Passive separation of waste ice cream

Ice cream manufacturers must waste a portion of their product, and butterfat is potentially a valuable and recoverable component of this waste. Little is known about the stability of the fat-in-water emulsion of commercial ice cream in the molten state. In the present study, examination of a wide variety of melted vanilla ice cream products revealed divergent separation patterns. Many products formed upper foam layers (circa 20–30% fat) and/or lower ‘whey’ layers (circa 1% fat). Increased temperature and centrifugal acceleration both sped the development of these layers. Whey phase density and viscosity measurement, as well as product label analysis, were used to investigate stability correlates, and the observation of lower stability among products containing greater concentration of ‘stabilizer’ ingredients reported. These results will support development of cost-effective butterfat recovery processes.