Table 3.
Decaffeination during extraction or caffeine extraction
| Process utilized | Parameters | Reference |
|---|---|---|
| Extraction of Caffeine from Green Tea Leaves | 2 h room temperature extraction using a 2 % phosphoric acid-40 % etoh solution | Choung and Lee 2011 |
| Caffeine from tea stalk and fiber wastes from Turkish tea | Mixing speed of 200 rpm, a water/tea wastes ratio of 18.5 (w/w), a temperature of 98.5 °C, a leaching duration of 16 min and a particle size range of 0.250–0.355 mm. | Gürü and Icen 2004 |
| Decaffeination by Polar Cosolvent-Modified Supercritical CO2 extraction from tea retaining catechins | 3,600 g of carbon dioxide at 333 K and 300 Bar for 4 g of tea soaked with 1 g of water | Huang et al. 2007 |
| Supercritical carbon dioxide extraction of caffeine from tea stalk and fiber wastes | Extraction time of 7 h, temperature of 60 °C, CO2 flow rate of 11 g/min, pressure of 250 bar and mean particle size of 0.202 mm | Icen and Guru 2009 |
| Supercritical carbon dioxide extraction of caffeine from tea stalk and fiber wastes with ethanol | Flow ratio of 5.23 g ethanol/100 g CO2 (10 g CO2/min), extraction time of 3 h, temperature of 65 °C, pressure of 250 bar and mean particle size of 0.202 mm. | Icen and Guru 2009 |
| Decaffienation by hot water | 1:20 (w/v) solid: liquid ratio at 100 °C for 3 min. Not suitable for black tea due to loss of Catechin content | Liang et al. 2007b |
| Microwave-enhanced vacuum ice water extraction (MVIE) for decaffeination | Solvent (ml) to solid (g) ratio 10:1, microwave extraction time 6 min, microwave power 350 w, time 2.5 h, vacuum ice water extraction with 87.6 % yield of caffeine | Lou et al. 2012 |
| Microwave assisted extraction of caffeine (4 %) | 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 |
Pan et al. 2003 |
| Co solvent assisted super critical fluid extraction for decaffeination | Supercritical fluid CO2 modified with 95 % (v/v) ethanol at 7.0 g per 100 g of CO2 at 300 bar and 70 °C for 120 min, with unavoidable considerable amount of EGCG loss | Park et al. 2007 |
| Simultaneous decaffeination and chlorophyll extraction using supercritical carbon dioxide (SC-CO2) | 3.0 g of 95 % (v/v) ethanol cosolvent per 100 g of CO2, 23 mpa pressure, 63 °C temperature and an extraction duration of 120 min for 10 g of green tea leaves | Park et al. 2012 |
| Decaffeination of Koren Tea | Extracting the green tea with water at 80 °C for 40 min, the extract was partitioned with water/chloroform, and then partition with water/ethyl acetate for catechin recovery | Row and Jin 2006 |
| Subcritical water assisted extraction of caffeine of Iranian Black tea leaf | 175 °C, water flow rate of 2 g/min, mean particle size Of 0.5 mm at 3 h of extraction | Shalmashi et al. 2007 |
| Caffeine in Hawaii tea leaves | Decrease in caffeine with increasing leaf age, moving from the bud to first and second leaves | Song et al. 2012 |
| Ultrasonic enhanced supercritical fluid extraction for decaffeination | Extraction pressure of 30 mpa, temperature at 55 °C, time of 4 h, 30 % moisture content, and ultrasound power of 100 W. | Tang et al. 2010 |
| Decaffeination from Iranian tea | 20–40 min and 80 °C for caffeine | Ziaedini et al. 2010 |