Milk Protein Aceip Hydrolysis Process And Fermented Dairy Products

Hydrolysis conditions of protease of milk protein were studied in the present paper. ACEIP of hydrolysates were separated, the ACEIP fermentation characteristics and process technique of ACEIP lactobacillus beverage were also studied. Research results are as follows:1. After analyzing ACEI activity variation and the inhibitory activity peak area of seven kinds of proteases in each optimum conditions, protease A was used to hydrolyze milk protein for production of ACEIP .2. Hydrolysis conditions of protease A were studied, the optimum conditions to produce ACEIP was: temperature 50℃, pH7.5, substrate concentration 5% and enzyme to substrate ratio 3% . Under those conditions, the ACEI activity was 92.44%, degree of hydrolysis (DH) was 24.89%, and IC50 was 0.8987mg.mL^-1.3. Distributions of molcular weight of hydrolysate ACEIP were measured by SCE, molcular weight of ACEIP with higher inhibitory activity were between 319Da and 1572Da. Thereinto, the highest ACEI activity was at 439Da and 1340Da took the second place.4.The ACEI activity of the hydrolysates derived from milk protein different parts were researched. Molcular weight of ACEIP with higher ACEI activity was between 319Da and 1572Da of whole milk protein, casein and whey protein entirely, but their molcular weight of ACEIP with highest ACEI activity was 439Da,1340Da and 604Da, and their inhibitory activity peak area was 20.04,22.16 and 15.04 respectively.5.Ultrafiltration, SCE and RP-HPLC were used to separate ACEIP. The hydrolysates of milk protein were separated by 5KDa-ultrafiltration membrane and 40KDa-ultrafiltration membrane in 40℃, 0.1MPa. The IC50 of 5KDa-ultrafiltrate was 0.5311mg.mL^-1,and 40KDa-ultrafiltrate was 0.8633mg.mL^-1.There were four fractions after the hydrolysates were separated by SephadexG-25,...