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.