Rheological characterization of a gel formed during extensive enzymatic hydrolysis

Extensive hydrolysis of whey protein isolate (WPI) by Alcalase 2.4L(R) caused a dramatic increase in turbidity and viscosity. A gel was formed after the degree of hydrolysis was greater than or equal to 18%, coinciding with < 16% -lactoglobulin and < 4% -lactalbumin remaining unhydrolyzed. Heat-induced and enzyme-induced WPI gels were compared. Frequency and strain dependence indicated that both gels could be considered as strong, physical gels.