Effect of Flavored, Carbonated Drinks on Salivary Flow, Salivary Composition, and Taste Perceptions

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.

Inclusion criteria

• 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

Exclusion criteria

• 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
• 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.