Stability to oxidation of spray-dried fish oil powder microencapsulated using milk ingredients

Microencapsulation of fish oil was achieved by spray-drying homogenized emu lsions of fish oil using 3 different types of casein as emulsifier and lact ose as filler. As the degree of aggregation of the casein emulsifier increa sed, the vacuole volume of the microencapsulated powders decreased. The she lf life of the powders increased as the degree of aggregation of the casein emulsifier increased at the high homogenization conditions. When micellar casein was used as emulsifier, the shelf life also increased as homogenizat ion conditions increased. Free fat but not surface fat was inversely relate d to shelf life. Since the type of casein used was confounded with the powd er vacuole volume, the increased shelf life may have been due to either fac tor.