大米陈化对淀粉颗粒间解聚和米胶质构的影响  

Effects of rice aging on disaggregation of starch granules and gel texture

作　　者：宋睿 郭玉宝[1] 朱世民 魏秦 刘昕煜 SONG Rui;GUO Yubao;ZHU Shimin;WEI Qin;LIU Xinyu(School of Biological and Food Engineering,Anhui Polytechnic University,Wuhu 241000,China)

机构地区：[1]安徽工程大学生物与食品工程学院,安徽芜湖241000

出　　处：《食品与发酵工业》2023年第9期238-243,251,共7页Food and Fermentation Industries

基　　金：国家自然科学基金面上项目(31671784)。

摘　　要：以相同粒度的武育粳3号新米和陈米的米粉粒子为研究对象,考察陈化对不同加热温度下粒径分布、显微形态、水合性质和米胶质构的影响,揭示陈化后大米中淀粉颗粒间解聚变化对米胶质构的影响,增强对陈化引起大米食用品质劣变机制的理解。结果表明,随着加热温度的升高,陈化后小粒径峰体积分数显著降低,且陈化使小粒径峰体积分数的降低幅度比新米更快,光学显微结果较好地支持了粒度分析结果。扫描电镜表明,陈化及高温下只有米粉粒子表面的淀粉颗粒发生解离,内部的淀粉颗粒间仍聚集在一起。同时,新米和陈米的米胶硬度和黏聚性随加热温度升高显著增大,可能是未解离的大颗粒支撑作用所致;陈米的米胶硬度更高而黏聚性更低,暗示陈化后所剩大颗粒在二次压缩时对外力的抵抗力降低,粒度分析结果较好地解释了米胶质构的变化。这些结果说明,淀粉颗粒间难以解聚是陈化后米胶质构变化的潜在原因,这有助于加深对稻米陈化机制的理解,也为改善稻米食用品质提供了实验依据。In this study,the effects of heating temperature on particle size distribution,microscopic morphology,hydration properties,and gel texture of fresh and aged rice flour particles with the same particle size as cultivar Wuyujing 3 were investigated to reveal the effects of disaggregation changes of starch granules after aging on rice gel texture and enhance the understanding of deterioration mechanism of rice eating quality caused by aging.Results showed that the small particle size peak volume fraction significantly decreased after aging,and aging made the reduction of peak volume fraction of small particle size faster.The light microscopy was consistent with the particle size analysis results.Scanning electron microscope showed that only the starch granules on the surface of rice flour particles could disaggregate at higher temperatures and after aging,while the starch granules inside were still aggregated together.Meanwhile,with the increase in heating temperature,the hardness and cohesiveness of rice gel of fresh rice and aged rice increased significantly,which may be caused by the skeletal role of the remaining larger particles.The higher hardness and lower cohesiveness of aged rice gel suggest that the resistance of the remaining larger particles to external forces decreased at the second compression.The results of particle size analysis well supported the change of rice gel texture.These results suggested that the difficulty of disaggregation between starch granules was the underlying reason for the change of gel texture after rice aging,which could be helpful to deepen the understanding of the rice aging mechanism and provide an experimental basis for improving rice eating quality.

关 键 词：大米 陈化 加热温度 淀粉颗粒 解聚 米胶质构 

分 类 号：TS231[轻工技术与工程—粮食、油脂及植物蛋白工程]