Accelerated tests for predicting long-term creaming stability of infant formula emulsion systems

Abstract

Models for sterilized, concentrated infant formulae were prepared from whey protein concentrate (WPC) and high-heat non-fat dry milk (NFDM) to yield a casein to whey ratio of 40:60%. The protein, carrageenan and lecithin levels were varied within a number of 2 × 3 factorial designs. Statistical techniques were used to evaluate the relationship of compositional factors to physical stability and to determine which emulsion stability test best predicted stability toward creaming after prolonged storage. Emulsion stability was assessed by gravitational and centrifugal creaming, relative viscosity, adsorbed protein and light scattering. Centrifugation and relative viscosity were the best predictors of 10 and 18-week stability, whereas emulsion activity index and particle size were poor predictors of stability in the infant formula model.