Food Structure


The role of milk serum proteins in the development of foam structure during the whipping of 38% fat cream was investigated. Proteins were removed from the aqueous phase by washing the cream with simulated milk ultrafiltrate. The natural protein complement was replaced with either casein or whey protein preparations. When creams with different protein compositions were whipped to a defined end point the structural properties of the foams were similar but removal of protein caused a 50% reduction in whipping time. Other creams were whipped for fixed times of between 30 and 180 seconds to investigate the development and formation of the foam structure. This was greatly influenced by the protein composition. The presence of whey protein resulted in an initial lag phase in structure development, which was not so apparent when the added protein was casein. The lag phase was attributed to differences in structure of globular and disordered proteins and their behaviour at interfaces.