Inhibition of enzymatic browning in actual food systems by the Maillard reaction products

BACKGROUND: The Maillard reaction occurring between amino acids and sugars produces neo-formed compounds having certain levels of antioxidant activity depending on the reaction conditions and the type of reactants. The objective of this study was to investigate enzymatic browning inhibition capacity of Maillard reaction products (MRPs) formed from different amino acids including arginine (Arg), histidine (His), lysine (Lys) and proline (Pro). RESULTS: The inhibitory effects of the MRPs on polyphenol oxidase (PPO) were determined. The total antioxidant capacity (TAC) of MRPs derived from different amino acids were in the order Arg > His > Lys > Pro. The TAC and PPO inhibition of MRPs were evaluated as a function of temperature (80-120 degrees C), time (1-6 h) and pH (2-12). Arg-Glc and His-Glc MRPs exhibited strong TAC and PPO inhibition. Increasing temperature (up to 100 degrees C) and time also increased TAC and PPO inhibition. Kinetics analysis indicated a mixed type inhibition of PPO by MRPs. CONCLUSION: The results indicate that the MRPs derived from Arg and His under certain reaction conditions significantly prevent enzymatic browning in actual food systems. The intermediate compounds capable of preventing enzymatic browning are reductones and dehydroreductones, as confirmed by liquid chromatographic-mass spectrometric analyses. (C) 2010 Society of Chemical Industry