Astringency and Bitterness Perception

Study Overview
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Brief Summary
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The investigators are conducting a study to better understand how the average consumer differentiates between bitter and astringent sensations, both of which are typically unpleasant sensations characteristic of some healthy foods. Astringency is the dry/rough sensation elicited by foods such as green bananas and some wines. Although trained scientists can differentiate between these stimuli, untrained participants rate them similarly, despite their differences. This confusion has created additional barriers in understanding the mechanism of astringent perception, which is currently debated. Understanding how to design experiments where untrained participants can clearly evaluate both sensations will lay the foundation to better understand astringency. One mechanism that is believed to contribute to astringency is the interaction of astringent stimuli with salivary proteins. Interestingly, the salivary protein profile may be influenced by consumption of fruits and vegetables. Therefore, the investigators will evaluate how bitter and astringent perceptions differ among high and low consumers of fruits and vegetables by collecting saliva following exposure to the stimuli. This knowledge will inform approaches to increase the appeal of healthy food.

Official Title
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Astringency and Bitterness Perception Among High and Low Fruit and Vegetable Consumers

Conditions
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Taste Bitter-Salty

Intervention / Treatment
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* Diagnostic Test: Astringency and bitterness perception


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI > 18 Exclusion Criteria: issues with taste, smell, swallowing, choking, or salivation trying to gain or lose weight

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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 |
| --- | --- |
| Low fruit and vegetable consumers<br>Participants with low F&V consumption, as defined by 24-hr dietary recall | Diagnostic Test: Astringency and bitterness perception<br>* Participants will be involved in 1-4 experiments that test how they rate and differentiate between bitter and astringent flavored beverage samples<br>|
| High fruit and vegetable consumers<br>Participants with high F&V consumption, as defined by 24-hr dietary recall | Diagnostic Test: Astringency and bitterness perception<br>* Participants will be involved in 1-4 experiments that test how they rate and differentiate between bitter and astringent flavored beverage samples<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Participant-generated sensory ratings of consumed samples | Liking and flavor intensity ratings on the general labeled magnitude scale | Through study completion, an average of three 30-minute visits | 
| Participant-generated groupings of consumed samples | Hierarchical clustering of sample similarity | Through study completion, an average of three 60-minute visits | 
| Participant-generated ratings of consumed samples relative to reference samples | Similarity ratings of samples compared to three reference samples on a visual analog scale | Through study completion, an average of three 60-minute visits | 
| Participant-generated check-all-that-apply ratings of consumed samples | 10-20 descriptors that are checked or unchecked by each participant to describe each sample | Through study completion, an average of three 30-minute visits |