Bean paste fermentation will produce aflatoxin, people often eat fermented foods such as tofu milk, bean paste, etc., such food in the production process, such as improper methods, easy to produce aflatoxin.

Aflatoxin-producing bacteria and toxicity conditions can produce aflatoxin of the most important species is Aspergillus flavus and Aspergillus parasiticus, in addition to Aspergillus spp. of Aspergillus niger, Aspergillus grey, Aspergillus ochraceus, etc., Penicillium spp. of penicillium orange Penicillium, Penicillium extensum, penicillium finger, etc., trichoderma, fusarium, rhizosphere molds, streptomycetes and so on can also produce aflatoxin. They produce aflatoxin under the following conditions: substrate, temperature, pH, relative humidity.