Prevalence of aflatoxin in dried okra (Abelmoschus esculentus) and tomatoes (Lycoperisicon esculentum) commercialized in Ibadan metropolis

Abstract

Hundred grams of each sample were collected from the four markets namely Oje, Bodiga, Shasha and Orita-merin in five replicate of 20gram in separate airtight sterile polythene bag to prevent further contamination until aflatoxin analysis was done and subsequent isolation and identification of fungi. Aflatoxins ExtractionAflatoxins was extracted from the samples as described by Hell, et al. [12] with modifications employed due to different weight and dryness of the samples. Dichloromethan was used to extract the toxin and allowed to evaporate to dryness in laminar air flow-hood chamber for 48 hours until analysed. Qualitative analysisFour micro litres of the dissolved extract were spotted on the thin layer chromatography (TLC) plates 20*10cm with aflatoxin standards G and I and then allowed to develop in a tank containing diethyl ether, methanol and water at the ratio of 96: 3: 1 respectively. The spots intensities were visually compared with those of standards under ultraviolet light 366 nm wavelengths [13]. Quantitative analysisAflatoxin quantification was done by scanning with CAMAG TLC Scanner3 (densitometer), which measured the absorbance and fluorescence of the toxin extracted [14]. Isolation of fungiDirect isolation method was employed for fungi isolation. The samples were surface sterilized in 70% ethanol for 10minutes and Prevalence of aflatoxin in dried okra (Abelmoschus esculentus) and tomatoes (Lycoperisicon esculentum) commercialized in Ibadan metropolis