Measurement of the partition of some milk constituents between the dissolved and colloidal phases

Abstract

The freezing point and pH of milk ultrafiltrate were different from the values obtained for the original milk. It was estimated that from 3·2 to 4·6% of the soluble material in milk was retained by the ultrafiltration membrane. Comparison of the composition of ultrafiltrate and rennet whey showed that the soluble material retained consisted mainly of calcium and citric acid. A similar effect was observed with dialysis, although the quantity of soluble material retained was much less. Rennet whey was considered more representative of milk serum than either ultrafiltrate or diffusate.