COMPARISON OF IN-VITRO PROTEOLYSIS OF CASEIN AND GLUTEN AS EDIBLE FILMS OR AS UNTREATED PROTEINS

In-vitro trypsin hydrolysis of two protein edible packaging films was studied and compared with that of their raw materials: casein and glut en. Both initial reaction rates and whole progress curves were conside red for this comparison. MichaeIis parameter values showed only small differences between casein film and untreated protein. The progress cu rve of the hydrolysis of these samples was described by the semi-empir ical Chrastil-Wilson model and no significant differences between the parameters of the correlative equation were obtained for the casein so lutions or casein films. The K-m value of gluten film was nearly 10 ti mes higher than that of raw gluten. In these samples, a good fit of da ta of the reaction time course was achieved by a first-order equation. Overall rate constant (k) values were greater for untreated samples; however, film samples seemed to yield a higher whole broken peptide bo nd concentration.