Schultz

De Gustibus non est disputandum‘Every man to his taste’:

A look at Food and Beverage Perception

Amanda Schultz

Nutrition 205 Lab Section 1

Lab Report 1

March 24, 2014

1

Schultz

Abstract

Previous research on beverage perception has shown that perception based on appearance is heavily influenced by color cues. Likewise, sensory evaluations conducted for food, indicate flavor is truly a combination of taste aroma and mouthfeel. To build upon an understanding of the role that color cues and taste preferences play on beverage and food, a sensory evaluation took place in the SDSU Food Prep Lab. The foods and Nutrition Students at SDSU participated in several tests examining beverages and food. In a beverage test, the color was observed for 5 beverages and panelists made associations with the beverages and other parameters. Panelists then evaluated 4 food products on: appearance, flavor, texture, aroma, consistency and mouth feel and chose a descriptive word for each. This was followed by several difference tests. The difference tests compared solutions of various concentrations of citric acid to solutions of apple juice. One exception was the duo-trio test, which followed a different protocol. Panelists received three identical cookies and identified the different sample, with reason. The tests in this study revealed that panelists participating in identical studies obtain different results because results are strictly subjective. This present outcome supports a need for continued study on the variables that influence peoples’ perceptions and preferences of foods and beverages.

2

Schultz

Introduction

Sensation is defined as, “the receptor response to bodily stimulation, whereas

perception, as defined in the Oxford dictionary, is awareness through the senses

interpreted in the light of experience” (Engelen 2008). In other words, sensation is the

response to a stimulant, and perception is the understanding of the body’s sensory

response. In sensory testing, panelists taste food and use discretion to evaluate the

samples according to the specific protocol of each test. Sensory evaluations look at the

human response to food to gain a deeper understanding of quality differences in food.

Objective tests study food quality by measuring their chemical and physical properties

(Brown 2011). The interactions between both the physical and chemical components are

measured, but objective tests leave some aspects of food quality profiles unexplored.

Some aspects of food are unable to be measured quantitatively so subjective tests utilize

panels of people to analyze food quality. According to Understanding Food Principles

and Prep, the human sensory organs are exemplary tools that unveil more about food

quality (Brown 2011). The degree to which appearance, texture, taste, and aroma allure

the human senses provides adequate evidence for food quality (Brown 2011).

In a series of sensory tests conducted at the San Diego State Food Prep Lab,

results and data were collected from a panel of 65 Foods and Nutrition students (12 male,

53 female). A beverage test was conducted to observe beverage color and associations

within established parameters. Students reported perceived sweetness, sourness,

artificiality, and naturalness of 5 liquids solely based on their color. Zampini found that

color influences the perception of flavor despite knowledge that color is a misleading

factor (2007). Their findings contributed to current understanding of how certain cues

given with misleading information about a beverage color can influence how flavors are

3

Schultz

identified. This study provides an understanding of color perception and it’s significance

in beverage preference. While there were an overwhelming number of panelists who

preferred one color, the preference for other colors showed the subjectivity of beverage

color preference.

Among the difference tests conducted in this study, the next one follows a

different protocol that utilizes food samples rather than beverage. This test is known as

the descriptive test. When describing food, the perception of appearance, flavor, taste,

aroma, texture and mouth feel are vital. Visual sensation is the first sense to perceive

food; it examines the appearance, color, size, shape and surface of the food. Taste

incorporates how the taste buds perceive food in 5 categories: bitter, salty, sour, sweet,

and umami. Flavor differs because it encompasses the overall impression of food,

considered a combination of taste, aroma and mouthfeel. Aroma is known to enhance the

human perception of food preference because our keen sense of smell establishes a more

robust flavor. Mouthfeel is the final component of flavor, a sensation that occurs in the

lining of the mouth that can include: pain, temperature, astringency, and tactile

stimulation (Brown 2011). Lastly, texture is how we interpret ‘tactile sensations’ based

on the structure of food and resistance to food (Brown 2011). In a descriptive test,

panelists are provided a predetermined list of words that describe food in terms of

appearance, flavor, texture, aroma, consistency and mouth feel. According to Pirastu and

others, taste and olfaction are the best indicators of food quality, and the individual can

use them to determine whether they like the food or not (Pirastu 2012). The visual and

sensory aspects of goldfish, raisins, almonds, and marshmallows will be further explored.

In another evaluation of beverage preference, difference tests were applied to

compare preferences among 2 or more beverage samples presented simultaneously.

4

Schultz

Compared to other tests that include more variables and require a ranking system, this

test only requires the comparison of 2 samples, referred to as a paired comparison test. In

this test, panelists were provided with 2 samples and asked to compare to determine

which one was more acidic. Following the paired comparison test, the triangle test

complied with a similar protocol. In contrast, rather than using two samples, this

difference test utilized three coded samples, only one of which contained citric acid

(Brown 2011). The panel was asked to decipher which one sample differed from the

other two; the likelihood that panelists would choose the correct odd sample was 30%.

