Study On Enzymatic Hydrolysis Of Whey Protein

The whey protein hydrolysis modification was studied according to its allergy.Whey protein concentrate WPC80 was hydrolyzed for 4h with protease A, trypsin, protease N, neutrase, protease S and protin SD and under the conditions of optimum temperature, pH and E:S(1900U/g), then measuring the content of hydrolysate allergens with competition enzyme-linked immunosorbent assay and molecular weight distribution with HPLC and evaluating bitter with quinine as based substance. The study showed vitality of protease A was high(142214.8 U/g),allergens of hydrolysis was low(Sig<0.05), peptides (180-1000 Da) content was high(87.18%), less bitter taste, low cost, but a secure commercial enzyme preparation; therefore, protease A was selected to be the best whey protein hydrolase.The regression model of four factors twice rotation perpendicular regressive design was adopted to optimize pH, temperature, E:S and hydrolysis time with protease A hydrolyzed whey protein allergen. The model was established with the allergent content as response surface: Y1 = 87.92 - 1.28x1 + 7.65x2 + 12.7641x3 - 12.26x4 + 0.65x1x2 +4.04x1x3+0.65 x1x4-12.26 x2x3+3.10 x2x4-5.77x3x4+2.85x12+9.70x22+4.75x32+6.25x42-17.59 x1x2 x3-11.2 x1x2 x4+3.57 x1x3 x4+26.1 x12x2+5.16 x12x4. By variance analysis, the model was highly significant(p<0.00010), lack of fit was no significant(p=0.0633), R2=0.9877, adjR2=9644, the error was less than 5%, then the model was a good reflection of protease A hydrolyzed whey protein allergens to reduce allergen reaction. The optimum hydrolysis process parameters: pH=6.98, T=61.40℃, E: S=1977.84U / g protein, t=2.4 h.