Use of enzymatically modified gelatin and casein as fillers in leather processing

Abstract

Prior research from this laboratory demonstrated that chemically modified collagen byproducts could be used effectively as fillers during leather processing. The gelatins were reacted with glutaraldehyde and, after application to veiny leather, these highly polymerized gelatins did fill and more importantly were bound to the substrate. The applications were followed by using fluorescently labeled gelatin that was added to a stock solution and the final products were examined under a microscope that had the capability of showing that the gelatins fluoresce. In this present study, fluorescently labeled gelatins were polymerized by using microbial transglutaminase as the cross-linking agent and the reactions took place in either the leather itself or the samples were first prepared and then added to the leather. Furthermore, we wanted to see, based on results from our earlier experiments in which we produced biopolymers from enzyme-modified gelatin and casein, if these products could also be effective fillers. In these experiments, we labeled casein as well as the gelatin. Varying conditions were examined for optimal filling results. The results showed that indeed these enzymatically prepared products could be used effectively as fillers and moreover were bound to the leather and would not easily be removed during further processing.