Ginkgolic acids-enriched nanoemulsions: A green strategy for broad-spectrum antimicrobial delivery

Ginkgolic acids (GAs) are potent natural antimicrobials, but their poor solubility hinders application. Recent studies have shown that nanoemulsions based on hydrophobic deep eutectic solvents (HDESs) can enhance the bioavailability of hydrophobic active ingredients. In our previous work, two HDESs were designed to efficiently enrich and extract GAs. We further developed HDES-in-water nanoemulsions (HDESNEs) as a delivery system for enhanced antimicrobial performance. Formulation was optimized using orthogonal design and response surface methodology. The resulting HDESNEs showed uniform droplet size (<20 nm), low polydispersity index (<0.1), and high encapsulation efficiency (>99 %). Antimicrobial assays demonstrated that HDESNEs significantly outperformed conventional GAs emulsions against two common foodborne bacteria (Escherichia coli and Staphylococcus aureus) and four plant pathogenic fungi (Aspergillus niger, Penicillium citrinum, Penicillium expansum, and Fusarium graminearum). These results showed that HDES-based nanoemulsions effectively improved GAs delivery and antimicrobial performance against multiple foodborne bacteria and plant pathogenic fungi. This study provides a green and efficient formulation approach that shows promising potential for antimicrobial applications in food preservation and agricultural protection.