Background and Objective: Aflatoxins are among the most important and hazardous fungal secondary metabolites, commonly produced in food and animal feed by certain Aspergillus species. Tea is one of the most widely consumed non-alcoholic beverages worldwide and is regarded as a healthy drink, with approximately two-thirds of the global population consuming it daily, particularly in the morning. This study aimed to monitor the presence of aflatoxins in black tea samples collected from Tehran, and to assess the safety of this commonly consumed beverage in the country.
Materials and Methods: In this study, 31 tea samples from different brands were collected in Tehran in May 2023 and analyzed for aflatoxin contamination using a nanoextraction method, followed by high-performance liquid chromatography (HPLC) equipped with a fluorescence detector.
Results: The limit of detection (LOD) values for aflatoxins G1, G2, B1, and B2 were 0.06, 0.35, 0.06, and 0.35 ng/g, respectively, and the limit of quantification (LOQ) values were 0.2, 1, 0.2, and 1 ng/g, respectively. The LOQ values of the present method are comparable to those reported in recent studies conducted in Spain, Austria, and Iran, which reported LOQs higher than 1 ng/g. According to the results obtained, none of the black tea samples from different brands available in the Tehran market contained detectable levels of the four types of aflatoxins (B1, B2, G1, and G2), even below the globally permissible limits (AFs ≥ 10 µg/kg).
Conclusion: Despite the absence of aflatoxin contamination in tea samples consumed in Tehran, previous studies worldwide suggest that tea can be contaminated with fungi and may support mycotoxin production under favorable temperature and humidity conditions. Therefore, ensuring tea safety requires attention to proper processing, adequate storage conditions, and the prevention of aflatoxin-producing fungal growth during production stages.
