TAKING IN THE WORLD AROUND US A LOOK INTO THE FIVE SENSES

Jennifer NewkirkNutr. 205 Section 4Linda Copp & Shiloah Fuller11/1/2013

ABSTRACT

The acceptability of food is determined by the five senses: sight, odor, taste, touch and hearing. These five senses help individuals decide which foods they like and are used by the food industry in food development and sales. Sensory evaluation uses analytical and affective tests to figure out consumer preferences and to evaluate food and products. In the San Diego State nutrition 205 food lab, eighty-nine students performed a variety of sensory tests including beverage color association test, descriptive test, paired comparison test, triangle test, ranking test, duo-trio and scoring test. Each test involved the use of one or more of the five senses and explored the ways in which they influence food perception. The beverage color association tests showed that even eye sight alone has a clear influence on beverage selection and flavor perception. The descriptive tests resulted in more varied results that show individuals five senses are not exactly the same and that people interpret the world around them differently. Preference, perception of flavor intensity, and acceptability were categories also tested. The following report aims to explore a variety of sensory tests and to explain the importance they have in the food industry.

INTRODUCTION

People understand and perceive the world around them through the five senses: sight, odor, taste, touch and hearing. Consciously or not, these sensory criteria play a critical role in every day food choices and the eyes are the first sense to begin the process. Sight allows us to differentiate colors, shapes, and deformities in which these visual cues can help further indicate a foods ripeness, texture, and concentration. Smell is grouped into five odors; spicy, flowery, fruity, resinous, burnt, and foul. Foods contain volatile molecules that are detected by the olfactory epithelium inside the nasal cavity then perceived and differentiated by the brain. Taste is typically considered the most important deciding factor in one’s selection of food. Most people will chose not to eat something if it simply doesn’t taste good. Taste buds on the tongue, in the mouth palates and pharynx contain taste receptor cells that send messages to the brain which translates electrical impulses into what humans know at “taste”. Tastes are described as sweet, sour, bitter, salty, and savory or umami, all of which play an important role in our food decisions. Touching foods with hands, in the mouth, or a combination of both can aid in the determination of texture, consistency, actual temperature, and chemethesis. Lastly, hearing too plays a role in assessing a foods quality. Sounds can help identify characteristics giving clues to a foods freshness or degree to which it has been cooked. There are a variety of other factors that affect food selection including culture, advertisement, and religious values, but the five senses make the ultimate decision whether or not a person will choose to eat something (Brown 2011).

Sensory evaluation analyzes panelists reactions to foods based on the five senses mentioned above and can be useful in medical research, sales and marketing, and food safety. The importance of sensory evaluation is seen in an article published in Critical Reviews in Food Science and Nutrition in which these tests are being used to help battle iron deficiency, the leading nutritional deficiency in the United States. Bovell-Benjamin and Guinard (2003) state, “The information gained from systematic sensory evaluation allows for the manipulation of the sensory attributes, and thus improvement of the sensory properties of the fortified food.” These simple tests are helping solve prevalent world issues. There are two different types of subjective food evaluation tests: analytical tests and affective tests. Analytical tests are used to detect differences whereas affective tests are used to detect one’s individual preferences. These tests help ask questions like “Which do you prefer?” and “In what way do the samples differ?” Objective tests are also used in sensory testing and help determine chemical and physical properties that aid in measuring food quality, but instead by method of measurements and instruments in place of humans (Brown 2011).

When one first sets eyes on a food, judgment on appearance is immediate. Color perception is just one aspect of appearance, but plays a significant influence in how a person may identify a food or product. In a test done by Stillman (1993) artificially flavored raspberry and orange beverages were left uncolored or colored red, orange, or green. Stillman found that color had a significant influence on the identification of both flavors. Participants were more likely to answer correctly if the beverage was red and least likely to answer correctly when the beverage was colored green. In a similar study by Philipsen and others (2006), subjects divided into two different age groups were given a cherry-flavored beverage that changed color from red through orange to yellow. As color changed away from red, the number of correct responses identifying the flavor as cherry decreased. In both studies, color affected the role in identifying the correct flavor of beverages. Receiving visuals signals from food and beverages contribute to how a person will react and respond to taste.

