Oral Evolution of Saliva Foam and Its Regulation on Aroma Release

Saliva in the oral cavity frequently exists as a foam, which dynamically forms and collapses during chewing. While saliva's role in bolus formation is well-established, how foam evolution influences aroma release remains poorly understood. We hypothesized that the constant creation and bursting of saliva foam significantly impact aroma release and its retronasal perception. This study investigates the effect of saliva foam dynamics on the release of a representative aroma compound, ethyl acetate, to showcase the effect of saliva foaming on odor release. Headspace release was correlated with foam structural changes, interfacial protein enrichment, and saliva's physicochemical properties. Results showed that saliva foam strongly modulates aroma release, thus allowing for new insights into retronasal perception and potential applications in designing saliva substitutes or protein-based flavor-delivery systems.