Enzymatic Preparation of Antioxidant Peptides Derived from Small Marine Fish

In this study,Small marine fish hydrolysates obtained by digestion respectively with flavor protease,neutral protease,trypsin and alkaline protease were comparatively determined for their hydroxyl free radical scavenging activity.It was found that small marine fish hydrolysate obtained with neutral protease exhibited the highest hydroxyl free radical scavenging activity and was rich in amino acids.By using a L9(34) orthogonal array design,the optimum conditions for hydrolyzing small marine fish with neutral protease to antioxidant peptides with the highest hydroxyl free radical scavenging activity were determined as follows: pH 7.0,liquid-to-material ratio 1:2,enzyme dose 500 U/g and reaction temperature 42 ℃,and the hydroxyl free radical scavenging rate of the resulting hydrolysate was over 95%.Sephadex G75 chromatographic separation showed that the obtained hydrolysate was mostly composed of peptides with molecular weight below 3000 D.