Students had to

record which temperature they would consume each drink at from the choices “cold”, “warm”,

“tepid”, and “hot.” After data was collected, the contents of each sample was revealed: light

yellow (Mountain Dairy Lemonade), dark yellow (Xtremo Citrico Vibrante Gatorade),

chartreuse (350mL Lemon Lime Gatorade + 150 mL Green Squall Powerade), dark chartreuse

(Green Squall Powerade), and emerald (Watermelon Gatorade). 

Difference tests

Evaluation of Food Products Using Descriptive Terms 

The first test conducted was the Evaluation of Food Products using Descriptive Terms

test. The first student in each row went up to the front of the classroom and put four dixie cups

per student on a tray; one containing two gold fish, the next two raisins, two almonds in the third

and the fourth contained two mini marshmallows. They then distributed one of each cup to every

person in their row. Each student was also provided with a cup of water to sip on between each

tasting as a way of cleansing the palate. Once everyone had received their samples, students were

instructed to taste each sample and evaluate the following features: appearance, aroma, flavor,

texture, consistency and mouth feel. The list of words used can be found in Appendix D. After

evaluation of each of the products, the instructor recorded data by a raise of hands. No talking or

facial expressions were allowed during this test. 

Paired Comparison Test 

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The purpose of this test was to compare the difference of two liquids based on their

sourness. The two samples were given a sample code in order to prevent biases based on their

names. Once again, the first person in each row was responsible for picking up and distributing

the samples to their row. It was very important that they didn’t mix up the samples before getting

them to each person in their row. Once everyone had received a sample the testing began. The

classroom was silent and students were warned not to look at their classmates or make any facial

expressions. Sample 635T1 was apple juice and sample 573T2 was apple juice containing 1%

citric acid. Students were to put a check next to the box of the sample that was the sourest. Water

was provided to cleanse the palate before and after each tasting. Once everyone had finished the

instructor asked for results by show of hands and data was recorded. 

Triangle Test

The triangle test was used to differentiate one sample from two other identical samples.

Everyone was provided with three samples: 777C1 (0% citric acid), 542E2 (0% citric acid),

112H9 (1% citric acid). As in all the other tests, the first person in each row was responsible for

obtaining and distributing the samples out to each person in their row. Once everyone had

received samples, testing began. Participants were once again advised to take a drink of water

between each sample. Students were to keep their eyes on their own table and refrain from

making any facial expressions. Once all students were finished the instructor recorded the data

using a show of hands. 

Ranking Test

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The ranking test was used to compare the sourness intensity of five different mixtures of

apple juice. Once again, the first person in each row was responsible for getting all samples for

every person in their row. As in the previous tests, each beverage had a code to prevent forming

bias opinions based on their names. From most sour to least the codes were: 555D7 (10% citric

acid), 192L3 (5% citric acid), 695F8 (2.5% citric acid), 543K8 (1% citric acid). Once every

participant had received a sample, the test began. Participants were to keep their eyes on the own

desk and avoid making faces in response to the sourness of the samples. Students were instructed

to take a drink of the water between each sample to cleanse the palate. The beverages were

scored on a scale of one through five with five being the most sour.  In the next column students

were asked to score the beverages based on preference using the same scale. When all students

had completed their testing, the instructor with the help of her aids recorded data using a show of

hands. 

Duo-Trio Test

This test was use to compare the difference of two vanilla wafer cookies; a name brand

versus a store brand. The standard was labeled 8175 and the samples were labeled 6104 and

1108. The lab technician passed out one standard and two samples. Once all participants had

received their cookies the testing began. Students were to taste each cookie and answer the

following two questions: 1. Which sample differs from the standard? 2. In your opinion, what is

the major difference? Driness? Crunchiness? Vanilla flavor less or more intense? Between each

sample students were directed to take a drink of the water provided in order to cleanse the palate.

As in all other tests, no talking or facial expressions were allowed. When all participants were

done taste testing, the instructor collected all results using a show of hands. 

