Taste PerceptionNCT06933290
Effect of Flavored, Carbonated Drinks on Salivary Flow, Salivary Composition, and Taste Perceptions
A study testing Beverage in people with Taste Perception and Saliva Production, run by PepsiCo Global R&D at 1 site in United States.
Trial summary
To determine the effect of flavored, carbonated drinks on salivary flow rate, saliva composition, and taste perceptions compared with control drinks (water, carbonated water, non-carbonated) Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Taste Perception, Saliva Production
- What is being tested?
- Beverage
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Mar 2025to 22 May 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Subject is male or female
- If female, subject is not pregnant or nursing (based on self-report)
- Subject is 18-45 years of age, inclusive
- Subject is a regular consumer of carbonated drinks (questionnaire)
- Subject is willing to avoid alcohol consumption 24 hours prior to visits
- Subject is willing to fast (no food or gum) for 2 hours prior to study sessions
- Able to speak, write, and read English
- Provision of written consent to participate
Who cannot join
- Subject smokes, vapes, or uses any nicotine/tobacco products (or has quit for less than 6 months)
- Subject currently has or recently had an illness (cold, flu, COVID) within the past month
- Subject has a condition affecting the oral cavity such as Xerostomia (dry mouth), Sores/lesions, Untreated dental caries, Major dental implants/appliances (including dentures)
- Subject has a reduced sense of taste (dysgeusia) or smell (parosmia)
- Subject has a health condition that would interfere with the study as indicated on the general health questionnaire (GHQ) (including cardiovascular, renal, or metabolic diseases)
- Subject has participated in a clinical trial within the past 30 days
Show all 9Show fewer
- Subject has participated in any PepsiCo trial within past 6 months
- Subject has a condition or is taking medication that the investigator believes would interfere with his/her ability to provide informed consent, comply with the study protocol, which might confound the interpretation of the study results, or put the person at undue risk
- Subject is employed by, or has a parent, guardian, or other immediate family member employed by a company that manufactures any products that compete with any PepsiCo product. If subject is unsure if a company would be considered a competitor to PepsiCo, they will be asked to please let the study investigator know the name of the other company and the nature of their relationship to that company before they sign the informed consent.
Trial locations and contacts
1 site in 1 country.
United States1 site
Gatorade Sports Science Institute
Valhalla, New York, 10595
About this study
To determine the effect of flavored, carbonated drinks on salivary flow rate, saliva composition, and taste perceptions compared with control drinks (water, carbonated water, non-carbonated)
Read the detailed description
Previous studies have shown that drinking a beverage can stimulate the production of saliva and alter its composition. These effects could impact oral processing and taste perceptions. Various ingredients in beverages such as carbonation may affect saliva and oral processing. The objective of this study is to determine the effect of flavored carbonated beverages on salivary flow rate, saliva composition (pH, mucins, carbonic anhydrase, and total protein), and taste perceptions compared with unflavored and non-carbonated control drinks.
- Conditions
- Taste Perception, Saliva Production
- Being tested
- Beverage
- Keywords
- taste, saliva, food pairing, salivary protein, mucin, salivary flow rate
- Medical subject headings
- Medullary cystic kidney disease 1
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BeverageOther
15 milliliter aliquot interspersed with tastants with a 3 minute break between tastants
| Study group | Role | What they receive |
|---|---|---|
| Flavored carbonated drink 1 | Experimental | Flavored carbonated beverage with nutritive sweeteners Receives: Other: Beverage |
| Flavored carbonated drink 2 | Experimental | Flavored carbonated beverage with non-nutritive sweeteners Receives: Other: Beverage |
| Flavored drink | Experimental | Flavored non-carbonated beverage with nutritive sweeteners Receives: Other: Beverage |
| Flavored non-carbonated drink | Experimental | Flavored non-carbonated beverage with non-nutritive sweeteners Receives: Other: Beverage |
| Carbonated Water | Experimental | Unflavored carbonated water Receives: Other: Beverage |
| Water | Experimental | Plain, unflavored, non-carbonated water Receives: Other: Beverage |
What is being measured
The primary outcome is the main question the study is designed to answer.
Salivary flow rate
5 minute passive drool saliva and 10 minute filter paper saliva (one sample each from tongue and palate) collected in a fixed sequence of tastant flavors (same for each session) and the assigned test beverage intervention (different for each session)
Measured: At each of six 2 hour test sessions 2-8 days apart at same time of day
Secondary outcomes (8)
Salivary pH
Lab test
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva carbonic anhydrase concentration
Lab test, unit mg/L
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva total protein concentration
Lab test, unit mg/ml
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva mucin 5B concentration Saliva mucin 5B concentration
Lab test, unit micrograms/ml
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva mucin 7 concentration
Lab test, unit micrograms/ml
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Taste perceptions
Labeled Magnitude Scale (LMS)) of intensity of perception rated from barely detectable to strongest imaginable (tastants such as sweet, sour, salty, bitter, umami).
