Structural characteristics and antioxidant activity of Chinese giant salamander enzymatic hydrolysate-glucose conjugates induced by ultrasound Maillard reaction

The effect of ultrasonic treatment on conformational and antioxidant activity of Maillard reaction products (MRPs) from Chinese giant salamander protein hydrolysate (CGSPH) was studied. The results indicated that the ultrasonic treatment significantly enhanced the MR progress. The degree graft (DG) of ultrasound treatment MR has increased by 1.6 times compared with traditional wet heating method. The morphology of CGSPH was markedly changed after MR and the structure of MRPs after ultrasonic treatment exhibited more disordered structures and irregular fragments. Moreover, the secondary and tertiary structures of CGSPH was significantly changed, and the content of amino was significantly decreased (especially ultrasound treatment MRPs) after MR. Most interestingly, compared with traditional wet heating MRPs, the ultrasound treatment MRPs exhibited higher antioxidant activity and its DPPH radical scavenging ability, ABTS radical scavenging ability and reducing power was 42.73 %, 71.65 % and 0.84, respectively. This may be due to the higher glycation sites of ultrasound treatment MRPs. Therefore, the ultrasonic treatment MR might be a promising way to improved antioxidant activities of protein hydrolysates.