A cottonseed meal containing aflatoxins was heated at atmospheric pressure in an effort to reduce the levels of these mycotoxins as measured by thinlayer chromatography. Temperature, period of heating, and moisture content of the meal were varied in these experiments. Heating at 60°and 80°C. did not lead to marked reductions in aflatoxin levels. More definite reductions were obtained at 100°C ., greater decreases taking place with increasing periods of heating and increasing mois-ture contents. The lowest level of aflatoxins Bi plus B2 achieved practically was about 44 p.p.b. obtained by heating 120 minutes at 100°C.

Cottonseed and peanut meals were treated with ozone to destroy or eliminate aflatoxins. High meal moistures (cottonseed 22%, peanut 30%), high temperature (100C), and longer treatment times favored inactivation as measured by thinlayer chromatography. Aflatoxins B1 and G1 were readily destroyed by the ozone processes whereas aflatoxin Be appeared relatively resistant. In cottonseed meal, 91% of the total aflatoxins was destroyed in 2 hr, a decrease from 214 to 20 ppb ; in peanut meal, 78% was destroyed in 1 hr, a decrease from 82 to 18 ppb. In both meals, aflatoxin B1 was totally inactivated within the times specified.

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.