激光粒度仪测定搅拌型酸奶粒径的研究

Particle size of stirred yoghurt with laser particle sizer

以搅拌型酸奶为研究对象,应用激光粒度仪检测酸奶的粒径,考察了不同因素对粒径测定的影响,同时,对市面上流行的八类酸奶的粒径进行了测试。结果表明:酸奶的粒径大小不仅与仪器的各种测试条件如搅拌速率、搅拌时间、超声强度、超声时间有关,而且与分散介质如水的pH值有关。另外,酸奶的粒径分布具有双峰特征,不同品牌的酸奶其粒径差异性明显,d_(0.1)、d_(0.5)、d_(0.9)及平均粒径分别在3.5~6.0μm、16~28μm、50~68μm、23~29μm。

The particle size of yoghurt was measured by laser particle size analyzer,and the influence of different factors on the determination of particle size was investigated.Meanwhile,the particle size of 8 kinds of popular yogurts on the market were measured.The results showed that the particle size of yoghurt was not only related to the several testing parameters such as stirring rate,stirring time,ultrasonic strength and ultrasonic time,but also to the pH value of dispersion media like water.In addition,yoghurt had the characterization of bimodal distribution,and there existed obvious differences on the particle size for different brands of yoghurt where d0.1,d0.5,d0.9 and average grain size were 3.5-6.0μm,16-28μm,50-68μm,23-29μm,respectively.