Aflatoxin Destruction in Corn Using Sodium Bisulfite, Sodium Hydroxide and Aqueous Ammonia

Abstract

Naturally contaminated yellow dent corn containing 235 ppb of aflatoxin 8 1 and 8 2 was adjusted to a moisture content of 20% and then treated for 24 h at ambient temperature with NaHS0 1 , NaOH or aqueous NH 1 at 0.5%, 1.0%, or 2.0% concentrations. All treatments were effective in reducing aflatoxin 8 1 and 8 2 levels. Sodium bisulfite was more effective in destroying aflatoxins than were NaOH or aqueous NH 1 at 0.5% and 1.0% concentrations, while NaOH and aqueous NH 1 were more effective than bisulfite at 2.0% concentration. Subjecting yellow corn samples to either NaHS0 1 , NaOH or aqueous NH 1 at 2.0% concentrations reduced aflatoxin 8 1 and 8 2 levels to below the FDA guideline of 20 ppb total aflatoxin. Sodium bisulfite was also effective in reducing the levels of aflatoxins in a white dent com sample containing 81 ppb of aflatoxin 8 1 and 12 ppb of aflatoxin 8 2 • Results suggest that NaHS0 3 , NaOH or aqueous NH 3 can be used to effectively destroy aflatoxins in corn and possibly other agricultural commodities. Aflatoxins are toxic secondary metabolites that can be produced on corn by the widely distributed fungi. Aspergillus flavus and Aspergillus parasiticus. Several investigations have demonstrated that aflatoxins are acutely toxic, teratogenic, carcinogenic and mutagenic (4.17.20).