Measurement of air cell distributions in dairy foams

Abstract

Abstract Air cell size distributions in two foamed dairy products, whipped cream and ice cream, were measured by scanning electron microscopy (SEM) and an optical light microscopy technique. Air cells in whipped cream were studied at 4°C, whereas air cells in ice cream were measured at draw temperature (−6°C). Both methods gave similar results for these aerated products. The mean air cell size for whipped cream was 29.3 μm as measured by optical microscopy, whereas SEM gave a mean size of 26.7 μm. For ice cream, mean air cell size from optical microscopy was 20.2 μm, and 19.6 μm for SEM. In ice cream, mean size increased to 40.0 μm after hardening and storage at −15°C. Measured overruns were within 5% of the overruns calculated from the air cell size distributions, indicating that the majority of air cells were counted with these techniques.