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Scoring Test

The objective of the scoring test was to compare the sourness intensity of samples

compared to a standard sample. The standard was given the sample code 0110 and contained

2.5% citric acid. The two samples were labeled 420M (containing 1% citric acid) and S723

(containing 5% citric acid). On a scale of one to seven, one being more sour and seven being less

sour, with the standard (0110) being number four. Once all participants had received their

samples, testing began. Panelists were once again instructed to take a drink of water between

each tasting to cleanse the palate. The classroom was quiet and students kept their eyes on their

own desks. Students wrote their scores of each sample down on their papers and once they were

done the professor began collecting data by a show of hands.  

Statistical Analysis

Data from all three classes (a total of 65 subjects) was analyzed. Data was then imputed

into an excel spreadsheet using percentages. Each specific category had its own calculated

percentages that were used to compare results. 

Results

Color Association/Perception of Beverages 

When evaluating the “sweetness” of the beverages, emerald came in with the highest

number of votes at 34%. Next was Dark Yellow with a total of 25% of the votes, followed by

Light Yellow with 20%, Dark Chartreuse at 15% and Chartreuse being perceived as the least

sweet with a total of 6% of the votes. The following results are pictured in Figure 1.

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20%

25%

6%15%

34%

Figure 1: Color Association/Preference of Beverages (Most Sweet)

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald

For the attribute “sourness”, Light Yellow had almost half the votes at 42% followed by

Dark yellow with 20%, Chartreuse with 17%, Dark Chartreuse with 16% and Emerald with only

5% of the total votes. 

42%

20%

17%

16%

5%

Figure 2: Color Association/Preference of Beverages (Most Sour)

Light Yellow Dark Yellow Chartruese Dark Chatreuse Emerald

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For the attribute “most artificial,” Emerald had majority of the votes with an 84%

followed by Chartreuse with 6%, Dark Chartreuse with 5%, Dark Yellow with 3% and Light

yellow with only 2% of the votes.

2% 3%

6%5%

84%

Figure 3: Color Association/Preference of Beverage (Most Atrificial)

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald

For “most natural” attribute, Light Yellow held the highest number of votes, by far, with

an 88%, followed by Dark Yellow and Chartreuse both with 4%, and Dark Chartreuse and

Emerald each with a small 2%. 

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88%

4%4% 2% 2%

Figure 4: Color Association/Preception of Beverages (Most Natrual)

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald

As far as preference goes, 60% of the subjects preferred to drink the Light Yellow

beverage, 17% preferred the Chartreuse, 11% Dark Yellow, 10% Dark Chartreuse , and only 2%

preferred the Emerald.

60%11%

17%

10%

2%

Figure 5: Color Association/Preception of Beverages (Most Preferred Beverage)

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald

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For the option “dislike the most”, 48% voted for Emerald, 26% voted for Dark yellow,

12% for both Light Yellow and Dark Chartreuse and 2% voted for Chartreuse. 

12%

26%

2%12%

48%

Figure 6: Color Association/Perception of Beverages (Most Disliked Beverage)

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald

When panelists were asked whether or not they would drink the beverage, at any

temperature, Light Yellow was the most preferred with 95% of the subjects willing to drink it.

60% of the panelists were willing to drink Chartreuse, 51% Dark Yellow, 45% Dark Chartreuse,

and only 23% were willing to drink the Emerald beverage at any temperature. Lastly, students

were asked whether or not they drink apple juice and 88% said yes, while the remaining 12%

said they do not drink apple juice.

As far as temperature is concerned, panelists were asked if they would rather drink each

beverage cold, hot, warm or tepid. 92% of the panelists said they would most prefer to drink the

Light Yellow beverage cold. 71% of the panelists voted for drinking the Dark Yellow beverage

cold. For Chartreuse, cold got the highest number of votes at 72%. Dark Chartreuse was also

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most preferred cold with 58%. Lastly, Emerald had 49% of its votes in the cold section, with

only 2-3% in the other areas (hot, warm, tepid). 

Light Yellow Dark Yellow Chartreuse Dark Chartreuse Emerald 0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Figure 7: Color Association/Preference of Beverages: Would You Drink This Beverage?

