Fat in the milk powder surface

Abstract

Milk powder is a highly versatile product produced by spray drying, which consists of removing water by exposing the product to a flow of dry and hot air. This product has a longer shelf life than fresh milk and offers positive points, such as greater microbiological and chemical stability and less restricted storage conditions. However, a large migration of fat to the surface of these powders has been widely documented in several studies. Part of this fat present on the powder surface is in the free form and associated with undesirable characteristics of the product, such as rehydration difficulties, lipid oxidation, increased viscosity, and others, leading to reduced product quality. Stabilizing the milk emulsion matrix before the atomization and drying steps is the best way to avoid free fat. In this bibliographic review, the characteristics of milk powder, characteristics of fat, as well as the occurrence of superficial free fat, the causes, and some of the possible solutions will be aborded.