Identification and quantification of fungi and mycotoxins from Pu-erh tea

Abstract Pu-erh tea originates from the province of Yunnan in south-western China. As this tea is produced by so called Aspergillus post-fermentation the question arises which molds and mycotoxins may be found in this tea. In total 36 samples of Pu-erh tea were investigated for their content of filamentous fungi and the mycotoxins aflatoxins B 1 , B 2 , G 1 , and G 2 , fumonisins B 1 , B 2 , and B 3 , and ochratoxin A. Fungi were isolated from all samples in a concentration of 1.0 × 10 1 to 2.6 × 10 6 colony forming units (cfu)/g tea, all together 19 fungal genera and 31 species were identified. The most prevalent species were Aspergillus acidus and Aspergillus fumigatus , followed by Zygomycetes and Penicillium species. Aflatoxins and fumonisins were not found in the samples investigated, ochratoxin A was detected in 4 of 36 teas (11.1%).