Aflatoxin Determination in Black Tea (Camellia Sinensis) – Status and Development of a Protocol.

Aflatoxins, toxic mold metabolites, are naturally contaminants of food and have
been reported on tea (Camellia sinensis), but there are no validated methods published
for its determination.Amethod has been standardized incorporating Tween-
20, a nonionic surfactant in the extraction solvent, with use of an immunoaffinity
column for cleanup followed by postcolumnphotochemical derivatization reversedphase
high-performance liquid chromatography.Acceptable recoveries of 76–100%
were observed when spiked with aflatoxins B1, B2, G1 and G2. Analysis of market
samples of black tea showed the presence of aflatoxigenic molds in 25.9% of samples,
and aflatoxin B1 was detected in one sample at a level of 19.2 mg/kg. Aflatoxin production
was observed in tea samples artificially inoculated with the conidia of an
aflatoxigenic strain of Aspergillus flavus.Major portion of the aflatoxins added to the
tea leaves remains in the residue when boiled with water, and 30.6% gets partitioned
into the filtrate,which is the component used to prepare the beverage.