Effects of chondroitin sulfate on properties of BSA-stabilized oil-in-water emulsion system

Abstract

Chondroitin sulfate(CS) is an anion glycosaminoglycan(GAG) consisting of repeating disaccharide units of [→4GlcAβ1→3GalNAcβ1→] with sulfated group, and usually derived from shark`s cartilage, sea cucumber wall, bovine organ, and snail. CS has been used as a dietary supplement for improving symptoms and arresting or reversing the degenerative process of osteoarthrosis. In this study, we intended to search the possibility of CS as a functional ingredient for age-targeted formula through a model emulsion. In order to collect a biochemical information of CS obtained from commercial products, molecular weight and purity of CS was determined by using Capillary electrophoresis(Beckman Coulter, USA). And, oil-in-water emulsion was formulated with mixture of 10%(w/w) BSA and various concentration of CS(0 to 1.0%, w/w) under different pH conditions. Zeta-potential and particle size was measured by Delsa™Nano C(Beckman Coulter, USA), EAI and ESI were spectrophotometrically determined(Ultrospec 2100 pro, UK), and creaming stability was scanned by using Turbiscan (Formulaction, france). Single peak of CS appeared around at 6min through CE analysis. At pH 7.0, only BSA-stabilized emulsion has no phase-separation, but increasing of CS concentration caused visible phase-separation. On the other hand, no phase-separation was shown in emulsions formulated at pH 3.0 and 11.0, and even more phase stabilization was observed at pH 5.0 in the presence of CS. This was confirmed by the analytical result of spectroturbidity & turbiscan. The pH dependence of the phase-separation of the BSA-stabilized emulsion was concerned in isoelectric point of BSA(pH4.8). Addition of Cs prevented phase-separation in near PI, suggesting a negative charges of CS stabilizing the dispersion stability through electrostatic interaction with BSA.