Mycotoxins in herbal teas marketed in Latvia and dietary exposure assessment

The occurrence of 12 mycotoxins has been analysed by liquid chromatography–time of flight mass spectrometry in the batch of 60 herbal teas purchased from drugstores in Latvia. Among the dry tea samples, 90% were positive for one to eight mycotoxins. Enniatin B and deoxynivalenol (DON) were the most frequently detected mycotoxins in 55% and 45% of the samples, respectively. DON reached the highest level, from 129 µg kg⁻¹ in herbal blend to 5,463 µg kg⁻¹ in wormwood tea. Ochratoxin A (OTA) and aflatoxin B₁ (AFB₁) were found in 10% and 20% of the samples at the concentrations ranged between 2.99–30.3 µg kg⁻¹ and 3.40–23.7 µg kg⁻¹. Studies of the tea infusion process indicated that 32–100% of DON and zearalenone present in dry teas were extracted into the infusions. Dietary exposure assessment was performed, using the determined mycotoxin levels and the available consumption data.