Fate of aflatoxins during bread making

Abstract

Fate of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) during dough fermentation and baking stages of wheat bread making process was studied. Bread dough samples were spiked with aflatoxins under controlled laboratory conditions at low (similar to 3.0 mu g/kg dry matter) and high (similar to 9.0 mu g/kg dry matter) levels for each of the toxins. Fermentation significantly (p<0.05) reduced concentration of toxins and reduction percentage in dry matter at low and high concentrations ranged from 28.0% (AFG1) to 33.6% (AFB2) and 30.6% (AFB2) to 33.7% (AFG2). Aflatoxin contents decreased significantly (p<0.05) by baking process and when the fermented dough was baked at 220 degrees C for 35 min, the maximum reduction was 57.4% (AFG1) at low toxin level and 55.7% (AFB2) at high toxin level. Total losses of aflatoxins during bread making process were 69.3% (AFG1)-70.4%(AFB2) at low level and 67.1% (AFB1)-69.8% (AFG1) at high level. These results indicate that fermentation and baking are effective in reducing aflatoxin levels. However, approximately half of the spiked toxins still remained in the bread and therefore complete decomposition of aflatoxins seems improbable during bread making process.