Abstract: In order to determine the most suitable enzyme to prepare antioxidant peptide from Caragana seed protein, gluten was chosen as the bioinformatic template of Caragana seed protein for simulated hydrolysis by four different enzymes including papain, pepsin, trypsin and V-8 protease based on the BIOPEP database. Based on degree of hydrolysis and linoleic acid oxidation inhibitory rate, papain plus 10% V-8 protease was regarded as the best enzyme for hydrolyzing Caragana seed protein. Using one-factor-at-a-time and orthogonal array design methods, the optimal hydrolysis parameters were obtained as follows: temperature 45 ℃, hydrolysis time 2 h, pH 5.0, and enzyme dosage 1%. As a result, six antioxidant peptides were obtained whose sequences were identified by mass spectrometry. The inhibition rate of LDEPDPL against linoleic acid oxidation was 50.3%. In conclusion, the computer-assisted enzymatic hydrolysis provides a novel strategy for directional preparation of antioxidant peptide from Caragana seed protein.

Key words: Caragana seed protein; antioxidant peptide; bioinformatics; lipid oxidation