摘要
本实验以大豆分离蛋白(soy protein isolate,SPI)为原料,在不同挤压系统参数下对大豆分离蛋白进行挤压,通过测定蛋白质溶解度、Zeta电位、粒径、蛋白质亚基及蛋白质二级结构,研究挤压温度、物料水分质量分数和螺杆转速条件对大豆蛋白构象的影响,揭示大豆拉丝蛋白形成机理。结果表明,随着挤压温度升高,SPI天然结构被破坏,内部巯基基团暴露,二硫键含量的增加促使蛋白形成团聚体,过高或过低的温度均不利于蛋白质聚集和形成稳定状态;在过低或过高物料水分质量分数条件下,挤出模口难以形成较完整的挤出物,物料水分质量分数在20%~22%时因水的保护作用使得挤出物状态最佳,形成体系均一的SPI聚集体。较低的螺杆转速(130 r/min以下)会使机械能输入不足,蛋白质不能完全变性和解聚;较高的螺杆转速(140 r/min以上)条件下,高剪切力促进了蛋白质原有天然结构的破坏,形成了分子质量较大的蛋白质聚集体。综上,在适当的挤出条件下挤压处理有助于获得最佳的挤出物品质,过于极端的挤出条件会造成挤出物成型困难或质地不均匀。本研究可为大豆拉丝蛋白品质优化提供理论依据。
The study investigated the effect of different extrusion parameters:temperature,material moisture of raw material,and screw speed on the conformation of soybean protein.After being extruded,soy protein isolate(SPI)was measured for protein solubility,zeta potential,particle size,protein subunits and protein secondary structure.Additionally,the formation mechanism of fibrous soybean protein was uncovered.The results showed that with an increase in extrusion temperature,the natural structure of SPI was destroyed,the internal groups were exposed,and the content of disulfide bonds increased,promoting the formation of protein aggregates.Too high or too low temperature was not conducive to the formation and stability of protein aggregates.At too low or too high raw material moisture content,a relatively complete extrudate was difficult to form at the extrusion mouth,while at raw material moisture contents of 20%–22%,the extrudate was in the best state due to the protective effect of water,and a uniform SPI aggregate was formed.Low screw speed(below 130 r/min)could lead to insufficient mechanical energy input,so that the protein was not completely denatured and depolymerized.While at high screw speed(above 140 r/min),the effect of high shear force promotes the destruction of the original natural structure of proteins,resulting in the formation of large protein aggregates.In summary,under appropriate extrusion conditions,the optimal extrudate quality can be obtained,while extreme extrusion conditions make extrusion molding difficult or result in nonuniform texture.This study can provide a theoretical basis for optimizing the quality of fibrous soybean protein.
作者
张浩嘉
朱秀清
孙莹
ZHANG Haojia;ZHU Xiuqing;SUN Ying(College of Food Engineering,Harbin University of Commerce,Harbin 150028,China;Tourism&Cuisine College,Harbin University of Commerce,Harbin 150028,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2023年第15期103-112,共10页
Food Science
基金
黑龙江省“百千万”工程科技重大专项(2021ZX12B04)。
关键词
双螺杆挤压
大豆蛋白
挤压参数
结构
twin-screw extrusion
soy protein
extrusion parameters
structure
