Encapsulation of resveratrol-loaded Pickering emulsions in alginate/pectin hydrogel beads: Improved stability and modification of digestive behavior in the gastrointestinal tract

Abstract

In this study, alginate/pectin hydrogel beads were prepared with different mixing ratios (9:1, 8:2, 7:3, 6:4, and 5:5) to encapsulate resveratrol-loaded Pickering emulsions using Ca2+ crosslinking. The system with a suitable ratio of pectin and alginate can enhance the encapsulation efficiency and loading capacity. Scanning electron microscopy (SEM) study confirmed that the hydrogel beads were spherical, in which Pickering emulsion was distributed evenly within the polymer network. Fourier Transform Infrared Spectroscopy (FTIR) study indicated that the hydrogel beads were formed by physical cross-linking. X-ray diffraction (XRD) study demonstrated that resveratrol existed in hydrogel beads with an amorphous or dissolved form. Besides, the stability and antioxidant capacity suggested that hydrogel beads could offer protection to resveratrol by preventing degradation through environmental stresses, while maintaining its antioxidant capacity. Importantly, hydrogels significantly reduced the release of free fatty acids and resveratrol during in vitro digestion compared to emulsions, especially with the appropriate ratio of sodium alginate and pectin. Overall, Pickering emulsions-loaded alginate/pectin hydrogel beads could offer a novel option for the preparation of low-calorie foods and a potential substitute model for controlling the release of free fatty acids contributing to the transportation of resveratrol.