Abstract:The enzymatic hydrolysis of perils protein by alkaline protease was optimized by face-to-face optimization test.The factors influencing the enzymatic hydrolysis were enzymatic hydrolysis time，enzyme dosage，enzymatic hydrolysis temperature，substrate concentration，deuterium concentration and emulsifying activity.The optimum conditions were obtained as follows：reaction temperature 50℃，enzyme dosage 2 000 U/g，reaction time 40 min，substrate concentration 5%，pH 9.Under these conditions，the emulsifying activity was 79.16 m2/g，which was 93.73% higher than that before modification.Enzymatic modification of violet.Scanning electron microscopy（SEM）and transmission infrared spectroscopy（FTIR）were used to analyze the structure of the modified proteins.The results of electron microscopy showed that the surface of the modified protein was expanded and the texture of the modified protein was looser than that of the unmodified protein.The results of infrared photometry showed that the modified protein had significant absorption peaks，indicating that new chemical bonds were formed after modification.