Effects of dynamic low temperature during the grain filling stage on starch morphological structure, physicochemical properties, and eating quality of soft japonica rice
Effects of dynamic low temperature during the grain filling stage on starch morphological structure, physicochemical properties, and eating quality of soft japonica rice
复制标题
灌浆期动态低温对软粳淀粉形态结构、理化性质及食味品质的影响
DOI：
10.1002/cche.10268
复制
发表时间：
2020-02-20
期刊：
影响因子：
2.4
通讯作者：
Zhang, Hongcheng
中科院分区：
文献类型：
--
作者：
Hu, Yajie;Li, Luan;Zhang, Hongcheng
背景与目的灌浆期温度是影响稻米品质和淀粉理化特性的重要环境因子。以两个软质粳稻品种为材料，研究了不同成熟动态温度下稻米淀粉的形态结构、糊化特性、糊化特性以及米饭的整体感官品质。结果表明：与常温（NT）相比，灌浆期动态低温（LT）处理增加了稻米直链淀粉含量，并显著影响了淀粉的结晶结构。这些结构变化包括相对结晶度、IR比（1，045/1，022 cm（-1））、片层峰强度和片层间距的降低。对于糊化特性，LT增加了消减值，降低了峰值、谷值、最终粘度和崩解值。但LT降低了糊化温度和糊化焓。结论灌浆期低温导致米饭食味品质劣变，其原因可能是直链淀粉含量高、糊化粘度低、糊化温度低、灌浆期平均温度为22 ℃，通过提高糊化特性和胶稠度，改善了软质粳稻的食味品质。
Background and objectives Temperature during the grain filling stage is the critical environmental factor affecting rice quality and starch physicochemical properties. Two soft japonica rice varieties were used to investigate starch morphological structure, gelatinization, and pasting properties, as well as the overall sensory quality of cooked rice under different ripening dynamic temperatures.Findings Compared to normal temperature (NT), dynamic low temperature (LT) during the grain filling stage increased amylose content and significantly influenced the crystalline structure of starch. These structural changes included the reduction in the relative crystallinity, IR ratio of 1,045/1,022 cm(-1), the lamellar peak intensity, and lamellar distance. With regard to pasting properties, LT increased the setback and decreased the peak, trough, final viscosities, and breakdown. However, LT reduced gelatinization temperature and enthalpy. For eating quality, the palatability of cooked rice under LT decreased, which was related to higher hardness as well as lower stickiness and gel consistency.Conclusions Low temperature during grain filling led to the deterioration of eating quality of cooked rice, and this deterioration could be attributed to high amylose content, low pasting viscosity, and reduced gel consistency.Significance and novelty The mean temperature at 22 degrees C during the grain filling stage improved eating quality in soft japonica rice by enhancing pasting properties and gel consistency.