Aflatoxins in peanut and cottonseed meal can be inactivated by treatment with gaseous ammonia. In pilot plant runs, contaminated peanut meal was ammoniated at two levels each of moisture content, reaction time, temperature and ammonia pressure. Thin layer chromatography indicated that ammoniation inactivated the aflatoxins (121 ppb) in the meal to a nondetectable level. With a similar treatment, total aflatoxins (350 ppb) in cottonseed meal were reduced to 4 ppb. A series of runs was made with large scale equipment using cottonseed meal conraining an average of 519 ppb total aflatoxins. Under optimum processing conditions, aflatoxin content of this meal was reduced to below 5 ppb and nondetectable levels.

Peanut meal containing aflatoxins was heat treated in the presence of moisture and chemicals to reduce the aflatoxin content. Treatments with ammonia, methylamine, sodium hydroxide and ozone were effective in either destroying afiatoxins or greatly reducing aflatoxin levels as indicated both by TLC analysis and feeding experiments with ducklings and rats. Weight gains for animals receiving the treated meals were essentially comparable to those for animals receiving aflatoxin-free meal. The treated meMs, however, had somewhat reduced protein efficiency ratios, as indicated by rat feeding tests. Complete elimination of aflatoxins from contaminated peanut meal was achieved by extraction with a 90% acetone-]0% water (w/w) solvent system. The extracted aflatoxin-free peanut meal gave good growth in the duckling and rat feeding tests, and had a relatively high protein efficiency ratio.

Organic and inorganic reagents have been tested for destruction or inactivation of the aflatoxins present in peanut and cottonseed meals. The treatments were made in a special laboratory-scale reactor, and were evaluated by determination of the aflatoxins in the products by thin layer chromatography. In some instances, a larger pilot-plant scale reactor was used. Ammonia, methylamine, sodium hydroxide and formaldehyde reduced aflatoxin levels and appear practical for large scale treatments. Effects of various reaction parameters including time, temperature and moisture content on the efficiency of these reagents are presented.