Study On Preparation Of Antioxidant Peptides From Buckwheat Albumin And Glutelin By Enzyme Hydrolysis

Taking degree of hydrolysis (DH%) and scavenging activity of O2-·as criterion, the alkaline protease hydrolysis of buckwheat albumin and glutelin were studied by orthogonal test. The obtained optimum albumin hydrolysis parameters were as follows: temperature 50℃, pH 10, concentration of substrate 20 g/L, dose of enzyme 10%, time 2h. With these parameters, the DH% can be reached 17.57%, the ratio of scavenging O2-·can be reached 37.06%. The obtained optimum glutelin hydrolysis parameters were as follows: temperature 45℃, pH 10, concentration of substrate 30 g/L, dose of enzyme 10%(w/w), time 2h. With these parameters, the DH% can be reached 20.72%, the ratio of scavenging O2-·can be reached 45.27%.The albumin hydrolyzate was separated by Sephadex G-25, then we obtained compositionⅠandⅡ.Their molecular weights were 20.89~204.2 kDa, and 219~691 Da. CompositionⅡwhose abilities for scavenging O2-·,·OH and DPPH·was the best, and the IC50 of compositionⅡwere 0.072 mg/mL, 0.26 mg/mL, 0.32 mg/mL. The compositionⅡcould inhibit the hemolysis of RBC significantly, the inhibitory ration was 42% with a 1.56mg/mL concentration. The amino acid content of Glu was 12.34 mg/100mg, which was the highest, and the contents of Asp, Arg, Gly and Lys were higher.The glutelin hydrolyzate was separated by Sephadex G-25, then we obtained compositionⅠandⅡ.Their molecular weights were 20.89~95.5 kDa, and 2138~4570 Da. CompositionⅠwhose abilities for scavenging the three free radicals was better, and the IC50 of compositionⅠw ere 0.21 mg/mL, 0.24 mg/mL, 0.31 mg/mL. The compositionⅠcould inhibit the hemolysis of RBC significantly, the inhibitory ration was 56% with a 0.6716mg/mL concentration. The amino acid content of Glu was 9.76mg/100mg, which was the highest, and the contents of Asp, Cys, Val and Arg were higher.