Characterization pf biopolymers prepared from gelatin and sodium caseinate for potential use in leather processing

Biopolymers formed from crosslinking of different proteins is an area of growing interest. Much has been reported in the literature on the properties of a variety of biopolymers synthesized by enzymatic treatment. These products have the advantage of possessing the unique properties of each protein and have the potential for generating novel products. Prior research from this laboratory demonstrated that gelatins of varying qualities could be enzymatically modified to give products with superior functional properties. These modified gelatins, when examined by SDS-PAGE, were highly polymerized as demonstrated by an increase in higher molecular weight species. In this study, we examined individually the properties of modified proteins from renewable resources, specifically gelatins and casein, as well as their enzymatically combined products. The physical properties and molecular weight distribution of the gelatin conjugate products show that the degree of crosslinking was enhanced by addition of even small amounts of the secondary protein. These unique reactions have the potential of generating products used in leather processing, more specifically in preparation of coatings or as fillers for the leather.