Pak. J. Bot., 45(3): 901-907, 2013. CHEMICAL COMPOSITION AND SENSORY EVALUATION OF TEA (CAMELLIA SINENSIS) COMMERCIALIZED IN PAKISTAN MUHAMMAD ADNAN 1 , ASIF AHMAD 1 , ANWAAR AHMED 1 , NAUMAN KHALID 2 , IMRAN HAYAT 1 AND IFTIKHAR AHMED* 3 1 Department of Food Technology, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan 2 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657, Tokyo, Japan 3* National Institute for Genomics & Advanced Biotechnology (NIGAB), National Agricultural Research Centre (NARC), Park Road, Islamabad-45500, Pakistan * 3 Corresponding author e-mail: iftikharnarc@hotmail.com; Phone: +92-51-844 3706, Fax: +92-51-9255 502 Abstract The quality of black and green commercial tea samples was accessed by physicochemical analysis, mineral analysis and sensory evaluation. Significant variations in physicochemical and organoleptic parameters were observed. The moisture, protein, fat, crude fiber, water extracts and ash contents of the commercial tea samples were found to be in the range of 2.46- 7.47, 0.87-1.141, 0.94-2.15, 11.23-17.21, 32.34-53.61, and 3.29-5.86%, respectively while caffeine and catechin were found in the range of 2.34-4.33% and 0-7.44%, respectively. The highest percentage of moisture, protein, fat, and crude fiber contents were observed in green tea samples while highest percentage of ash and water extracts were observed in black tea samples. Calcium, magnesium, sodium, potassium and manganese were found to be in the range of 1.47-3.84 mg/l, 2.97- 5.66 mg/l, 0.39-1.83 mg/l, 3.01-4.00 mg/l., 1.09-2.43 mg/l, respectively with maximum amounts found in green tea as compared to black tea. Introduction Tea is the second most consumed beverages in the world after water and is grown in 30 countries worldwide. It was primarily originated in South Eastern China but recently it is cultivated in many countries across tropical and subtropical regions all over the world and has more than 82 different species (Krafczyk & Glomb 2008; Sultana et al., 2008; Akhlas et al., 2003). Tea is the extract of leaves, leaf nodes and internodes of plant (Camellia sinensis) which is consumed as extract in hot water rather than being eaten as such. It is also referred to as an aromatic liquid product which has been made by curing the leaves by applying water in hot form (Xiao et al., 2008). The high consumption of tea is attributed to richness in important substances having cool, a little bitter flavor, antioxidant properties and health benefits (Dimitrios, 2006). The chemical components in tea include alkaloids (theobromine, caffeine, theophylline), polyphenols (catechins, flavonoids), amino acids, polysaccharides, volatile acids, vitamins, lipids as well as inorganic elements (Monobe et al., 2008; Wei et al., 2010; Xiong et al., 2012). The regular consumption of tea can contribute to the daily dietary requirement of some of the important minerals (Powell et al., 1998). A lot of health benefits of tea were reported by researchers which may include antitumor (Dimitrios, 2006), anti-carcinogenic (Katiyar & Mukhtar, 1996) and anti-arteriosclerotic agents (Mukhtar et al., 1994). To gain these health benefits tea is used in form of powders, soft extracts and strong infusions (Gardner et al., 2006). Green tea catechins (GTC), is an important constituent of tea which have received much attention as protective agent against cardiovascular disease and cancer (Reto et al., 2007). Tea polyphenols and Tea polysaccharides including flavonoids play an important role in bio- activities of tea (Anesini et al., 2008; Kato et al., 2008). The chemical composition of tea varies and largely depends on climatic conditions, horticultural practices, soil, growth altitude, plucking season, sorting, grading, processing, extraction, storage and drying (Pelillo et al., 2002; Le Gall et al., 2004). Variability in composition is an important factor that dictates the taste, flavor and health benefits of a specific type of tea (Hara et al., 1995). There is a direct association between tea quality and the content of tea amino acids, caffeine and polyphenols in tea leaf (Cheng, 1983; Khalid et al., 2011). The per capita consumption of tea worldwide averages 4 fluid ounces per day (Zhu et al., 2006). But in Pakistan per capita consumption is one kilogram and after United Kingdom, Pakistan is the second largest country that imports both raw and processed tea from abroad (Latif et al., 2008). There are different types of tea and tea brands available in the Pakistani market having variation in their composition and quality, but no study has yet been reported in Pakistan regarding compositional analysis of local tea brands in relation to quality. So keeping in view these facts, this research study was planned to evaluate the variation in the composition of commercially tea brands available in the market and to find out the association between tea components that may affect its organoleptic qualities. Materials and Methodology Sample collection and preparation: Different brands of tea samples (10 black tea and 5 green tea samples) were collected randomly from different locations in Rawalpindi, Pakistan, the selection was done on the basis of brand popularity and likeness among people. Both local and International brands were selected for this study. Samples were ground and passed through sieve No.30 to get homogenous size material. All the reagents used were of analytical grade except acetonitrile and acetic acid