Water-in-oil-in-water (W/O/W) emulsions with antioxidant and bacteriostatic capabilities: A preliminary exploration of food preservation films

The development of stable water-in-oil-in-water (W/O/W) emulsions for edible preservation coatings and films, utilizing their properties, deserves scientific attention. In this study, oregano essential oil and D‑sodium erythorbate were simultaneously loaded into W/O/W emulsions, and the homogenization conditions of the W/O/W emulsions were optimized. The structure and interactions of gum Arabic (GA) and whey protein isolate (WPI) as the outer phase were analyzed. Stable W1/O/W2 emulsions with excellent antimicrobial and antioxidant activities could be produced under the conditions of GA: WPI at 1:1 and W2: W1/O at 5:5. The diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2′-azinobis-(3-ethylbenzenthiazoline-6-sulphonic acid) (ABTS) radical scavenging rates were 86.35 % and 89.35 %, and the inhibition zone diameters for S. aureus and E. coli were 14.03 ± 0.42 mm and 14.17 ± 0.70 mm, respectively. Finally, the W1/O/W2 emulsions were successfully applied to prepare chitosan-based films. This study has the potential to promote the application of W/O/W emulsions in food preservation, emphasizing the need for advancements for real-world adaptability. [Display omitted] •The ratios of WPI: GA and W2: W1/O influenced the stability of W/O/W emulsions.•Emulsification parameters of W/O/W emulsions were optimized.•W/O/W emulsions encapsulated oregano essential oil and D-sodium erythorbate.•The W/O/W emulsions exhibited both antibacterial and antioxidant properties.•The W/O/W emulsions were utilized for the preparation of edible films.