In vitro digestion rate of fully gelatinized rice starches is driven by molecular size and amylopectin medium-long chains
In vitro digestion rate of fully gelatinized rice starches is driven by molecular size and amylopectin medium-long chains
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DOI：
10.1016/j.carbpol.2020.117275
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发表时间：
2021-02-15
影响因子：
11.2
通讯作者：
Yu, Wen-Wen
中科院分区：
文献类型：
--
作者：
Li, Cheng;Gong, Bo;Yu, Wen-Wen
本研究旨在研究淀粉精细分子结构对其完全糊化阶段体外消化率的影响。研究了15种完全糊化的大米淀粉的消化动力学，并将其与淀粉链长分布和分子大小分布相关联。采用斜率对数和一阶动力学模型对溶出曲线进行拟合。结果表明，完全糊化的大米淀粉有两个同时消化的部分（快消化和慢消化）。慢消化部分的速率常数与淀粉分子大小，尤其是支链淀粉分子的速率常数有显著的相关性。从流体动力学角度看，较大的支链淀粉分子往往含有较多的较短的分支而较少的长链。这减缓了α -淀粉酶对淀粉的水解，而AMG的作用则受到较少的拮抗阻碍，从而提高了整体消化率。本研究为水稻育种家和生产商开发淀粉消化率降低的大米产品提供了重要信息。
In current study, the effects of starch fine molecular structures on its in vitro digestibility at fully gelatinized stage were investigated. The digestion kinetics of 15 fully gelatinized rice starches were obtained and correlated with starch chain-length distributions and molecular size distributions. Both logarithm of slopes and parallel first-order kinetic model were applied to fit the digestion curves to a few kinetics-based parameters. Result showed there were two simultaneous digestion fractions (fast versus slow) for fully gelatinized rice starches. The rate constants of slowly-digestible fraction significantly correlated with starch molecular sizes, especially with that of amylopectin molecules. Hydrodynamically larger amylopectin molecules tend to contain more shorter branches but less long chains. This slows down the starch hydrolysis by alpha-amylase while the action of AMG is less antagonistically hindered, increasing overall digestion rate. This study provides important information for rice breeders and manufacturers to develop rice products with reduced starch digestibility.