Primary research on sampling scheme for analyzing mycotoxin distribution in wheat and rice fields

Background: Mycotoxins are among the most severe food contaminants. Deoxynivalenol and aflatoxin contamination are predominant in wheat and rice, respectively. Nowadays, there are no standardized and approved grain-sampling schemes worldwide. This study aimed to develop a scientific grain-sampling scheme to investigate the regularity of mycotoxin distributed in wheat and rice fields. The data were analyzed with analysis of variance and cluster analysis to select a better sampling scheme.

Results: Considering the influences of the weather before harvest (temperature, humidity, wind direction, and other conditions), we sampled grains from different places in different farmlands and detected the mycotoxin content of the sampled grains. The mycotoxin content had extremely significant differences in the area of rice fields (P<0.01) and significant differences in the area of wheat fields (P<0.05). The filtering effect existed peripheral the field areas, especially peripheral the humid areas, where the fungi were filtered and the toxin were easily produced. Furthermore, the upwind direction peripheral the field areas cause more filterature effect than other wind direction. Although 97% of mycotoxins in wheat can be removed through the shelling process, the toxin content were not obviously affected by rice lodging in the field. According to the cluster analysis, the peripheral and middle areas were divided into the same group with higher mycotoxin content.

Conclusion: This paper developed a sampling scheme to detect the mycotoxin content of wheat and rice in the field, considering the temperature and humidity of the weather, locations, and other grain contamination conditions before harvest. Meanwhile, the sampling rule of lodging and wind direction in the field was also assayed. © 2021 Society of Chemical Industry.