MYCOBURDEN OF TOMATO (Lycopersicum esculentum MILL), INOCULATION-INDUCED MYCOTOXIN PRODUCTION AND CONTROL BY PASSIVE MODIFIED ATMOSPHERE

Abstract

The effect of fungi of tomato fruits (Lycopersicum esculentum) were investigated at Ijebu-Ode, south western Nigeria. Aspergillus niger, Fusarium oxysporum, Rhizopus stolonifer and Curvularia species were isolated from deteriorating tomato and used for inoculating fresh and healthy tomato samples. The isolates (Aspergillus niger, Fusarium oxysporum, Rhizopus stolonifer and Curvularia species) were then inoculated separately into healthy tomato samples. Storage of samples in modified atmospheres and the effects of inoculation on quality changes were also evaluated. Modified atmospheres designed by packing the samples inside a polythene bag of 12μm thickness significantly maintained the quality of the samples compared with the controls. The isolates were then evaluated for mycotoxin production using thin layer chromatography and mycotoxigenic potential was assessed by animal feeding trial using rats of the wistar strain fed orally with different concentrations of the mycotoxin extracts. Mycotoxins were detected from tomato samples inoculated with Rhizopus, Aspergillus and Fusarium species, before and after autoclaving for 15 min at 121oC. Experimental rats fed on mycotoxin extracts developed symptoms of neurotoxicity. Most of the fungal isolates showed great potential for mycotoxin production, which is of concern in public health. Modified atmosphere created by using sterile polythene bags of different thicknesses is therefore recommended for control of fungi infection of tomato fruits and extension of shelf life.