The probability that panelists chose the correct sample in the following test was slimmer

than the preceding test because more samples were examined. The next test examined is

termed the ranking test. Ranking tests have more than 2 samples simultaneously

presented, and the panel must rank the samples in accordance with a specific

characteristic. Panelists ranked 5 solutions of various citric acid concentrations on the

basis of sourness and preference with a ranking of 1 being most sour and five being least

sour. The ranking test also recorded the panelists’ preferences of the 5 samples, ranked

from 1 through 5, with a ranking of one being most preferred and five being least

preferred. Most panelists preferred the solution with no citric acid but some chose

solutions with some percentage of citric acid. As examined in one study, sucrose, the

disaccharide of glucose and fructose, is capable of concealing other tastes and can resist

being suppressed by other tastes (Gren 2010). If sucrose has this capability, the

likelihood that the apple juice suppressed the sourness of citric acid in the current

experiment is high. With it's focus on only one characteristic, the advantage of the

ranking test is it’s validity of the results it provides.

5

Schultz

To establish a deeper understanding of sensory testing of food, a separate test

comparing two food samples to a standard was conducted. Known as the duo-trio test,

this test is significant in commercial entities. Companies test for quality of products after

slight alterations in the quality control, in ingredients, or in storage/packaging in search

of the best quality (Lee 2007). Panelists received Nabisco Brand Nilla Wafers (as a

standard) and were asked to compare 2 more cookies, one of the like and a Safeway

Vanilla Wafers brand to decide which differed from the original standard. This study

will examine what distinguishes the samples from each other.

In another examination of citric acid solutions, a final test observed liquids using

a rating test, in which three solutions were presented simultaneously. One solution of a

citric acid and apple juice mixture was labeled standard, and the other two solutions were

ranked in comparison of the reference. A one represented most sour and a 7, the least

sour.

6

Schultz

Methods

Environment

At San Diego State University, a sensory evaluation took place in the Food

Preparation Lab of West Commons. The room was arranged with individual desks in the

center, directly facing the front countertop where the Professor stood. The perimeter of

the room consisted of food prep tables, sanitation sinks, food prep sinks, cabinetry,

refrigeration systems, induction stove tops and appliances. For the duration of the test,

panelists occupied the desks in very close proximity of one another. Panelists were

instructed to remain quiet and mask all facial expressions for the duration of the

experiment to prevent from influencing each other’s responses. The professor did not

sanction chattering from the students, but distractions were inevitable in the close

quarters of the Lab.

The room was well lit, and maintained at a cold temperature, with the doors

closed to block outside noise. Professor Copp, the instructor of the evaluation, proctored

the experiment from the front of the room, and observed from around the room

throughout the course of the experiment. Behind Professor Copp, the lab assistant,

Melissa, input all panelist responses into the database. Meanwhile, the Lab technician

Sharon was responsible for gathering and providing the necessary materials to the

students.

Panelists

The study was conducted in 3 separate class sections, each at a different time of

day. The entire panel consisted of 65 students, 91% undergraduates studying Foods and

Nutrition and 9% Graduate students studying Foods and Nutrition at San Diego State

7

Schultz

University. Of the 65 students, 12 were male and 53 were female. Section 1 had 22

students, section 2 had 22 students, and section 3 had 21 students.

The remaining demographics are a compilation of results from a questionnaire

provided to all 3 sections. Panelists were between the ages of 19 to 45+. The mean of

ages was 32 and the standard deviation was 7.3598. Forty percent were under age 21 and

4% were over age forty. The marital status consisted of, 91% single adults, 5% married

adults and 5% divorced adults. A total of 15% lived independently, 29% lived with one

other roommate and 55% lived with 2 or more roommates. Additionally, panelists were

asked whether or not they smoked and 1 of the 65 said yes. The final question pertained

to students with food allergies. There were 8 students total with food allergies. Of the

total, 88 % of students did not have allergies and 12% had allergies, there was 1 allergen

to soy and others including nuts, wheat, dairy, melon, bleu cheese and gluten.

Beverage Color and Association with Other Parameters

Beginning this test, the Lab Technician Sharon placed 5 glass beakers on the front

countertop, each containing a different colored beverage. They were arranged side by

side, each 5 inches from the next, in a straight line. Beakers were placed in order of

lightest to darkest from left to right. The instructor recommended that panelists move

closer if their view of samples was obstructed.

The color association and perception of beverages, is a visual test in which 5

beverages are judged comparatively on color and sorted into 6 parameters. Each panelist

had a questionnaire that included a list of 6 parameters: sweetness, sourness, artificiality,

naturalness, most preferred and most disliked. Rather than ranking each beverage for all

6 parameters, the instructor verbally revised the instructions. The Professor advised the

panel to observe the beverages and select one beverage for each parameter, the one that is

8

Schultz

best depicted by the implications of the parameter. One beverage could be used twice or

not at all. Each descriptive parameter could only have one corresponding beverage. Also

included in the questionnaire, the panelists answered whether or not they drank apple

juice. At the end of the test, panelists had to answer whether they would drink the

beverage: yes or no, and if they would drink the beverage, at what temperature?.

