Nanopartículas e nanofibras incorporadas com óleos essenciais: desenvolvimento, caracterização e avaliação da atividade antifúngica e inseticida

Abstract

Brazil is the second largest food producer in the world. Coffee production suffers from loss of production due to contamination of coffee plantation leaves by the fungus Hemileia vastatrix, known as coffee rust, as well as contamination of coffee beans by the mycotoxigenic fungi Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus flavus and Aspergillus parasiticus. The main factor that causes the loss of production of red fruits is the attack of the fly Drosophila suzukii. Essential oils are secondary metabolites produced by plants, their diverse chemical composition gives these substances several biological properties, such as antifungal and insecticidal. To make the use of essential oils in industrial systems viable, they have been incorporated into nanoparticles and nanofibers. These nanostructured systems enable a controlled volatility of essential oils, as well as protect their constituents from external factors that can lead to structural change as well as their degradation. The objective of this study was to produce, characterize and evaluate the in vivo and in vitro antifungal activity of poly(ε-caprolactone) nanoparticles incorporated with the essential oils of Corymbia citriodora, Eucalyptus grandis, Eucalyptus camaldulensis on the fungus Hemileia vastatrix; to produce, characterize and evaluate the insecticidal activity in vivo and in vitro of poly(ε-caprolactone) nanoparticles incorporated with the essential oil of Rosmarinus officinalis on the fly Drosophila suzukii; to produce, characterize and evaluate the antifungal and antimycotoxigenic activity of poly(lactic acid) nanofibers incorporated with the essential oil of Corymbia citriodora and its isomeric constituents β-citronellol and citronellal on mycotoxigenic fungi. The results found were promising, verifying that the nanostructured systems were able to reduce the severity of coffee rust caused by the fungus Hemileia vastatrix by up to 90.75%, a result similar to synthetic fungicides. Regarding insecticidal activity, the nanostructured systems showed a result of LD50 at a concentration of 17.5 mL/L on the fly Drosophila suzukii. The nanofibrous systems showed antifungal activity against the microorganisms Aspergillus ochraceus, Aspergillus parasiticus and Aspergillus westerdijkiae, inhibiting by 99 and 100% the production of ochratoxin A and the mycelial growth, respectively. The innovative results indicate the feasibility of applying nanoparticles and nanofibers as a controlled release system of essential oils and monoterpenes to combat Hemileia vastatrix and mycotoxigenic fungi, as well as to control the fly Drosophila suzukii.