Preparation and Characterization of Fish Oil Pickering Emulsions Stabilized by Resveratrol-Loaded Gliadin/Chitin Nanocrystal Composite Nanoparticles

Unsaturated fatty acids present in fish oil offer various physiological benefits to the human body. However, their susceptibility to oxidation severely limits their potential applications. The purpose of this study was to develop Pickering emulsions stabilized from a composite of resveratrol-loaded gliadin nanoparticles and oxidized chitin nanocrystals (GR/OC) to protect fish oil from oxidation. The effects of the GR/OC composite on the characterizations of fish oil Pickering emulsions were investigated, including the microstructure, physicochemical properties (stability and rheological behavior), and digestion properties in vitro. The results revealed that an increased concentration of the GR/OC composite significantly reduced the droplet size and improved the ambient stability of the emulsions (in terms of pH, ionic strength, temperature, and storage time). Confocal laser scanning microscopy images depicted that the GR/OC nanoparticles were uniformly dispersed at the interface between water and fish oil (W-O interface). This distribution formed a protective envelope around the droplets. Remarkably, the addition of 2% GR/OC nanoparticles stabilized the Pickering emulsions and showed the most positive effect on the antioxidant capacity compared to that of the control group. These stabilized emulsions maintained lower peroxide values and acid values, which were 1.5 times less than those of the blank control during the 14 day accelerated oxidation experiment. Furthermore, the Pickering emulsions stabilized by GR/OC nanoparticles exhibited the ability to protect fish oil from contamination by gastric juices and facilitate the intestinal absorption of omega-3 polyunsaturated fatty acids. The findings suggest that these GR/OC-stabilized Pickering emulsions offer a promising alternative for delivering fish oils in various industries, including the food industry.