Evaluation of Food Products with Descriptive Terms

In the protocol for the evaluation of food products, panelists had to evaluate 4

company food products on the basis of 6 parameters: appearance, flavor, texture, aroma,

consistency and mouth feel. Two pieces of each: goldfish, raisins, almonds or

marshmallows were placed in 2 oz. cups. The panel size in this test varied due to

allergens and gluten intolerance. While the professor discussed the protocol, cups of

distilled water and samples were simultaneously distributed to each panelist. Sharon and

Melissa progressed from the left of the room, going up and down the isles to the right

side of the room, dispersing sample cups. Melissa instructed panelists to take 1 sample

cup of raisins and one cup of goldfish from her tray. After sampling began, Sharon

placed the cups of marshmallows and almonds on each of the panelists’ desks.

Panelists each had a list of the 6 predetermined parameters. Panelists observed

and tasted the samples, cleansing their palette in between samples with distilled water.

After each sample, panelists recorded the best word describing the sensation for each

parameter. Upon completion of the evaluation, Melissa recorded results into the

database.

Difference Test: Paired Comparison

Of the multiple difference tests conducted in this study, the first test was the

paired comparison test. A paired comparison test involves two coded samples, presented

9

Schultz

simultaneously. Panelists were instructed to sample two solutions and choose the sample

with the greater intensity of sourness. The students were testing a 1% citric acid

concentration in comparison to a 0% citric acid concentration. The test was put on hold

until the lab technician returned from obtaining materials. Upon Sharon’s return, the

Professor instructed the first person in each row to go to the front countertop and receive

2 oz. sample cups for each student in their row. Professor Copp instructed, a ‘scant’

amount to of each solution to be poured into each cup, enough so each person receives

one of each sample. Once all sample cups were poured, students dispersed one cup of

each solution to the panelists in their row. The panelists carried the tray of samples

labeled with the appropriate codes to each desk so students could pick their samples.

Until all panelists obtained their samples, the students were instructed to wait patiently to

begin sampling. Panelists were instructed to remain quiet, and again, panelists were

reminded to cleanse their pallet between samples. Subsequently, panelists took note of

the solution they perceived as more sour.

Difference Test: Triangle Test

The triangle test is a comparison of three samples; panelists must determine which

one of three is the odd or different sample. Again the protocol must be completed

simultaneously. The first row of students was instructed to go to the front of the room to

obtain 2oz. sample cups for the panelists in their row. The six students dispersing the

contents stood at the front of the room, and took turns pouring the containers of liquid

into the appropriate number of cups for their row. Students used their own discretion to

pour a ‘scant’ amount into each sample cup. Once all sample cups were evenly poured,

the six panelists took their trays of samples to their row of students. They proceeded

from the front to the back of their rows.

10

Schultz

The Professor reiterated that students could not talk and must cleanse their palate

in between samples with the distilled water provided. The three samples were to be tried

in a specific order, unbeknownst to the panelists, the order was: Apple juice with 0 %

citric acid, followed by Apple juice with 0 % citric acid, followed by Apple juice with 1

% citric acid. Again panelists are reminded to cleanse with water in between and then

document their results.

Difference Test: Ranking Test

A ranking test is a difference test where more than 2 samples are simultaneously

presented. Panelists taste the samples in a predetermined order, and rank them according

to intensity of a particular characteristic. Panelists give the sample that has the strongest

characteristic a number 1. The student panel had to rank the samples in order of sourness

[1] being most sour to [5], the least sour; there could not be ties. After tasting, panelists

ranked them from most preferred [1] to least preferred [5]. The first person in each row

of students went to the front of the room, to pour the sample solutions into 2 oz. cups.

They were instructed to pour a ‘scant’ amount, rather than measuring 1 oz. of each

solution as instructed. All panelists received one cup for each of the 5 sample solutions.

The sample cups were dispersed by the row leaders, from the front of the row to the back.

Sampling began when everyone was seated, and had obtained their samples. The proctor,

Professor Copp reiterated that the panel should take the samples in order, as provided in

accordance to their codes. The order unbeknownst to panelists was, 2.5% citric acid, then

0 % citric acid, then 5 % citric acid, then 1 % citric acid, and lastly 10% citric acid.

Panelists were told to taste in this order, and cleanse their palette in between. They were

permitted to re-sample, following the proper cleansing protocol. The beverages were

ranked from most sour to least sour.

11

Schultz

Difference Test: Duo Trio

The duo trio test examines three samples that are identical in appearance but

differ by brand. The panel size was 63 because 2 students were gluten intolerant.

Panelists ate a standard cookie and proceeded to taste the two remaining cookies, always

cleansing their palette in between. Then panelists had to distinguish which sample was

different from the standard and why. Sharon, the Lab Technician wheeled in a tray of

three plates of cookies. Each plate was concealed by a cloth and wrapped in a clear

plastic wrap so panelists could not easily see the samples. Sharon walked around first

with the plate of standard cookies. Professor Copp and Melissa came after to assist in

distributing the second and third types. Panelists were instructed to wait for everyone to

receive three cookies before beginning the test. To ease in distinguishing samples, it was

recommended to place the samples on their correlating sample code printed on the

handout. The professor proceeded to instruct panelists to try the standard first, followed

by sample #2 and then sample #3. The first cookie sampled was Nabisco Nilla Wafers.

The second Sample was Safeway brand vanilla wafers, and the third brand was Nabisco

Nilla Wafers as well. After sampling, panelists chose which sample was different and

whether the reason was dryness, crunchiness, or less vanilla.

