Appearance and Size of Micelles from Bovine Milk

Electron micrographs of a number of milks from individual cows were prepared by a replica method technique, and average micelle diameters determined by appropriate calculations based on visual counts o the number of micelles in various size ranges. The milks were also analyzed for several inorganic constituents and proteins, and their stability at 140 C detcrnfined. Results indicate that the major factors influencing mieelle size were total soluble calcium and n-casein (as a per cent of total casein). Citrate concentration was also related to micelle diameter, but this is thought to be an indirect effect, as citrate was the major factor influencing the concentration of sol-ubIe calcium. Ionie calcium was not significantly related to average nficelle diameter.