The effect of freeze‒thaw cycles on the physicochemical stability and nutritional composition of camel milk

Abstract

Pretreatment for dairy processing sometimes requires freezing and thawing to ensure a steady supply of fresh raw milk. On this basis, a series of studies were conducted to ascertain the impact of freeze-thaw cycles on the physicochemical stability and nutritional quality of camel milk. The findings demonstrated that while the lipid content and apparent viscosity of camel milk were significantly reduced, the acidity and quantity of short- and medium-chain free fatty acids were enhanced by repeated freeze‒thaw cycles. Freeze‒thaw cycles have been demonstrated to result in an increase in protein oxidation in camel milk, which in turn has been observed to give rise to a shift in the secondary structure towards random coils. The particle size distribution of camel milk exhibited aggregation of the proteins, which consequently reduced the physical stability of the camel milk. The results of this study may help to deepen our understanding of the quality characteristics of raw camel milk materials while providing methodological references and scientific support for the storage of raw camel milk.