Protective effect of microencapsulation consisting of multiple emulsification and heat gelation processes on immunoglobulin in yolk

Two different emulsification methods involving multiple emulsification and heat gelation were used for preparation of whey protein-based microcapsules containing immunoglobulin in yolk (IgY). The residual activity of IgY during the emulsion preparation and the effects of microencapsulation on IgY stability under harsh conditions were investigated. The residual activity of IgY in an emulsion prepared with a membrane emulsifier was higher than for an emulsion using a homogenizer. Microencapsulated IgY showed remarkable stability against both pepsin and acid. Both microencapsulated IgY and nonencapsulated IgY were relatively stable in bile and artificial intestinal juice. Microencapsulated IgY retained 74% of initial activity during heat treatment. There were no significant differences in the residual activities of microencapsulated IgY under storage temperatures of 4, 25, and 37°C.