CHEMICAL COMPOSITION AND BIOLOGICAL ACTIVITY OF ESSENTIAL OIL FROM MENTHA PIPERITA L. LEAVES ON THE QUALITY OF MANGO PUREE DURING STORAGE

Abstract

The aim of this study was to evaluate the effect of essential oil (EO) from fresh leaves of Mentha piperita L. on the conservation of mango puree during storage. The results of physicochemical characterization of mango puree underlined its high nutritional potential, with carbohydrates, carotenoids and vitamin C contents of 9.5±0.4%, 20.05±0.03 mg/100g and 21.03±0.05 mg/100g respectively. Microbiological analyses revealed that Aspergillus and Mucor were the most common genera of fungi identified from mango puree in Benin by using a taxonomic schemes primarily based on morphological characters of mycelium and conidia. The isolated fungi include Aspergillus parasiticus, A. versicolor and Mucor spp. Antifungal assay, performed by the agar diffusion assay, indicated that essential oil exhibited high antifungal activity against the growth of fungi. The minimal inhibitory concentration (MIC) of the essential oil was found to be 2.0 μL.mL-1for A. parasiticus and A. versicolor; and 1.0 μL.mL-1 for Mucor spp. The Minimal Fungicide Concentration (MFC)was recorded to be 2.5 μL.mL-1 for A. parasiticus and A. versicolor; and 1.5 μL.mL-1 for Mucor spp. Chemical analysis by GC/MS of the oil led to the identification of 15 components, characterized by menthol (46.7%), neomenthol (8.28%) and 1.8-cinéole (6.49%) as major components. Results obtained during the evaluation of the physicochemical characteristics of the mango puree stored by adding EO, indicated a significant decrease in the pH, carotenoids and vitamin C contents. However, with EO concentration of 2.5 μL.mL-1, the pH of stored mango puree was 6.4±0.7 after 15 days of preservation, with a high carotenoids and vitamin C contents of 19.02±0.07 mg/100g and 21.01±0.03 mg/100g. The EO of Mentha piperita L., with high antimicrobial property, offers a novel approach to the management of fruits derivate products during storage.