Preparation of Humidity-Responsive Cinnamon Essential Oil Nanomicelles and its Effect on Postharvest Quality of Strawberries

Biodegradable materials have attracted considerable attention to be applied in maintaining food quality and safety due to their ability of a sustained release of antimicrobial agents. In this study, cinnamon essential oil (CEO) loaded poly (ethylene glycol)-poly (ε-caprolactone) (PEG-PCL) micelles (CEO-micelles) were prepared for humidity-controlled CEO release and preservation of strawberry quality. The CEO-micelles with spherical shape and uniform size were obtained, and a high encapsulation rate (92.00 ± 1.77%) of CEO was achieved. X-ray diffraction demonstrated that the CEO was successfully encapsulated in PEG-PCL micelles. The release rate could be controlled by adjusting the relative humidity (RH) and 75% RH was favorable for CEO release from micelles (with 72% total amount release in 7 days). The encapsulation of CEO with high concentrations in PEG-PCL micelles reduced the cytotoxicity. Additionally, CEO-micelles exhibited high antifungal activity against Botrytis cinerea , the main pathogenic fungus of strawberry. Finally, the application of CEO-micelles to the preservation of strawberries had a positive effect on changes in decay rate, weight loss, firmness, color, and total soluble solids. These findings suggested that the CEO-micelles could be fabricated to humidity responsible nano-vesicles for preservation of fruit or vegetable with controllable release profile.