Yao Yuan, Zhang Jingmin, Ding Xiaolin
Department of Food Science, Wuxi University of Light Industry, Wuxi, Jiangsu 214036, People's Republic of China.
J Agric Food Chem. 2003 Jul 2;51(14):4066-71. doi: 10.1021/jf0209488.
Starch retrogradation is the main cause of quality deterioration of starch-containing foods during storage. The current work investigated the effect of partial beta-amylolysis on the retrogradation of rice starch and the potential of beta-amylase in preparing rice products with extended shelf life. Isolated amylopectin, whole rice starch, and rice flour from a regular rice cultivar were partially hydrolyzed by either reagent-grade or food-grade beta-amylase. The degree of beta-amylolysis was expressed as average external chain length () for isolated amylopectin or the degree of hydrolysis (%) for other starch systems. Pulsed nuclear magnetic resonance was used to monitor starch retrogradation during storage at 4 degrees C. The results indicated that partial beta-amylolysis using reagent-grade beta-amylase retarded amylopectin retrogradation by shortening the of amylopectin. When was below DP 11.6, the amylopectin retrogradation was essentially inhibited. Partial beta-amylolysis had a similar effect on the amylopectin retrogradation in the whole starch system. The maltose produced in beta-amylolysis might slightly attenuate the retrogradation-retarding effect of partial beta-amylolysis. The effect of food-grade beta-amylase on starch retrogradation was also evident, although less effective than that of reagent-grade beta-amylase. The retrogradation-retarding effect of food-grade beta-amylase was also demonstrated in rice flour system, indicating a potential method for controlling the starch retrogradation of rice products.
淀粉回生是含淀粉食品在储存过程中品质劣化的主要原因。本研究考察了部分β-淀粉酶解对大米淀粉回生的影响以及β-淀粉酶在制备货架期延长的大米制品中的潜力。用试剂级或食品级β-淀粉酶对常规水稻品种分离出的支链淀粉、全大米淀粉和米粉进行部分水解。β-淀粉酶解程度用分离出的支链淀粉的平均外链长度（）表示，或用其他淀粉体系的水解度（%）表示。采用脉冲核磁共振技术监测4℃储存期间淀粉的回生情况。结果表明，使用试剂级β-淀粉酶进行部分β-淀粉酶解可通过缩短支链淀粉的平均外链长度来延缓支链淀粉的回生。当平均外链长度低于DP 11.6时，支链淀粉的回生基本受到抑制。部分β-淀粉酶解对全淀粉体系中的支链淀粉回生有类似作用。β-淀粉酶解产生的麦芽糖可能会略微减弱部分β-淀粉酶解的回生延缓效果。食品级β-淀粉酶对淀粉回生的作用也很明显，尽管不如试剂级β-淀粉酶有效。食品级β-淀粉酶在米粉体系中也表现出回生延缓作用，表明这是一种控制大米制品淀粉回生的潜在方法。
