Distribution and variation of fungi and major mycotoxins in pre- and post-nature drying maize in North China Plain

•Fungi infection was significantly higher in pre-drying samples than post-drying.•F. verticillioides and F. graminearum were predominant species in maize kernels.•FB1 and DON were the major mycotoxins presented in the samples, followed by ZEN.•DON contamination was significantly higher in post-drying samples than pre-drying.•Occurrence of mycotoxins is highly in accordance with incidence of relevant fungi.

Forty-four pre- and post-nature drying maize kernels were collected from North China Plain and assessed for fungi infection and mycotoxins contamination. The percentage of fungi infection was significantly higher in pre-nature drying samples than post-nature drying samples except for Fusariuim graminearum, which increases from 6.06% to 24.09%. Fusarium, Aspergillus, Alternaria and Trichoderma were main genera. Fusarium verticillioides (24.77%) and F. graminearum (15.08%) were predominant species, followed by Aspergillus niger (7.51%) and Aspergillus flavus (4.93%). FB1 and DON were the major mycotoxins presented in the samples, followed by ZEN. All samples showed FB1 ranging from 16.5 to 315.9 μg/kg. All post-nature drying maize kernels showed DON ranging from 5.8 to 9843.3 μg/kg, while 7 of 22 pre-nature drying samples contaminated with DON ranging from 50.7 to 776.6 μg/kg. The samples contaminated with ZEN in pre- and post-nature drying maize were 3, with the content ranging from 60.5 to 147.6 μg/kg and from 40.7 to 1056.8 μg/kg, respectively. Only 1 sample contaminated with AFB1 of 148.4 μg/kg. The occurrence of mycotoxins is highly in accordance with the incidence of the corresponding mycotoxin-producing fungi. This is the first comprehensive comparison of fungi infection and mycotoxins contamination between pre- and post-nature drying maize kernels.