Studies on Fungal Load, Total Aflatoxins and Ochratoxin A Contents of Gamma-irradiated and non-irradiated Sesamum indicum Grains from Abuja Markets, Nigeria

Abstract

The fungal load, total afl atoxins (B1, B2, G1 and G2) and ochratoxin A (OTA) contamination of 36 samples of Sesamum indicum L. grains from Abaji, Gwagwalada, Kubwa and Karu in the Federal Capital Territory, Abuja, Nigeria were investigated. A total of 135 fungal isolates belonging to fi ve genera—namely, Aspergillus, Curvularia, Penicillium, Fusarium and Ascochyta—in decreasing order of prevalence were isolated from the non-irradiated grains. Only 34 isolates were obtained from the irradiated seeds at 3 kGy. Aspergillus spp. were observed in all the non-irradiated grain samples. Some fungal species were observed in irradiated grains treated with 3 kGy but none in the grains irradiated with 6–15 kGy. There was no consistent and no signifi cant (P > 0.05) reduction in the total afl atoxins and ochratoxin A contents of irradiated samples from the four markets at 3 to 12 kGy. However, all the sesame grains exposed to irradiation at 15 kGy had comparatively the least total afl atoxins and ochratoxin A contents. Multiple mycotoxin analysis and the nutritional quality of the irradiated mold-free grains should be further investigated.