[Fungi N-nitrosamines and mutagens in the extract of the sour corn-soybean cakes from high incidence area of stomach cancer].

Sour corn-soybean cake is the main food of the inhabitants in high incidence area of stomach cancer in Linqu county Shandong province. In the extract of the sour corn-soybean cakes, twelve mycotoxin-producing fungi and 3 N-nitrosamines (NDMA, NDEA, NMEA) were detected and the finding rates of the fungi and the N-nitrosamines were 93.3% and 92.3%, respectively; the concentration of NDMA was 0.4-3.8 ng/ml, NDEA 0.2-8.1 ng/ml, and NMEA 0.3-1.4 ng/ml. The positivity rate of the Ames test (most positive materials were direct mutagens) was 44.12%. The experimental results showed that the extract of the sour corn-soybean cakes containing carcinogenic and mutagenic subjects could have some causal relationship with the incidence of stomach cancer.