Texture is a palpable response either in the mouth or with the hands to a physical characteristic of a food. Each individual interprets the tactile sensations of touch, pressure, and movement differently, but ultimately understands these three sensations as texture. The differences in food textures are due to structural makeup and the forces applied by the teeth, tongue, roof of mouth, and utensils (Brown 2011). The food industry pays great attention to the texture of food and knows it is a driving force behind whether or not a product will sell. The food industry is constantly altering textures to maintain consumer acceptance. In order to optimize acceptance of products, descriptive texture tests are commonly conducted. The textural property of any food product is of utmost importance and this is especially true for cheeses. Consumers purchase and identify with a product by texture characteristics before the food is even tasted. People go to the store and expect that the type of food or cheese they are purchasing is consistent in texture from one to the next. The cheese making process is extremely complicated and classifies some cheeses solely based on their texture. Here texture has significant implications within the cheese industry. In a texture analysis experiment by Lakhani’ and others (1991), various properties of Cheddar cheese were tested, one including texture. Cheddar cheese made from ultrafiltered milk was compared to a control and commercial Cheddar cheese by sensory testing and instrumental measures. Panelists used descriptive words to express the texture in relation to mouth feel. Based upon the test results, Lakhani’ found very different results between the three. The cheese made from ultrafiltered milk was less preferred in texture in comparison to the control and commercial Cheddar cheese. The texture of a food is directly connected to consumer acceptability.

Not only can texture be a deciding factor when it comes to food, but if it doesn’t taste good, why eat it? In a study by Yeu. K and others (2008), the consumer acceptance of an extruded based soy breakfast cereal with high protein was tested. Consumer acceptance was tested for taste, aroma, and texture with the influence of adding milk and cinnamon. This high protein soy based cereal was also compared to that of its supermarket competitors. This study found that aroma and taste acceptance ratings increased with the addition of cinnamon. Similar to the studies done in this lab, taste can be seen as a deciding factor in food choice.

There are many different desirable and undesirable attributes to certain foods. While these attributes may vary from one individual to the next, many people prefer certain appearances over other. The appearance of a fruit or vegetable on the outside lures and most often determines if a consumer buys it from the grocer or not. Humans are hardwired to be drawn to attractive things. In a consumer acceptance study by Kuttappan and others in 2012, consumers were asked to rate the degree of acceptance of three breast fillets of poultry each with varying degrees of white striations in the muscle fibers. Seventy-five consumers participated in this study and responded to an increase in striations with an increase in degree of dislike. This study proved that the appearance of a product does indeed affect the consumer’s acceptance.

An abundance of factors affect the way in which humans perceive food through the five senses. At San Diego State University in the Nutrition 205 Food Principles and Preparation course, students used seven different subjective tests, both descriptive and difference tests, in order to gather sensory information about how panelists respond to different foods. The major goals of the study were to learn proper administration of sensory tests, evaluate the effect of color on judgment of beverages, evaluate appearance, flavor, texture, aroma and consistency of specific foods, identify differences in samples, identify differences in samples compared to a standard, and to rank a series in order of intensity and preference. A descriptive test, texture profile, paired comparison, triangle, ranking, duo-trio, and scoring test were used in order to do so.

METHODS

Panelists

A total of 89 panelists (10 male and 79 female, 19-35 y old) participated in the sensory evaluation tests (N=89). Panelists consisted of San Diego State University students enrolled in the Nutrition 205 course. Prior to testing, each student was given a “Demographic Questionnaire” (Appendix A) in which they were asked to answer a series of questions. The questions asked the panelists about age, gender, major in school, student status, marital status, living arrangements, smoking habits, and if they had any food allergies. Each panelist answered the questions by circling and filling in their appropriate information. The data was then recorded in a computer software program spreadsheet where panelist answers were compiled by the lab technician. Some panelists did not participate in tests due to food allergies and religious purposes and were taken into account during data collection.

The majority of panelists were female (89%) with only a few male (11%). Majority of the panelist were single (93%) with the remaining married (6%) and divorced (1%). 100% of the panelists were Foods and Nutrition majors at San Diego State University with 73% undergraduate and 27% graduate students. Over half of the panelists lived with two or more roommates (61%) and the remainder with one roommate (27%) or alone (12%). 10% of the panelist had some type of food allergy and only 1% were smokers. Samples of allergies included shellfish, salmon, cinnamon, eggs, vanilla, mayonnaise, dairy, vanilla, gluten, or soy.

Environment

The sensory evaluation tests were conducted indoors within a school laboratory classroom. Panelists were all seated in parallel rows facing the doors and front of the room. Panelists were seated in small wooden school desks three feet apart from one another. The room was brightly lit with white light evenly distributed. All areas were well illuminated. The space was clean with waste disposal bins provided at the front of the room. The testing room temperature was comfortable with humidity moderate and free from background odors. The room was equipped with proper ventilation and good air quality. The area was free from decorations and most walls were white and bare as not to cause any distractions for the panelists or alter the test results. Room doors were kept shut to avoid outside disruptions and were insulated from surrounding classroom noise. Bathrooms were located outside and downstairs from the testing location.

