Protocol 1: Sampling for "food bolus" study This part of the study allowed a complete description of the physical / rheological properties of bolus after good or poor mastication of the pork meat cooked according to the 2 previously described conditions. The analysis of these properties is followed all along the chewing sequence, until bolus swallowing. For that, boli are collected at different moments during the sequence of mastication. Subjects stopped chewing when indicated by the experimenter, and spat out the entire bolus with the saliva. This protocol also allows the release of carnosine and amino acids from the meat matrix during mastication to be studied.