Difference Test: Scoring or Rating Test

In this protocol, the panel tested 3 samples. One sample was a standard that

panelists tasted and used as a reference point for the other samples. Panelists tested all

three samples and then decided which sample was more intensely sour and which sample

was less sour than the standard. Again, the first student of each row went to the front of

the classroom to pour the samples into sample cups. Once each student had the sample

cups completely poured, they could disperse them to their row. It was not discerned

12

Schultz

whether students must take the samples in any order. One sample was 1% citric acid the

other was 5% citric acid. From a scoreboard of 1 to 7, the reference was rated a 4 on a

scale of sourness. Seven represented the least sour and number one represented the most

sour. Panelists were instructed to conduct this experiment like previous tests, cleansing

in between samples with distilled water. The panelists first tested the reference, followed

by either the 5% or 1% citric acid.

13

Schultz

Results

Beverage Color and Association with Other Parameters

Prior to this test, panelists said whether or not they drank apple juice. Of 65

panelists, 88% said yes and 12% said no. The beverage and color association test used 5

different colored beverages. The beverages and colors are as follows: light yellow—

Mountain Dairy Lemonade, dark yellow— Xtremo Citrico Vibrante Gatorade, chartreuse

— 350 mL Lemon Lime Gatorade plus 150 mL Green Squall Powerade, dark chartreuse

— Green Squall Powerade, emerald green— Watermelon Gatorade. The panel consisted

of 60 participants, of which 34% panelists perceived emerald green to be the sweetest

beverage. Followed by 25% perceiving dark yellow as the sweetest, 20% for light

yellow, 15% for dark chartreuse and 11% for chartreuse. See Figure 1.

20%

25%

10%

15%

34%

Sweetest Perceived Beverage

light yellow 20%

dark yellow 25%

chartreuse 11%

dark chartreuse 15%

emerald green 34%

Figure 1

A total of 42% of panelists said light yellow was the most sour. Twenty percent

of panelists thought dark yellow, 20% said chartreuse, 20% said dark chartreuse. The

remaining 5% said the most sour was emerald green. See Figure 2.

14

Schultz

42%

20%20%

20%5%

Most Sour Percieved Bev-erage

light yellow 42%dark yellow 20%chartreuse 20%dark chartreuse 20%emerald green 5%

Figure 2

Eighty-two percent thought the most artificial beverage was emerald green. This

was followed by, 6% for chartreuse, 5% for dark chartreuse, 3% for dark yellow and the

other 2% of panelists said light yellow was the most artificial. See Figure 3.

2%3% 6%5%

82%

Most Artificial Perceieved Beverage

light yellow 2%dark yellow 3%chartreuse 6%dark chartreuse 5%emerald green 82%

Figure 3

The ranking of naturalness resulted in 88% choosing light yellow as the most

natural. Two percent chose the following as the most natural: dark yellow, chartreuse,

and dark chartreuse. Emerald green was not ranked in naturalness. See Figure 4.

15

Schultz

88%

2%2%

2%

Most Natural Perceived Bev-erage

light yellow 88% dark yellow 2%chartreuse 2%dark chartreuse 2%emerald green 0%

Figure 4

The beverage of choice among the panelists was light yellow, 60% chose this as

the preferred choice. This was followed by 17% who chose chartreuse, and then 9%

chose dark yellow, followed by 8% dark chartreuse and 2% emerald green. See Figure 5.

60%

9%

17%

8% 2%Most Preferred Beverage

light yellow 60% dark yelloe 9%chartreuse 17%dark chartreuse 8%emerald green 2%

Figure 5

The ranking of disliked beverages was related to the preferred beverages.

Emerald green was chosen by 52% of panelists as their least preferred choice. Followed

by 26% dark yellow, 12% light yellow, 12% dark chartreuse and only 2% chartreuse.

See Figure 6.

16

Schultz

12%

26%

2%12%

52%

Least Preferred Beverage

light yellow 12%

dark yellow 26%

chartreuse 2%

dark chartreuse 12%

emerald green 52%

Figure 6

In regards to temperature, cold was the preferred temperature. Panelists who

would choose not to drink a beverage are not included in this data set. Ninety-two

percent would drink light yellow cold, 71% would drink dark yellow cold, 72% would

drink chartreuse cold, 58% would drink dark chartreuse cold and 49% would drink

emerald green cold. For light yellow, 6% would drink it hot, 2% would drink dark

yellow hot, 5% would drink chartreuse hot, 5% would drink dark chartreuse hot, 3%

would drink emerald green hot. Regarding warm temperature, 2% said yes to light

yellow, 6% said yes to dark yellow, 2% said yes to chartreuse, 2% said yes to dark

chartreuse, and 2% said yes to emerald green. At last, tepid was preferred over warm by

18% for light yellow, 5% said yes to dark yellow, 9% said yes to chartreuse, 8% said yes

to dark chartreuse, and 3% said yes to emerald green. See Figure 7.

