farzad koravand

The effect of enzymatic treatment time of microbial transglutaminase (MTGase) on the characteristics of whey protein isolate (WPI) films was investigated. Results shown that the properties of MTGase-treated films were affected by increasing the enzymatic treatment time. Enzymatic treatment at lower incubation time, i.e. for 1 h, significantly resulted in higher values of tensile strength (TS) and lower values of elongation at break (EB) as compared to control film. In the MTGase-treated films, the TS values decreased gradually and EB values increased progressively with increasing incubation time from 1 to 3 h. Water vapor permeability (WVP)and total soluble matter(TSM) of control film in comparison with MTGase-treated films decreased from3.6 ×10 10 to 2.31 ×10 10 g m-1 s-1 pa-1 and from 37.07 to 19.97 percent, respectively. However, as the time of enzymatic treatment was increased the TSM and WVP were gradually increased.