Phospholipo-proteins which have been enzyme modified may be used as an emulsifier to improve the emulsion stability of frozen products, e.g., during the freeze thaw and vacuum cool processes. Especially preferred is use of the enzyme phospholipase A to modify egg yolk and to use the modified egg yolk as an emulsifier in frozen products. Creation of a more stable emulsion can be expected to improve the overall appearance of the final product both in the frozen state and after the product has been reheated. Although egg yolk is preferred, examples of other phospholipo-protein containing substances include casein, skim milk, buttermilk, whey, cream, soybean, yeast, whole egg, blood serum and wheat proteins.