Postharvest control of Aspergillus niger in mangos by means of essential oils

Abstract

The use of essential oil as an alternative mean to synthetic fungicides has been considered in the past years for management of the postharvest decay of fruits in order to ensure more safe and long storage life of these perishable commodities. Aspergillus niger is one of the most dangerous fungal pathogen which can cause postharvest diseases in fresh mangos. The aim of this study was to assess the effectiveness of essential oil from four aromatic plants (Thymus vulgaris, Salvia mirzayanii, Artemisa persica, and Rosmarinus officinalis) in comparison to fungicide ‘Mancozeb’ against A. niger under in vitro and in vivo conditions. After inoculation of mango fruits with an isolate of A. niger followed by curative treatments with essential oil, the main physical and chemical attributes of mangoes were determined under postharvest condition. The in vitro results showed that colonies of A. niger were totally inhibited by application of essential oil of T. vulgaris (at all the tested concentrations) and A. persica (1500 μl/l). While, S. mirzayanii showed the lowest effect at 1000 μl/l if compared with the other essential oils. The results of the in vivo experiments showed that treatments with T. vulgaris and S. mirzayanii essential oil had significant (P<0.05) effects in preventing fruit decay at 1000 μl/l after 10 days of storage, while, R. officinalis essential oil significantly (P<0.05) reduced deterioration of mango fruits at 500 μl/l, followed by A. persica. Rosemary also showed the highest fruit firmness in comparison with other treatments. Also, the essential oils maintained higher chlorophyll content. The results of this work showed that application of essential oil on mangos assurance both a significant preservation on their quality attributes by controlling, at the same time, decaying caused by A. niger during the postharvest phase.