WouldWould Not

Evaluation of Food Products Using Descriptive Terms 

When evaluating food products using descriptive terms, there were several preselected

terms to choose from. When the data was interpreted, only the terms that gained the highest

percentage of votes were listed. For the evaluation of the appearance of Goldfish using

descriptive terms, 23% of the panelists described the sample as “dry,” followed by “golden

brown” with 17% of the votes, and “symmetrical” and “puffy” both with 13% of the votes. In

terms of flavor, 79% of the subjects described the goldfish as “salty,” with the remaining 21%

voting “sharp.” 56% said the texture was “crispy,” and another 34% said “crunchy.” When

describing the aroma of goldfish, 38% said it smelt like “nothing,” while another 34% said

“flavory.” Over half of the subjects (58%) said the consistency of the sample was “brittle” while

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31% said “cheesy.” For mouth feel the number of votes was nearly split in half between two

different terms; “crispy” and “crunchy.” 

Table 1: Evaluation of Goldfish Using Descriptive Terms

Appearance Flavor Texture Aroma Consistency MouthfeelDry 23% Salty 79% Crisp 56% Nothing 38% Brittle 58% Crispy 51%

Golden brown 17%

Sharp 21% Crunchy 34% Flavory 34% Cheezy 31% Crunchy 49%

Symmetrical 13%

For the evaluation of the appearance of raisins, 25% of the panelists described them as

“dry”. While 22% of the subjects described the raisins as “sunken,” 14% said they were “dark.”

11% said they were “sticky" and another 11% said “asymmetrical.” When describing the flavor

of a raisin, 58% said it was “sweet,” and another 32% said “fruity.” For consistency, 55%

described them as “chewy,” and 29% said “gummy.” As far as texture was concerned, 32% said

“chewy,” 29% said “gummy,” and another 15% said “gelatinous.” When asked about the aroma

of the raisins, 38% of panelists selected “sweet,” 31% said “fruity” and 15% said the raisin smelt

like “nothing.” When asked about the mouthfeel, over half of the subjects (58%) said “sticky.” 

Table 2: Evaluation of Raisins Using Descriptive Terms

Appearance Flavor Texture Aroma Consistency MouthfeelDry 25% Sweet 58% Chewy 32% Sweet 38% Chewy 55% Sticky 58%Sunken 22% Fruity 32% Gummy 29% Fruity 31% Gummy 29%Dark 14% Gelatinous

15%Nothing 15%

When almonds were evaluated, 34% of the panelists described their appearance as “light-

brown” and 23% described them as “dry.” Another 18% described them as “golden-brown,” and

only 11% said “smooth.” The remaining 14% said they were either “rounded,” “smooth,” “dull,”

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“symmetrical,” or “grainy.” When panelists were asked to describe the flavor of the almond

sample, 92% of them said “nutty.” When asked about the mouthfeel of the sample, 58% said

“crunchy,” and another 22% said “gritty.” When it came to texture, 35% of subjects said

almonds were “hard,” 20% said they were “firm,” and 15% said they were “crunchy.” 98% of

them said the aroma of the almond was “nothing.” “Chewy” was used by 46% of the class to

describe the consistency and 45% said “thick.

Table 3: Evaluation of Almonds Using Descriptive Terms

Appearance Flavor Texture Aroma Consistency MouthfeelLight Brown

34%Nutty 92% Hard 35% Nothing 98% Chewy 46% Crunch 58%

Dry 23% Flat 5% Firm 20% Flavory 2% Thick 45% Gritty 22%Golden Brown

18%Crunchy 15%

When evaluating marshmallows by looking at them, 83% of all subjects described their

appearance as “puffy.” Another 6% said “dry,” and 5% “smooth.” “Symmetrical,” “dull,” and

“fine” each accounted for 2% of the total votes. As pertaining to flavor, 70% of panelists said the

marshmallow was “sweet,” and 22% said “floury.” When asked about the aroma, 89% of all

subjects described it was “sweet,” with an additional 11% saying “flowery,” or “nothing.” When

texture was described, there was a large variation in votes. 27% described it was “springy,” 25%

said “velvety,” 17% said “tender,” and 11% said “gummy.” Gummy was also selected by 56% of

panelists to describe the consistency. Over half of all subjects (56%) described the mouthfeel as

“smooth,” and both “sticky” and “slimy” gained 17% of votes accounting for 34% of all votes. 

