An active edible coating based on cellulose nanofiber stabilized Pickering emulsion: Toward prolonging the shelf life of strawberries

This study presents the development of an active edible coating based on TEMPO-oxidized cellulose nanofibers (TOCNFs) derived from rice husk, functioning as both an encapsulation carrier and a stabilizer for Pickering emulsions containing lavender essential oil (LEO). Increasing LEO and TOCNF concentrations improved encapsulation efficiency (44 to 75%) and loading capacity (14 to 22%). TOCNFs exhibited amphiphilic behavior and reduced interfacial tension from 58.09 ± 0.03 to 40.12 ± 0.05 mN/m that enhanced the formation of stable emulsions. Higher TOCNF concentrations led to smaller droplet sizes, a decrease in zeta potential, and prevention of creaming index over 28 days of storage. The optimized formulation (1% TOCNF and 50% LEO) showed excellent stability under varying temperature, pH, and salt conditions, indicating resistance to environmental stresses. The TOCNF/LEO emulsions were formulated using a sage seed mucilage solution and applied as a coating for strawberries stored at 4°C. In addition, the formulated emulsions demonstrated antifungal activity against Aspergillus spp. and Penicillium spp., with minimum inhibitory concentrations of 1700 and 2000 µg/mL, respectively. Compared to uncoated samples, application of the coating on strawberries stored at 4°C effectively delayed quality deterioration, including weight loss, pH changes, firmness reduction, and microbial growth over a 9-day period. Overall, this study highlights the dual functionality of TOCNFs in stabilizing bioactive emulsions and delivering antimicrobial effects. The developed system offers a sustainable and efficient approach for food preservation, utilizing agricultural waste to produce a high-performance, environmentally friendly edible coating for extending the shelf life of fresh produce.