Aflatoxins distribution in fractions derived from tofu production.

Tofu or bean curd is obtained from soybean seeds being a widespread food product in Asia. The commodity used for its production can be contaminated with aflatoxins, which are secondary metabolites synthetised by species of and . Intake of contaminated food products causes toxic effects on consumers. The aim of this work was to study aflatoxin distribution in fractions obtained from pilot-scale tofu production with contaminated soybeans. The presence of the aflatoxins B, B, G and G (AFs) in soaking water, okara, whey and tofu was analysed. Aflatoxin analysis was performed by HPLC with fluorescence detection. The distribution of aflatoxins in all the analysed fractions was not a normal distribution. The liquid fractions (soaking water and whey) had less contamination than solid fractions (tofu and okara). The percentage AFB remaining in nutritionally important fractions, okara and tofu, was between 6.2% and 67.7% (median = 18.1%) and 0.5% and 13.2% (median = 3.5%), respectively. AFB, AFG and AFG had a similar distribution. These results showed that throughout tofu production, AFs can be present in the products intended for human consumption.