Saliva matters: Reviewing the role of saliva in the rheology and tribology of liquid and semisolid foods. Relation to in-mouth perception

Abstract

In recent years, the dynamic aspects of the oral perception of food have increasingly been taken into account in food texture characterization. At the same time, the experimental settings of instrumental measurements have also been emulating “oral contexts” more closely. The aspects related to in-mouth handling that have been incorporated into food studies include using saliva as a key material. Semisolid (or liquid) food does not usually need mastication but undergoes more subtle processes involving the tongue and palate, among other buccal structures, in which saliva is omnipresent. Creaminess, mouthfeel and astringency are central sensory sensations for which oral handling and consequently, saliva is pivotal. The present review examines the experimental considerations involved in using saliva in the rheology and tribology of liquid and semisolid foods. It also analyses some instrumental parameters that have been related to sensory attributes of liquid and semisolid foods.