Controlled release of riboflavin encapsulated in pea protein microparticles prepared by emulsion-enzymatic gelation process

Riboflavin was encapsulated in pea protein microparticles crosslinked by transglutaminase and the release properties of this system was studied in simulated gastric (pH = 1.2) and intestinal (pH = 7.4) fluids. The microparticles were obtained from a water-in-oil emulsion and subsequent enzymatic gelation. In presence of polyglycerol polyricinoleate as hydrophobic surfactant, magnetic agitation was preferred to high-speed homogenization in order to form spherical microparticles of similar to 150 mu m average size. The encapsulation efficiency of crystallized riboflavin (RF) varied from 74% to 84% depending on the amount of loaded RF (0.1-1.0 wt%). According to the kinetic power law model, the release mechanisms of riboflavin under simulated gastrointestinal conditions were governed by diffusion in absence of digestive enzymes and by a support degradation phenomenon in their presence. The designed microparticles represented a potential system for the delivery of riboflavin up to the intestinal digestion phase.