Color Association/Perception of Beverages

The first test conducted was the “Beverage Color Association Test” in which participants were asked to rank the beverages with sourness, sweetness, naturalness, artificiality, and preference and dislike. While panelists were seated, the laboratory technician carefully placed five clear glass beakers in the front of the room labeled individually by color in order of the following: light yellow (Mountain Diary Lemonade), dark yellow (Xtremo Citrico Vibrante Gatorade), chartreuse (350ml Lemon Lime Gatorade plus 150ml Green Squall Powerade), dark chartreuse (Green Squall Powerade), and emerald green (Watermelon Gatorade). Based on the appearance and mainly color, panelists were asked to rank the beverages on a scale of 1 to 5, one being the least and five being the most. Panelists were also asked at what temperature they would drink the beverage and required to respond with the following responses; hot, warm, tepid or cold. Lastly, panelists were asked if they would drink the beverage and asked to only reply either “yes “or “no”. Panelists were given a sensory testing beverage questionnaire in which they recorded their data (Appendix C). All data was collected by the lab technician and recorded in a data sheet.

Descriptive Test

Texture Profile

In this test, the textures of four different foods (goldfish, raisins, almonds, and marshmallows) were evaluated using descriptive terms. Panelists were given small white cups filled with samples of each, asked to taste, and choose from a list of terms the best description of appearance, flavor, texture, aroma, consistency, and mouthfeel. Panelists were given a list of descriptive words prior to the test to choose descriptive words from (Appendix D). At the end of testing, panelists raised their hands for each descriptive word they chose for a particular product and data was recorded by the lab technician accordingly.

Difference Tests

Paired Comparison TestThe paired comparison test was conducted to determine beverage sample “sourness”. The lab technician placed two beakers in the front of the classroom labeled individually with sample codes to distinguish the two. One panelist from each row walked to the front of the room and collected enough samples of each to distribute to their seating row. Samples were poured into small paper cups and placed on each panelist’s desk. Panelists were then asked to taste the beverages and discern the most sour and least sour of the two samples. After tasting concluded, panelist were asked to raise their hands according to which sample they perceived to be more sour out of the two; number of hands raised were recorded by the lab technician accordingly.

Triangle Test

The triangle test was conducted to distinguish which of the beverages differed from the other two. The lab technician place three jars in the front of the room each labeled individually with corresponding numbers to distinguish the samples from each other. Panelists from the front of each row were asked to collect one of each sample for each person in their row. The beverage samples were poured into small white paper cups and placed on each desk distinguishing the different codes with the samples being careful not to mix them up. Panelists were asked to taste each sample in no particular order and decide which sample was different from the other two. The lab technician asked panelists to raise their hands to indicate which of the three samples they believed differed from the others and the numbers were recorded in the data sheet.

Ranking Test

In this test, panelists were presented with five different beverage samples and asked to rank each beverage on their sour intensity in relation to their preference. The first panelist from each row again went to the front of the room and gathered small white cups each filled with a corresponding coded beverage and distributed them to their row. Panelists were told to drink the coded samples, making sure to cleanse the pallet with water in between, and rate the sour intensity in order of their personal preference. The samples contained the following different percentages of citric acid: 0%, 1%, 2.5%, 5%, and 10%. Panelists recorded their data on a piece of paper and then reported their preferences to the lab proctor who recorded the data by hands raised in a spreadsheet.

Duo-Trio Test

The duo-trio test asked panelists to determine which cookie sample differed from the standard presented first. Cookies were identified by number codes. The lab technician presented each panelist with a standard cookie in which they were asked to consume first. After everyone finished tasting the sample cookie, panelists were presented the second two samples to taste. Panelists were asked to tell which sample differed from the standard and also in their opinion what was the major difference. Panelists recorded and filled in their answers on a sensory evaluation sheet (Appendix B) provided at the beginning of the test and hands were raised in correlation to responses. Data was recorded by the lab technician into a data sheet.

Scoring Test

The scoring test was conducted to rate the sour intensity of beverages in relation to a reference sample. The lab technician brought in three different glass beakers labeled with different codes. The first from each row collected small white cups of three different beverages. The first was labeled reference sample 0110 which contained 2.5% citric acid and had been given an arbitrary score of 4. They were asked to cleanse their pallet and then taste the next two samples (cleansing in between) and rate their sour intensity relative to the reference. Scores were rated on a scale from 1-7, 1 being more sour and 7 being less sour than the reference. The sample 420M contained 1% citric acid, while the sample S723 contained 5% citric acid. Panelists recorded the sour intensity on a sensory evaluation paper where the data was collected by raise of hands and entered into a data sheet (Appendix B).

Statistical Analysis

For each individual test, totals were gathered by number of hands raised and added into a data spreadsheet in excel by the laboratory proctor. All data was compiled and totals were added up and changed into percentages in order for the information to be analyzed.

