Antioxidative Activity and Volatile Profiles of Maillard Reaction Products between Giant Salamander (Andrias davidianus) Peptides and Glucose during the Heating Process

To improve the antioxidant activity and flavor characteristics of giant salamander peptides, the changes in pH, browning extent, DPPH radical scavenging capacity, and reducing ability in Maillard reaction products (MRPs) between giant salamander peptides and glucose during the heating process (95 & DEG;C and 0, 1, 2, 3, and 4 h) were investigated. The difference in volatile compounds of the MRPs was also analyzed by gas chromatography-ion mobility spectroscopy. The results indicated that the pH value of the MRPs shrank with the proceeding of heating time, while the browning extent and antioxidative capacity increased. 58 volatile compounds including 24 aldehydes, 12 alcohols, 8 esters, 5 ketones, 4 pyrazines, 2 furans, 1 pyridine, 1 ether, and 1 olefin were detected among the MRPs. At different stages of the reaction, the MRPs were dominated by aldehydes, and the relative amount of aldehydes first decreased and then increased with the intensification of the reaction time; the relative content of esters increased first and then decreased; the relative content of alcohols decreased gradually; and the relative amount of pyrazine and furan exhibited a significant increasing tendency. Principal component analysis (PCA) revealed that the cumulative contribution rate of the first two components reached 87.3%, indicating that the volatile compounds of MRPs at different reaction times were well differentiated. The correlation analysis demonstrated that the antioxidant activity was positively associated with the browning extent, ketones, furans, and pyrazines. These results might offer a certain reference for modifying the physicochemical traits of giant salamander peptides.