Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/3377
標題: Optimizing Recovery and Purity ofTea Polyphenols by Membrance Separation Using Response Surface Methodology
應答曲面實驗設計法蒐尋螺捲膜組分離綠茶多酚類最適條件
作者: 黃詠勤
Huang, Yung Chin
關鍵字: 螺捲微過濾與超過濾膜組
spiral wound micro-filtration and ultra-filtration membrances
應答曲面實驗設計法
綠茶
兒茶素
熱壓水
萃取與純化
response surface methodology
green tea
catechins
hot pressuriz
出版社: 化學工程學系
摘要: 本論文以螺捲微過濾(MF)與超過濾(UF)薄膜分離製程,探討濾液溫度(10度至30度)與流速(50 ml/min至100 ml/min)對熱壓水萃綠茶湯中兒茶素的純度、回收率、濃縮因子、兒茶素與咖啡因之比值與EGCg回收率的變化情形,並以應答曲面實驗設計法(RSM),搜尋膜分離製程之最適條件。 熱壓水萃物之兒茶素純度為28.9 wt%,優於攪拌水萃物的24.7 wt%,經過MF及UF兩種膜分離製程,可得到熱壓水萃過膜液固形物中最大兒茶素純度為59 wt%,且咖啡因含量只佔過濾物總重的1.75 wt%。由中心點為75 ml/min與20度的應答曲面模擬之結果指出,當UF膜組的操作範圍在流速50~69 ml/min且溫度在10~11度時,預測兒茶素純度達54 wt%最高值。但在此時的兒茶素回收率只有81 wt%,會損失19 wt %的兒茶素。且EGCg的回收率僅有62 wt%。由20組實驗數據指出,此操作條件的過濾時間為最長,EGCg有可能因長時間操作而逐漸氧化流失,且兒茶素與咖啡因的比值亦隨著降低。實驗數據顯示當濾液溫度低於25度時,可得到總兒茶素對咖啡因的最大比值,但其與流速無顯著關係。再由中心點為75 ml/min與15度的應答曲面模擬結果指出,當UF膜組的操作範圍在流速50~87 ml/min且溫度在10~11度時,預測兒茶素純度亦達54 wt%最高值。且在10~20度時,溫度對兒茶素回收率、總兒茶素對咖啡因比值與EGCg回收率影響不顯著。
This study investigated the effect of filtration temperature and flow rate of a spiral wound micro-filtration and ultra-filtration membrances module on the purity, recovery, concentration factor of catechins and the ratio of catechins to caffeine as well as the recovery of (-)-Epigallocatechin-3-gallate (EGCg) of the hot pressurized water extracts by using the response surface methodology (RSM). Temperature ranged from 10 oC to 30 oC and flow rate ranged from 50 ml/min to 100 ml/min. The recovery and purity of catechins of hot pressurized water extracts have been significantly enhanced by the ultra-filtration membrance through the successful separation of large amount of glycosides and impurities from the crude extracts. Our experimental data showed that the purity of catechins of hot pressurized water extracts is increased from 28.9 wt% up to 59 wt%, while caffeine is limited within 1.75 wt%. A center composite design of 75 ml/min and 20 oC RSM regression model predicted the highest purity of catechins (i.e. 54 wt%) at flow rates between 50 and 69 ml/min and at temperatures between 10 and 11 oC. However, at these conditions, the recoveries of catechins and EGCg were lowest. Finally, the ratio of catechins to caffeine attained a maximum value at temperature below 25 oC and was irrelevant to the flow rate. An another center composite design of 75 ml/min and 10 oC RSM regression model predicted the highest purity of catechins (i.e. 54 wt%) at flow rates between 50 and 87 ml/min and at temperatures between 10 and 11 oC. The effect of temperature on the recovery of total catechins, the ratio of catechins to caffeine and the recovery of EGCg were not significant.
URI: http://hdl.handle.net/11455/3377
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