超声辅助喷雾干燥对蛋清蛋白热聚集及凝胶特性的影响

Effects of Ultrasound-Assisted Spray Drying on Thermal Aggregation and Gel Properties of Egg White Protein

为探究超声辅助喷雾干燥(ultrasonic-spray drying,U-SD)对蛋清蛋白的热聚集及凝胶品质的影响,以喷雾干燥(spray drying,SD)、真空冷冻干燥(vacuum freeze drying,FD)为对照,对所制备的蛋清粉凝胶的分子分布、结构和流变学性能、持水性、质构特性等进行测定。结果表明:超声预处理使蛋白质发生了大分子聚集;蛋清蛋白主要表现为黏弹性流体性质;U-SD蛋清蛋白的二级结构含量中α-螺旋与β-折叠含量均稍有增加;U-SD蛋清粉的凝胶硬度最大,其中弹性、咀嚼性和回弹性均显著大于其他组(P<0.05),失水率显著降低(P<0.05),表现出更好的凝胶特性;荧光显微镜证实超声辅助处理可以促进蛋清蛋白发生强烈的聚集。

The effects of ultrasound-assisted spray drying(U-SD)on the thermal aggregation and gel properties of egg white powder were studied.Spray drying(SD)and vacuum freeze drying(FD)were taken as the controls.The molecular distribution,structure,rheological properties,water holding capacity,and texture properties of the egg white powder gel prepared by U-SD were analyzed.The results showed that the macromolecules were aggregated by ultrasonic pretreatment.The egg white powder gel mainly presented the property of viscoelastic fluid.The content ofα-helices andβ-sheets in the egg white protein prepared with U-SD increased slightly compared with that in other groups.The egg white powder prepared with U-SD had the largest gel hardness,higher elasticity,chewiness,and resilience,and lower water loss rate than other groups(P<0.05),demonstrating better gel properties.Fluorescence microscopy showed that the ultrasonic pretreatment promoted the strong aggregation of egg white protein.