【作者】 范震； 李慧静； 张波；

【Author】 Fan Zhen;Li Huijing;Zhang Bo;Institute of Agricultural Products Processing,Chinese Academy of Agricultural Sciences,Integrated Laboratory of Grain and Oil Processing and Comprehensive Utilization Technology,Ministry of Agriculture and Rural Affairs;School of Food Science and Technology,Hebei Agricultural University;

【机构】 中国农业科学院农产品加工研究所农业农村部粮油加工综合利用技术集成实验室； 河北农业大学食品科技学院；

【摘要】 离子键、氢键、疏水相互作用等非共价键和二硫键共价键是维持小麦蛋白空间结构的主要作用,其占比的变化可能是小麦加工特性差异的本质。相互作用占比可采用溶解和溶胀程度来表征,其原理在于特定溶剂破坏相互作用后提高了蛋白质的溶解度,蛋白质在溶解前会发生溶胀。采用0.05 mol/L和0.6 mol/L两个不同浓度梯度的氯化钾、氯化钠盐溶液中溶解度差可以表征小麦蛋白中离子键数量。添加1.5 mol/L尿素和未添加尿素溶解度差可以表征小麦蛋白中氢键数量。添加2%十二烷基硫酸钠溶液和未添加溶解度差可以表征小麦蛋白中疏水相互作用数量。谷蛋白溶胀值、Zeleny沉降指数、持溶剂力等指标反映蛋白质的溶胀程度。二硫键采用0.1%DTT或巯基乙醇来还原,可结合非共价相互作用破坏的基础上检测链间和链内的二硫键。需注意的是如特定溶剂中包含氮元素的,在蛋白质检测方法上需采用三氯乙酸将蛋白质氮沉淀后再检测,以避免非蛋白氮对结果的干扰。更多还原

【Abstract】 Non covalent bonds such as ionic bond,hydrogen bond and hydrophobic interactions,and covalent bonds such as disulfide bonds play a key role in maintaining the network structure of wheat proteins,and their changes in proportion may be the essence of differences in wheat processing characteristics.The proportion of interaction can be characterized by solubility and swelling behavior of proteins,which is based on the principle that specific solvents increase the solubility of proteins after disrupting the interaction and swelling occurs before protein dissolution.The proportion of ionic bond can be characterized by the differences in soluble proteins between samples added 0.05 mol/L NaCl and 0.6 mol/L NaCl,hydrogen bond between 0.6 mol/L NaCl and 0.6 mol/L NaCl+1.5 mol/L Urea,and hydrophobic interactions between 0.6 mol/L NaCl and 0.6 mol/L NaCl+2% SDS.The swelling behavior of wheat proteins can be characterized by swelling index of glutenin,Zeleny sedimentation index and solvent holding capacity.The disulfide bond is reduced using 0.1 % DTT or mercaptoethanol,and intra-chain and inter-chain disulfide bond can be measured after breaking non-covolent bonds in wheat protein.It should be noted that if nitrogen exists in the solvent,trichloroacetic acid shall be used to precipitate the nitrogen in proteins before detection to avoid interference from non-protein nitrogen.更多还原