Key Technologies of Enzymatic Preparation for DP 6–8 Chitooligosaccharides

Abstract

AbstractDegree of polymerization (DP) 6–8 chitooligosaccharides are edible hydrolyzates from chitosan and possess excellent bioactivities, especially for a potential antitumor ingredient. The objective of this study was to develop a promising enzymatic attempt for DP 6–8 chitooligosaccharides preparation. Chitosan (2%, w/v) was dissolved in acetic acid. Sequentially, six types of nonspecific enzymes were used to compare chitosanolytic activities under the optimum conditions. Results indicated that cellulase was most capable of hydrolysis, whereas others were slightly acted. The phenomenon resulted from the glycosidic bonds that existed in the chitosan. Based on preliminary experiments, cellulase and chitosanase were combined employing to digest chitosan. The enzyme mixture promoted the hydrolysis degree and the yield of resulting chitooligosaccharides were measured through high‐performance liquid chromatography. Data showed that the highest yield of DP 6–8 chitooligosaccharides reached to 79.8% w/w by hybrid enzymes adding simultaneously at pH 5.3 and 45°C after 6 h.Practical ApplicationsChitooligosaccharides are widely used in the pharmaceutical, food industry and agricultural field because of its excellent and specific bioactivities, depending on the degrees of polymerization (DPs) of chitooligosaccharides. For instance, chitooligosaccharides with DP 6–8 have potential antitumor activity that could be used as ingredients for pharmaceutical drugs, health‐care food and formula products. Another very important potential application of chitooligosaccharides with DP 6–8 is as a potent plants elicitor that could be an environment‐friendly biological stress‐resistant agent to replace chemical reagents in the agricultural field. Hence, the study of preparation methods of chitooligosaccharides with DP 6–8 is important and valuable.