Oolong tea

Onyxide 200 Oocysts Oolites Oolong tea Oomycetes Oospora destructor Oospora sp. 02-oxidoreductase OP-2507 [101758-79-6] Opacifiers Opacifying agent... 

FIa.VOnoIOxida.tlon, The fermentation process is initiated by the oxidation of catechins (1) to reactive catechin quinones (13), a process catalyzed by the enzyme polyphenol oxidase (PPO) (56). Whereas the gaHocatechins, epigaHocatechin, and epigaHocatechin gaHate, are preferred, polyphenol oxidase can use any catechin (Table 2) as a substrate. This reaction is energy-dependent and is the basis of the series of reactions between flavanoids that form the complex polyphenoHc constituents found in black and oolong teas. 

The differences in types of tea are due not to the variety of the tea, but rather to the tea processing. The same basic tea leaves can produce green, black or oolong teas, although some varieties of tea leaves are more suited to certain types of tea. So-called herbal teas are produced from mixtures of flowers, berries, peels, seeds, leaves and roots from many different plants. They are quite different from tea. However, combinations of these herbal materials and tea leaves are also present in the market. 

Tea leaf contains 2.5-4.0% caffeine (1,3,7-trimethylxanthine) on a dry weight basis and smaller quantities of the related methylxanthines, theobromine (3,7-dimethylxanthine 0.2-0.4%) and theophylline (1,3-dimethylxanthine ca. 0.02%). Although it is said that var. sinensis is slightly lower in caffeine than var. assamica, black, green and oolong tea beverages all contain about the same levels of caffeine (Cheng and Chen, 1994). 

MASAO s, SAiTO H and TAKEO T (1994) Irritation test of skin and eye mucosa on oolong tea water-soluhle extracts , Preclinical Rep of the Central Inst for Exp Animals, 19 (3), 199-203. 

NAKABAYASHI T (1991) Chemical compounds in tea , in Nakabayashi T, Ina K and Sakada K, Chemistry and Functions of Green, Black and Oolong Teas, Kawazahi, Japan, Koogaku Press Ltd, 20-42. 

The conversion of freshly harvested green leaf to products of commerce is carried out in factories on large tea estates. When tea is grown on small plots, manufacturing is effected at centralized facilities. The three major types of tea manufacturing result in the production of green tea, black tea, and oolong tea. 

Oolong tea is only partially oxidized, so that its appearance and chemical composition is somewhat intermediate between that of green and black tea. It is manufactured primarily in the People s Republic of China and in Taiwan. 

Tea provides a broad spectrum of flavor experience there is a considerable degree of diversity in the flavor of different varieties green tea and oolong tea provided very different taste sensations from those of black tea flavorants and other additives allow for still greater variety tea is appreciated both as a hot and a cold beverage. 

Oolong Tea Anxi Oolong Ben Shan Dai Bamboo Dragon Balls... 

Fig. 2.62. HPLC chromatogram of (a) jasmin (green) tea, (b) Fujian Oolong tea, (c) pu-erh tea and (d) black tea at 280 nm. Peak identification 1 = gallic acid (GA) 2 = (-)-epigallocatechin (EGC) 3 = (-)-epigallocatechin gallate (EGCG) 4 = epicatechin (EC) 5 = (-)-epicatechin gallate (ECG) 6 = caffeine (CA) 7 = ( — )-catechin gallate (CG). Reprinted with permission from Y. Zuo et al. [178].

CS005 Hashimoto, F., G. 1. Nonaka and 1. Nishioka. Tannins and related compounds. LVl. Isolation of four new acylated flavan-3-ols from oolong tea. Chem Pharm Bull 1987 35(2) 611-616. 

CS018 Moon, ]. H., N. Watanabe, Y. Ijima, A. Yagi and K. Sakata. Cis-and trans-linalool 3,7-oxides and methyl salicylate glycosides and (Z)-3-hexenyl beta-D-glucopyranoside as aroma precursors from tea leaves of oolong tea. Biosci Biotech Biochem 1996 60(11) 1815-1819. 

CS115 Nobumoto, Y., K. Kubota, A. Koba-yashi and T. Yamanishi. Structure of alpha-farnesen in the essential oil of CS126 oolong tea. Agr Biol Chem 1990 ... 

Mihara, R. et al., A novel acylated quercetin tetraglycoside from oolong tea (Camelia sinensis) extracts. Tetrahedron Lett., 45(26), 5077, 2004. 

Matsumoto N, Kohri T, Okushio K, Hara Y. 1996. Inhibitory effects of tea catechins, black tea extract and Oolong tea extract on hepatocarcinogenesis in rat. Jpn J Cancer Res 87 1034-1038. 

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