Aplicação combinada de quitosana e óleo essencial de Mentha piperita L. no controle de fungos patógenos pós-colheita.

Abstract

Numerous factors had interfered in the reduction of food production. Within this framework, the attack of pathogenic fungus have received prominence, due to their big impact in agriculture. The postharvest diseases are responsible for losses, in many cases, up to more than 50%. The control of diseases and pests in agriculture have been intensified and carried out through the usage of synthetic products, that has caused organisms' resistance, demanding increased amounts of them, what is leading to serious environmental and population health risks. This study aimed to evaluate the effectiveness of the combined application of (CHI) and the essential oil (EO) of Mentha piperita like natural alternative antimicrobial compounds to the inhibition of Rhizopus stolonifer (URM 3728), Aspergillus flavus (URM 4540), Botrytis cinerea (URM 2802) e Penicillium expansum(URM 3396), highlighted pathogens, in the laboratory field. The CHI and the EO from M. piperita present minimum values of inhibitory concentration of 8 mg/mL and 5,0 µL/mL, respectively, facing all the studied fungus. The combined application of CHI and EO from M. piperita L., in distinct inhibitory and subinhibitory concentrations caused significant reduction in the growth of A. flavus, A. niger, R. stolonifer, B. cinerea e P. expansum (>96%). The inhibition of the spores germination also achieved expressive values (>90%) in all the concentrations, facing all the fungus. The remarkable antifungal effect, observed in the consequence of the joint application of CHI and EO from M. piperita L., in subinhibitory concentrations, suggests a potentiated antifungal effect in the decrease of the postharvest losses arising the action of such biological contaminants.