Temperature-induced effects on crystallization behaviour, solid fat content and the firmness values of milk fat

Summary The temperature at which milk fat was crystallized was found to influence its firmness values, crystalline conformation and the percentage solid fat at 5 °C. Extremely rapid cooling of milk fat using liquid N2 (LNT) gave a product which, although it contained a relatively high solid fat content, was less firm and possessed a wider plastic range than milk fat crystallized at 15, 5 or –20 °C. Polymorphic transitions occurred in the LNT milk fat when it was subsequently held at 15 °C but not at 5 °C. Apparently the particular polymorphic modification has an important role in rheological behaviour.