Unlocking curcumin's revolutionary: Improvement of stability and elderly digestion by soybean oil bodies and soybean protein-chitosan complex based Pickering emulsion

Abstract

Curcumin shows promise for disease prevention and health improvement, but its limited water solubility and vulnerability to degradation reduce its bioavailability, while its biological fate in elderly is unclear. Oil bodies are natural pre-emulsified oil droplets that serve as carriers for functional nutrients. In this study, soybean protein isolate (SPI) was complexed with chitosan (CS) for the purpose of stabilizing the soybean oil body-curcumin emulsion, resulting in the formation of the soybean isolate protein-chitosan-soybean oil bodies-curcumin Pickering emulsion (SPI-CS-SOB-C). The study examined the digestive properties, bioaccessibility of curcumin, free fatty acids (FFA) release, and microstructure changes of SPI-CS-SOB-C through an in vitro elderly digestion model. The findings indicated that curcumin was effectively encapsulated within the SPI-CS-SOB-C, achieving an encapsulation efficiency of 97.7 %, which resulted in notable enhancements in light, heat, and storage stability, as well as an extended half-life of curcumin to 85 months. In vitro elderly digestion demonstrated that SPI-CS-SOB-C notably enhanced the bioaccessibility of curcumin, increasing it from 14.3 % to 51 %. The low FFA release of SPI-CS-SOB-C (23.06 %) suggested its potential suitability for incorporation into low-fat food products and using in food products for the elderly. The results of this study could offer theoretical insights for the utilization of oil bodies in food applications and the delivery of functional nutrients.