NATURAL OCCURRENCE OF MYCOTOXINS IN FUSARIUM INFECTED BEANS

This is the first report on the discovery of several mycotoxins in nat urally infected mouldy navy beans (Phaseolus vulgaris L.) with distinc t whitish grey to pink discoloration. Species of Fusarium isolated fro m the mouldy beans included F. avenaceum, F. culmorum, F. graminearum, F. moniliforme, F. oxysporum, F. solani and two Fusarium spp. Three t ypes of bean samples were analysed for mycotoxins: (a) healthy beans w ithout any apparent discoloration, (b) beans with pink discoloration, and (c) a mixture of beans with whitish grey and pink discoloration. T he results indicated that diacetoxyscripenol (DAS), deoxynivalenol (DO N), T-2 toxin (T-2) and fumonisin B-1 (FB1) were present in type B and C samples but not in the healthy type A samples. Quantification of DA S, DON, and T-2 and of FB1 were achieved by gas chromatography and hig h performance liquid chromatography, respectively. The results showed that DAS, DON, T-2 and FB1 were not evident in the healthy samples, bu t in type B and type C samples, DAS, DON, T-2 and FB1 in the amounts o f 9.2, 6.5, 5.5 and 0.5 mu g/g, and of 3.3, 3.1, 13.5 and 1.1 mu g/g, respectively, were detected. Further research is under way to determin e which species of Fusarium is responsible for the production of speci fic toxins.