RESULTS

Color Association/Perception of Beverages

On average, most of the 89 panelists (n=89) responded similarly in their perception of beverage sweetness, sourness, naturalness, artificiality, and preference in relation to the beverage colors. Panelists were first asked whether or not they drank apple juice and asked to answer yes, or no. 68% replied yes, and 32% said they did not drink apple juice (See Figure 1). For sweetness, the top three were emerald receiving the most votes (44%), then light yellow (26%), and dark yellow (19%) (See Figure 2). For sourness, light yellow received the most votes (45%), dark yellow (18%), and chartreuse (15%) (See Figure 3).

*Section 2 data not included in the above graph

For most artificial panelists perceived the emerald colored beverage to be most artificial (80%) with the rest of the beverages receiving less than 10% votes. For naturalness, 96% thought light yellow was the most natural (See Figure 4). Majority of panelists preferred the light yellow beverage (69%) followed by chartreuse (13%), and dark chartreuse (8%). Over half of panelists preferred emerald the least (60%) followed by dark yellow (27%), and dark chartreuse (6%) (See Figure 5).

In response to temperature and consumption almost all panelists said they would consume all beverages at a cold temperature with all colors receiving above 94%. Most panelists did not want to consume any of the beverages at a warm, tepid or hot temperature all receiving less than 6% willingness (See Table 1).

Table 1: Willingness to Consume at Cold, Warm, Tepid, and Hot Temperatures Answered With Yes or No Rated by Nutrition 205 Students

Light Yellow

Dark Yellow

Chartreuse

Dark Chartreuse

Emerald

Cold

94%

94%

94%

96%

94%

Warm

0%

2%

2%

1%

0%

Tepid

4%

4%

3%

3%

6%

Hot

2%

0%

1%

1%

3%

Texture Profile

In the texture lab descriptions varied. Goldfish appearance was described as golden brown (38%), dry (27%), and tied between symmetrical, rough, and grainy (7%). Flavor was recorded the most as salty (78%), stale (7%), and sharp (6%). Texture the most for crunchy (51%), crisp (37%) and flaky and gritty (3%). Aroma the most for burnt (29%), then nothing 54%) followed by spicy (9%). Consistency received the most for brittle (48%), then cheesy (24%), followed by thin (13%). Mouthfeel received the most for crisp (45%), crunchy (37%), followed by gritty (11%) (See Table 2).

TABLE 2: Top 3 Descriptive Words of Appearance, Flavor, Texture, Aroma, Consistency, and Mouthfeel for Goldfish Rated by Nutrition 205 Students.

Appearance

Flavor

Texture

Aroma

Consistency

Mouthfeel

Golden Brown – 38%

Salty – 78%

Crunchy – 51%

Burnt – 29%

Brittle – 48%

Crisp – 45%

Dry – 27%

Stale – 7%

Crisp – 37%

Nothing – 54%

Cheesy – 24%

Crunchy – 37%

Rough/Grainy/

Symmetrical – 7%

Sharp – 6%

Flaky/Gritty – 3%

Spicy – 9%

Thin – 13%

Gritty – 11%

Other –20%

Other – 6%

Other – 9%

Other – 7%

Other – 11%

Other – 2%

*Some participants did not participate in this test due to personal reasons.

For the raisin, appearance was described as sunken (24%), glossy (18%), and dark (17%). Flavor was described as sweet (52%), fruity (53%), and flowery (7%). Texture the most for chewy (43%), gummy (24%), and rubbery (13%). Aroma received the most for fruity (43%), sweet (39%), and flowery and nothing (8%). Consistency was described as chewy (47%), gummy (25%), and rubbery (22%). Mouthfeel described as sticky (62%), slimy (12%), followed by smooth (11%) (See Table 3).

TABLE 3: Top 3 Descriptive Words of Appearance, Flavor, Texture, Aroma, Consistency, and Mouthfeel for Raisins Rated by Nutr. 205 Students

Appearance

Flavor

Texture

Aroma

Consistency

Mouthfeel

Sunken – 24 %

Sweet – 52%

Chewy – 43%

Fruity – 43%

Chewy – 47%

Sticky – 62%

Glossy – 18%

Fruity – 35%

Gummy – 24%

Sweet – 39%

Gummy – 25%

Slimy – 12%

Dark – 17%

Flowery – 7%

Rubbery – 13%

Flowery/Nothing – 8%

Rubbery – 22%

Smooth – 11%

Other – 41%

Other – 7%

Other – 20%

Other – 2%

Other – 6%

Other – 15%

*Some participants did not participate in this test due to personal reasons.

Almond appearance was described most as dry and golden brown (27%), light brown (26%), and dull (4%). Almond flavor described as nutty (81%), flat (12%), and stale 3(%). Texture was described as hard (26%), crunchy (25%), and firm (22%). Aroma received the most votes for nothing (91%), burnt (6%), and flowery (2%). The almond consistency was described as thick (56%), chewy (35%), and thing and rubbery (3%). Mouthfeel was described most as crunchy (62%), followed by gritty (21%), and crisp (8%) (See Table 4).