17

Schultz

Light yellowDark yellow

ChartreuseDark chartreuse

Emerald green

0% 20% 40% 60% 80% 100%

Preferred Temperature to Drink Beverages

Tepid

Warm

Hot

Cold

% of Panelists

Bev

erag

e T

ype

Figure 7

Panelists were asked whether or not they would drink the beverage. When 65

panelists equals 100%, 95% would drink light yellow, 51% would drink dark yellow,

60% would drink chartreuse, 45% would drink dark chartreuse, 23% would drink

emerald green. See Figure 8.

Light yellow

Dark yellow

Chartreuse

Dark chartreuse

Emerald green

0% 20% 40% 60% 80% 100% 120%

Would you Drink the Beverage?Yes or No

yes

no

% of Panelists

Bve

rage

Typ

e

Figure 8

The final questionnaire of the beverage test was whether people drank apple juice,

88% said yes and 12% said no. See Figure 9.

18

Schultz

88%

12%Do you drink Apple

Juice?% panelists said yes

% panelists said no

Figure 9

Evaluation of Food Products with Descriptive terms

In the descriptive test of food products, only the descriptions with the top three

percentages will be documented below. The first food evaluated was the Goldfish, which

varied in the number of panelists participating because of allergies and gluten intolerance.

Sixty- four total panelists observed the appearance of goldfish. Percentages were

calculated and appearance was described as dry by 23%, 17% described the goldfish as

golden brown, 13% described it as symmetrical and 13% described it as puffy. Of 64

panelists, 62 panelists described flavor, 79% described it as salty, 21% said sharp and no

other descriptions were chosen. Again, 62 panelists observed the texture of goldfish.

Fifty six percent said it was crisp, 34% said crunchy and 6% said flaky. Sixty-five

panelists described the aroma, 38% described aroma as nothing, 34% said it was flavory

and 22% said burnt. A total of 62 panelists described the consistency and mouthfeel.

Consistency was described by 58% as brittle, 31% said cheezy and 10% said thin.

Mouthfeel was described by 50% to be crunchy, 42% said crisp and 5% said smooth. See

Table 1.

19

Schultz

Evaluation of Goldfish with Descriptive Terms

Appearance Dry: 23% Golden Brown: 17% Symmetrical &Puffy: 13%

Flavor Salty: 79% Sharp: 21% NA

Texture Crisp: 56% Crunchy: 34% Flaky: 6%

Aroma Nothing: 38% Flavory: 34% Burnt: 22%

Consistency Brittle: 58% Cheezy: 31% Thin: 10%

Mouthfeel Crunchy: 50% Crisp: 42% Smooth: 5%

Table 1

In total, 65 panelists participated in the testing of the raisins. Percentages were

calculated, and 25% described the appearance as dry, 22% described the appearance as

sunken, and 14% described the appearance as dark. Fifty eight percent described the

flavor as sweet, 32% said fruity, 3% said flowery and 3% also said bitter. Regarding

texture, 32% said chewy, 29% said gummy, and 15% said gelatinous. The aroma was

described by 38% as sweet, by 31% as fruity, and 15% said it had no aroma. The

consistency was described by 55% to be chewy, 29% said it was gummy and 12% said it

was rubbery. Mouthfeel was said to be sticky by 58%, smooth by 20% and 12% said

gritty. See Table 2.Param

eters

Descriptive Terms

20

Schultz

Evaluation of Raisins with Descriptive Terms

Appearance Dry: 25% Sunken: 22% Dark: 14%

Flavor Sweet: 58% Fruity: 32% Flowery/ Bitter: 3%

Texture Chewy: 32% Gummy: 29% Gelatinous: 15%

Aroma Sweet: 38% Fruity: 31% Aroma: 15%

Consistency Chewy: 55% Gummy: 29% Rubbery: 29%

Mouthfeel Sticky: 58% Smooth: 20% Gritty: 12%

Table 2

Almonds were evaluated by a total of 65 panelists. Appearance was described by

34% as light- brown, by 23% as dry and 18% as golden-brown. The flavor was described

by 92% as nutty, by 5% as flat and by 3% as stale. The texture was described by 35% as

hard, by 20% as firm and 15% said crunchy. Aroma was said by 98% to be nothing and

2% said it was flavor, these were the only terms used to describe aroma. Consistency

was described by 46% as chewy, by 45% as thick and by 5% as rubbery. Mouthfeel was

said by 58% to be crunchy, by 22% to be gritty and by 9% to be crisp. See Table 3.

Evaluation of Almonds with Descriptive Terms

Table 3

Descriptive Terms

Parameters

Descriptive Terms

21

Appearance Light Brown: 34% Dry: 23% Golden Brown 18%

Flavor Nutty: 92% Flat: 5% Stale: 3%

Texture Hard: 35% Firm: 20% Crunchy: 15%

Aroma Nothing: 98% Flavor: 2% N/A

Consistency Chewy: 46% Thick: 45% Rubbery: 5%

Mouthfeel Crunchy: 58% Gritty: 22% Crisp: 9%

Parameters

Schultz

The panel for marshmallows varied in size due to dietary restrictions. The panel

for appearance consisted of 65, 83% said it was puffy, 6% said it was dry and 5% said

smooth. Flavor and texture had a panel of 63 due to dietary restrictions. Flavor was

described by 70% as sweet, by 22% as floury and by 8% as pasty. Texture was described

by 27% as springy, by 25% as velvety and by 17% as tender. Aroma was described by

89% as sweet, by 6% as nothing and 5% as flowery. Consistency was described by 56%

as gummy, 21% chose the term chewy and 14% chose the word rubbery. Mouthfeel was

described by 56% as smooth, by 17% as both slimy and sticky, and by 8% as slick. See

Table 4.

