Model for foam stabilization of homogenized cream by comparative examinations with non-homogenized cream

The aim of this study was to characterize the foam stabilization mechanism of homogenized cream. For this purpose parallel experiments with homogenize d and non-homogenized cream were carried out. The structure formation durin g the whipping of cream was able to be monitored by detecting the increase of viscosity, fat globule coalescence and development of the air bubble siz es; The particular differences established were that homogenized cream requires a much longer period of whipping, and that in the case of homogenized crea m no measurable coalescence takes place throughout the whole whipping proce dure. The whipping process of homogenized cream can be divided into time phases. Air is introduced into the system and a surface between air bubbles and ser um is created (Phase 1), which is covered immediately by beta-casein and wh ey protein (Phase 2). As the air surface increases more and more small fat globules with a stable secondary membrane, mainly consisting of casein, rea ch the air bubbles(Phase 3). Membrane proteins are restructured by means of surface forces when they are in direct contact with the air by means of su rface forces, resulting in an orientation of hydrophobe casein parts to the direction of the: air. The hydrophobe casein parts that are laid open addi tionally induce the flocculation of the fat globules (Phase 4). The stabili zation of the cream foam is realized by aggregation of the fat globules by means of casein-casein interactions in form of calcium bridges.