Effects of post–silking low temperature on the physicochemical properties of waxy maize starch
Effects of post–silking low temperature on the physicochemical properties of waxy maize starch
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吐丝后低温对糯玉米淀粉理化性质的影响
DOI：
10.1016/j.ijbiomac.2021.07.171
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发表时间：
2021
影响因子：
8.2
通讯作者：
陆大雷
中科院分区：
文献类型：
--
作者：
杨欢;魏琪;陆卫平;陆大雷
生育后期低温是影响夏玉米籽粒品质的重要非生物胁迫。以苏玉糯5号和玉糯7号两个糯玉米杂交种为试材，研究了低温处理对淀粉结构和功能特性的影响。田间试验分别于7月1日（正常播种期）和8月1日（晚播期）播种。在盆栽试验中，植物在7月1日播种，在自然环境中生长直至吐丝，并经受两个吐丝后温度（常温和LT分别设定为28/20和23/15 °C）。结果表明，晚播（8月1日）或吐丝后低温处理的淀粉颗粒多为椭圆形多面体的小颗粒。低温胁迫淀粉中支链淀粉短链比例高，相对结晶度低。LT降低了糊化粘度、糊化焓和糊化温度，但增加了凝沉趋势。结果表明，低温条件下小麦淀粉糊化粘度降低，凝沉性增强，主要是由于淀粉颗粒尺寸、支链淀粉链长和RC降低所致。
Low temperature (LT) at late growth stages is an important abiotic stress that affects the grain end–use quality of summer maize. In the present work, two experiments were conducted to study the effects of LT on the structural and functional properties of starches using two waxy maize hybrids (‘Suyunuo5’ and ‘Yunuo7’). In field trial, the plants were sown on July 1 (normal sowing date) and August 1 (late sowing date). In pot trial, the plants were sown on July 1, grown at natural environment till silking, and suffered two post–silking temperatures (normal temperature and LT were set as 28/20 and 23/15 °C, respectively). The result showed that the starch was composed of more small granules with oval polytope when sown late (August 1) or subjected to LT post–silking. The LT–stressed starch presented high proportion of short amylopectin chains and low relative crystallinity (RC). LT reduced the pasting viscosity, gelatinization enthalpy, and gelatinization temperatures but increased the retrogradation tendency. In conclusion, the low pasting viscosity and high retrogradation tendency under LT condition were caused by the decreased granule size, amylopectin chain length, and RC.