蛋白质用量和比例对淡奶油理化性质的影响

Effects of protein content and composition on the physicochemical properties of whipping cream

研究了酪朊酸钠用量及质量分数为3%的蛋白质用量下酪朊酸钠和大豆分离蛋白不同比例对淡奶油粒度分布、界面蛋白及流变学特性的影响,分析了其作用机理。结果表明:随着酪朊酸钠体积分数的增加,淡奶油上层粒径先减小后增大,在4%处达最小值,峰值为0.18μm,黏度和屈服应力增大,界面蛋白含量升高,界面蛋白浓度先减小后增大,剪切稀化程度先增强后减弱;蛋白质总用量为3%时,增加大豆分离蛋白比例,样品粒度增大,界面蛋白质量分数由2.96%降至2.56%,剪切速率为60s-1时黏度由0.154Pa·s增加至0.297Pa·s,屈服应力增大,剪切稀化加剧。

The effects of sodium caseinate content and proportion of sodium caseinate and soy protein on the droplet size distribution, surface protein and rheologieal properties of whipping cream were studied, and the possible mechanisms were also analyzed. Results show that with the increase in sodium caseinate, the particle size at the top cream decreases first and then increases, and sample of 4% gets the minimum value. The apparent viscosity, yield stress and surface protein content increase, while surface protein concentration increases first and then decreases; the shear-thinning characteristic is also improved first and then weakened. As the total protein content is fixed at 3%, with the increase in soy protein isolate ratio, the droplet size and yield stress increase, the shear-thinning characteristic is improved and the surface protein content decreases from 2. 96% to 2. 56%, the apparent viscosity increases from 0. 154 Pa·s to 0. 297 Pa·s at the shear rate of 60 s-1.