MICROENCAPSULATION BY SURFACTANT-GELATIN INSOLUBLE COMPLEX - EFFECT OF PH AND SURFACTANT CONCENTRATION

The interactions between gelatin and sodium dodecyl sulfate (SDS) were studied, and the conditions which favor formation of insoluble comple x of gelatin-SDS were applied to form microcapsules of oil droplets. I t was found that the insoluble complex is formed only while the protei n has a net positive charge, at pH 4.0, and only at a narrow range of surfactant concentrations, below the critical micellar concentration. The composition of the coating layer around the oil droplets was evalu ated as a function of SDS/gelatin ratio. The maximal adsorbed amount o f gelatin and SDS on the oil droplets corresponds to the SDS concentra tion in which the zeta potential was minimal and in which insoluble ge latin-SDS particles were obtained in absence of the oil phase. (C) 199 7 Academic Press.