Abstract:Fish scale of grass carp was used as row material for collagen extraction， and then the extracts were used for antioxidative peptide and angiotensin converting enzyme inhibitory peptide preparation. The optimal process of collagen extraction was as follow： acetic acid （0.3 mol/L）was added with the ratio of 1 ∶ 15（g/ mL） and extracted for 24 h under low temperature， then centrifugated and the residues were further extracted for 48 hours by 2 % protease with the ratio of 1 ∶ 10（g/mL）. By this process， the extraction rate of collagen was 49.58 %. The optimal process of antioxidative peptide preparation was as follow： collagen concentration was adjusted to 12.5 mg/mL， 4 % papain solution was added with the volume ratio of 10 ∶ 1， and then enzymatic hydrolysis for 75 minutes under 60 ℃. The inhibition ratio of the end product to ATBS+ free radical was 45.7 %. The optimal process of angiotensin converting enzyme inhibitory peptide preparation was as follow： collagen concentration was adjusted to 20 mg/mL and pH to 4.0， 6 000 U acid proteinase was added to 10 mL collagen solution， and then enzymatic hydrolysis for 3 hours under 37 ℃. The inhibition ratio of the end product to angiotensin convert－ ing enzyme was up to 98.8 %. These results can provide some reference for resource utilization of the byproducts of aquatic product processing.