Key Laboratory of Crop Genetics and Physiology of Jiangsu Province / Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, 225009, China; Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province / Joint International Research Laboratory of Agriculture & Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
Key Laboratory of Crop Genetics and Physiology of Jiangsu Province / Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, 225009, China; Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province / Joint International Research Laboratory of Agriculture & Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
Food Chem. 2024 Nov 30;459:140392. doi: 10.1016/j.foodchem.2024.140392. Epub 2024 Jul 14.
Three rice varieties underwent the field natural extreme high temperature (EHT) with daily average temperature over 30 °C from 21 to 89 days after sowing, and had transparent, chalky and floury grains. The structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains were investigated. Compared with control transparent grains, floury grains subjected to EHT markedly decreased the contents of amylose molecules, amylopectin A chains and amylopectin B1 chains and increased the contents of amylopectin B2 and B3+ chains and the average branch-chain length of amylopectin. Both transparent and floury grains had A-type starches, but floury grain starches exhibited higher relative crystallinity, gelatinization temperature, retrogradation and pasting viscosities than transparent grain starches. Floury grain starches had lower hydrolysis rates than transparent grain starches. Native starches were more resistant to digestion but gelatinized and retrograded starches were more prone to digestion in floury grains than in transparent grains.
三种水稻品种在播种后第 21 至 89 天经历了田间自然极端高温（EHT），日平均温度超过 30°C，产生了透明、粉质和垩白的籽粒。研究了透明和粉质籽粒中原淀粉的结构、糊化特性和酶水解。与对照透明籽粒相比，经历 EHT 的粉质籽粒显著降低了直链淀粉分子、支链淀粉 A 链和支链淀粉 B1 链的含量，增加了支链淀粉 B2 和 B3+链以及支链淀粉平均支链长度的含量。透明和粉质籽粒均具有 A 型淀粉，但粉质籽粒淀粉表现出更高的相对结晶度、糊化温度、回生和糊化粘度。粉质籽粒淀粉的水解速率低于透明籽粒淀粉。天然淀粉的消化抗性更高，但在粉质籽粒中，糊化和回生淀粉比透明籽粒更容易消化。
