ABSTRACT
The bulk of the lipids in milk, 97%–98%, are triacylglycerols (TG), with sterols (mostly cholesterol) and phospholipids next in quantity (Table 6.1). The di-and monacylglycerols (DG and MG, respectively) and nonesteri* ed fatty acids (FA) in quantities greater than traces are the products of postharvest lipolysis. Freshly drawn milk that is promptly pasteurized or frozen and stored at –70°C contains little of these lipolytic compounds. However, increased milking frequency, a practice that is increasing in the dairy industry, increases lipolysis in fresh milk (Wiking et al., 2006). The FA of commercial milk do not vary greatly in proportion because of the averaging effect of pooling by milk processors; many FA that are found in milk in low or minute quantities may have important nonnutritive roles as nutriceuticals (Milner, 1999; Parodi, 2006).
