The effect of Maillard reaction on flavour development of protein hydrolysates from cheese.

This study aims to explore the effect of the Maillard reaction (MR) on flavour development of cheese protein hydrolysates. In addition, the effects of proteolysis, lipolysis, and the degreasing process on the MR have been explored. Cheese protein hydrolysates subjected to different treatments were heated with glucose and xylose, and their amino reactant components, colour parameters, and volatile compounds were determined. The results showed that the MR significantly affected the content of free amino acids, peptides, and volatile flavours of cheese protein hydrolysates. Peptides below 1500 Da and most of the free amino acids were the important amino reactants during the MR. 3-Ethyl-2,5-dimethylpyrazine, 2,5-dimethylpyrazine, 2-undecanone and 2-heptanone were the key volatile components of the MR products. The results also indicated that N-terminal amino acids of the peptide chain were easier to be reacted than C-terminal amino acids and thus produce a pyrazine-like flavour in the MR.