Microencapsulating Properties of Whey Proteins. 1. Microencapsulation of Anhydrous Milk Fat

Anhydrous milk fat was microencapsulated in whey protein concentrates and a whey protein isolate by spray drying. The effects of microencapsulating agent type and concentration (10 to 30% wtlwt) and of fat load (25 to 75% wt/wt) on the microencapsulation yield and efficiency were determined. Encapsulation yields of more than 90% were obtained for all evaluated systems. Microencapsulation efficiency was enhanced by increased solids concentration of wall solutions only in systems with low fat load. Microencapsulation efficiency was adversely affected by anhydrous milk fat load. Protein to lactose ratio affected the microencapsulation efficiency. Partial (50%) replacement of whey proteins by lactose resulted in the highest (95%) microencapsulation efficiency even at 75% fat load. Spherical microcapsules in which the milk fat was well isolated from the environment were obtained in all cases. The results indicate that microencapsulation of anhydrous milk fat by whey proteins is feasible and may have new applications for milk fat in food and dairy products. (Key words: anhydrous milk fat