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Table 4: Evaluation of Marshmallows Using Descriptive Terms

Appearance Flavor Texture Aroma Consistency MouthfeelPuffy 83% Sweet 70% Springy 27% Sweet 89% Gummy 56% Smooth 56%

Dry 6% Flowery 22% Velvety 25% Flowery 6% Chewy 21% Sticky 17%Smooth 5% Tender 17% Nothing 5% Slimy 17%

Paired Comparison Test 

When asked to compare the sourness of two sample beverages to each other (apple juice),

98% of the panelists voted that sample 573T2 was the most sour (1% citric acid) while the other

2% said sample 635T1, containing 0% citric acid, was the most sour.  

Triangle Test

For the triangle test, 97% of all participants identified sample 112H9 (1% citric acid) as

being the sample that was different from samples 777C1 and 542E2, both containing 0% citric

acid. The remaining 3% thought sample 542E2 was different from the other two. 

Figure 8: Identifying the Odd Sample

112H9777C1542 E2

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Ranking Test

Five different beverages were rated on a scale of one to five, one being the most sour and

five being the least sour. Sample 555 D7 (10% citric acid) received 98% of votes for being

ranked number one. For number two, sample 192 L3 (5% citric acid) received the highest

number of votes (89%) followed by sample 695 F8 (2.5% citric acid) with 9% of votes. Rank

number three received an 86% vote for sample 695 F8 (2.5% citric acid). The fourth ranking had

an 89% vote for sample 543 K8 (1% citric acid). Lastly, number five brought in 95% of all votes

for sample 495 P2, which did not contain any citric acid. 

1 2 3 4 50%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Figure 9: Sourness of Beverages

Perc

enta

ge o

f Vot

es

Duo-Trio Test

For the comparison of three cookies, a standard and two samples, 94% of subjects voted that

sample 6104 was different from the standard (8175) with only 6% voting sample 1108 was

different from the standard. When asked what they thought made the cookie different from the

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sample, 48% said “crunchiness,” 35% said “less vanilla,” and the remaining 17% said

“dryness.” 

48%

35%

17%

Figure 10: Evaluation of Differences Between the Standard and Sample Vanilla Wafer

Crunchiness Less Vanilla Dryness

Scoring or Rating Test

Subjects were asked to score two samples beverages on a scale from one to seven, one being the

most sour and seven being the least sour. The beverages were to be compared to a reference

sample that was ranked a number four on the scale of sourness. 46% of student subjects ranked

sample S723 (5% citric acid) as being number one (as sour as it could get.) 43% scored it at

number two on the scale. Of the remaining 11%, 6% ranked it at a number three, and 5% gave it

a number five. When asked to analyzed sample 420M (1% citric acid) 69% of panelists ranked it

as a number six on the sourness scale. Number seven accounted for 14% of the votes, number

five held 11% of the votes, 2% ranked it a number four and 4% ranked it as a number three. 

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1 2 3 4 5 6 70% 2% 3% 2%

11%

69%

14%

46% 43%

6%0% 3% 0% 0%

Figure 11: Scoring of Sourness of Two Samples Containing Citric Acid

420M S723

Discussion

All of the above tests are standard tests done by the food industry in an effort to create the

most desired products for consumers. By using the Color of Association/Preference of Beverage

test we found that color has a direct effect on how people perceive a beverage. It was found that

the more pigmented the beverage is, the more sweet it is perceived to be. Emerald and Dark

