Improvement of the performance of gelatin and soybean lecithin-stabilized curcumin microcapsules through addition of soybean polysaccharides and solid lipids

Although curcumin (Cur) possesses anti-inflammatory, antioxidant, anti-cancer, and antibacterial properties, its poor water solubility, chemical instability, and low bioavailability limit the scope of its biological application. Here, novel microcapsules with gelatin/soybean lecithin/soluble soybean polysaccharides (SSP) as the complex wall materials and mono- and distearate glycerides (MDSG) as the core material were developed to encapsulate Cur. Zeta potential, particle size, Fourier transform infrared (FTIR), and intrinsic fluorescence analyses confirmed the adsorption between SSP and gelatin/soybean lecithin complex interfaces. FTIR, X-ray diffraction, differential scanning calorimetry, and confocal laser scanning microscopy indicated that Cur was dissolved or dispersed in the solid core of MDSG by an amorphous form and covered by the complex wall materials. Cur microcapsules were irregular aggregates with an average particle size of about 60 μm. The addition of SSP and MDSG increased the encapsulation efficiency of Cur (up to 93.0 ± 1.8 %). In vitro release study revealed that SSP and MDSG decreased the release rate of Cur, and the microcapsules exhibited sustained release behavior in the intestinal fluid. Chemical stability study indicated that SSP and MDSG could provide good protection for Cur. The present Cur microcapsules have promising potential for application in the food industry. • Soybean polysaccharides improved the encapsulation efficiency of curcumin. • Solid lipids increased the encapsulation efficiency of the encapsulated curcumin. • Soybean polysaccharides and solid lipids enhanced the controlled release of curcumin. • Soybean polysaccharides and solid lipids protected curcumin against oxidation.