Improving the oxidative stability of fish oil nanoemulsions by co-encapsulation with curcumin and resveratrol

Tuna fish oil (TFO), is a rich source of omega-3 fatty acids comprising particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for the human’s health enhancement. However, their foremost problems are poor solubility, low bioavailability, and easy oxidization, which limit their wide range of applications in food and pharmaceutical products. The aim of this research is to develop TFO nanoemulsions encapsulating curcumin (CUR) and resveratrol (RES) as co-antioxidants, stabilized with different concentrations of two modified starches including Purity Gum 2000 (PG) and Purity Gum Ultra (PGU). The effect of diverse quantities of modified starches on droplet size, droplet charges, viscosity, and oxidative stability of produced nanoemulsions was assessed at different storage temperatures (4, 25, and 40 °C). Furthermore, to assess the antioxidant activity and capacity of loaded nanoemulsions, DPPH, and ABTS assays were used, respectively. Among various samples, PGU2.5 and PG9 emulsified by PGU and PG2000 had showed the premium results of stability during storage at all temperatures over other formulations. Even at 40 °C, 199.10 μL/mL of PGU2.5 and 258.59 μL/mL of PG9 were required to attain the level of DPPH IC50, which were the lowest concentration as compare to other nanoemulsions. Taken together, it was accredited that co-encapsulation of CUR and RES inside the TFO nanoemulsion-based delivery systems can be efficient for the production of functional foods.