Sodium caseinate (NaCN) obtained from A1A2 (regular) and A2 milks were compared for their viscosity, particle size and structure, and their absorption polystyrene particles surfaces. It was found that the viscosity as a function of concentration follows that of hard spheres dispersion, and is well described by the Quemada equation for concentrations up to 10 wt%, yielding a swelling ratio of Q=4.48 ± 0.01 mL/g. Dynamic light scattering measurements showed that the number and intensity average diameters were ∼10 and ∼68 nm, respectively. The difference is likely to be due to the presence of a few large NaCN particles. Small angle X-ray scattering showed that the radius of the particles was approximately ∼7 nm and that the NaCN internal structure was not homogeneous. NaCN formed a ∼10 nm protein layer at the surface of the latex particles with an estimated full surface coverage of 15.6 mg/m². While these findings are within the values reported in the literature for NaCN solutions, this study showed that there is no obvious difference between the NaCN derived from A1A2 and A2 milks.

比较了从A1A2（常规）和A2牛奶中获得的酪蛋白酸钠（NaCN）的粘度，粒度和结构，以及它们吸收的聚苯乙烯颗粒表面。发现粘度随浓度的变化遵循硬球分散的粘度，并且由Quemada方程很好地描述了浓度高达10 wt％时的溶胀率Q =4.48±0.01毫升/克 动态光散射测量表明，数均直径和强度平均直径分别为〜10和〜68 nm。差异可能是由于一些大的NaCN颗粒的存在。小角度X射线散射表明颗粒的半径约为〜7nm，并且NaCN内部结构不均匀。NaCN在乳胶颗粒的表面形成约10 nm的蛋白质层，估计的总表面覆盖率为15.6 mg / m ²。尽管这些发现在有关NaCN溶液的文献报道的值之内，但这项研究表明，源自A1A2和A2牛奶的NaCN之间没有明显差异。