韧化及湿热处理对大米淀粉理化特性和微观结构的影响  

Effects of annealing and heat- moisture treatment on the rice starch physicochemical properties and microstructure

作　　者：刘成梅[1] 杨晓会[1] 钟业俊[1] 徐梦涵[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《食品工业科技》2016年第5期49-53,共5页Science and Technology of Food Industry

基　　金："十二五"国家科技支撑计划(2012BAD37B02-02);农业部热带作物产品加工重点实验室开放基金(KLTCPP-201404)

摘　　要：针对目前鲜有的韧化和湿热处理对大米淀粉改性效果的对比研究,本文采用韧化及湿热处理大米淀粉,对比分析韧化处理和湿热处理对大米淀粉溶解度、膨胀度、消化性、糊化特性、微观结构及晶体结构的影响。结果显示,经韧化处理后,淀粉溶解度、膨胀度及还原糖释放率上升,凝胶强度升高,淀粉更易于糊化,但热稳定性降低;而经湿热处理后,淀粉溶解度、膨胀度和还原糖释放率明显降低,糊化凝胶强度减小,且更难于糊化,但淀粉的热稳定性提高,回生性降低。X-衍射分析表明,处理后大米淀粉依然为"A"型图谱,但结晶度逐步下降,韧化处理1 d及湿热处理6 h后降幅明显。扫描电镜显示,棱角分明的淀粉颗粒经韧化处理后,淀粉棱角逐渐熔化,颗粒逐步链状粘结、团聚链变长;而湿热处理后淀粉颗粒逐渐熔化至融合。由此可知,高含水量淀粉经热处理后凝胶强度更高,溶解性及膨胀性更好;而较低含水量淀粉经热处理后消化性更低、热稳定性更好。At present ,there is little reports about the modification effects of annealing and heat-moisture treatment on the rice starch.In our research,rice starch was modified by annealing and heat-moisture treatment,the effects of annealing and heat-moisture treatment on the rice starch solubility, swelling degree, digestibility, pasting properties, microstructure and crystal structure were compared and analyzed.It was found that, after annealing,the solubility,swelling degree and reducing sugar release rate of rice starch were increased slightly, the starch gel showed higher strength, and it was easier to be pasted, but the thermal stability of rice starch was lower.While after heat-moisture treatment ,the solubility, swelling degree and reducing sugar release rate of rice starch was found to be decreased significantly,the strength of its gel was lower,and it was also difficult to be pasted, but its thermal stability was higher and the retrogradation of starch was decreased.X-ray diffraction pattern showed that rice starch modified by these treatments still showed A-type crysatllinity, but its crystallinity was decreased gradually, and after annealing 1 d or being heat-moisture treated for 6 h, it fell significantly.The SEM results showed that, after annealing treatment,the starch angular began to melt,the particles gradually bonded together and formed a long- chain line,while after being heat-moisture treated,the starch particles gradually melted and fused.It was clear that the gel strength of starch with high moisture content was higher after heat treatment,and the solubility and swelling power was also better, but the digestibility of starch with low moisture content was lower after heat treatment, and the thermal stability was imloroved.

关 键 词：大米淀粉 韧化处理 湿热处理 理化特性 微观结构 

分 类 号：TS231[轻工技术与工程—粮食、油脂及植物蛋白工程]