利用超臨界二氧化碳萃取肉桂中之精油成份：並與水蒸氣蒸鎦法進行比較

Supercritical Carbon Dioxide Extraction of Cinnamomi Cortex: In Comparison with a Steam Distillation Method

本研究利用超臨界二氧化碳萃取技術(SFE CO2)，進行肉桂精油的粗萃取率(crude extraction yield)評估測試。在本實驗中選用下述四種不同的萃取條件：A：35℃，1500psi；B：35℃，3500psi；C：50℃，1500psi；D：50℃，3500psi。當萃取溫度在35℃時，壓力從1500psi變成3500psi，肉桂的精油粗萃取率從4.25±0.18%提高到5.01±0.10%；當萃取溫度固定在50℃時，壓力的提高，有更明顯的租萃取率增加趨努，從1.79±0.14%提高到5.61±0.06%。另一方面，利用水蒸氣蒸餾法，其萃取率為4.00±0.19%。因此，如果選擇適當的SFE CO2萃取條件對肉桂精油粗萃取而言，SFF CO2具有較高之粗萃取率。為了要評估萃取後肉挂殘渣在中藥製劑上的再回收利用，我們也針對原肉桂粉末，萃取後殘渣，及萃取出之精油作桂皮酸(Cinnamic acid)的定量分析，其結果顯示，萃取後肉桂殘渣中指標成分挂皮酸的含量仍保有原藥材的50%左右，因此，肉柱殘渣在精油萃取後，進行中藥製劑的再利用是可行的。最後，我們的結論是：在考慮粗萃取率及肉桂殘渣的再回收的雙重標準下，四種不同的SFE CO2萃取條件中，以3500psi，35℃的條件最為適當。

By using a supercritical carbon dioxide extraction (SFE CO2) technique, we extracted essential oils from Cinnamomi Cortex. Four different extraction conditions were used in this study: (A) 1500 psi, 35℃; (B) 3500 psi, 35℃; (C) 1500 psi, 50℃; and (D) 3500 psi, 50℃. At 35℃, the yield of SFE CO2 increased from 4.25±0.18% to 5.01±0.10% as the extraction pressure was changed from 1500 psi to 3500 psi. At 50℃, this increase was even more obvious and the yield of SFE CO2 increased from 1.79 ± 0.14% to 5.61 ± 0.06% as the extraction pressure increased. The lowest yield at the condition of 1500 psi, 50℃ could be due to a higher evaporation rate at the higher temperature in comparison with the condition of 1500 psi, 35℃. By using the most popular extraction method (steam distillation method), the yield was 4.00 ± 0.19%. Results revealed that SFE CO2 does have a better crude extraction yield than the steam distillation method if one selects an optimum condition. In order to assure the recycle potential of the extracted Cinnamomi Cortex, we also quantified the content of cinnamic acid in that. It was found that after SFE CO2 extraction (3500 psi, 35℃), the quantity of the cinnamic acid in the extracted Cinnamomi Cortex was about 50% as compared to the original Cinnamomi Cortex. After steam distillation, the quantity of cinnamic acid had only 40% left in the original Cinnamomi Cortex. We concluded that considering both the yield and recycle potential, the ideal condition of our four different SFE CO2 operation to extract the essential oil from Cinnamomi Cortex was 3500 psi, 35℃.