Characterization of the Constituents and Antioxidant Activity of Brazilian Green Tea (Camellia sinensis var. assamica IAC-259 Cultivar) Extracts

Abstract

Freeze-dried extracts from Camellia sinensis var. assamica IAC-259 cultivar named Brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. Their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector. The antioxidant activity of the major green tea compounds and Brazilian green tea extracts was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The levels of caffeine were higher in the summer samples (p < 0.05); otherwise, there were no significant variations related to the catechin contents between spring and summer samples. The sonication method using water/acetone as solvent had a high efficiency to extract not only epigallocatechin gallate but also epicatechin gallate (p < 0.05). Antioxidant activities of the Brazilian green tea extracts were not significantly different among seasons and extraction systems. The antioxidant data (IC50) of the Brazilian green tea extracts showed a significant correlation with their epigallocatechin gallate and epicatechin gallate contents (p < 0.05).

Optimization of the Extraction of Antioxidants and Caffeine from Maté (Ilex paraguariensis) Leaves by Response Surface Methodology

“…In addition, Hayouni, Abedrabba, Bouix, and Hamdi (2007) reported that water and organic sol-IJFS April 2013 Volume 2 pages 69-80 vents used individually or in mixtures, such as acetone:water:acetic acid (90:9.5:0.5) and ethylacetate:methanol:water (60:30:10), significantly affected the total polyphenol contents of Quercus coccifera L. and Juniperus phoenicea L. fruit extracts. Ethanol-water mixtures were found to be suitable for extraction of total polyphenols from plant tissues with variable polyphenolic composition, including milled soybeans (Jokić et al, 2010), black and green tea (Astill, Birch, Dacombe, Humphrey, & Martin, 2001;Sairro et al, 2007), black currants (Cacace & Mazza, 2003), apple pomace (Wijngaard & Brunton, 2010), red fruit by-products (Lapornik, Prosek, & Wondra, 2005), and jabuticaba skins (Santos, Veggi, & Meireles, 2012). Spigno, Trarnelli, and De Faveri (2007) found that a high concentration of water in ethanolwater mixtures (below 50%) reduced the extraction of polyphenols from grapes.…”

Differences in quality parameters between types of commercial tea from Argentina

“…The tea plant (Camellia sinensis (L) O. Kuntze) is cultivated all over the world and each zone of growing produces a product with differential qualities as a result of climate and edaphic site conditions, farming techniques and industrialization (Parra, 2007;Saito et al, 2007). Teas from the genus Camellia can be divided into three categories based on the tea manufacturing (fermentation) process: green tea (unfermented), oolong tea (partially fermented), and black tea (fully fermented) (Kim, Goodner, Park, Choi, & Talcott, 2011).…”

“…The major producers of C. sinensisare China, India and Sri Lanka, but the cultivation of tea on a large scale has spread subsequently to many other parts of Asia, Africa and South America (Saito et al, 2007;Parra, 2007). Tea was firstly introduced to Argentina in 1923 with seeds brought from Georgia.…”

“…The quality of tea is dependent, in the first instance, on the chemical composition of the harvested shoots, and in the second instance, on the way in which they are handled, processed and stored (Yao et al, 2005). Many factors, such as geographical location, cultivar species, season, age of the leaves, climate and horticultural practices (soil, water, minerals, fertilizers) may influence the chemical composition of tea leaves (Saito et al, 2007;Jayasekera, Molan, Garg, & Moughan, 2011;von Staszewski, Pilosof, & Jagus, 2011;Kerio, Wachira, Wanyoko, & Rotich, 2012). Because of these factors, the chemical characterization of teas from different origins is very important considering that these studies are currently scarce (Saito et al, 2007).…”

“…Many factors, such as geographical location, cultivar species, season, age of the leaves, climate and horticultural practices (soil, water, minerals, fertilizers) may influence the chemical composition of tea leaves (Saito et al, 2007;Jayasekera, Molan, Garg, & Moughan, 2011;von Staszewski, Pilosof, & Jagus, 2011;Kerio, Wachira, Wanyoko, & Rotich, 2012). Because of these factors, the chemical characterization of teas from different origins is very important considering that these studies are currently scarce (Saito et al, 2007). The moisture content, water extract, crude fibre content, total polyphenol content and antioxidant capacity have long been regarded as important international standards for quality control of tea (ISO 3720, 2011;Yao et al, 2006;Anesini, Ferraro, & Filip, 2008;Smiechowska & Dmowski, 2006;Ravichandran, 2004;Jayasekera et al, 2011;von Staszewski et al, 2011).…”