Priority PAHs in orthodox black tea during manufacturing process Inderpreet Singh Grover & Satnam Singh & Bonamali Pal Received: 30 March 2012 / Accepted: 27 November 2012 / Published online: 8 December 2012 # Springer Science+Business Media Dordrecht 2012 Abstract Orthodox black tea is obtained from fresh leaves followed by withering, rolling, fermentation and drying. The presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) was studied in fresh leaves and at various stages of manufacturing. Benzo(a)pyrene (2A: probable human carcinogen) was found in dried tea leaves only whereas, naphthalene (2B: probable human carcinogen) was present during all the stages of manu- facturing. Dry tea leaves showed higher content of total 16 PAHs (∑PAHs) about 3 and 211 times than present in withered and dried leaves, respectively. Chrysene, ben- zo[g,h,i]perylene, indendo[1,2,3-c,d]pyrene, dibenzo[a, h]pyrene and benzo[a]antracene were not found during manufacturing stages of tea. Keywords PAH . Tea leaves . Soxhlet extraction . Gas chromatography Introduction Tea is widely consumed beverage and health effects of tea leaves have been studied by scientists for a long time (Weisburger 1997; Wheeler and Wheeler 2004). Scientific evidence indicates that the consumption of tea might have health-promoting properties like reduc- tion of cholesterol, depression of hypertension, anti- microbial effects and several other pharmacological activities (Kurodo and Hara 1999; Liu et al. 2000). But residues of certain contaminants, viz. heavy met- als, fluoride and pesticides, which may pose a health threat to tea drinkers, have been occasionally detected (Cai et al. 2003; Kumar et al. 2004; Wong et al. 2003). Polycyclic aromatic hydrocarbons (PAHs), a class of compounds that consist of two or more fused aromatic rings, are well-known class of carcinogens found in some foods (Singh and Parkash 2007; Lin et al. 2004). Gaseous and particle-bound PAHs can be transported over long distances before deposition, and may accu- mulate in vegetation (Lin et al. 2004). This could indi- rectly cause human exposure to PAHs through food consumption, and thus might pose a human health threat. Tea leaves possess a high surface area, so they may accumulate PAHs, especially from air (Lin and Zhu 2004). During the preparation of various types of tea (green tea, black tea, white tea, etc.) technical processes such as withering, rolling, fermentation and drying are involved. Black tea is produced by fermenting the slightly withered leaves for many hours before being either smoke fired, flame fired or steamed. In contrast, green tea is not fermented, but the leaves are steamed or pan fired to inactivate the polyphenol oxidase, thus avoiding oxidation. White tea is produced by air- drying the unopened leaf buds followed by short heating and air-drying. Oolong tea is prepared by withering the Environ Monit Assess (2013) 185:6291–6294 DOI 10.1007/s10661-012-3025-y Electronic supplementary material The online version of this article (doi:10.1007/s10661-012-3025-y) contains supplementary material, which is available to authorized users. I. S. Grover : S. Singh (*) : B. Pal School of Chemistry and Biochemistry, Thapar University Patiala, 147004 Punjab, India e-mail: dsstietp@yahoo.com