Chemical and Biological Evaluation of Aflatoxin After Treatment with Sodium Hypochlorite, Sodium Hydroxide and Ammonium Hydroxide

Aflatoxin B1 was mixed with eleven concentrations of sodium hydroxide, sodium hypochlorite and ammonium hydroxide. Aflatoxin was quantitated by fluorometric determination and toxicity of aflatoxin treated with NaOH and NH4OH was evaluated by the brine shrimp assay. Detoxified aflatoxin B1 was then screened for mutagenicity using the Salmonella /mammalian microsome mutagenicity test (Ames test). Sodium hydroxide, sodium hypochlorite and ammonium hydroxide reduced fluorescence by 92, 96, and 94%, respectively, at concentrations of 25, 11, and 875 mg per 50 g. A high negative correlation was observed between decrease in fluorescence and increase in survival of brine shrimp (r = 0.88) for aflatoxin treated with NaOH and NH4OH. Equivalent amounts of aflatoxin B1 (0.05 μg) and aflatoxin B1+ detoxified B1 (0.05 μg + 0.05 μg, respectively) were not significantly different (P>0.05) in the number of revertants resulting in the Ames test. Therefore, aflatoxin B1 in the presence of detoxified aflatoxin did not increase in mutagenicity.