Assessment of aflatoxin levels in herbal green tea available on the Moroccan market

Abstract Tea is a popular beverage known worldwide with health benefits for consumers. It was considered safe and healthy for centuries. However, recent investigations reported that herbal tea might be contaminated by fungi and mycotoxins. The purpose of this study was to assess, for the first time, the levels of aflatoxins (AFs) in 129 herbal green tea samples obtained from retail shops and supermarkets in three Moroccan areas (El Jadida, Kenitra and Meknes). Aflatoxins were quantified by liquid chromatography coupled to a fluorescence detector and the confirmation of the suspected samples was done by LC-MS/MS. Analytical results indicate that out of 129 total samples, 76 samples (58.9%) were found to be contaminated with AFs. In positive samples, AFB1 levels ranged from 1.8 to 6.7 ng/g in tea samples from Meknes, and from 4.4 to 41.8 ng/g in those from Kenitra. The maximum recorded AFB1 level was 41.8 ng/g, while the maximum total AFs amount was 116.2 ng/g. This study revealed also that 38 (29.5%) and 12 (9.3%) out of 129 total samples exceeded the levels of 10 ng/g and 5 ng/g, which are the maximum levels set by Moroccan regulations of total AFs and AFB1 in some spices and aromatic plants, respectively.