INVESTIGATION OF THE MECHANISMS OF STABILIZATION OF FOOD EMULSIONS BY VEGETABLE PROTEINS

A number of experimental methods have been used for investigation of the Microheterogeneous components of corn oil in water emulsion systems stabilized with tomato seed protein isolate. Light-scattering studies on the initial aqueous protein solution have shown the presence of protein aggregates much bigger than single molecules. The dilational behavior of oil/water interfaces after a swift expansion or compression was found to comply with the rheological model of Maxwell (see reference 27). Observations of the thin aqueous films between oil phases allow us to suggest that the presence of protein aggregates inside the film, the electrostatic repulsion and the surface viscoelasticity are factors contributing to the film stability. A comparison with other vegetable protein speices (from soya and lupine beans) is performed in some of the experiments. The measurements of the stability of batch emulsions show that the studied protein isolates act as effective stabilizing agents.