Fabrication of polysaccharide-based high internal phase emulsion gels: Enhancement of curcumin stability and bioaccessibility

A simple approach was developed to formulate polysaccharide-based high internal phase emulsions (HIPEs) using complexes of sugar beet pectin (SBP), tannic acid (TA), and chitosan (CS) to stabilize the system. The ability of pectin to stabilize the HIPEs was significantly improved after it formed complexes with TA, which were likely held together by hydrogen bonding. The stability of the HIPEs was further improved by adding CS, which was attributed to the formation of a 3D biopolymer network around and between the oil droplets. The impact of TA concentration, CS concentration, and pH on the oil droplet size, microstructure, and rheology of the HIPEs was investigated. Compared with SBP/TA complexes, the SBP/TA/CS complexes facilitated the formation of stable HIPEs with a gel-like texture and good stability to centrifugation, dilution, thermal treatment, and ultraviolet light. HIPEs prepared from SBP/TA/CS complexes were shown to delay lipid digestion and improve curcumin bioaccessibility. These findings provide a useful approach for designing HIPE-based soft solids from natural ingredients that can be used in foods and other commercial products.