Studies on Whey Protein Concentrates. 2. Foaming and Emulsifying Properties and their Relationships with Physicochemical Properties

Foaming, emulsifying, and physicochemical properties of membraneprocessed Cheddar-cheese-type whey protein concentrates were studied to understand the relationship between structure and function. The concentrates were prepared from cheese whey obtained from skim milk, whole miJ.k. and buttermilkenriched skim milk. In comparison with the other whey protein concentrates, concentrates prepared from skim milk whey had lower surface hydrophobicity and concentrates prepared from buttermilkenriched skim milk whey had lower solubility. Whey protein concentrates prepared from whole milk whey had poor foaming and emulsifying properties. Among the compositional and the physicochemical attributes studied, free fat, bound fat, ash, calcium, denaturation enthalpy, and denaturation temperature were related to solubility, foaming, and emulsifying properties of whey protein concentrates. In general, free fat and bound fat were negatively related with foaming and emulsifying properties, whereas, ash, calcium, and denaturation enthalpy were positively related with foaming and emulsifying properties. Regression models were developed for predicting solubility, foaming, and emulsifying properties from various physicochemical attributes of the whey protein concentrates.