Table 1.
Optimized polyphenol extraction strategies
| Tea biomolecule | Extraction condition | Reference |
|---|---|---|
| Polyphenols content-in-extracted solids (PES) in black tea | 50:1 water-to-tea ratio and 40 min | Chandini et al. 2011 |
| Catechins in Green Tea Leaves | 2 h room temperature extraction using a 2 % phosphoric acid-40 % etoh solution | Choung and Lee 2011 |
| Selective extraction and preconcentration of epicatechin | Solid-phase extraction (SPE) by molecularly imprinted polymer prepared from acrylamide monomer | Ding et al. 2006 |
| Catechin extraction from milk tea beverage (Brewed green tea combined with skim milk) | Use of pepsin (40.0 mg/ml) | Ferruzzi and Green 2006 |
| Polyphenol from yellow tea | Extraction with ultrasound probe than ultrasonic bath in 75 % aqueous ethanol medium | Horžić et al. 2012 |
| Total polyphenol (TP) | 50 % (ml/ml) of ethanol concentration, 20:1 (ml/g) of liquid/solid ratio and 500mpa of high hydrostatic pressure for 1 min by high hydrostatic pressure extraction (HHPE) | Jun et al. 2009 |
| Major catechins from green tea | 50 % (v/v) ethanolic solvent extraction, solvent to tea ratio 20 ml:1 g, 400mpa pressure for 15 min by ultrahigh pressure extraction | Jun et al. 2010 |
| Two scale extraction for production of catechin- enriched tea drinks | Brewing green tea at 1:50 tea/water ratio in water thermostated at 30 °C for 30 min followed by water extraction of leaves by squeezing and then second brewing step in water maintained at 75 °C for 40 min | Labbé et al. 2008; Bazinet et al. 2007 |
| The first brewing step at 50 °C for 10 min. Followed by water extraction of leaves by squeezing and then soaked for 10 min, for the second brewing step, at 80 °C water. The Two-step extraction procedure was repeated three times | ||
| Extraction of catechin from Longjing tea | 400 W, 1 min irradiation duration, 1:15 gm/ml tea to water ratio by Microwave assisted extraction | Li et al. 2010 |
| Total catechins | 50 % (v/v) ethanol for 10 min for dry tea, and 75 % (v/v) ethanol for 10 min for fresh tea leaf. For commercial purpose water mediated extraction at 80 °C | Liang et al. 2007 |
| Tea polyphenols | Membrane separation by nanofiltration with G-membrane in 80 % of ethanol solution | Nwuha 2000 |
| Tea catechin | 4 min microwave-assisted time, 50 % (v/v) ethanol concentration in water, liquid/solid ratio of 20:1 (ml/g) and pre leaching time of 90 min by microwave assisted extraction | Pan et al. 2003 |
| Aqueous extaction of catechins | Either high temperature (95 °C) and short extraction time (5–10 min), or lower temperature (60 or 80 °C) and longer extraction time (20 min) to avoid catechin degradation and ratio of solvent to material (100 ml:1 g) or lower ratios (40 ml:1 g or 9 ml:1 g) and a multi-step extraction procedure to obtain more catechin | Perva-Uzunalic et al. 2006 |
| Polyphenol extraction from white and black tea | Accelerated phenolic extraction from green tea by lemon juice addition in water extract, for prolonged extraction of catechin with aqueous ethanol (40 %) | Rusak et al. 2008 |
| Epicatechin (EC), epicatechin Gallate(ecg), epigallocatechin (EGC), and epigallocatechin gallate(egcg), the major four catechin from Hawaii tea leaves | Increase in content of four catechins with increasing leaf age, moving from the bud to first and second leaves | Song et al. 2012 |
| Concentration of tea polyphenols by molecular distillation and drying by spray drying | 70 °C distillation temperature, 10 ml/min flux, and 1,200 n/min rotational speed for concentration and 170 °C distillation temperature, 3 ml/min feed flux, 30 % feed concentration, and 30 m3/h wind capacity for drying | Tang et al. 2011 |
| Catechin by water extraction | 80 °C for 30 min, a tea particle size of 1 mm, a brewing solution ph <6 and a tea to- water ratio at 50:1 (ml/g) for maximal extraction and tea to- water ratio at 20:1 (ml/g) for cost efficiency along with maximal yield | Vuong et al. 2011b |
| Total polyphenol | 60 % ethanol concentration, solid-to-liquid ratio 1∶ 12 g/ml at 80 °C, 10 min under the microwave power of 600 W. | Wang et al. 2010 |
| Catechins From green tea | Ethanol concentration, 50 %; pressure, 490 mpa; and liquid/solid ratio, 20 ml/g by ultrahigh-pressure extraction | Xu et al. 2012 |
| Polyphenols From Iranian tea | 20–40 min and 80 °C for EGC, EC and 80 min and 90 °C for catechin, EGC and EGCG | Ziaedini et al. 2010 |
| EC, ECG, EGC, and EGCG | 7 min of steeping at a constant 100 °C at pH 3 | Zimmermann and Gleichenhagen 2011 |