Glycoconjugates, herein glyco-protein conjugates, composed of protein and saccharide chains are the main components of the interfibrillar matrix in skin which need to be fully removed in the leather making process. The application of glycosidases can assist unhairing and skin fiber opening-up, resulting in the improvement of leather quality, by breaking the glycoconjugates safely and efficiently in mild conditions. The biotechnology assisted by glycosidases, a big family of over 200 kinds of enzymes, has a great potential but the related mechanisms and the efficiency of different glycosidases are still not clear, which interferes with its wide application. To screen the proper glycosidases, a novel method of evaluating the catalytic hydrolysis properties of glycosidases towards skin glycoconjugates based a special hide powder substrate, simulating the actual leather processing, was established through detecting the produced amount of the total sugar in the solution. The special substrate was prepared, the determination conditions were optimized, then the performances of several typical glycosidases were evaluated and their application effects in soaking process of leather making were also investigated. The results show that the optimum testing conditions are lower than 4 h of the reacting time, optimally 2 h, and lower than 40 U/mL of the enzyme concentration, optimally 0-25 U/mL based on 2 g of the substrate; the results to evaluate the properties of some glycosidases based on the established method are positively related to their applying effects in soaking. The new method with better repeatability can be used as an available tool to correctly select glycosidases and optimize process parameters for correct use.
A novel method for the quantitative characterization of the simultaneous plasticizing and filling performance in ultrasonic plasticization micro injection molding
