Abstract:Starch is the main component of human staple food and the main source of energy supply. The improvement of starch nutrition quality is of great value to human health. Enzymatic modification is an important method to improve the starch quality due to its advantages of high efficiency, high specificity, and compliance with clean label. This research mainly studied the synergistic modification effect of cyclodextrin glucosyltransferase (CGTase) and cyclodextrinase (CDase) on corn starch. The structure and digestibility of modified starch products were analyzed by adding CGTase alone, CGTase and CDase simultaneously, and CGTase and CDase sequentially. The results indicated that the dual-enzyme modification significantly increased the proportion of malto-oligosaccharides in the products, while that of cyclodextrins decreased significantly. After modified in three ways, the starch structure was significantly depolymerized. The chain length ratios of DP 13~24, DP 25~36 and DP > 37 decreased, while the chain length ratio of DP < 13 increased significantly. In addition, the content of resistant starch was significantly increased after enzymatic modification. Thus, dual-enzyme modification via CGTase and CDase has a good application prospect in improving the nutritional quality of starch.
