Astringency and Bitterness Perception

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

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.

Study Overview

• Status: Completed
• Conditions: Taste Bitter-Salty
• Intervention / Treatment: Diagnostic test: Astringency and bitterness perception

• Study Type: Observational
• Enrollment (Actual): 92

Contacts and Locations

Study Locations

• United States
  • Indiana
    • West Lafayette, Indiana, United States, 47907
      • Purdue University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

• Not underweight (BMI > 18 kg/m^2)
• Not be trying to gain or lose weight
• Males and females 18-45
• No known issues with taste, smell, swallowing, choking, or salivation

Description

Inclusion Criteria:

• BMI > 18

Exclusion Criteria:

• issues with taste, smell, swallowing, choking, or salivation
• trying to gain or lose weight

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Low fruit and vegetable consumers; Participants with low F&V consumption, as defined by 24-hr dietary recall	Diagnostic test: Astringency and bitterness perception; Participants will be involved in 1-4 experiments that test how they rate and differentiate between bitter and astringent flavored beverage samples
High fruit and vegetable consumers; Participants with high F&V consumption, as defined by 24-hr dietary recall	Diagnostic test: Astringency and bitterness perception; Participants will be involved in 1-4 experiments that test how they rate and differentiate between bitter and astringent flavored beverage samples

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: Purdue University

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 30, 2017
• Primary Completion (ACTUAL): May 30, 2018
• Study Completion (ACTUAL): May 30, 2018

Study Registration Dates

• First Submitted: May 24, 2017
• First Submitted That Met QC Criteria: May 25, 2017
• First Posted (ACTUAL): May 31, 2017

Study Record Updates

• Last Update Posted (ACTUAL): August 28, 2018
• Last Update Submitted That Met QC Criteria: August 27, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: 082-007

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No