Role of saliva in oral food perception.

Saliva is the first fluid that comes into contact with food during oral processing. Because saliva is the medium that bathes the taste receptors, is the fluid through which taste and aroma compounds are released into the oral cavity and is mixed continuously with food during bolus formation, it is an essential actor in oral chemosensory perception. The complexity of saliva composition, with compounds originating from different salivary glands, from gingival crevicular fluid, from micro-organisms and from food debris, together with its variable nature increases the possibilities for interactions with food compounds and for different roles in perception. These factors are increasingly being taken into account in current research on food perception. The aim of this paper is to review the principal roles of saliva in oral perception, with particular focus on chemosensory perception. These include the protection of taste buds, the effects of flow rates, salivary hormones, electrolytes and organic compounds, and finally the impact of perception on salivary secretions.