TABLE 4: Top 3 Descriptive Words of Appearance, Flavor, Texture, Aroma, Consistency, and Mouthfeel for Almonds Rated by Nutrition 205 Students.

Appearance

Flavor

Texture

Aroma

Consistency

Mouthfeel

Dry/Golden Brown – 27%

Nutty – 81%

Hard – 26%

Nothing – 91%

Thick – 56%

Crunchy – 62%

Lt. Brown – 26%

Flat – 12%

Crunchy – 25%

Burnt – 6%

Chewy – 35%

Gritty – 21%

Dull – 4%

Stale – 3%

Firm – 22%

Flowery – 2%

Thin/Rubbery – 3%

Crisp – 8%

Other – 13%

Other – 3%

Other – 27%

Other – 1%

Other – 2%

Other – 9%

*Some participants did not participate in this test due to personal reasons.

The last food item to be described was the marshmallows. Appearance was described as puffy (83%), rounded (7%), followed by a tie between dull and smooth (2%). Flavor was described the most as sweet (69%), followed by floury (15%), and pasty (12%). Texture was described most with a tie between springy and gummy (22%), followed by velvety (17%), and chewy (9%). The aroma of the marshmallows received the most votes for sweet (87%), then nothing (7%), followed by flowery (3%). Marshmallow consistency was described most as smooth (44%), then sticky (29%), and slimy (19%). For mouthfeel, panelists described it as smooth (44%), sticky (29%), and slimy (19%) (See Table 5).

TABLE 5: Top 3 Descriptive Words of Appearance, Flavor, Texture, Aroma, Consistency, and Mouthfeel for Marshmallows Rated by Nutrition 205 Students.

Appearance

Flavor

Texture

Aroma

Consistency

Mouthfeel

Puffy – 83%

Sweet – 69%

Springy/Gummy – 22%

Sweet – 87%

Gummy – 33%

Smooth – 44%

Rounded – 7%

Floury – 15%

Velvety – 17%

Nothing – 7%

Chewy – 27%

Sticky – 29%

Dull/Smooth – 2%

Pasty – 12%

Chewy – 9%

Flowery – 3%

Butter – 9%

Slimy – 19%

Other – 2%

Other – 0%

Other – 26%

Other – 0%

Other – 20%

Other – 3%

*Some participants did not participate in this test due to personal reasons.

Paired Comparison Test

In the paired comparison tests, 99% of the panelists were able to determine that sample 573T2 with 1% citric acid was more sour than sample 635T1 with 0% citric acid (See Figure 6).

Triangle Test

In the triangle test, almost all the panelists were able to accurately determine which sample differed from the other two. Ninety-eight (98%) of panelist determined that sample 112H9 with 1% citric acid was different from samples 777C1 and 542E2 both with 0% citric acid (See Figure 6).

Ranking Test

For the first portion of the ranking test, 97% of the panelists thought that the beverage with 10% citric acid was the most sour and the beverages containing 5% 1% and 0% citric acid each received 1% of votes for most sour (See Table 6). The preference of the beverages varied more (See Table 6). 57% of the panelists preferred the 0% citric acid beverage and 27% preferred the 1% citric acid beverage. Most panelists (94%) least preferred the 10% citric acid beverage the most (See Table 7).

Table 6: Ranking Test of Five Samples of Apple Juice Containing Different Amounts of Citric Acid from Most Sour (1) to Least Sour (5) by Nutrition 205 Students.

1

2

3

4

5

695F8 – 2.5%

0%

8%

88%

2%

2%

495P2 – 0%

1%

2%

2%

8%

87%

192L3 – 5%

1%

89%

7%

2%

1%

543K8 – 1%

1%

2%

2%

87%

8%

555D7 – 10%

97%

1%

1%

1%

0%

Table 7: Ranking Test of Five Samples of Apple Juice Containing Different Amounts of Citric Acid from Most Preferred (1) to Least Preferred (5) by Nutrition 205 Students.

1

2

3

4

5

695F8 – 2.5%

7%

9%

75%

7%

2%

495P2 – 0%

57%

21%

9%

8%

3%

192L3 – 5%

4%

6%

9%

79%

2%

543K8 – 1%

27%

63%

6%

6%

0%

555D7 – 10%

1%

2%

1%

1%

94%

Duo-Trio Test

The majority of panelists (96%) stated that the First Street (Smart and Final) Vanilla Wafer differed from the standard Nabisco Nilla Wafer. Only the remaining 4% of panelists were unable to distinguish the correct differing cookie (See Figure 7). Panelists were given three options for how the cookies differed from the standard. Fifty-seven (57%) believed the cookie contained less vanilla, 27% believed it differed in crunchiness, and 15% believed it was drier than the standard (See Figure 8).

