Active food packaging based on Pickering emulsions of essential oils stabilized by cationic cellulose nanofibers

Abstract

Due to environmental concerns about non-biodegradability of conventional plastic packaging, there is a growing shift towards sustainable alternatives such as paper-based food packaging. In this context, Pickering emulsions have been developed, incorporating clove and thyme essential oils and stabilized by cationic cellulose nanofibers (CCNFs). This study evaluates the antioxidant and antimicrobial performance of emulsion-coated paper based on varying concentration of constituents. The innovative aspect of this research lies in the use of CCNFs as bio-based stabilizing agent. Their high aspect ratio and surface charge inhibit droplet coalescence and enhance emulsion stability. The stable emulsions demonstrated a fine droplet size and high zeta potential. They exhibited potential antioxidant activity, achieving 92 % of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging. Coated paper exhibited significant antibacterial efficacy, inhibiting Listeria monocytogenes by 99.99 % and Escherichia coli by 99 %, alongside notable antifungal activity against Aspergillus niger. Increasing CCNFs content, improved the barrier properties and functional performance of the coated substrate. Specific migration into food simulants remained minimal, confirming the suitability of material for food contact application. FESEM analysis showed that the emulsion effectively and partially occluded the pores of the paper. This developed coating system demonstrates potential for active applications, offering an eco-friendly alternative to traditional packaging materials.