Antifungal potentials of ten selected plants against fungi associated with postharvest spoilage of fruits

Abstract

The aim of this research was to screen selected plants for their antifungal activities against some fungi commonly associated with post-harvest spoilage of fruits. Nine (9) selected fungi (Aspergillus flavus, A. fumigatus, A. niger, Colletotrichum sp., Fusarium oxysporum, Mucor sp., Penicillium digitatum, Rhizopus stolonifer and Trichoderma texanum) were isolated from some diseased fruit crops collected from local markets in Lagos, Nigeria. The antifungal potentials of ethanolic and aqueous extracts of Aframomum melegueta, Allium cepa, A. sativum, Capsicum annum, Curcuma longa, Cymbopogon citratus, Ocimum basilicum, Piper guinensis, Syzygium aromaticum and Zingiber officinale were investigated on the growth of these fungi using the agar well diffusion method. The treatments were carried out in triplicates and the antifungal activities were measured on the basis of the diameter of zone of inhibition. Sterile distilled water and ketoconazole were used as positive and negative controls respectively. Every fungus examined at varying concentrations showed different degrees of inhibitions as a result of antifungal constituents present in the plant extracts. Aqueous extracts of O. basilicum and P. guinensis showed growth inhibition against most of its tested fungi, with Colletotrichum sp. being the most inhibited by ethanolic extraction of the former. Also, ketoconazole inhibited the growth of these fungi while the negative control did not show any inhibition. Thus, the usage of these spices could help to improve food safety and reduce the risk of spoilage.