In-vitro Mycological activity of essential oil from Zingiber zerumbet rhizomes

Abstract

The volatile oil (1.12%) from the Z. zerumbet rhizomes were extracted using Clevenger’s distillation. The GC and GC-MS profile of the Z. zerumbet volatiles revealed several components of which Zerumbone was the principal compound (49.8%) followed by α-Caryophyllene (20.1%) and trace of other compounds. The antifungal property of volatiles was studied against Aspergillus flavus and Aspergillus ochraceus. The fungal species were susceptible to volatiles, and the minimum fungicidal concentration (MFC) was 160 ppm for A. flavus and 175 ppm for A. ochraceus.The studies with the food toxigenic organisms treated with volatiles were significant. It revealed substantial inhibition of mycelia, spore germination, reduction in biomass, carbohydrate, protein, chitin and genetic constituents. The inhibitory action of zerumbet volatile oil on A. flavus and A. ochraceus involves cell wall damage and distortion in the metabolism. The SEM of A. flavus and A .ocharceus illustrates that treatment with the oil leads to distortion of hyphae and the absence of conidiophores. The Z. zerumbet volatiles (100 ppm) were found to be antimycotoxin on maize as food substrates and were dose-dependent on confirmation by HPLC. Z. zerumbet oil is potentially useful as biopreservative because of its antifungal and antimycotoxin efficacy.