Study On Functional Properties And Antioxidant Activity Of Maillard Reaction Products Derived From Fish Protein Hydrolysates Of Yellow Stripe Trevally

In this paper, functional properties and antioxidant activity of Maillard reaction products(MRPs) derived from protein hydrolysates of yellow stripe trevally(Selaroides leptolepis) were studied. Basic ingredients of yellow stripe trevally were determined; using different types of proteases hydrolyzed fish protein, optimal hydrolysis protease was filtered out. Effect of degree of hydrolysis(DH) and pH on functional properties of hydrolysates, and DH and concentration on antioxidant activity of hydrolysates were studied. Effect of temperarure and pH on functional properties of MRPs, and temperarure and time on antioxidant activity of MRPs were studied. Kinetics of fish protein hydrolysates of yellow stripe trevally and glucose Maillard reaction promoted by ultrasonic were investigated. Effect of ultrasonic power and pH on functional properies of MRPs, and ultrasonic power and time on antioxidant activity of MRPs were studied. The conditions of Maillard reaction promoted by ultrasonic optimized by response surface method. Effect of MRPs on antioxidant function of serum and liver of normal mice were studied.The results show that the protein content of yellow stripe trevally fish protein was 16.3%, the best hydrolytic protease was trypsin, the emulsifying activity, foaming capacity, Fe2+chelating ability, DPPH radical and hydroxyl radical scavenging ability were the best, when the DH of hydrolysates was 10.8%. When reaction temperature was 120℃, the pH and free amino acid content of MRPs declined rapidly, the intermediates compounds(A294) and browning intensity(A420) aggravated intensely, the content of HMF and acrylamide increased gradually. Solubility, emulsifying activity and emulsion stability, foaming and foam stability, DPPH radical scavenging ability and reducing power improved significantly(p<0.05); in vitro digestibility, the hydroxyl radical scavenging and Fe2+chelating ability of MRPs declined, compared with 100℃. For the kinetics of fish protein hydrolysates of yellow stripe trevally and glucose Maillard reaction promoted by ultrasonic: pH, intermediates compounds(A294) and browning intensity(A420) changes followed zero-order kinetics, the loss of free amino groups followed first-order kinetics; browning(A420)required highest activation energy. When ultrasonic power was 400 W, the pH and free amino acid content of MRPs declined rapidly, the intermediates compounds(A294) and browning intensity(A420) aggravated intensely, the content of acrylamide increased gradually, HMF were not found. Solubility, emulsifying activity and emulsion stability, foaming and foam stability, DPPH radical scavenging ability, reducing power and Fe2+chelating ability improved significantly(p<0.05), compared with 200 W. Optimal conditions of ultrasound promoting Maillard reaction: concentration of hydrolysates 25mg/mL, hydrolysates and glucose mass ratio1:2, reaction temperature 82℃, ultrasonic power 300 W, ultrasonic time 108 min, under this condition, measured the degree of grafting was 24.06%. In vivo antioxidant experiment: MRPs can significantly increase the level of SOD, GSH-PX and GSH in serum and liver of mice(p<0.05). Ultrasound promotion can speed up the Maillard reaction rates, reduce browning and generation of hazardous substances, Maillard reaction can significantly enhance the functional properties and in vitro and in vivo antioxidant activity of fish protein hydrolysates of yellow stripe trevally.