Improving the antimicrobial activity of d-limonene using a novel organogel-based nanoemulsion

The purpose of this research was to develop a novel antimicrobial delivery system by encapsulating d-limonene into an organogel-based nanoemulsion and investigating its antimicrobial activity. The d-limonene organogel-based nanoemulsion was prepared by high pressure homogenization method. The surfactant concentration had a major impact on the dropletsʹ formation and distribution. At the optimal condition (10% w/w Tween 80, 100 Mpa, and 10 Cycles) the smallest droplet size (d ≈ 36 nm) could be obtained, which has shown a narrow structure and good stability. Results from the antimicrobial activity have shown the encapsulation of d-limonene (4% w/w) into the organogel-based nanoemulsion contributed to the increase of its antimicrobial activity. In addition, the mechanism of d-limonene organogel-based nanoemulsion against the tested microorganisms was studied by the electronic microscope observation and the cell constituent release. This research would have an important implication for the design of more efficient antimicrobial systems for food preservation and production.