| Abstract: | New Protein Stabilized O/W-Emulsions The formation and stabilization of o/w-emulsions were investigated with faba bean globulin isolate and the corresponding acetylated derivative as model substances in dependence on concentration at constant pH-value and on pH-value at constant concentration as well. A centrifugal equilibrium method was developed and the protein distribution in the phases after centrifugation was determined. Optimal conditions (concentration, pH-value and preparation of emulsion) lead to a coating of the oil droplets with protein being stable against coalescence. It is possible to separate those coating droplets in a form of stabile concentrate of emulsion. The acetylated derivative is a more efficient emulsifier and stabilizer than the unmodified faba bean globulin is. For oil droplet size distribution and comparable stability less protein is needed in the case of acetylated derivative. At the same time a stronger interaction between the aqueous phase of the emulsion and the coated oil droplets was found. This is reflected by the existence of a mechanical barrier against the separation of this aqueous phase. The results fo the coalescence stable concentrates of emulsion are the reason to search for a new principle producing o/w-emulsions. |