Descriptive Evaluation of Marshmallows with Terms

Appearance Puffy: 83% Dry: 6% Smooth: 5%

Flavor Sweet: 70% Floury: 22% Pasty: 8%

Texture Springy: 27% Velvety: 25% Tender: 17%

Aroma Sweet: 89% Nothing: 6% Flowery: 5%

Consistency Gummy: 56% Chewy: 21% Rubbery: 14%

Mouthfeel Smooth: 56% Slimy: 17% Slick: 8%

Table 4

Paired Comparison Test

In the paired test, 98% said the 1% citric acid had a greater intensity of sourness

and 2% said the apple juice with no citric acid concentration had a greater intensity of

sourness. See Figure 10.

Parameters

Descriptive Terms

22

Schultz

98%

2%

Sample with the Greater In-tensity of Sourness

1% Citric Acid

Apple Juice, 0% citric acid

Figure 10

Triangle Test

In the triangle test, 97% said the 1% citric acid was the odd sample, 0% said the

second sample of 0% citric acid apple juice was different and 3% thought the third

sample of 0% citric acid apple juice was the odd sample. See Figure 11.

1% Citric Acid 0% Citric Acid Apple Juice sample 1

0% citric Acid Apple Juice

sample 2

0%20%40%60%80%

100%120%

Identifying the Odd Sample

Series1

Sample Type

% o

f Pan

elis

ts

Figure 11

Duo trio Test

For the duo trio test, 94% thought the Safeway brand of vanilla wafers was

different from the standard Nabisco vanilla wafer. There was 6% who said the Nabisco

wafers were different from the standard [See Figure 12]. Forty-eight percent attributed

the difference to crunchiness, 35% said it had less vanilla, and 17% said it was dryness.

See Figure 13.

23

Schultz

Standard: Nabisco Vanilla Wafers

Safeways Brand Vanilla Wafers

Nabisco Vanilla Wafers

0% 20% 40% 60% 80% 100%

Identifying which Cookie is the Odd Sample

Series1

% of panelists

Sam

ple

Typ

es

Figure 12

Dryness

Crunchiness

Less Vanilla

0% 10% 20% 30% 40% 50% 60%

Identifying the Difference between the Odd sample and Standard Cookie

Series1

% of panelists

Wh

y th

e sa

mp

le d

iffe

res

from

th

e st

and

ard

Figure 13

Rating test

For the rating test, the panel consisted of 64 participants who rated 2 samples

from 1-7, in relation to the standard that received a number 4. The number 1 represented

the more sour liquid and a number 7 represented the less sour liquid. In total, 46% gave

the 5% citric acid a rating of 1, 43% gave the 5% citric acid a 2, and 6% gave the 5%

citric acid a 3. Also, 2% gave the 1% citric acid a 4, 11% gave the 2% citric acid a 5,

69% gave the 1% citric acid a 6 and 14% gave the 1% citric acid a 7. See Figure 14.

24

Schultz

1 2 3 4 5 6 70%

10%

20%

30%

40%

50%

60%

70%

80%

Rating Sour Intensity of 2 Samples%

of P

anel

ists

Figure 14

The Ranking Test

The panel of 65 students ranked 5 citric acid concentrates in order of most sour

[1] to least sour [5]. Ninety- eight percent said the 10% concentrate was most sour, 0%

gave it a 2, 0% gave it a 3, 0% gave it a 4, 0% gave it a 5. The 2.5 % citric acid

concentrate was not ranked a 1, 9% gave it a 2, 86% gave it a 3, 6% gave it a 4, and 0%

gave it a 5. The 1% citric acid concentration was not ranked a number 1, 2% gave it a 2,

5% gave it a 3, 89% gave it a 4, 5% gave it a 5. The 0% citric acid concentration was not

ranked a 1, a 2 , or a 3, but it 5% gave it a 4, and 95% gave it a 5. Lastly the 5% citric

acid concentration was ranked number 1 by 2%, number 2 by 89%, a 3 by 9%, and was

not given a number 4 nor was it given a 5. See Figure 15.

25

Schultz

1 2 3 4 50%

10%20%30%40%50%60%70%80%90%

100%

Ranking 5 Citric Acid Concentrations on Inten-sity of Sourness: Most Sour(1) to Least Sour(5)

10% Citric Acid

2.5% Citric Acid

1% Citric Acid

0% Citric Acid

5% Citric Acid

Ranking of Sour Intensity from 1-5

% o

f Pan

elis

ts

Figure 15

These five solutions were also ranked in order of most preferred [5] to least

preferred [1]. The 10% citric acid concentration was only ranked a 4 and 5, 3% gave it 4

and 97% gave it 5. The 2.5% citric acid concentrate was ranked 1 by 14%, number 2 by

12%, number 3 by 72%, number 4 by 5%, and 5 by 0%. The 1% citric acid concentrate

was ranked by 31% as a 1, by 46% as a 2, by 12% as a 2, by 8% as a 4, and by 2% as a 5.

