Cutoff Ostwald ripening stability of eugenol-loaded Pickering emulsion stabilized by chitosan particles and long-term antibacterial coating activity evaluation.

Plant essential oils such as eugenol exhibit broad-spectrum antimicrobial and antioxidant properties but suffer from high volatility, poor water solubility, and rapid release, limiting their application in food preservation. To address these challenges, we developed chitosan-based Pickering emulsions with effective suppression of Ostwald ripening and long-term coating antimicrobial activity. The Ostwald ripening inhibition, long-term stability, release behavior, and coating antimicrobial performance of eugenol-loaded chitosan Pickering emulsions were systematically investigated. Chitosan Pickering emulsions encapsulating pure eugenol exhibited optimal stability at pH 6.5; however, complete suppression of Ostwald ripening was not achieved. At pH 6.5, the incorporation of 2.5% corn oil effectively inhibited Ostwald ripening of the eugenol emulsions, conferring long-term stability over a 150-day storage period. Chitosan Pickering emulsions exhibited superior sustained release of eugenol compared to Tween emulsions, attributed to their inherent film-forming capability. The 95% eugenol-loaded chitosan Pickering emulsion exhibited the slowest release rate and the most prolonged coating antimicrobial activity, achieving a maximum coating duration of 48 days under simulated conditions. These findings highlight the potential of this chitosan Pickering emulsion system as a promising and adaptable platform for developing high-performance, long-lasting antimicrobial edible coatings to extend food shelf life.