کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6405782 | 1330925 | 2012 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves](/preview/png/6405782.png)
The decaffeination of green tea using supercritical carbon dioxide (SC-CO2) was optimized by response surface methodology (RSM) for the maximal removal of caffeine, and the coextration of chlorophylls was also monitored during decaffeination. The experimental conditions for the SC-CO2 extraction of caffeine were set up according to the Box-Behnken design of RSM. The relationships between the extraction yield of caffeine and various parameters used for the SC-CO2 extraction such as pressure, temperature and concentration of ethanol were studied at a fixed CO2 flow rate. The extraction yields of caffeine and total chlorophyll were significantly influenced by extraction pressure, temperature and concentration of cosolvent, and their extraction yields behaved almost in parallel at different extraction conditions that were obtained by varying pressure, temperature and ethanol cosolvent concentration. At the optimal decaffeination conditions such as 3.0 g of 95% (v/v) ethanol cosolvent per 100 g of CO2, 23 MPa, 63 °C and an extraction duration of 120 min for 10 g of green tea leaves, the extraction yields for caffeine and catechins were 96.60% (w/w) and 40.61% (w/w), respectively, and the substantial coextraction of total chlorophyll (43.09% of the total amount) was also observed during the decaffeination process.
⺠Decaffeination of green tea using supercritical carbon dioxide was optimized by RSM. ⺠Coextration of chlorophylls was also monitored during decaffeination. ⺠Extraction yields of caffeine and chlorophylls behaved almost in parallel. ⺠At 23 MPa and 63 °C with ethanol cosolvent, extraction yield for caffeine was 96.60%.
Journal: LWT - Food Science and Technology - Volume 45, Issue 1, January 2012, Pages 73-78