干燥方法对大豆分离蛋白热诱导聚集体的影响  

Effects of drying method on heat-induced aggregate of soy protein isolate

作　　者：李向红[1] 刘展 李伟 华欲飞[3] 裘爱泳[3] 

机构地区：[1]长沙理工大学化学与生物工程学院,长沙410076 [2]宁波中普检测技术服务有限公司,宁波315192 [3]江南大学食品学院,食品科学与技术国家重点实验室,无锡214122

出　　处：《农业工程学报》2008年第10期258-261,共4页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(20476040);江苏省自然科学基金(BK2005011)

摘　　要：为了深入了解干燥方法对大豆蛋白热聚集体的影响,从而有利于控制大豆制品的结构和质构,该文比较了常用的两种干燥方法对大豆分离蛋白热聚集体的分子量分布、粒径分布以及二级结构的影响。体积排阻色谱(SEC-HPLC)分析结果表明干燥前蛋白溶液主要由三部分组成(即聚集体,中间体以及未聚集部分),随着浓度的增加聚集体部分相应增加,冷冻干燥后样品的中间体显著减少,聚集体部分增加明显,喷雾干燥后中间体部分基本消失;激光光散射(LLS)的结果进一步证明干燥后的蛋白质聚集体具有较为均匀的粒径分布且体系的平均粒径增加;红外分析结果显示α-螺旋和无规卷曲都略有降低,但是β-折叠有明显的增加。上述结果表明干燥过程中聚集体体系的结构发生了重组,形成了尺寸较大且分布更为均匀的结构,这对在生产中选择合适的干燥方式,更好的控制大豆分离蛋白的聚集及凝胶结构有一定的指导意义。In order to understand the effects of drying method on the heat-induced aggregates and control the structure and texture of soy product, this paper studied the molecular weight distribution, particle size distribution and secondary structure of heat aggregated soy protein isolate obtained by freeze-drying and spray-drying. SEC-HPLC revealed that the heated solution without drying was composed of three major fractions （aggregates, intermediate fractions and un-aggregated molecules） and the aggregate fraction increased at higher protein concentration. After freeze-drying, the sample had lower intermediate fraction and higher aggregate fraction, but after spray-drying, the intermediate fraction disappeared. At the same time, LLS showed the more homogeneous particle size distributions with the average hydrodynamic radius increased when the heat aggregated soy protein isolates were dried. FT-IR analysis of the dried samples demonstrated that there was a small decrease in the α-helix and random coil components, and an increase in the proportion of the β-sheet. These results showed that the structure of the aggregate rearranged during drying, and a more uniform structure with larger size formed. These experiments suggested novel strategies for producing soy protein aggregates and gels with controlled properties.

关 键 词：冷冻干燥 喷雾干燥 大豆分离蛋白 热聚集体 介观尺度 二级结构 

分 类 号：TS201[轻工技术与工程—食品科学]