The influence of beverages on the stimulation and viscoelasticity of saliva: Relationship to mouthfeel?

The viscoelasticity and secretion rate of stimulated saliva depends on food and beverage related stimuli, and it is demonstrated that this may subsequently influence the sensory properties and particularly the mouthfeel and afterfeel associated with the product being consumed. Using saliva donated by twelve volunteers, it is shown that acidic beverages such as peach flavoured iced tea and a fizzy cola stimulate significantly higher flow rates of whole mouth saliva that has greater elasticity in comparison to that generated following stimulation by water. In comparison, mechanical action from chewing flavourless gum and the stimulation from sucking a mint also stimulate high flow rates of saliva, although it is significantly less elastic than that from acid-based stimuli. However, the viscosity of human whole mouth saliva is relatively insensitive to beverage type, chewing, or mint. It is speculated that the stimulation of highly elastic saliva in response to acidic beverages is a defence mechanism for protecting the teeth from acid erosion. A separate sensory panel was used to identify key mouthfeel attributes that are likely to be related to the response of saliva, including: tongue dryness, mouth moistness, amount of saliva, tongue sensation, and throat drying. These results indicate that saliva viscoelasticity and flow rate alter dramatically in response to what a consumer eats and drinks, and that this in turn may affect mouthfeel and other organoleptic properties.