Hyaluronic Acid-Functionalized Cellulose Nanofiber-Stabilized Pickering Emulsion Incorporated into Sodium Alginate Coatings for Blueberry Preservation

Abstract The development of sustainable postharvest technologies is essential for reducing food losses while minimizing reliance on synthetic packaging materials. In this study, a hyaluronic acid (HA)-functionalized, cellulose nanofiber (CNF)-stabilized Pickering emulsion edible coating was formulated using sodium alginate as the film-forming matrix and parsley essential oil as the bioactive component. Ultrasound was employed as an emulsification aid during preparation, and the resulting formulations exhibited strong electrostatic stability, with zeta-potential values ranging from − 40.13 to − 82.87 mV, together with favorable oil-binding capacity. HA functionalization promoted uniform droplet dispersion and contributed to the formation of a compact polymer network. Among the formulations, SA/0.5 HA-PE showed the highest oil-binding capacity, the lowest water vapor permeability, and the most homogeneous internal structure. When applied to blueberries stored at 25°C for 10 days, the coating reduced weight loss to 8.07–8.42% compared with 13.30% in the control, while also contributing to firmness retention, physicochemical quality preservation, and inhibition of fungal deterioration. Correlation and principal component analyses indicated associations among moisture loss, firmness, and other quality attributes during storage. Overall, the results demonstrate the potential of the ultrasound-assisted HA-functionalized CNF Pickering emulsion coating as a bio-based approach for blueberry preservation. However, because a non-ultrasound control was not included, the specific contribution of ultrasound to the observed emulsion and coating properties cannot be isolated.