Sorting of Oral Sensations

Study Overview
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Brief Summary
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Recent research indicates that fatty acids in food may have a taste. There is no lexicon to describe the sensation of the fatty acids, but participants frequently describe the sensation as bitter or sour. The proposed study will ask participants who have been screened for their ability to detect fatty acids to sort a variety of taste stimuli, including sweet, sour, salty, bitter, umami, and fatty acid tastes. Observing how the participants sort the stimuli will allow us to determine if the fatty acid taste is unique from other taste sensations.

Detailed Description
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Panelists will be screened for their ability to discriminate 0.5% linoleic acid emulsion from the blank using two sequential tetrad tests. Panelists will wear nose clips during the tests. Panelists must successfully complete both tetrads in order to qualify for the study. Panelists who qualify for the full study will provide written informed consent as well as data on their ethnic background, age, and their habitual fat intake. Heights and weights will be measured. After completing the screening tests and the demographic questions, panelists will receive 15 samples (for the first group: All tastes sorting) or 12 samples (for the second group: Bitters sorting). When panelists receive the samples, they will be instructed to put on nose clips and keep the clips on for the duration of the test. Participants will be provided with water for rinsing their mouths as well as a cup to spit the samples into after tasting. Panelists will be provided with more water and additional spit cups as necessary. Next, panelists will be instructed to: Taste each sample, spit it into the spit cup, and rinse with water. Then, sort the samples into groups you believe are similar. Groups may contain as many or as few samples as you desire. You may have as many or as few groups as you desire. Once they have decided on their groups, they will write in a description for each group and rate the group for its overall similarity. After finishing this initial sorting task, if panelists have more than two total groups, they will be instructed to select the two groups they believe are most similar to each other and combine them. If panelists still have more than two total groups, they will be instructed to combine the two most similar groups again. This will continue until panelists only have two groups remaining. At each level, panelists will rate the new, combined group for its overall similarity on a visual analog scale, as before. Data from this sorting task will be compiled in to dissimilarity matrices for each participant, showing how many groups it took them before each sample was combined with each other sample. This data will be analyzed to determine if the fatty acid samples are similar or unique in sensation from other taste qualities.

Official Title
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Sorting of Oral Sensations

Conditions
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Taste Qualities, Primary Tastes

Intervention / Treatment
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* Other: Tasting solutions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy (self report), normal taste function Exclusion Criteria: Medication that alters taste sensation, failed to detect 0.5% linoleic acid emulsion, allergic to dairy or nuts

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sorting all tastes<br>This group will receive 15 samples to taste and sort into groups. The samples included: a blank solution, hexenoic acid, decenoic acid, oleic acid, linoleic acid, glucose, fructose, sodium chloride (2), citric acid, acetic acid, quinine, urea, monosodium glutamate, and inosine monophosphate. | Other: Tasting solutions<br>* Participants will taste a variety of food grade compounds including: hexenoic acid, decenoic acid, oleic acid, linoleic acid, glucose, fructose, salt, citric acid, acetic acid, quinine, urea, caffeine, sucrose octaacetate, propylthiouracil, phenylthiocarbamide, monosodium glutamate, and inosine monophosphate.<br>|
| Sorting bitter tastes<br>This group will receive 12 samples to taste and sort into groups. The samples included: blank solutions (2), decenoic acid, oleic acid, linoleic acid, quinine (2), urea (2),caffeine, sucrose octaacetate, and propylthiouracil. | Other: Tasting solutions<br>* Participants will taste a variety of food grade compounds including: hexenoic acid, decenoic acid, oleic acid, linoleic acid, glucose, fructose, salt, citric acid, acetic acid, quinine, urea, caffeine, sucrose octaacetate, propylthiouracil, phenylthiocarbamide, monosodium glutamate, and inosine monophosphate.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Similarity of taste sensations | Participants sort the solutions into groups, and then combine the groups based on which samples are similar in oral sensation. This is used to determine how similar or different each sample is from the others. We are primarily interested in how the fatty acids (hexenoic acid, oleic acid, linoleic acid, and decenoic acid) are sorted, and whether they are distinct from other tastes. | 1 visit (only visit) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of dietary fat on taste sensation sorting | Dietary records will be used to classify participants' diets as high or low in fat. The analysis of similarity among samples will be repeated and compared between these two groups. We are primarily interested in how the fatty acids (hexenoic acid, oleic acid, linoleic acid, and decenoic acid) are sorted, and whether they are distinct from other tastes. | 1 visit (only visit) | 
| Effect of genetic ability to taste propylthiouracil on taste sensation sorting | Participants will be classified by their ability to taste 6-n-propylthiouracil (using filter papers wil phenylthiocarbamide and using data from sorting the bitter compounds). Tasters and non-tasters of this compound will be compared in their sorting of the different solutions. This will be done for the Sorting Bitter tastes group only. We are primarily interested in how the fatty acids (hexenoic acid, oleic acid, linoleic acid, and decenoic acid) are sorted, and whether they are distinct from other tastes. | 1 visit (only visit) | 
| Effect of gender on taste sensation sorting | Sorting patterns by males and females will be compared as well. We are primarily interested in how the fatty acids (hexenoic acid, oleic acid, linoleic acid, and decenoic acid) are sorted, and whether they are distinct from other tastes. | 1 visit (only visit) | 
| Effect of BMI on taste sensation sorting | Sorting patterns by lean, overweight, and obese participants will be compared as well, using the data collected on height and weight to calculate body mass index. We are primarily interested in how the fatty acids (hexenoic acid, oleic acid, linoleic acid, and decenoic acid) are sorted, and whether they are distinct from other tastes. | 1 visit (only visit) |