FATE OF AFLATOXINS DURING COOKING PROCESS AND EFFECT OF FOOD COMPONENTS ON THEIR STABILITY

The fate of 4 kinds of aflatoxins, aflatoxin B1, B2, G1, and G2, during cooking processes, especially boiling, were investigated. The samples, in which aflatoxin contamination was found in our survey, were cooked to evaluate the behavior of aflatoxins during the cooking process so that we could better estimate the real intake of aflatoxins from those aflatoxin-contaminated foods. Using corn, buckwheat, adlay, nutmeg and white pepper naturally or artificially contaminated with aflatoxins, we cooked porridge from the corn and adlay, and used the nutmeg and white pepper as seasoning in sauteing and making soup. Sixty percent or more aflatoxins remained after any one of the cooking processes, and there was no significant difference among the 4 aflatoxins in rate of loss. In other words, the aflatoxins could not be effectively degraded or eliminated in either sauteing or boiling processes. In spite of the fact that the degradation rate of aflatoxins contained in foods was found to be 10-30%, other data show that more than 80% of aflatoxins are degraded by boiling them alone, which seems to suggest that some compounds exist in food that protects aflatoxins. We also studied this point and confirmed that such a protective effect is exerted by reducing saccharides (such as glucose), proteins and amino acids, but not inorganic salts.