*Sample 8175 (Standard) = Nabisco Nilla Wafer

Scoring Test

For the scoring test, the first sample beverage given to the panelist (Sample 0110 ) with 2.5% citric acid was given and arbitrary score of 4. Panelists rated on a scale from 1-7, 1 being the most sour, that the 5% citric acid sample was most sour (58%). 19% of panelists believed the 1% citric acid was most least sour giving it a score of 7 and 61% giving the same sample a score of 6 (See Figure 9).

DISCUSSION

Beverage Testing Analysis

In the beverage tests conducted by Stillman and Philipsen, both sought to find if color had any effect on the choices and perceptions people had about a particular beverage’s flavor. Stillman (1993) used a variety of individuals ranging in age to assess if the color of a beverage changed their perception of the beverage taste. Stillman used two different artificially flavored beverages, raspberry and orange, and left them uncolored or colored red, orange or green. The participants of the study were much less likely to identify the beverage flavor when the color was green and more likely to identify the correct beverage flavor when it was red. Stillman’s study concluded that the color of a beverage indeed affected an individual’s perception of beverage flavor even when they were aware that the color might not be indicative of the flavor.

Philipsen and others, sought to explore a similar concept, but instead used two different age groups as subjects. In a similar study by Philipsen and others (2006), subjects divided into two different populations were given a cherry-flavored beverage that changed color from red through orange to yellow. The first group was over 60 and the second group consisted of young adults. The study found that as color changed away from red, the number of correct responses identifying the flavor as cherry decreased, but was most apparent in the older population. Interestingly enough, a change in color intensity did not play a role in perceived sweetness nor did color concentration play a role in the perceived beverage flavor intensity.

In both studies, color affected the role in identifying the correct flavor of beverages. Receiving visuals signals from food and beverages contribute to how a person will react and respond to taste. The studies by Stillman, Philipsen and others back up the results from the color association and perception of beverage tests performed in this lab. The results from this study also support that beverage color does affect taste intensity and acceptability. Results also revealed that color may play a significant role in beverage acceptance based on temperature. In comparison, the tests conducted by Stillman and Philipsen included a population of individuals that was not present in the panelist of this beverage association test. The age range of panelists in this study averaged age 20. The panelists in these beverages tests were also all students majoring in Foods and Nutrition at San Diego State University which may have altered the data and placed a bias in the results whereas the previous studies mentioned did not contain any panelists with this type of background.

Panelists perceived that the emerald beverage was the sweetest and the light yellow as the sourest out of the presented colored beverages. The possible reason for this outcome is that many people associate the color with something they have previously consumed or are familiar with. Panelists may have associated the light yellow with the sourness of lemonade and associate the emerald color with that of a watermelon giving a possible reason as to why people assume beverage taste by color. These preconceived notions play a role in consumer acceptance. As for the preferred temperature of beverages, almost all panelists stated they would prefer all the drink varying in color at a cold temperature over warm, tepid, or hot. This may have been affected by the fact that all beverages were taken out of the refrigerator upon testing giving a false idea to the panelists they the beverages were meant to be consumed at a cooler temperature.

Descriptive Tests

During the texture profile test panelist were asked to choose from a list of descriptive words and pick the one that they felt accurately described the appearance, flavor, texture, aroma consistency and mouthfeel of the food. Instead of just observing the products, the panelist now were able to use a combination of taste, sight, hearing, smell, and touch.

In the study by Lakhani’ and others (1991) the various properties of Cheddar cheese were analyzed based on texture and preference. A texture profile panel of nine individuals were chosen based upon their competency in taste testing and received training prior to the testing. Panelists were asked to generate descriptive vocabulary to use in the tests. Lakhani’s panelists compared the textural characteristics of the Cheddar cheese made from ultrafiltered milk to that of a control and commercial Cheddar cheese and attempted to draw a connection between the textural properties of the cheese and consumer acceptability. Lakhani’s study found that the panelist generally agreed on the same texture differences of the cheeses deciding that the cheese made from ultrafiltered milk was less preferred over the others.

During the texture profile test conducted in this experiment, descriptive word choices varied throughout the panel, but had a generaal higher percentage of similar choices for 1 to 3 of the descriptive words. All words seemed to vary in number of votes. The test performed by Lakhani supports the idea that all people perceive with their five senses characteristics about a food item differently in one way or another.

In this test, panelists were given a pre-chosen list of words to select from when describing food attributes. This differed from Lakhani’s test in that the panelist themselves generated their own list of words to describe the food products based on three general food category attributes and decided on ten descriptive words total. In this lab, the panelists were told to only choose words listed on the texture profile descriptive words sheet and were not given the training or option to choose their own. Having a pre-chosen list of words could have given the test some bias in that no other options were available. If a panelist felt none of the words described the food accurately or were unfamiliar with a word, they were subjected to choose one nonetheless. Some categories such as appearance had a larger word bank to choose from than other categories possibly making it difficult to choose just one word. This test also used a panel with no background in food testing to describe the attributes. Some panelist may have been unfamiliar with the words presented due to lack of experience in food testing or may never have encountered a food that they could identify the attribute with.

