Roles of Chondroitin Sulfate in Oil-in-Water Emulsions Formulated Using Bovine Serum Albumin

Abstract

Chondroitin sulfate (CS) effects on phase stability and actions in bovine serum albumin (BSA)-stabilized emulsions at different pH values were studied. Emulsion activity and stability were evaluated at CS concentrations ranging from 0 to 0.1% (w/w). BSA-CS emulsions showed unique behaviors under different pH values. CS destabilized emulsion phases drastically at pH 3.0 and gradually at pH 7.0. However, at pH 5.0, CS exerted concentration-dependent effects on emulsion stability and caused a decrease in particle size. CS is negatively charged with concentrationdependency at all pH values. However, different roles were observed when the surface charge of BSA was changed. CS formed interfacial layers via charge interactions with BSA to form complexes that sufficiently saturated the surface of oil droplets and prevented phase-separation via steric hindrance and repulsive forces, especially near the protein isoelectric point.