Recent Patents on Food, Nutrition & Agriculture, 2009, 1, 203-215 203 1876-1429/09 $100.00+.00 © 2009 Bentham Science Publishers Ltd. Green Tea Extract-Patents and Diversity of Uses Samuel T. Saito* 1 , Grace Gosmann 2 *, Cristina Pungartnik 1 and Martin Brendel 1 1 Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Estadual de Santa Cruz (UESC), Ilhéus, BA, Brazil, 2 Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil Received: March 24, 2008; Accepted: June 22, 2009; Revised: June 30, 2009 Abstract: Green tea is one of the most consumed beverages in the world. Presently, Camellia sinensis has become a source not only for the development of several food extracts but also nutraceutical, cosmetic and medicinal purposes. The technology developed to produce these extracts aims to improve the organoleptic characteristics of the products as taste and smell, and their shelf life. But it also searches to demonstrate some medicinal attributes like antioxidant, anti-aging, anti-tumor and anti-viral activities in relation to the chemical composition of the green tea catechins, especially (-)- epigallocatechin gallate (EGCG). The target of this review is to present the various patents related to the extraction methods and their claims, and to discuss the evidence found in the literature about the pharmacological activities of green tea. It summarizes the recent progress in technology to obtain the green tea extract and in clinical studies on its applications. Health-promoting products and disease-preventing applications of green tea extract or compounds isolated from it also take part of this text. Keywords: Green tea extract, EGCG, patent, Camellia sinensis, catechin, pharmacological activity. INTRODUCTION Green tea (GT), is a popular and ancient beverage brewed from dried leaves of the tea bush (Camellia sinensis (L.) O. Kuntze). World tea production of GT had passed from 3.15 million tons in 2003 to 3.6 million tons in 2006. India and China contributed to about 50% of the tea world output. FAO projections up to 2017 indicate that world GT production is expected to grow at the considerably faster annual rate of 4.5% than that of black tea, with a projected annual growth of 1.9% [1, 2]. Canned and bottled GT drinks are getting popular worldwide and the main focus of producers is on obtaining purified extracts with higher stability and better taste, thus allowing longer shelf-life for food application. There are two varieties of C. sinensis: var. sinensis and var. assamica. Generally, GT made in Japan and China is produced from var. sinensis, while black tea is made from var. assamica. It is assumed that due to differences between both varieties, genetic variability of hybrids (which yielded a large amount of clones) and also other factors, such as season, age of leaves, climate and horticultural conditions can influence the composition of many important compo- nents of tea, e.g., content of (-)-epigallocatechin gallate (EGCG, 4.4 to 15.3% dry basis) and theanine (0.2 to 4.8% dry basis) [3, 4]. Green tea extracts (GTE), containing tea solids including caffeine, amino acids (theanine, glutamic acid, arginine) and *Address correspondence to these authors at the Faculdade de Farmácia, Av. Ipiranga 2752, 90610-000 Porto Alegre, RS, Brazil; Fax: +55 51 3308- 5437; E-mail: grace.gosmann@ufrgs.br Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Estadual de Santa Cruz (UESC), Rod Ilhéus-Itabuna, km16, 45662-000 Ilhéus, BA, Brazil; Fax: +55 73 3680-5226; E-mail: samuelsaito@hotmail.com flavanols (catechins), also have become a source for alimentary, nutraceutical, cosmetic and medicinal uses. GT catechins have a wide range of pharmacological activities that include antihypertensive, antioxidative, antitumoral and hypolipidemic properties, amongst others. Parallel, many other patents are focusing on the improvement of GTE or selected constituents for health applications. Some of these products hold great promise for effective treatment of high mortality diseases such as cancer, AIDS and SARS [5-11]. Not surprisingly, a recent search of literature revealed more than 700 citations containing the term “green tea extract” related to patents describing methodology of GTE preparation or its utility, bioactivity and other technology applied to obtain new GT products; for EGCG more than 4,000 references were found [12]. GT, therefore, has received increasing commercial and industrial attention once it has considerable importance for specific health appli- cations of its constituents, such as catechins, especially EGCG, caffeine (CAF), theanine and ascorbate [13,14]. These components and other catechins, e.g. (+)-catechin and (-)-catechin (C); (+)-gallocatechin and (-)-gallocatechin (GC); (-)-catechin gallate (CG); (-)-gallocatechin gallate (GCG); (-)-epicatechin (EC); (-)-epigallocatechin (EGC); (-)- epicatechin gallate (ECG), are shown in Fig. (1). This review summarizes current patents on GTE extraction, purification and fractionation methods to obtain GT ingredients that can be used in food, cosmetic, nutra- ceutical and medicinal products. Our work is mainly focused on patents claimed in USA, Europe and Japan due to scarcity of information on Chinese patents. METHODOLOGY OF GREEN TEA EXTRACTION AND PURIFICATION Originally, typical extractions of tea described in the first patents used hot or cold water to form a dilute extract