Study on Preparation and Antioxidant Activity of Enzymatic Hydrolysis Peptide from Squid Organ

[Objective]To discuss the preparation and antioxidant activity of enzymatic hydrolysis peptide of squid organ.[Method] Peptide was extracted from squid organ by Trypsin,the effects of enzymolysis temperature,time,enzyme dose and pH on degree of hydrolysis and antioxidant activity were studied through single factor and orthogonal experiment.Different molecular weight peptide oxidation resistance was evaluated by testing the scavenging activity of hydroxyl free radicals,and reducing power.[Result] Degree of hydrolysis reached to maximum under the conditions of enzymolysis temperature 35 ℃,enzymolysis time 5 h,total enzyme dose 5 000 U / g and pH 7.5.The scavenging activity of hydroxyl free radicals reached to maximum under the conditions of enzymolysis temperature 40 ℃,enzymolysis time 7 h,total enzyme dose 4 500 U / g,and pH 8.0.The peptides was fractionated according to molecular weights(MW) using three different molecular weight cut-off membranes(10,5 and 3 kDa) and were separated to three fractions,3-5 kD with the highest hydroxyl free radicals scavenging activity and 3 kD with the highest reducing power.[Conclusion]Hydrolysis peptide of squid organ has a good antioxidant activity and differed in molecular weight.