Response Surface Methodology to Study Fat Destabilization and Development of Overrun in Ice Creams Produced with Polyunsaturated Safflower Oil and Milk Fat Blends

Abstract

Effects of safflower oil concentration (0 to 52% of the total fat), emulsifier concentration (0 to .32%), and freezing temperature (−5.3 to −2.5°C) on maximum overrun and fat destabilization of ice cream were studied.Experimental ice cream mixes were whipped and partially frozen in a laboratory batch ice cream freezer over 30min. Semifrozen samples were collected periodically and analyzed for percent overrun and extent of fat destabilization. Fat destabilization was determined by a turbidity test and by microscopic examination.A central composite experimental design, analyzed by response surface methodology, was used to elucidate main effects and interactions. Increasing safflower oil tended to depress overrun but with little effect on fat destabilization. The effect of emulsifier concentration and freezing temperature on development of overrun depended upon the safflower oil concentration, but the effect of these variables on fat destabilization was independent of safflower oil concentration. Thus, changes in the extent of fat destabilization alone were insufficient to explain the whipping properties of ice cream containing polyunsaturated fat.Ice cream containing high levels of safflower oil can be made with typical overrun through proper formulation and processing changes.