Properties of films produced by cross-linking whey proteins and 11S globulin using transglutaminase

Transglutaminase (TG) was used to produce films from whey protein isolate, soybean 11S globulin and a mixture of the two (1:1, wt/wt). Solubility of TG cross-linked films was lower than that of control films at pH 3, 4, 6 and 8, Solubility of control films in 6.6M urea and in 10% SDS was higher than that of TG cross-linked films. Hydrolysis of control and TG cross-linked films by trypsin and alpha-chymotrypsin was similar after 24h incubation. Mean thickness of films ranged from 69 to 77 mu m and there were no differences among thicknesses. Average tensile strength values of TG cross-linked films were two times greater than those of the homologous controls.