LAUSR

Bovine serum albumin (BSA), whey protein isolate (WPI), insulin and a casein hydrolysate were entrapped in chitosan-polyphosphoric acid (PPA) beads. The in vitro release of protein from the beads in simulated gastric fluid (SGF, pH 3) and simulated intestinal fluid (SIF, pH 7) was evaluated. High entrapment efficiencies were achieved for intact proteins (>95% in all cases) but entrapment was lower for the casein hydrolysate (circa 50%), possibly indicating a physical or steric entrapment of the proteins in these chitosan-PPA beads. Inhibited release of BSA, in both SGF and SIF, was achieved with low PPA concentration. Insulin and WPI were effectively retained in SGF and gradually released in SIF. Peptides from casein hydrolysate were partially (circa 35%) but quickly released in SGF with no further release in SIF. Overall, these results indicate that chitosan-PPA beads show potential for lower gastrointestinal delivery of bioactive protein material.