The 0% concentration was ranked 1 by 54%, 2 by 28%, 3 by 11%, 4 by 5%, and given a

5 by 3%. Lastly, the 5% citric acid concentrate was ranked a 1 by 2%, a 2 by 12%, a 3 by

5%, a 4 by 82% and not ranked a number 5. See Figure 16.

26

Schultz

1 2 3 4 50%

10%20%30%40%50%60%70%80%90%

100%

Ranking of Citric Acid Concentration from Most Preferred(1) to Least Preferred(5)

10% Citric Acid

2.5% Citric Acid

1% Citric Acid

0% Citric Acid

5% Citric Acid

Ranking of Preference

% o

f Pan

elis

ts

Figure 16

27

Schultz

Discussion

Beverage Color and Association with Other Parameters

The beverage test asked panelists to observe 5 colored beverages and evaluate

their degree of sweetness, sourness, artificiality, naturalness, most preferred and most

disliked based solely on appearance. The light yellow beverage was ranked most natural

and also most desirable, whereas the emerald green was ranked as most artificial and also

the least desirable. The correlation between naturalness and preference for the light

color, and artificiality and dislike of the darkest color indicate the interrelationship

between perceived color, flavor and preference. A previous study by Zampini looked at

the way color influenced peoples’ perception of the flavor of solutions. According to this

study, colored solutions are strongly associated with flavor. For instance he found that

orange was usually associated with orange, green associated with lime, yellow frequently

associated with lemon and blue associated with spearmint (Zampini 2007). With an

understanding of these findings, the results of such a test may be skewed due to a

panelists’ bias towards color or flavor. Panelists’ in Zampini’s study knew that color was

not a clue for flavor, but the results show that colors were misleading (Zampini 2007).

For instance, the flavors lime and lemon both evoke a sour taste, and usually are

associated with the colors yellow and green. This observation that yellow and green are

commonly perceived as sour can elicit flawed data in our test. Figures 1 and 2 provide

evidence for this claim because both yellow solutions and the chartreuse (light green)

were rated highest in sourness, whereas the emerald green was decidedly the sweetest

beverage.

28

Schultz

Evaluation of Food Products with Descriptive Terms

Panelists evaluated goldfish, raisins, almonds and marshmallows according to

appearance, flavor, texture, aroma, consistency and mouthfeel. The size of the panel in

this evaluation varied because of gluten intolerance and allergies. Each food item had a

list of parameters and unique descriptive terms associated with them. The data revealed

that flavor was among other parameters with a high percentage, indicating that panelists

perceived flavor the same. A study on Genetics of Food Preferences (2012) discussed

how food preferences determine what people choose to eat, and the role of genetics in

establishing those preferences. According to recent research, food preferences stem from

the interaction of genetics and the environment (Pirastu 2012). In Pirastu’s study, mice

were used to prove that an aversion of food was due to a lack of genes and receptors

responsible for that taste preference (Pirastu 2012). This justifies why some panelists’

had different perception of flavor. Research presented by Pirastu and others found, if

these genes were not present, the mice could develop an acceptance of the taste through

exposure to the food. In our test, the samples were universal foods, so most likely the

panelists had tasted such foods prior to the study. This factor contributed to their

familiarity with the food, and the commonality in word choice.

Taste perception involves multiple variables, so it is very unique to the individual.

The terms are open to interpretation and the panelists’ observation may be more

empirical rather than an entirely logical standpoint. Looking back at Figures 10-13,

results for texture were also very close in number. A previous study, by Foster and others

(2011) examined the process of chewing and what occurs at each step. His finding was,

early on in mastication the hard/crackle factor of food was dominant, this was perceived

as crisp, and was followed by brittle and stickiness at the end of chewing. The words

29

Schultz

crisp, brittle, and sticky all fall under the parameter of texture in our descriptive test.

Based on the results of Fosters study, choice of descriptive words is subjective to when

(during chewing) the panelist observed texture (Foster 2011). Other studies examining

the perception of taste and texture look at saliva. Attributes of the mouth are unique to

the individual, and when saliva combines with food, it has a diluting effect, breaks down

the food, the flavors, or lubrication, which are detected by the oral receptors in the mouth

(Engelen 2008). These factors contribute to detecting texture, and explain that people

have different texture perception because of empirical observation of food rather than one

of logic.

Difference Tests

In the ranking test, panelists were provided 5 semi-apple juice solutions with

various percentages of citric acid added. They ranked each on the intensity of sourness

and then the degree of preference. Data of the ranking test was not comprehensive

because the ranking numbers were scattered across the board in relation to preference.

Some panelists preferred the sour solutions to the sweeter solutions as indicated in Fig.

16. Recent research suggests that sucrose sweetness can mask sourness and sucrose is

resistant to being overpowered by other tastes (Gren 2010). According to this study,

some people may be less sensitive to the sourness due to the sucrose, but some panelists

may still prefer the sensation that sour taste elicits. These results are also attributable to

the paired comparison test that tested for sourness.

