Aflatoxin inactivation: treatment of peanut meal with formaldehyde and calcium hydroxide

A peanut meal contaminated with ca. 600 ppb aflatoxins was treated with formaldehyde alone and in combination with calcium hydroxide in a benchscale reactor, operated both sealed and at atmospheric pressure. In general, thin layer chromatographic assays revealed that addition of calcium hydroxide to formaldehyde caused greater inactivation of the toxins than did formaldehyde alone. With the reactor sealed and 25% moisture in the meal, treatments for 1 hr with 0.5% and 1.0% formaldehyde plus 2.0% calcium hydroxide yielded products having 3 and 1 ppb aflatoxins, respectively, whereas under reflus at atmospheric pressure with 20% meal moisture, 1 hr treatment with 1.0% calcium hydroxide yielded a product with 5 ppb aflatoxins.