NCT03883880

Brief Summary

A counterbalanced, crossover design will be used to evaluate whether exposure to flavors vs. a control over time alters the perception of the flavor by changing an individual's salivary protein profile. Participants will complete 3 acute tasting protocols (baseline, after intervention 1, after intervention 2). The interventions will be with the flavor (epigallocatechin gallate, linolenic acid, capsaicin) or a control, in counterbalanced order, and will involve swishing and swallowing a solution of that sample 5 times per day for two weeks. Each of these flavors will be a separate sub-study.

Registry Overview

Registry-reported information. Elapsed time and enrollment totals alone do not measure study progress or recruitment pace.

Recruitment status
terminated
Actual enrollment (reported)
32 participants
Study completion date

December 1, 2021

Actual (reported)
Listed locations
1 countries · 1 sites

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Dates and qualifiers reported by the registry. Estimated dates do not confirm that a milestone has occurred.

  1. Study Start

    January 5, 2019

    Actual (reported)

  2. First Submitted

    March 18, 2019

    Actual (reported)

  3. First Posted

    March 21, 2019

    Actual (reported)

  4. Primary Completion

    September 24, 2019

    Actual (reported)

  5. Study Completion

    December 1, 2021

    Actual (reported)
Last Updated
May 25, 2023
Status Verified
May 2023
Last Update Submitted
May 23, 2023

Conditions

Diet, Food Choice, Taste

Keywords

dietfood choicetaste

Outcome Measures

Primary Outcomes (3)

  • Salivary proteins

    Subjects saliva will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). The proteomic composition of the saliva samples will be established, and used to evaluate relationships with other outcome measures.

    9 months per sub-study (intervention type)

  • Flavor intensity ratings

    Flavor intensities for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rate (in duplicate) the intensity of flavor from the following solutions: flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ratings will be evaluated in context of the timeline of the exposure as well as the salivary proteome.

    9 months per sub-study (intervention type)

  • Flavor rankings

    Flavor rankings for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rank the following solutions from most to least intense: Flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ranking data will be used an another method to gather information on what solutions are most intense to the subject, as the intensity ratings may have complications due to order effects during tastings. These rankings will also be evaluated in context of the timeline of the exposure as well as the salivary proteome.

    9 months per sub-study (intervention type)

Study Arms (3)

Epigallocatechin gallate

EXPERIMENTAL

Epigallocatechin gallate solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups.

Other: Epigallocatechin gallateOther: Epigallocatechin gallate control

Linoleic acid

EXPERIMENTAL

Linoleic acid emulsion will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups.

Other: Linoleic acidOther: Linoleic acid control

Capsaicin

EXPERIMENTAL

Capsaicin solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups.

Other: Capsaicin solutionOther: Capsaicin control

Interventions

Epigallocatechin gallateOTHER

Colored solution prepared with epigallocatechin gallate to be consumed daily for two weeks during the epigallocatechin gallate intervention.

Epigallocatechin gallate
Epigallocatechin gallate controlOTHER

Colored control solution to be consumed daily for two weeks during the epigallocatechin gallate intervention.

Epigallocatechin gallate
Linoleic acidOTHER

Colored emulsion prepared with linoleic acid to be consumed daily for two weeks during the linoleic acid intervention.

Linoleic acid
Linoleic acid controlOTHER

Colored control solution to be consumed daily for two weeks during the linoleic acid intervention.

Linoleic acid
Capsaicin solutionOTHER

Colored solution prepared with capsaicin to be consumed daily for two weeks during the capsaicin intervention.

Capsaicin
Capsaicin controlOTHER

Colored control solution to be consumed daily for two weeks during the capsaicin intervention.

Capsaicin

Eligibility Criteria

Age18 Years - 45 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Agree to maintain current diet throughout intervention
  • Agree to inform us if medication use changes during study.
  • Willing and able to taste and consume samples, as well as take pictures to document use of the flavor during intervention.

You may not qualify if:

  • Known issues with salivation, taste, or smell
  • Taking medications other than birth control
  • User of tobacco products or electronic cigarettes within the last 30 days

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Purdue University

West Lafayette, Indiana, 47907, United States

Location

Related Publications (1)

  • Davis LA, Running CA. Repeated exposure to epigallocatechin gallate solution or water alters bitterness intensity and salivary protein profile. Physiol Behav. 2021 Dec 1;242:113624. doi: 10.1016/j.physbeh.2021.113624. Epub 2021 Oct 14.

    PMID: 34655570DERIVED

MeSH Terms

Interventions

epigallocatechin gallateLinoleic Acid

Intervention Hierarchy (Ancestors)

Linoleic AcidsFatty Acids, EssentialFatty Acids, UnsaturatedFatty AcidsLipidsFatty Acids, Omega-6

Study Officials

  • Cordelia Running, PhD

    Purdue University

    PRINCIPAL INVESTIGATOR

Enrollment

32 participants — actual enrollment reported by the registry.

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Assistant Prof. Nutrition Science

Study Record Dates

First Submitted

March 18, 2019

First Posted

March 21, 2019

Study Start

January 5, 2019

Actual (reported)

Primary Completion

September 24, 2019

Actual (reported)

Study Completion

December 1, 2021

Actual (reported)

Last Updated

May 25, 2023

Record last verified: 2023-05

Locations

US(1)