Ma Zhimin, Guan Xiao, Gong Bo, Li Cheng
School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, P.R. China.
Food Funct. 2021 May 11;12(9):4060-4071. doi: 10.1039/d1fo00202c.
A germination treatment was explored in this study as a green strategy to reduce the in vitro starch digestibility of cooked quinoa. The alterations of chemical compositions, starch chain-length distributions (CLDs) and rheological characteristics of quinoa flours after the germination treatment were characterized. Results showed that a significant alteration of amylose CLDs and the starch digestibility was observed for cooked quinoa flours after different germination times. By fitting starch digestograms to the logarithm of slop (LOS) plot and the combination of parallel and sequential kinetics model (CPS), two starch digestible fractions with distinct rate constants were identified. Pearson correlation analysis further found that the observed starch digestive characteristics could be largely explained by the alterations of amylose CLDs caused by the germination treatment. More specifically, the rapidly digestible starch fraction mainly consisted of amorphous amylopectin molecules and amylose intermolecular crystallites. On the other hand, the slowly digestible starch fraction was largely formed by intramolecular interactions among amylose short chains (degree of polymerization (DP) < 500). These results suggest that germination may be a promising way to develop cereal products with slower starch digestibility.
本研究探索了一种发芽处理方法，作为降低熟藜麦体外淀粉消化率的绿色策略。对发芽处理后藜麦粉的化学成分、淀粉链长分布（CLD）和流变学特性的变化进行了表征。结果表明，不同发芽时间后，熟藜麦粉的直链淀粉CLD和淀粉消化率发生了显著变化。通过将淀粉消化图拟合到斜率对数（LOS）图以及平行和连续动力学模型（CPS）的组合，确定了具有不同速率常数的两个淀粉可消化部分。Pearson相关性分析进一步发现，观察到的淀粉消化特性很大程度上可以由发芽处理引起的直链淀粉CLD变化来解释。更具体地说，快速消化淀粉部分主要由无定形支链淀粉分子和直链淀粉分子间微晶组成。另一方面，缓慢消化淀粉部分主要由直链淀粉短链（聚合度（DP）<500）之间的分子内相互作用形成。这些结果表明，发芽可能是开发淀粉消化率较低的谷物产品的一种有前途的方法。