Descriptive tests do not provide any information on product acceptability which make them more beneficial when combined with product acceptance tests in order to find what attributes are associated with acceptance.

While collecting the data from the descriptive tests, panelists were required to raise their hands for every descriptive word and votes were tallied in this way. This process of data collection was extremely tedious and time consuming. The process was also confusing making some of the panelist frustrated. In future tests, a more efficient method of data collection should be used for tests that involve many possible answers.

Difference Tests

Paired Comparison Test

99% of the panelist overwhelmingly identified that the sample with 1% citric acid was more sour than the 0% citric acid sample. Results such as this are helpful in showing there is a definite difference between samples if almost all of the 89 participants were able to distinguish a clear change. Again in this test, no preference or product acceptability was analyzed therefore it may be better utilized when combined with a product acceptance test.

Panelists were all seated in rows two feet apart from each other allowing them to see the reactions of their fellow testers. Even when asked not to look around the room when testing the samples, some panelist could see the reactions on the faces of others helping them to determine which sample of the two was more sour. Results may have benefitted from separation of panelist during testing in order to eliminate this bias.

Triangle Test

Again here, a significant amount of panelists were able to differential the correct beverage that differed from the other two. Most panelist correctly identified the beverage containing 1% was different from the other two beverages containing 0% citric acid. Data collection accuracy may have benefitted if panelist were separated further disabling them from viewing the reactions of those around them. The majority vote is a good indication that samples differed in a significant way and that that difference plays a role in our senses. As mention by Brown (2011), there are many factors that are involved in food selection, but the senses make the ultimate decision whether or not a food item will be consumed. The data received from this test would be better understood if compared to a preference test.

Duo-Trio Test

Panelists were accurately able to distinguish which cookie differed from the standard in this test. Fifty-seven percent (57%) of panelist believed the cookie contained less vanilla while 27% believed it different in crunchiness and 15% stated it was drier. Panelists were able to hear the cookie crunch, smell it, and feel the texture all affecting their perception of differences. Similar to the consumer acceptance test conducted by Kuttappan and others in 2012, consumers were able to distinguish a difference in chicken breast meat and relate it to a preference based on outer appearance.

Scoring Test

Results varied for the scoring test. Most panelists were able to correctly identify which beverage was most sour and least sour with votes varying in between. The varying results between could be due to some confusion in the way the test what conducted. Some panelists were confused as to how they were supposed to rate the beverage and this definitely may have played a role in the results. In the study by Yeu. K and other (2008), taste played a role in food evaluation. In the scoring test, and many of the previous mentioned tests involving citric acid, the intensity of the citric acid flavor may have distracted the panelist from the task of scoring. Often the beverage was so sour the panelist wanted nothing, but to take a sip of water to clear the taste from their mouth. This possibly may have altered the outcome by not allowing the panelist to fully experience the flavor intensity of each beverage.

Overall, the test performed in the San Diego State University Nutrition 205 food lab sought to explore the effects of the five senses on food evaluation and acceptance by testing the beverages and food based on appearance, texture, flavor, taste, aroma, and texture. This sensory lab found that food evaluation is an extremely valuable resource for the food industry and can be a continuing resource for future consumer research. Sensory testing can provide the food and even medical industry an outlet to grow and meet the needs of their customers. Panelists and participants in these tests can vary in many ways making it sometimes difficult to accurately assess findings. It is of uttermost importance to follow proper sensory analysis procedures to avoid any type of distraction or error in results. For future studies panelist should be given strict guidelines to follow prior to testing. Gum use should be restricted, smokers should be excluded, the atmosphere should be free of noise and distractions, tests should be kept to a short time length, and eating meals prior to tests should be regulated. Data collection should be conducted after tests instead of during so panelists do not lose their ability to concentrate and answer the questions correctly. There was much room left for human error when the data was compiled at the end of the testing as well. Calculations contained human error that could have been avoided with more careful compilation of data that must be taken under consideration for future testing. Even with some human error, the experiments were able to accurately portray the varying opinions of consumers when it comes to food and food products and express the way in which all five senses play a part in food selection.

REFERENCES

Brown, Amy. 2008. Understanding Food: Principles and Preparation. 3rd ed. Belmont, Ca: Thomson Wadsworth. Pgs. 23-28.

Bovell-Benjamin, A. , & Guinard, J. (2003). Novel approaches and application of contemporary sensory evaluation practices in iron fortification programs. Critical Reviews in Food Science and Nutrition, 43(4), 379-400.

