Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel; Biotechnology and Food Engineering Program, Guangdong Technion-Israel Institute of Technology, Shantou 515063, China.
Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Food Chem. 2024 Jun 30;444:138622. doi: 10.1016/j.foodchem.2024.138622. Epub 2024 Jan 29.
Three cultivars of waxy rice starch with different multi-scale structures were subjected to α-amylase hydrolysis to determine amylopectin fine structure, production of oligosaccharides, morphology, and crystallinity of the partially hydrolyzed starch granules. α-amylases hydrolyzed the amylopectin B2 chain during the initial stage of hydrolysis, suggesting that it is primarily located in the outer shell of the granules. For waxy rice starch with loose structure, α-amylases attacked the crystalline and amorphous regions simultaneously in the initial stage, while for starch granules with compact structure, the outer shell blocklet (crystalline structure) can be a hurdle for α-amylases to proceed to hydrolysis of the internal granule structure. The ability of α-amylases from porcine pancreatic α-amylases to attack the outer shell crystalline structure was lower than that of α-amylases from Bacillus amyloliquefaciens and Aspergillus oryzae. These results show that α-amylase source and rice cultivar combinations can be used to generate diverse structures in degraded waxy rice starch.
三种不同多尺度结构的蜡质稻米淀粉经α-淀粉酶水解，以确定支链淀粉精细结构、低聚糖生成、部分水解淀粉颗粒的形态和结晶度。α-淀粉酶在水解的初始阶段水解支链淀粉 B2 链，表明其主要位于颗粒的外壳层。对于结构疏松的蜡质稻米淀粉，α-淀粉酶在初始阶段同时攻击结晶区和无定形区，而对于结构致密的淀粉颗粒，外壳块（结晶结构）可能是阻碍α-淀粉酶进一步水解内部颗粒结构的障碍。来自猪胰α-淀粉酶的α-淀粉酶攻击外壳结晶结构的能力低于来自解淀粉芽孢杆菌和米曲霉的α-淀粉酶。这些结果表明，α-淀粉酶来源和稻米品种的组合可用于生成降解蜡质稻米淀粉的不同结构。
