Application of PEG-coated antioxidant nanoliposomes in alginate-based edible coatings to improve oxidative stability of fish (Oncorhynchus mykiss) fillets

Fish fillets are highly susceptible to oxidation due to their rich content of unsaturated fatty acids, leading to spoilage and the formation of undesirable flavors and odors. In recent years, antioxidant packaging (particularly in the form of edible coatings) has garnered considerable interest as an effective strategy to mitigate oxidative degradation. In this study, nanoliposomes encapsulating hydrolyzed flaxseed meal protein, a natural antioxidant, were coated with polyethylene glycol (PEG) at concentrations of 0.1, 0.3, and 0.5 g/10 mL to improve their stability. Among the tested formulations, the PEG-coated nanoliposomes at 0.3 g/10 mL exhibited the most favorable physicochemical properties, including microencapsulation efficiency of 73.54 %, particle size of 653.3 nm, and zeta potential of 9.93 mV. This formulation also demonstrated the highest antioxidant activity, with a total antioxidant activity of 1.339 (absorbance at 695 nm), DPPH radical scavenging activity of 95.43 %, and strong iron ion chelating ability. Consequently, it was selected as the optimal formulation for incorporation into an alginate-based edible coating at varying concentrations. Among the tested coatings, alginate coating enriched with 15 g/L PEG-coated nanoliposomes showed optimal antioxidant performance and improved oxidative stability of fish fillets. • Coating nanoliposomes with flax protein via PEG improves antioxidant stability. • Alginate-based edible coatings prevent lipid oxidation in fish fillets. • Adding antioxidant nanoparticles to coatings increases stability in fish fillets.