Division of Food Science and Technology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, 190025, India.
Department of Food Technology, Islamic University of Science and Technology, Awantipora, 192122, India.
Sci Rep. 2021 Jun 8;11(1):12047. doi: 10.1038/s41598-021-91537-0.
Eight commonly cultivated and consumed rice varieties of Northern Himalayan regions and a popular high amylose rice variety were characterized at Wx locus and evaluated for resistant starch (RS), in-vitro starch digestibility, predicted glycemic index (pGI), glycemic load (GL) and textural parameters. Cytosine and thymine repeats (CT)n at waxy locus (Wx) showed high association with apparent amylose content (AAC). Both pGI and GL varied substantially within the selected varieties. The pGI was relatively lower in high and intermediate amylose Indica varieties compared to low amylose Japonica ones. However, Koshikari despite being a low amylose variety showed relatively lower pGI and GL, due to its higher RS, dietary fiber, protein and fat content. It was thus presumed that in addition to AAC, RS and other grain components also affect the glycemic response. Inherent resistance to enzymatic hydrolysis was also found to be higher in firm textured and less sticky rice varieties. The genotypes-Lalat, Basmati-1509 and Koshikari, in view of their low to moderate pGI and relatively higher RS content, can be explored in future breeding programmes to develop rice varieties whose consumption will help to prevent hyper/hypo glycemic responses in Northern Himalayan regions, where daily staple diet is rice.
对来自喜马拉雅山北部地区的 8 个常见栽培和食用的水稻品种和一个受欢迎的高直链淀粉水稻品种在 Wx 基因座进行了特征描述，并评估了它们的抗性淀粉（RS）、体外淀粉消化率、预测血糖指数（pGI）、血糖负荷（GL）和质构参数。蜡质基因座（Wx）处的胞嘧啶和胸腺嘧啶重复（CT）n 与表观直链淀粉含量（AAC）高度相关。在所选择的品种中，pGI 和 GL 变化很大。与低直链淀粉粳稻品种相比，高直链淀粉籼稻和中直链淀粉籼稻品种的 pGI 相对较低。然而，Koshikari 尽管是低直链淀粉品种，但由于其 RS、膳食纤维、蛋白质和脂肪含量较高，其 pGI 和 GL 相对较低。因此，可以假定除 AAC 外，RS 和其他谷物成分也会影响血糖反应。还发现，在质地坚硬和粘性较低的大米品种中，对酶水解的固有抗性也较高。鉴于其低到中等的 pGI 和相对较高的 RS 含量，基因型 Lalat、Basmati-1509 和 Koshikari 可以在未来的育种计划中进行探索，以开发食用这些品种有助于预防喜马拉雅山北部地区高/低血糖反应的水稻品种，因为那里的日常主食是大米。
