Coated whey protein/alginate microparticles as oral controlled delivery systems for probiotic yeast

TLDR

The study encapsulated viable Saccharomyces boulardii in whey protein isolate/alginate microparticles to protect and deliver the probiotic through the gastrointestinal tract. WP/ALG microparticles (62/38 ratio) were fabricated by extrusion/cold gelation, coated with alginate or whey protein by immersion, and their swelling, yeast survival, matrix loss, and release were examined in simulated gastric and intestinal fluids with pepsin and pancreatin. Coated WP/ALG microparticles resisted pepsin in SGF, increased yeast survival to 60% versus 10% for free cells, and released yeast in SIF following delayed swelling, indicating their promise as oral delivery systems for probiotic yeast.

Abstract

Viable Saccharomyces boulardii, used as a biotherapeutic agent, was encapsulated in food-grade whey protein isolate (WP) and alginate (ALG) microparticles, in order to protect and vehicle them in gastrointestinal environment. Yeast-loaded microparticles with a WP/ALG ratio of 62/38 were produced with high encapsulation efficiency (95%) using an extrusion/cold gelation method and coated with ALG or WP by a simple immersion method. Swelling, yeast survival, WP loss and yeast release in simulated gastric and intestinal fluids (SGF and SIF, pH 1.2 and 7.5) with and without their respective digestive enzymes (pepsin and pancreatin) were investigated. In SGF, ALG network shrinkage limited enzyme diffusion into the WP/ALG matrix. Coated and uncoated WP/ALG microparticles were resistant in SGF even with pepsin. Survival of yeast cells in microparticles was 40% compared to 10% for free yeast cells and was improved to 60% by coating. In SIF, yeast cell release followed coated microparticle swelling with a desirable delay. Coated WP/ALG microparticles appear to have potential as oral delivery systems for Saccharomyces boulardii or as encapsulation means for probiotic cells in pharmaceutical or food processing applications.