Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072, Australia.
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, Jiangsu Province, China.
Food Chem. 2019 Jun 30;284:270-278. doi: 10.1016/j.foodchem.2019.01.065. Epub 2019 Jan 18.
The gelatinization behavior of rice flour and isolated starch and the texture of cooked rice were examined both for fresh and aged samples successively. The whole and debranched starch molecular structures of the starches extracted from the flour and hot water-washed leachate of the cooked rice were characterized, using size-exclusion chromatography, to elucidate the molecular origins of the functional changes. For all variety, the native and leached starches of the aged rice had significantly smaller average total molecular sizes, higher proportions of short amylopectin chains, and smaller average chain length of amylopectin compared to fresh rice. The structural changes are consistent with the observed higher peak and final viscosity, lower pasting temperature, greater hardness and lower stickiness of cooked rice kernels for aged rice, based on established structure-property relationships. This study can be used to suggest ways in which some improved functional properties could be obtained with less expenditure for storage.
研究人员分别对新鲜和陈化大米的米粉和分离淀粉的糊化行为以及米饭的质构进行了研究。利用凝胶渗透色谱法对从米粉和米饭热水洗脱物中提取的淀粉的全淀粉和去支链淀粉的分子结构进行了表征，以阐明功能变化的分子起源。对于所有品种，陈化大米的天然淀粉和洗脱淀粉的平均总分子大小明显较小，短直链淀粉比例较高，支链淀粉的平均链长也较小。根据已建立的结构-性能关系，这些结构变化与观察到的陈化大米米饭的峰值和最终黏度较高、糊化温度较低、硬度较大、粘性较低的结果一致。本研究可用于提出在不增加储存成本的情况下获得某些改善的功能特性的方法。
