灌浆期不同时段高温对稻米淀粉理化特性的影响  

Effects of High Temperature in Various Phases of Grain Filling on Rice Starch Physicochemical Properties

作　　者：沈泓[1] 姚栋萍 吴俊[1] 罗秋红 吴志鹏 雷东阳[2] 邓启云[1] 柏斌[1] SHEN Hong;YAO Dongping;WU Jun;LUO Qiuhong;WU Zhipeng;LEI Dongyang;DENG Qiyun;BAI Bin(State Key Laboratory of Hybrid Rice,Hunan Hybrid Rice Research Center,Changsha 410125,China;College of Agronomy,Hunan Agricultural University,Changsha 410128,China;Agricultural and Rural Bureau of Dong'an County,Yongzhou 425900,China)

机构地区：[1]湖南杂交水稻研究中心杂交水稻国家重点实验室,长沙410125 [2]湖南农业大学农学院,长沙410128 [3]东安县农业农村局,湖南永州425900

出　　处：《中国水稻科学》2022年第4期377-387,共11页Chinese Journal of Rice Science

基　　金：三亚崖州湾科技城管理局2020年度科技计划资助项目(SKJC-2020-02-006);湖南省作物种质创新与资源利用重点实验室科学基金开放项目(19KFXM09)。

摘　　要：【目的】研究灌浆期不同时段高温对稻米淀粉组成、结构和理化特性的影响,揭示高温对稻米淀粉理化特性影响的时段效应,阐明高温、结构和功能之间的关系。【方法】以耐热水稻品种黄华占和热敏感的9311近等位基因系为实验材料,利用人工气候箱设置高温[38℃(昼)/30℃(夜)]和对照[28℃(昼)/22℃(夜)],研究灌浆前期(齐穗期后1-15 d)和后期(齐穗期后16 d至成熟)高温对稻米的加工品质、外观品质、淀粉组成、支链淀粉链长分布、粒度分布、胶稠度、黏度特性、糊化特性、结晶特性和颗粒形态的影响。【结果】灌浆期高温使糙米率、精米率、整精米率显著下降,使垩白粒率和垩白度显著升高,导致加工品质和外观品质变差。灌浆期高温使总淀粉含量、直链淀粉含量、短支链淀粉含量、大淀粉粒占比、直/支链淀粉比显著下降,而中等支链淀粉含量、小中淀粉粒占比、糊化温度和糊化焓显著上升,黏度特性显著改变,结晶类型不变但结晶度显著改变,淀粉颗粒表面出现小孔,表面变得凹凸不平,导致淀粉颗粒更加碎片化和蒸煮食味品质变劣。灌浆期不同时段高温对稻米品质的影响不同,灌浆前期高温对稻米淀粉的影响大于灌浆后期,耐热品种受影响小于热敏感品种。灌浆前期高温处理下供试材料具有较高的消减值和较低的崩解值,黏度特性变差;灌浆后期高温处理下供试材料具有较低的消减值和较高的崩解值,黏度特性变好。【结论】灌浆前期高温对淀粉理化特性的影响最大,进而导致稻米的加工品质、外观品质和蒸煮食味品质变劣,灌浆后期高温提升了黏度特性。【Objective】The effects of high temperature on the composition,structure and physicochemical properties of rice starch at different parts of grain filling were studied to reveal the effect of high temperature and the relationship among high temperature,structure and function.【Method】Heat-tolerant Huanghuazhan and heat-sensitive near-isogenic lines of 9311 were used as experimental materials.The experiment was conducted in artificial climate boxes at high temperature(38℃/30℃)and control temperature(28℃/22℃)to clarify the effects of high temperature during early(1-15 d after full heading)and late(from 16 d after full heading to maturity)grain-filling on rice processing quality,appearance quality,starch composition,amylopectin chain length distribution,particle size distribution,gel consistency,viscosity,gelatinization,crystalline properties and starch granule morphology.【Result】High temperature at grain-filling stage significantly reduced brown rice rate,polished rice rate and head milled rice rate,but significantly increased chalky grain rate and chalkiness,resulting in poor processing and appearance quality.High temperature during grain filling obviously decreased total starch contents,amylose content,short chain amylopectin content,percentage of large granule,amylose/amylopectin ratio,while increased medium chain amylopectin content,percentage of small&medium granule and gelatinization temperature,gelatinization enthalpy and significantly affected viscosity properties,relative crystallinity with same crystalline type,as well as pitting and unevenness on the surface of the starch granules,making starch granules more fragmented and cooking and eating quality worse.The effects of high temperature at different times of grain filling stage on rice quality were different.The damage degree of high temperature at early grain filling stage was greater than that at late grain filling,and the effect on the heat-tolerant variety was less than that of the heat-sensitive variety.The high temperature at earl

关 键 词：水稻 灌浆期 高温 淀粉组成 理化特性 

分 类 号：S511[农业科学—作物学]