Abstract: The succession of fungal microflora and the change of aflatoxin B1 (AFB1) during natural fermentation of Pixian horsebean paste were investigated using PCR-DGGE and ELISA analysis. The results showed that Aspergillus oryzae, Amylomyces rouxii, Rhizopus oryzae, Pichia anomala, and Debaryomyces hansenii were dominant during natural fermentation of Pixian horesebean paste, with A. oryzae as the predominant strain at both the starter propagation stage and incipient fermentation stage. A. rouxii and R. oryzae were the dominant strains during the starter propagation stage, while P. anomala and D. hansenii were the dominant strains during the incipient fermentation stage. The amount of AFB1 in all samples was less than the GB standard of 5μg/kg. During the starter propagation and incipient stages, AFB1 concentration revealed a gradual increase and then kept stable after the 14th day. Accordingly, more attention should be paid to the starter propagation stage for the biological control of AFB1.

Key words: Pixian horsebean paste, PCR-DGGE, fungal microflora, ELISA, AFB1