Poly(lactic acid) nanocapsules containing lemongrass essential oil for postharvest decay control: In vitro and in vivo evaluation against phytopathogenic fungi

The increased demand for pesticide-free foods has also increased the search for healthier and environmentally friendly alternatives in agriculture. Essential oils are known to possess natural antifungal properties, becoming a reliable alternative for commercial fungicides, especially for postharvest decay control. However, essential oils are volatile and photodegradable, which reduces their long-term activities. This work presents the development of a lemongrass essential oil-containing poly(lactic acid) nanocapsules. They have shown in vitro antifungal activity against Colletotrichum acutatum and Colletotrichum gloeosporioides with a MIC dosage of 0.1% (v/v) for both phytopathogens. In the in vivo assay with postharvest apples, the ones treated with encapsulated essential oil showed bitter rot lesions three times smaller than the ones treated with non-encapsulated essential oil, or in comparison to the apples in positive control. The methodology led to stable nanocapsules with spherical morphology, a mean diameter of 96.4 nm, and with an encapsulation efficiency of 99%.