Green Tea Caffeine-Free

Bryan (2008) Psychological effects of dietary components of tea caffeine and L-theanine. Nutr. Rev., 66, 82-90. 

Cabrera, R. Artacho, R. Gimenez (2006) Beneficial effects of green tea—A review. J. Am. Coll Nutr, 25, 79-99. 

Kakuda (2002) Neuroproteetive effects of the green tea components theanine and catechins. Biol Pharm. Bull, 25, 1513-1518. 

Mukhtar (2007) Tea polyphenols for health promotion. Life Sci., 81, 519-533. 

Mohanpuria, V. Kumar, S. K. Yadav (2010) Tea caffeine Metabolism, functions, and reduction strategies. FoodScl Biotechnol, 19, 275-287. 

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Green tea quality is dependent to a large extent on amino acid levels, especially that of theanine.97 Ascorbic acid content, although very low, also correlates positively with quality. Free reducing sugars and catechin gallates show a negative correlation.98 Caffeine levels do not have much effect on quality. 

In contrast to the decaffeination of coffee, which is primarily executed with green coffee, black tea has to be extracted from the fermented aromatic material. Vitzthum and Hubert have described a procedure for the production of caffeine-free tea in the German patent application, 2127642 [11]. The decaffeination runs in multi-stages. First, the tea will be clarified of aroma by dried supercritical carbon dioxide at 250 bar and 50°C. After decaffeination with wet CO2 the moist leaf-material will be dried in vacuum at 50°C and finally re-aromatized with the aroma extract, removed in the first step. Therefore, the aroma-loaded supercritical CO2 of 300 bar and 40°C will be expanded into the extractor filled with decaffeinated tea. The procedure also suits the production of caffeine-free instant tea, in which the freeze-dried watery extract of decaffeinated tea will be impregnated with the aromas extracted before. 

K Ohta, A Yoshida, K Harada. HPLC analysis of free amino acids and caffeine in green tea cultivated by hydroponics. Nippon Nogei Kagaku Kaishi 69 1331-1339, 1995. 

Green tea protein, moisture, total nitrogen, caffeine, theanine, total free amino acid... 

Although green tea usually contains less caffeine than black tea, it is by no means caffeine-free. A cup of black tea may contain as much as an espresso (about 100 mg). A cup of green tea typically contains about one third of this amount. High tatmin content in green tea slows down the take-up of caffeine and moderates the stimulating effect. Recent research shows that the presence of an amino acid named L-theanine is also significant (Fig. 3.25). 

Evaluating different layer materials and mobile phases, a twofold development on TLC silica gel was most successful for the separation of especially caffeine and chlorophyll from the target pesticides in tea samples. (Figure 10.11) The modified HTpSPE procedure for black and green tea resulted in colorless extracts free... 

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