The role of saliva in aroma release and perception.

Aroma perception is an important factor driving food acceptance. Volatile organic compounds (VOCs) are released from the food matrix and then reach the receptors located in the nasal cavity, leading to their perception. These steps are closely dependent on the physicochemical properties of the volatile compounds and the food matrix, but also on human physiology. Among the different physiological parameters involved, the literature reports that saliva has various effects on VOCs and therefore appears as a major actor impacting the perception of aroma. This article reviews how saliva takes part in aroma release, considering both in vitro and in vivo approaches, and how it may affect perception. It describes the direct mechanisms (molecular interactions, enzymatic conversion, salting-out effect, dilution) involving salivary components (salts, proteins including enzymes, microbiota) that can modify the release of aroma compounds. It also considers the indirect impact of saliva, such as changes of aroma diffusion through modification of the physicochemical properties of the food matrix.