Résumé
Sourness is mainly caused by the detection of protons. This perception may act as a warning signalling the presence of a high concentration of acid dangerous for the body, of unripe fruits, or of spoiled foods contaminated by microorganisms. Numerous organic and mineral acids are responsible for sourness. A low level of sour taste is attractive to humans and animals in some foods such as citruses, while it is aversive when present at a high level. The release of acids in the mouth during eating and the perception of sourness may be influenced by the food matrix composition and structure. The perception of particular aromas can modulate acid perception through perceptual interactions. Overall, there is less work on sour perception than on bitter, salty, and sweet perceptions. Saliva has been suggested to act as a buffering system affecting the way we perceive the sourness of acids. Sourness also influenced the overall acceptability of imitation fruit beverages prepared with these acids.