The paired comparison test found that nearly every participant could taste which

solution contained citric acid. A study completed by Stevenson and others, found that

odor affects the taste of something, beverage or food. The study suggested that

perception relies on both the sense of smell and taste sensations. Therefore, the smell of

30

Schultz

a sample has an influence on the perceived sweetness, creating a preconception of what it

would taste like (Stevenson 1999). This could explain why in the paired comparison test,

most everyone said the solution with high Citric acid content had a more sour taste.

Based on the study from Stevensen and others, the sweetness detected by the olfactory

receptors produce the same sensation as taste of sweetness.

The percentage of panelists who thought the apple juice was the sour beverage is

caused by human error. The apple juice concentration was supposed to be taken first,

followed by the 1% citric acid concentration. Error could easily produce faulty results if

the panelist forgot to cleanse their palette with water and the remnants of the apple juice

taste made the sour beverage taste sweeter (Gren 2010).

The rating test also looked at two solutions with citric acid and compared them to

a standard sample. Panelists were asked to rate two solutions from 1 (more sour) to 7

(less sour) in relation to the standard solution given a number 4. Various numbers were

chosen to rate the two solutions. One possible explanation for this is how saliva plays a

significant role in perception of sourness. According to Foster, saliva mediates the

puckering feeling also referred to as the astringency of a food that occurs when

something sour is sensed (Foster 2011).

Duo Trio

In this sensory evaluation of cookies, two students could not participate due to

gluten intolerance, creating a sample size of 63. This study presented a standard cookie

and asked panelists to taste two other samples and determine the cookie that was different

from the standard. There are possible limitations to understanding and relying on results

from this evaluation because the panel consisted of untrained sensory analysts. There is

dispute over whether or not training panelists’ affects results of a study. In the duo-trio

31

Schultz

test, comparing the standard Nabisco Nilla Wafers to Safeway brand, 6% thought the

sample Nabisco Nilla Wafer differed from the standard Nabisco Nilla Wafer. Previous

research looked at whether training was valuable to obtain reliable results from panelists.

According to Labbe and others, training is a way to familiarize panelists with products so

they are better able to detect differences. In the current sensory evaluation, not all

panelists detected the difference between Safeway brand and Nabisco brand. The same

study discovered that before training, no one was able to detect more than six out of 17

attributes, and after, they could detect at least 8 (Labbe 2004). Because the panelists in

Labbe’s study had never done a study before, and training improved the accuracy of

results, it is probable that training would improve the SDSU Sensory Lab results as well.

Possible Errors and Limitations

Possible errors or faults in the conduction of the study may have created faults in

the data. For the duration of this study, there was intermittent chatting amongst some

panelists and the instructors. The study did not take place in the appropriate setting

where panelists would have been segregated. The discussions on the side may have

distracted the panelists and affected the results. In addition, there was confusion in some

of the tests. In the descriptive test of food samples, the instructors disagreed over

whether or not marshmallows were vegan or vegetarian. Momentarily the test was put on

hold and resumed when they were finished.

Another possible human error could be due to a panelist not cleansing their palette

between samples. Distilled water was provided prior to all tests because it is crucial to

try each sample on a clean slate. Failure to do so could impede on accurate perception of

samples. In relation to beverage, the consumption of coffee prior to the study could have

left a coffee residue in the panelists’ mouth. This would have impaired the panelists’

32

Schultz

acute sense of taste. A last complication in the study could be due to the disorganization

throughout the course of the evaluation. Instructors were not always blunt on when to

officially begin each study, panelists started at various times and those who finished early

could have urged the others to rush through their tests, producing faulty results.

33

Schultz

References

Brown A. 2011. Sensory Evaluation. In: Walteer J, Beathard K, editors. Understanding Food Principles and Preparation. 4th edition. Wadsworth: Cengage Learning.

Engelen L, DerBilt A. 2008. Oral Physiology and Texture Perception of Semisolids. Journal of Texture Studies 39.1: 83-113.

Foster K, Grigor J, Cheong J, Yoo M, Bronlund J, Morgenstern M. 2011. The Role of Oral Processing in Dynamic Sensory Perception. Journal of Food Science 76.2: R49-R61.

Gren B, Lim J, Osterhoff F, Blancher K, Nachtigal D. 2010. Taste Mixture Interactions: Suppression, Additivity, and the Predominance of Sweetness. Physiology and Behavior 101.5 731-737.

Labbe D, Rytze A, Hugi A. 2004. Training is a critical step to obtain reliable product profiles in a real food industry context.Food Quality and Preference 15.4: 341-348.

Pirastu N, Robino A, Lanzara C, Athanasakis E, Esposito A, Tepper B Gasparini P. 2012. Genetics of Food Preferences: A First View from Silk Road Populations. Journal of Food Sci 77.12: S413-S418.

Stevenson RJ, Prescott J, Boakes R. 1999. Confusing Tastes and Smells: How Odours can Influence the Perception of Sweet and Sour Tastes. Chemical Sciences 24: 627-635.

Zampini M, Sanabria D, Philips N, Spencer C. 2007. The Multisensory perception of flavor: Assessing the influence of color cues on flavor discrimination responses. Food Quality and Preference 18.7: 975-984

Lee H, Kim K. 2007. Difference test sensitivity: Comparison of three versions of the duo–trio method requiring different memory schemes and taste sequences. Food Quality and Preference 19.1: 97-102.

34