Effect of gamma irradiation on aflatoxin production by aspergillus parasiticus

ABSTRACT

Exposure of aflatoxins produced by A. parasiticus grown on sterile raw peanuts to specific gamma irradiation doses induced reduction in aflatoxins with increasing gamma irradiation dose than did aflatoxin from non-irradiated sterile raw peanuts [control]. The reduction of aflatoxins ranged from 9.3 to 29.7%, 13.9 to 37.3%, 0.96 to 16.8% and 0.72 to 60.3% for AFB1, AFB2, AFG1 and AFG2, when the culture was irradiated at 0.5 to KGY, respectively. On the other hand, non- sterile raw peanuts that was inoculated with conidia of the fungus and then incubated for 2 weeks at 30C following irradiation resulted in reduction in aflatoxins ranged from 18.2 to 89%, 26 to 96%, 35.4 to 85.2% and 17.3 to 76.4% for AFB1, AFB2, AFG1 and AFG2, respectively. Irradiated raw peanuts culture following inoculation with conidia of the fungus and then incubated for 2 weeks at 30C resulted in reduction of toxin [s] production ranged from 4.9 to 28.4%, 16.8 to 54.7%, 1.71 to 18.6% and from 9.13 to 30.4% in AFB1 AFB2, AFG1 and AFG2 when cultures irradiated at 0.5 to 5 KGY, respectively. Inoculation of either sterile or non-sterile raw peanuts cultures following irradiation resulted in completely degradation of aflatoxin [s] at higher doses between 2.5 to 5 KGy for sterile substrates and at 2.5 to 4 KGy for non-sterile raw peanuts