自然发酵对小米淀粉分子结构及凝胶特性的影响  

Effect of Natural Fermentation on the Gel Properties and Molecular Structure of Millet Starch

作　　者：曹龙奎[1,2] 寇芳[1] 康丽君[1] 沈蒙[1] 宁冬雪 夏甜天 王维浩[1,2] CAO Longkui;KOU Fang;KANG Lijun;SHEN Meng;NING Dongxue;XIA Tiantian;WANG Weihao(College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China;National Cereals Engineering Technology Research Center, Daqing 163319, China)

机构地区：[1]黑龙江八一农垦大学食品学院,黑龙江大庆163319 [2]国家杂粮工程技术研究中心,黑龙江大庆163319

出　　处：《食品科学》2017年第14期127-131,共5页Food Science

基　　金：黑龙江省重大科技攻关项目(GA15B301);黑龙江八一农垦大学研究生创新科研项目(YJSCX2017-Y54)

摘　　要：研究自然发酵对小米淀粉凝胶特性及分子结构的影响,旨在为发酵小米淀粉改性机理的研究提供理论基础,为实现机械化、产业化生产发酵小米制品提供科学依据。采用内蒙古黄金苗小米自然发酵144 h,研究发酵对小米淀粉分子结构的影响,分析小米淀粉凝胶特性的变化,结果:自然发酵使小米淀粉的颗粒表面遭到侵蚀,但发酵未改变淀粉的A型结晶;发酵后淀粉的基团峰位未发生变化,但峰强减弱;发酵后Ⅰ区(支链淀粉)、Ⅱ区(直链淀粉)的重均分子质量降低,数均分子质量升高,未发酵小米淀粉的重均分子质量为2.5×10~4~5.9×10~5 g/mol,发酵后小米淀粉重均分子质量为2.2×10~4~5.4×10~5 g/mol。发酵后小米淀粉的回生值、最终黏度较未发酵小米淀粉降低425、470 m Pa·s;糊化温度、热焓值分别上升1.62℃、7.05 J/g;发酵后淀粉凝胶的硬度降低60.735 g,弹性降低0.707,且发酵96 h后,淀粉的凝胶特性基本趋于平稳。自然发酵后小米淀粉的分子结构发生变化,淀粉的凝胶特性改变,更适宜生产利用淀粉抗老化特性制得的产品。In this study,we investigated the effect of natural fermentation on the gel properties and molecular structure ofmillet starch,aiming to provide a scientific and theoretical basis for the study of the mechanism of the modification of milletstarch after fermentation for mechanized and industrial production of fermented millet products.Changes in the molecularstructure and gel properties of millet starch(the‘Huangjinmiao’variety from Inner Mongolia)were examined after144hof natural fermentation.The results were showed that the surface of fermented starch granules was eroded,whereas thecrystalline structure did not change and remained A-type.The position of X-ray diffraction peaks of starch granules did notchange after fermentation,but the peak intensity was reduced.Moreover,the weight-average molecular mass of both regionⅠ(amylopectin)andⅡ(amylose)was decreased from2.5×104–5.9×105to2.2×104–5.4×105g/mol and the numberaveragemolecular mass was increased.The setback,peak viscosity of millet starch were decreased by425and470mPa·s ascompared to those before fermentation,gelatinization temperature and enthalpy value were increased by1.62℃and7.05J/g,and gel hardness and elasticity were decreased by60.735g and0.707,respectively.After fermentation for96h,the gel propertiesof starch tended to be stable.The findings revealed that both the molecular structure and gel properties of millet starch after naturalfermentation were changed,being more suitable for the production of starch products with resistance to retrogradation.

关 键 词：自然发酵 淀粉 凝胶特性 分子结构 

分 类 号：TS231[轻工技术与工程—粮食、油脂及植物蛋白工程]