Stillman, J.A. (1993), Color Influences Flavor Identification in Fruit-flavored Beverages. Journal of Food Science, 58: 810–812.

Philipsen, D.H., Clydesdale, F.M., Griffin, R.W. and Stern, P. (1995), Consumer Age Affects Response to Sensory Characteristics of a Cherry Flavored Beverage. Journal of Food Science, 60: 364–368

Lakhani, S., Gullett, E. A., Ferrier, L.K. and Hill, A.R. (1991), Texture Analysis of Cheddar Cheese Made From Ultrafiltered Milk. Journal of Food Quality, 14: 251–271.

Yeu, K., Lee, Y. and Lee, S.-Y. (2008), Consumer Acceptance of an Extruded Soy-Based High-Protein Breakfast Cereal. Journal of Food Science, 73: S20–S25.

V. A. Kuttappan,Y. S. Lee, G. F. Erf, J.-F. C. Meullenet, S. R. McKee and C. M. Owens (2012), Consumer Acceptance of Visual Appearance of Broiler Breast Meat with Varying Degrees of White Striping. Poult. Sci. May 2012 vol. 91 no. 5 1240-1247.

Robles-Sánchez, R.M., Islas-Osuna, M.A., Astiazarán-García, H., Vázquez-Ortiz, F.A., Martín-Belloso, O., Gorinstein, S. and González-Aguilar, G.A. (2009), Quality Index, Consumer Acceptability, Bioactive Compounds, and Antioxidant Activity of Fresh-Cut “Ataulfo” Mangoes (Mangifera Indica L.) as Affected by Low-Temperature Storage. Journal of Food Science, 74: S126–S134.

APPENDIX

A. Demographic Questionnaire

B. Sensory Evaluation: Duo-Trio and Scoring/Rating Test

C. Sensory Testing Beverage Questionnaire

D. Texture Profile Descriptive Words

APPENDIX A

APPENDIX B

APPENDIX C

APPENDIX D

Figure 1: Nutrition 205 Student Responses to the Question "Do You Drink Apple Juice?"

Figure 4: Nutrition 205 Student Responses to the Question "Do You Drink Apple Juice?"

YesNo0.510.24

Figure 2: Perceived Beverage Sweetness by Color Rated by Nutrition 205 Students.

Sales

Light YellowDark YellowChartreuseDark ChartreuseEmerald0.260.190.047.0000000000000007E-20.44

Figure 3: Perceived Beverage Sourness Rated by Nutrition 205 Students.

Sales

Light YellowDark YellowChartreuseDark ChartreuseEmerald0.450.180.150.120.1

Figure 4: Ratings of Artificiality and Naturalness of Light Yellow, Dark Yellow, Chartreuse, Dark Chartreuse, and Emerald Beverages Based on Color Rated by Nutrition 205 Students.

Most Artificial

Light Yellow Dark YellowChartreuseDark ChartreuseEmerald0.010.090.040.060.8Most Natural

Light Yellow Dark YellowChartreuseDark ChartreuseEmerald0.960.020.0100

Beverage Colors Observed

Percentage of Votes

Figure 5: Preference Based on Color of Light Yellow, Dark Yellow, Chartreuse, Dark Chartreuse, and Emerald Beverages Rated by Nutrition 205 Students.

Prefer MostLight YellowDark YellowChartreuseDark ChartreuseEmerald0.690.040.130.080.06Prefer Least

Light YellowDark YellowChartreuseDark ChartreuseEmerald0.040.270.030.060.6

Beverage Colors Observed

Percentage of Votes

Figure 6: Ratings of Sourness by Comparison Between Two Samples Rated by Nutrition 205 Students.

Most Sour

Sample 635T1 (0% Citric Acid)Sample 573T2 (1% Citric Acid)0.010.99

Figure 6: Identification of Which Apple Juice Containing Citric Acid Differs from the Others by Nutrition 205 Students

Identification of Which Apple Juice Containing Citric Acid Different from the Others by Nutrition 205 Students

2%

98%

0% Citric Acid (777C1)0% Citric Acid (542E2)1% Citric Acid (112H9)02.247E-20.97750000000000004

Figure 7: Which Cookie Differs from the Standard? Rated by Nutrition 205 Students.

Sales

Sample 6104 - First Street (Smart and Final) Vanilla WaferSample 1108 - Nabisco Nilla Wafers0.960.04

Figure 8: Why Does the Sample Differ from the Standard? Rated by Nutrition 205 Students.

Sales

DrynessCrunchinessLess Vanilla0.150.270.56999999999999995

1% Citric Acid (420M)

12345670.010.0400.010.130.610.195% Citric Acid (S723)

12345670.579999999999999960.350.06000.010

Sour Intensity

Percentage of Votes

25