High-throughput sequencing was used to study the relationship between the fungal diversity and ZEN in coix seeds under different conditions
Mycotoxins easily contaminate coix seeds used for medicine and food. Although the research on the detection of harmful mycotoxins has gradually increased, the research on the factors that lead to its contamination of mycotoxins has not yet been reported. Here, we investigated if stir-frying affected the mycotoxins and fungal community of coix seeds and if different storage environments led to change mycotoxins and fungal diversity. We found that zearalenone (ZEN) was very easy to contaminate coix seeds. And it only did not find ZEN content increase which stir-fried coix seeds storage at room temperature. Moreover, stir-frying had a significant impact on the fungal community of coix seeds. And environmental humidity had a more significant effect on the fungal community of sitr-frying coix seeds than raw coix seeds. A total of 6 genera of fungi were negatively correlated with ZEN and Fusarium. These fungi have antibacterial effects or degrade mycotoxins. And Rhizopus oryzae abundance in the stir-fried coix seeds stored at room temperature, which could degrade mycotoxin, were significantly different from the other three groups. That may be one of the reasons why no increase in ZEN content was found in this group. Collectively, these results indicate that whether the coix seeds were stir-frying and the humidity of the storage environment would affect the composition of the fungal community on their surface and affect the content of the harmful ZEN. That provides ideas and a basis for researching the safe storage of coix seeds.