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day.
Beverage liking
9-point hedonic scale rating from 1=Dislike extremely to 9= Like extremely
Measured: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Adverse Events
Safety
Measured: Symptoms reported at each test day and between visits from Screening to test day six
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2025
- Study start24 Mar 2025
- Primary completion22 May 2025
- Study completion22 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Taste PerceptionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- PepsiCo Global R&D
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Lindsay Baker, PhD, Principal investigator, PepsiCo, Inc. Sports Science
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06933290
- Sponsor's protocol ID
- PEP-2423
- Status last verified
- Jun 2026
- First submitted
- 1 Apr 2025
- Last updated
- 30 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Flavored, Carbonated Drinks on Salivary Flow, Salivary Composition, and Taste Perceptions
- ClinicalTrials.gov ID
- NCT06933290
- Acronym / sponsor ID
- PEP-2423
- Conditions
- Taste Perception, Saliva Production
- Keywords
- taste, saliva, food pairing, salivary protein, mucin, salivary flow rate
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- PepsiCo Global R&DIndustry (pharma, biotech, devices)
- Study start
- 24 Mar 2025 (actual)
- Primary completion
- 22 May 2025 (actual)
- Study completion
- 22 May 2025 (actual)
- First posted
- 18 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To determine the effect of flavored, carbonated drinks on salivary flow rate, saliva composition, and taste perceptions compared with control drinks (water, carbonated water, non-carbonated)
Detailed description
Previous studies have shown that drinking a beverage can stimulate the production of saliva and alter its composition. These effects could impact oral processing and taste perceptions. Various ingredients in beverages such as carbonation may affect saliva and oral processing. The objective of this study is to determine the effect of flavored carbonated beverages on salivary flow rate, saliva composition (pH, mucins, carbonic anhydrase, and total protein), and taste perceptions compared with unflavored and non-carbonated control drinks.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| Flavored carbonated drink 1 | Experimental | Other: BeverageFlavored carbonated beverage with nutritive sweeteners |
| Flavored carbonated drink 2 | Experimental | Other: BeverageFlavored carbonated beverage with non-nutritive sweeteners |
| Flavored drink | Experimental | Other: BeverageFlavored non-carbonated beverage with nutritive sweeteners |
| Flavored non-carbonated drink | Experimental | Other: BeverageFlavored non-carbonated beverage with non-nutritive sweeteners |
| Carbonated Water | Experimental | Other: BeverageUnflavored carbonated water |
| Water | Experimental | Other: BeveragePlain, unflavored, non-carbonated water |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Subject is male or female
- If female, subject is not pregnant or nursing (based on self-report)
- Subject is 18-45 years of age, inclusive
- Subject is a regular consumer of carbonated drinks (questionnaire)
- Subject is willing to avoid alcohol consumption 24 hours prior to visits
Key exclusion criteria (9 listed)
- Subject smokes, vapes, or uses any nicotine/tobacco products (or has quit for less than 6 months)
- Subject currently has or recently had an illness (cold, flu, COVID) within the past month
- Subject has a condition affecting the oral cavity such as Xerostomia (dry mouth), Sores/lesions, Untreated dental caries, Major dental implants/appliances (including dentures)
- Subject has a reduced sense of taste (dysgeusia) or smell (parosmia)
- Subject has a health condition that would interfere with the study as indicated on the general health questionnaire (GHQ) (including cardiovascular, renal, or metabolic diseases)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Beverage15 milliliter aliquot interspersed with tastants with a 3 minute break between tastants | Other | Carbonated Water, Flavored carbonated drink 1, Flavored carbonated drink 2, Flavored drink, Flavored non-carbonated drink, Water |
Primary outcome
Salivary flow rate
Time frame: At each of six 2 hour test sessions 2-8 days apart at same time of day
5 minute passive drool saliva and 10 minute filter paper saliva (one sample each from tongue and palate) collected in a fixed sequence of tastant flavors (same for each session) and the assigned test beverage intervention (different for each session)
8 secondary outcomes
Salivary pH
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva carbonic anhydrase concentration
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva total protein concentration
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva mucin 5B concentration Saliva mucin 5B concentration
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Saliva mucin 7 concentration
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Taste perceptions
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day.
Beverage liking
Time frame: Sequence of repeated sampling over 2 hours on each of 6 test days with a different beverage and the same tastants each test day
Adverse Events
Time frame: Symptoms reported at each test day and between visits from Screening to test day six
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lindsay Baker, PhD principal investigator
PepsiCo, Inc. Sports Science
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Beverage in people with Taste Perception and Saliva Production, run by PepsiCo Global R&D at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Salivary flow rate (time frame: At each of six 2 hour test sessions 2-8 days apart at same time of day). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Jun 2026.