湿热处理对大米淀粉多层次结构及消化特性的影响  

Effect of Heat-moisture Treatment on the Digestibility and Multi-scale Structures of Rice Starch

作　　者：王宏伟[1] 李晓玺[1] 黄吉东 陈玲[1] 

机构地区：[1]华南理工大学食品科学与工程学院、华南理工大学淀粉与植物蛋白深加工教育部工程研究中心、广东省天然产物绿色加工与产品安全重点实验室,广东广州510640 [2]广东中轻枫泰生化科技有限公司,广东茂名525427

出　　处：《现代食品科技》2017年第6期184-188,157,共6页Modern Food Science and Technology

基　　金：“十三五”国家重点研发计划项目(2016YFD04012021);国家自然科学基金-广东省联合基金重点项目(U1501214);广东省“扬帆计划”引进创新创业团队专项资助(2014YT02S029)

摘　　要：为了明晰湿热处理前后大米淀粉多层次结构与消化性能之间的关系,本研究采用体外模拟法测定湿热处理前后大米淀粉的消化性能,并通过小角X射线散射(SAXS)、X射线衍射(XRD)和凝胶渗透色谱-多角度激光光散射(GPC-MALS)等现代分析技术考察湿热处理前后大米淀粉不同层次结构的变化。研究表明,湿热处理可引起大米淀粉半结晶片层的有序化程度下降,降低其结晶程度和分子量;同时,伴随着淀粉颗粒内部层状、结晶及分子链结构的破坏,淀粉-脂质复合物的形成及Mw>2×107 g/mol的高分子量片段的降低和Mw<5×106 g/mol的低分子量片段比例的增加(0%增至21.3%)有利于大米淀粉慢消化和抗消化性能的提高,而当Mw<5×106 g/mol比例增至32.1%时,可能由于低分子量片段较多,反而阻碍了慢消化和抗消化性能的提高。研究结果为湿热处理加工技术调控淀粉及淀粉质食品的消化性能提供了理论支撑和基础数据。To understand the relationship between the multi-scale structures of rice starch and its digestibility before and after heat-moisture treatment（HMT）, the digestibility levels of rice starch before and after HMT were determined by in vitro simulation HMT-induced alterations in the multi-scale structures of rice starch were evaluated by small-angle X-ray scattering, X-ray diffraction, and gel permeation chromatography coupled with multi-angle light scattering. The study showed that the degree of the semi-crystalline lamellae order, relative crystallinity, and molecular weight of rice starch were reduced by HMT. Additionally, damage to the crystalline, lamellar, and chain structures inside the starch granules, formation of V amylose-lipid complex, decreased levels of high-molecular weight（Mw〉2×107 g/mol） fragments, and an increased proportion（0% to 21.3%） of low-molecular weight（Mw〈5×106 g/mol） fragments favored the formation of slowly digestible starch and resistant starch.. However, when the proportion of the starch fragment with Mw〈5×106 g/mol was increased to 32.1%, excess low-molecular weight fragments lead to the formation of rapidly digestible starch. The results provide a theoretical basis and basic data for the adjustment and control of the digestibility of novel functional starch and/or starchy products by using HMT.

关 键 词：大米淀粉 湿热处理 消化性能 结构 

分 类 号：TS235.1[轻工技术与工程—粮食、油脂及植物蛋白工程]