Mycotoxins Detection and Fungal Contamination in Black and Green Tea by HPLC-Based Method

This study investigated the presence of fungal contamination, total aflatoxins (AF), and ochratoxin A (OTA) in black and green tea samples. A total of 60 tea samples underwent extraction and subsequent treatment using immunoaffinity columns. High-Performance Liquid Chromatography (HPLC) coupled with a fluorescence detector (FD) was employed for the quantitative determination of AF and OTA levels. Additionally, tea samples were cultured to identify the fungal species present. The results revealed that 24 (40%) of the samples were contaminated with AFs, although none exceeded the acceptable limit of 10 µg/kg. Conversely, all analyzed samples were found to be contaminated with OTA. Notably, 3 black tea samples (6.6%) and 1 green tea sample (6.7%) contained OTA levels surpassing the standard limit of 10 µg·kg⁻¹. The mean concentration of OTA was observed to be higher in black tea compared to green tea. *Aspergillus niger* was identified as the predominant fungal species isolated from both black and green tea samples. The study concludes by recommending regular monitoring during the tea processing stages to improve quality, given the significant mycotoxin contamination observed. The analytical method utilized HPLC-FD, which is a common and effective technique for mycotoxin analysis, especially when coupled with appropriate sample preparation like immunoaffinity columns for enhanced selectivity and sensitivity in complex food matrices.

This study investigated the presence of fungal contamination, total aflatoxins (AF), and ochratoxin A (OTA) in black and green tea samples. A total of 60 tea samples underwent extraction and subsequent treatment using immunoaffinity columns. High-Performance Liquid Chromatography (HPLC) coupled with a fluorescence detector (FD) was employed for the quantitative determination of AF and OTA levels. Additionally, tea samples were cultured to identify the fungal species present. The results revealed that 24 (40%) of the samples were contaminated with AFs, although none exceeded the acceptable limit of 10 µg/kg. Conversely, all analyzed samples were found to be contaminated with OTA. Notably, 3 black tea samples (6.6%) and 1 green tea sample (6.7%) contained OTA levels surpassing the standard limit of 10 µg·kg⁻¹. The mean concentration of OTA was observed to be higher in black tea compared to green tea. Aspergillus niger was identified as the predominant fungal species isolated from both black and green tea samples. The study concludes by recommending regular monitoring during the tea processing stages to improve quality, given the significant mycotoxin contamination observed. The analytical method utilized HPLC-FD, which is a common and effective technique for mycotoxin analysis, especially when coupled with appropriate sample preparation like immunoaffinity columns for enhanced selectivity and sensitivity in complex food matrices. Research Background and Significance Mycotoxins, toxic secondary metabolites produced by certain fungi, pose significant health risks when ingested through contaminated food and beverages. Among these, aflatoxins (AFs) and ochratoxin A (OTA) are particularly notorious due to their carcinogenic and nephrotoxic effects, respectively. Tea, a globall