Ochratoxin A in bulk consignments of wheat, durum wheat, and barley sampled before and after trans-Pacific shipment

Samples of 165 bulk wheat, durum wheat, and barley consignments were taken during loading in western Canada and unloading in Japan from September 2018 through September 2022. The 330 paired samples were analyzed for ochratoxin A (OTA). OTA was observed at concentrations ranging from 0.16 to 3.3 µg/kg, predominantly in wheat and durum wheat. Concentrations of OTA were not consistently greater in unloading as compared to loading samples from the same bulk consignments, nor was there correlation between OTA concentration at unloading and the duration of transport, suggesting the storage conditions during transport were not conducive to Penicillium verrucosum proliferation and OTA production during the mean transport time of 29 days. A lack of correlation of OTA concentrations in loading and unloading samples reflected the heterogeneous distribution of this mycotoxin in bulk grain and emphasized the importance of proper sampling to mitigate the impact of the heterogeneous distribution on variance of OTA measurements, and on inspection of compliance.