Natural occurrence of fumonisins B₁ and B₂ in corn in four provinces of China

Abstract

Fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) are the most abundant fumonisins (FBs) occurring worldwide in maize, infected mainly by Fusarium verticillioides and F. proliferatum. A total of 307 corn kernel samples were collected from 45 districts of Gansu, Shandong, Ningxia and the Inner Mongolia provinces of the north and northwest China. The samples were analysed for FB₁ and FB₂ by high-performance liquid chromatography. The FBs (FB₁+ FB₂) incidence rate in samples from Gansu, Shandong, Ningxia and Inner Mongolia were 31.5%, 81.1%, 46.2% and 53.6%, respectively. Average FBs concentration was 703 μg/kg and the concentrations ranged from ≤11 to 13,110 μg kg⁻¹. Results were compared with the European Commission (EC) regulation for FB₁+ FB₂ in unprocessed maize for human consumption of 4 mg kg⁻¹. Contamination in 17 samples was higher than these levels. More than 80% of the samples from Liaocheng county, which is located in the Shandong province, were contaminated with FBs, with a mean total FB concentration of 2496 μg/kg. The result was significantly different from that of the Inner Mongolia (1399 μg/kg), Ningxia (373 μg/kg) and Gansu (175 μg/kg). Average exposure to FBs (0.12 μg/kg body weight/day) is within the provisional maximum tolerable daily intake of 2.0 mg/kg of body weight set by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives.

Keywords:

• fumonisins
• corn
• China
• climatic conditions

Acknowledgement

The authors express their sincere thanks to the earmarked fund for China Agriculture Research System (nycytx-02).