Yellow had the highest number of votes for sweetness and are the two of the brightest and most

pigmented colors to choose from. When evaluating the sourness of beverages, it appeared that

perception of sourness decreased as the colors got darker. Light Yellow had the highest

percentage of votes for “most sour.” This could be because people associate the light yellow

color with sour food or drinks that they are familiar with such as lemonade. The next

characteristic evaluated was most artificial. This test had very similar results to the “sweetest”

beverage test. The darker colors received more votes and it decreased as the color intensity

decreased. When identifying the most “natural” beverage, the majority of panelists voted for

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Light Yellow, with only 12% voting for something else. This could be due to the fact that bright

colors are associated with being artificial. As far as preference goes, the lighter the color, the

higher acceptance score it received. The darker the colors got, the less subjects were willing to

try them. This test also reviled that people are most likely to drink their beverages cold, if at all.

The five beverages (Light Yellow, Dark Yellow, Chartreuse, Dark Chartreuse and Emerald) had

the highest number of votes for willing to drink cold over any other temperature. A study done

on Consumer Attitude and Sensory Evaluation of Marshmallows (Zellner 2010) revealed that

participants are more willing to try beverages that have colors that correspond to their flavor.

One reason that students weren’t willing to try certain beverages could have been that they

associated the colors with flavors that they dislike, or weren’t sure what flavor the drinks might

be because the colors used were not commonly used colors.

Evaluation of food products using descriptive terms showed varying opinions on food

product and also showed similar characteristics in very different products. This test showed

many different answers for one question; while some foods only had one descriptive word gain a

100% vote, many others were unevenly split between several words. This could be due to the

fact that panelists were given a word bank to choose from for each question. Some answers may

have been chosen simply because the word they would have selected wasn’t available to them.

Had panelists been able to “fill in the blank,” the results may have been more accurate which

would only benefit the company selling the product. In a study done on olives, it was shown that

an unfamiliar texture made it more complex to give a description of them. The study showed that

olives produced outside of the United States have a different texture and are not favored by

American’s for this reason. This shows that if any of the samples tasted were unfamiliar to

panelists, it may have been difficult for them to describe them, especially if there were only

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certain words to choose from. (Lee and others 2013.) Another study (Yoon and others 2013)

showed that aromas can positively or negatively correlate with people’s willingness to try a

product. It is highly important for companies to consider this when developing a new product.

Doing sensory evaluation of aroma of products is well worth their time because while aroma

may not seem like it’s of huge importance; it is directly associated to whether or not consumers

are willing to try it. 

In the paired comparison test, it was very easy for panelists to identify the different

concentrations of citric acid in apple juice. 98% of panelists correctly chose sample 573T2 as

being the sourest beverage. This experiment was straight forward and because of the consistent

votes, it is safe to say that this sample could be considered a standard. One thing that could have

been improved for this experiment would have been adding more panelists to make the study

more credible. While the results may have been consistent, most companies would like to use a

large sample size before relying on the results of a study. In the study on marshmallows (Ungure

and others 2013), it is shown that consumers can easily identify different concentrations of

ingredients that are added to the product they are used to. When high concentrations of bee

pollen were added to their marshmallows, they were able to detect the taste and suggest less was

added. This further proves that paired comparison tests are helpful and necessary when doing

sensory testing. 

The triangle test revealed the same results as the paired comparison test. Panelists did not

have a difficult time identifying which of two samples was most sour. 97% identified sample

112H9 (1% citric acid) as being different from the other two samples that did not contain citric

acid. Panelists seem to have an easy time identifying sourness of beverages. This is more than

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likely due to the fact that sour is a very distinct taste. One risk taken when doing a triangle test is

having the taste of the first sample affect the taste of the second. This could easily manipulate the

results, even if a sip of water was taken in-between samples. 

The ranking test was very straight forward in this experiment. Similar to the paired

comparison test and triangle test, panelists found ranking different concentrations of sourness to

be easy. Every rank showed a percentage of at least 86% but most were above 90%. Once again,

it’s easy to run into mistakes after trying several samples one after another. It is assumed that

each participant takes a sip of their water to clean the palette between samples, but there is no

way of guaranteeing that this is happening. With more than a few samples, panelists can start to

experience taste fatigue and all samples may end up tasting very similar. Another error that could

have affected the results of the test would be if panelists confused the ranking scale. If anyone

thought number five was the sourest, this could have skewed the results of the test. 

