The Effect of Pretreatment (Spray Drying) on the Yield and Selected Nutritional Components of Whole Camel Milk Powder

Abstract

The effect of spray drying on the composition of camel milk powder was evaluated. A full factorial experimental design was used to see the effects of inlet temperature (160 °C, 140 °C, and 120 °C), atomization pressure (800, 600, and 400 bar) and feed flow rate (5, 4, and 3 rev/s) on cyclone and vitamin C recoveries. Principal components analysis (PCA) was used to check classification of spray dried whole camel milk powders based on their processing conditions and multiple correspondence analysis (MCA) on the fatty acid profiles. The average proximate composition of the camel milk viz., fat, protein, lactose, and total solid were 3.0%, 3.21%, 3.01%, and 10.29% respectively. The powder yield (cyclone recovery) increased with increasing inlet temperature and decreasing feed flow rate. High outlet temperature and pressure decreased vitamin C recovery. As a result of PCA of the camel milk powders, they were classified into high heat treated and low heat treated milk powders while the MCA of the fatty acid profiles of camel milk powders were classified into high pressure and low pressure treated powders and it was concluded that higher atomization pressure caused increase in the content of fatty acids. PRACTICAL APPLICATION: Drying of camel milk (using spray drying) can extend its shelf life. The spray drying process must be optimized in order to retain the nutritional properties of the milk and the techno-functional characteristics of the powder. Here, the effect of the spray drying conditions on the yield and selected nutritional components of the milk powder was studied using a bench top spray dryer. However, there is need to translate these findings to an industrial volume dryer. These findings will play a big role in future spray drying operations since retention of important nutritional components is an important part of food processing.