双螺杆挤压对山药淀粉与大豆分离蛋白复合物结构和性能的影响

Effects of Twin-Screw Extrusion on the Structure and Properties of Yam Starch and Soybean Protein Isolate Complex

研究了双螺杆挤压处理对山药淀粉与大豆分离蛋白复合物的影响,以及添加不同替代量的挤压粉对面团的影响。以山药淀粉为原料,添加不同比例的大豆分离蛋白后进行挤压,挤压粉替代部分小麦粉制备成面团,测定挤压粉的溶解度和膨胀度、糊化特性以及添加挤压粉前后面团的流变学特性等。结果表明,天然山药淀粉和山药淀粉与大豆分离蛋白复合物经过挤压后结构破裂、不完整,表面凹凸不平,大豆分离蛋白含量越多,挤压后结构越粗糙。挤压处理后的样品与未处理组相比,膨胀度降低,溶解度升高,峰值黏度和崩解值等糊化参数均降低,大豆分离蛋白含量越多,膨胀度越高,溶解度越低,糊化参数值越低。挤压粉添加至面团中后,质构特性、弹性模量(G′)和黏性模量(G″)发生改变,但G′始终高于G″,呈现固体性质。添加了挤压粉的小麦粉制备的面团的G′和G″轻微降低,硬度、弹性、黏性、咀嚼性降低,而添加量为5%的挤压粉比添加量为10%的挤压粉表现出的黏弹性好。但当挤压粉中大豆分离蛋白添加量达到50%时,黏弹性、硬度与对照组相近。因此,大豆分离蛋白的加入会影响食品的挤压工艺,为山药淀粉的开发提供了新思路。同时,也可以通过挤压粉来改变面团的硬度和黏弹性等性质。

In this paper,the effect of twin-screw extrusion treatment on the yam starch and soybean protein isolate complex and the effect of adding different amount of extruded flour on the dough are studied.Take yam starch as the raw material,add different proportions of soybean protein isolate and then extrude,replace part of wheat flour with extruded flour to prepare dough,and the solubility,dilatation,gelatinization of the extruded flour and rheological properties of dough before and after adding the extruded flour are measured.The results show that the structure of natural yam starch and yam starch-soybean protein isolate complex is broken and incomplete after extrusion,and the surface is uneven.The higher the content of soybean protein isolate,the rougher the structure after extrusion.Compared with the untreated samples,the extruded samples have lower dilatation,higher solubility and lower gelatinization parameters such as peak viscosity and disintegration value.The higher the content of soybean protein isolate,the higher the dilatation,the lower the solubility,the lower the gelatinization parameter value.When extruded flour is added into dough,the texture properties,elasticity modulus(G')and viscosity modulus(G")change,but G'is always higher than G",showing solid properties.The G'and G" of the dough prepared with wheat flour added with extruded flour slightly decrease,and the hardness,elasticity,viscosity and chewiness decrease.5%addition amount of extruded flour shows better viscoelasticity than that of 10%addition amount of extruded flour.However,when the content of soybean protein isolate in extruded flour reaches 50%,the viscoelasticity and hardness are similar to those of control group.Therefore,the addition of soybean protein isolate will affect the extrusion process of food,which has provided a new idea for the development of yam starch.At the same time,the hardness and viscoelasticity of dough can be changed by extruded flour.