The duo-trio test was used to compare two samples to a standard. Results for this

experiment were not as uniform as they were for other test. Out of the three descriptive words

panelists had to choose from, percentages varied with the highest one only gaining 48%. A 6%

error was shown in this experiment with 94% of panelists successfully identifying which sample

cookie was the same as the standard. Panelists also had to choose between “dryness,”

“crunchiness,” and “less-vanilla” as what made the odd cookie different from the other two. This

may not provide the best results because panelists may have though there was another reason the

cookies tasted different. If one company was using these results to make their cookie more

similar to the other brand, they may add more vanilla if “less-vanilla” received the highest

percentage of votes. There is a possibility that these panelists didn’t actually believe “less-

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vanilla” was the different, but were forced to make one of three choices and chose the most

accurate one they could. A way to improve this test may be adding a blank where panelists have

a chance to say what they think makes the cookies different. The proctor of the test could also

provide a word bank to help panelists who may have trouble identifying the word that fits best.

When comparing the results of the scoring test, results were not as uniform as the other

tests that compared sourness of beverages. Two samples were to be placed on a scale of one to

seven (one being the most sour) and number four was assigned to the reference sample. The

highest percentage a rating received was a 69%, so it’s clear to see that results were not

consistent. A downfall to this test is that many subjects automatically assume that one sample

will be placed above the sample and one below, which may not always be correct. This can skew

the results of the experiment. 

In conclusion, further research is necessary before assuming generalizations. The panel

for this study was far too small for a respectable and credible study. The objective of the

experiment was to introduce untrained Nutrition 205 students to sensory evaluation. Although

objectives were met, there was room for error. If a panelist was not paying attention when votes

were being taken, they could have voted more than once per category or could have forgotten to

vote all together. This could skew the results, especially if it happened with more than one

panelist. The fact that subjects were in the same room without barriers between them could also

have skewed results because one individual’s choice may be affected by others. Many of these

things would be modified in a real sensory test to avoid room for error, however it was a great

first time experience for untrained San Diego State Students. 

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References 

Brown, AC. 2008. Understanding Food: Food Principals and Preparation. Belmont, CA: Thomson/Wadsworth, 2008. Print. 

Kemp SE. 2008. Application of Sensory Evaluation in Food Research. International Journal of Food Science & Technology. 43:1507-1511. Available from Wiley Online Library. August 8,2008.

Lee SM, Kitsawad K, Sigal A, Flynn D, Guinard JX. 2012. Sensory Properties and Consumer Acceptance of Imported and Domestic Sliced Black Ripe Olives. Journal of Food Science. 77:S439-S448. Available from Web of Science. December 13, 2012. 

Mitchell M, Brunton NP, Wilkinson MG. 2011. Impact of Salt Reduction on the Instrumental and Sensory Flavor Profile of Vegetable Soup. Food Research International. 44:1036-1043. Available from Science Direct. March 12, 2011.

Ungure E, Straumite E, Brasava SM. 2013. Consumer Attitude and Sensory Evaluation of Marshmallow. Proceedings of the Latvian Academy of Sciences. 67:442. Available from Versita. December 1, 3013.

Yoon KH, Chang YI, Lee GH. 2013. Characteristic Aroma Compounds of Cooked and Fermented Soybean (Chungkook-jang) Inoculated with Various Bacilli. Journal of Food Science and Agriculture. 93:85-92. Available from Wiley Online Journals. June 12, 2012.

Zellner DA. 2010. Art on the Plate: Effect of Balance and Color on Attractiveness of, Willingness to Try and Liking for Food. Food Quality and Preference [Serial Online]. 21:575- 578. Available from ScienceDirect. March 8, 2014.

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Appendices:

A. Demographic QuestionnaireB. Sensory Testing Beverage Questionnaire C. Duo-Trio Test / Rating Test SurveyD. Descriptive Word List

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