Influence of Multiple Parameters on the Crystallinity of Dairy Powders

Abstract

Caking in powdered foods is one of the factors that is not welcomed by the consumer and seriously affects the quality perception of the product. This research investigated the caking tendency of cheese and milk powders (stored at 40%, 50%, 60%, and 70% relative humidity) by considering both the surface fat content and moisture adsorption by using low field, Time Domain 1H Nuclear Magnetic Resonance. Caking of cheese powders were found to be more than milk powders. On the other hand, surface fat content of whole fat milk powder had an abrupt change due to lactose crystallization at 60% relative humidity, which corresponded to a critical moisture content of 10%. A similar behavior was seen for low fat milk at 7% moisture content, at which cracks and the loss of hydrophobic barrier in the structure facilitated the rearrangement. The effect of salt content on the caking of milk and cheese powders had a higher impact on the crystallinity, following lactose content and fat content, respectively.

Keywords: NMR, crystallinity, Caking, fat content, moisture adsorption