The Study On The Enzymatic Hydrolysis And Properties Of The Enzymatic Hydrolysate Of Casein

Many studies suggested that the enzymatic hydrolysis of casein has biological competence.In our country,the study in this field was late.There's a wide gap when compared with developed countries.This thesis consisted of three parts.the study on the enzymatic hydrolysis of casein in series I scavenging activity of enzymatic hydrolysates of casein on free radicals in series II ;the study on the immunological competence of enzymatic hydrolysis of casein in series III.Series I The Study on The Enzymatic Hydrolysis of Casein The enzymatic hydrolysis of casein by trypsin and papain was systematically studied through the quadratic combination universal rotary design and response-surface analysis.Effects of influencing parameters including temperature,pH value and enzyme/substrate ratio on the changing pattern of the degree of hydrolysis was determined under the condition of substrate concentration 6g/l,and hydrolysis time lh.The statistical optimization was used to optimize by the regression equaton.Results indicated that the best combination of parameters for trypsin was temperature 58℃,pH value 7.4,and enzyme/substrate ratio 0.7%;the optimal enzymatic hydrolysis conditions of papain were: temperature 58.53%,pH value 5.0 and enzyme/substrate ratio 7.4%,the degree of hydrolysis was high under the optimum conditions.Series II Antioxidant Acticity of Two Enzymatic Hydrolysates of Casein The casein was hydrolysed using trypsin and papain in this experiment,and the hydrolyzates collected from different times of hydrolysis were lyophilized.The capability of scavenging hydroxyl radical and DPPH radical of the hydrolyzate was estimated.The results suggest that the different concentration of enzymatic hydrolysates showed different antioxidant properties in the same systems.For example,In the system of scavenging hydroxyl radical of enzymatic hydrolysates.The high concentration of enzymatic hydrolysates (1.00%) showed strong properties of scavenging hydroxyl radical,and the inhibition rate could reach the summit of 19.50%(2h).While the low concentration showed strong prooxidant properties,and the inhibition rate was just -54.48%(3h).However,the same concentration of enzymatic...