Occurrence of multiple mycotoxins in various types of rice and barley samples in Thailand

The prevalence of mycotoxins is often increased by climatic conditions prevailing in tropical regions. Therefore, consumers in tropical countries such as Thailand have a higher risk of mycotoxin exposure. Existing reports have revealed mycotoxin contamination in rice. This study was conducted to determine the occurrence of multiple mycotoxins in barley and nine types of rice sold in Thailand and to assess consumer health risk. A total of 300 samples collected from various markets in Thailand were analyzed for the presence of 16 mycotoxins using a QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure and a triple quadrupole mass spectrometer equipped with an electrospray ionization source. Of the 300 samples, 124 (41.33%) were contaminated with at least one mycotoxin, and 38.71% of the mycotoxin-positive samples were simultaneously contaminated with more than one toxin. The incidence of mycotoxin contamination differed among the rice and barley samples. Beauvericin, diacetoxyscirpenol, zearalenone, and aflatoxins were the most frequently found mycotoxins. However, the concentrations of regulated mycotoxins were below the regulatory limits. The assessed mycotoxin exposure does not represent a health risk for Thai consumers because the estimated exposure concentrations were lower than the tolerable daily intake values established by the Joint FAO/WHO Expert Committee on Food Additives. However, our findings suggest that continued monitoring of mycotoxin contamination in rice and barley and concomitant risk assessments are warranted. HIGHLIGHTS o Contamination with multiple mycotoxins was found in rice and barley. o BEA, DAS, ZEA, and aflatoxins were the mycotoxins most frequently found in samples. o The assessed mycotoxin exposure does not represent a health risk for consumers.