| 摘要: | 萃取精油的方式有很多，最常見的方法是以有機溶劑萃取，但這些有機溶劑在分離過程時產生的揮發性化合物會造成人體與環境的危害，並且增加燃燒與爆炸的風險，除此之外，有機溶劑會殘留於萃取物中，進一步的分離過程會增加實驗的成本。超臨界流體萃取(SFE)近年來是精油萃取的一種熱門方式，特別是以二氧化碳作為溶劑，其無毒、不易燃燒、容易取得、可循環利用…等多種優勢，大幅降低實驗的風險與成本。而超臨界相的二氧化碳是一種非極性溶劑，其高擴散度和低黏度的特性很適合萃取低分子量的化合物，達成超臨界的條件也相對容易，使用的能源相對較少。
本次實驗以超臨界二氧化碳烘箱設備萃取澳洲茶樹(Melaleuca alternifolia)之葉子部位(以下簡稱茶樹)，透過壓力、以及溫度的改變，探討精油產率的變化。首先，以索氏萃取法得出茶樹粗脂肪率作為超臨界流體萃取(SFE)的產率參考，實驗採用三水準兩因子3^2設計，壓力設定2000psi、3000psi與4000psi，溫度設定40℃、50℃與60℃，以動靜態相平衡設備進行半流動式萃取，所得的產率再比對粗脂肪率是否差異過多。實驗結果以雙因子變異數分析與二階線性迴歸分析，探討最佳產率的實驗條件以及各項因子與因子間交互作用的顯著性，並對兩因子能得到的最大產率進行預估。
There are many ways to extract essential oils. The most common method is extraction with organic solvents, but, the volatile compounds generated by these organic solvents during the separation process will cause harm to human body and the environment, and increase the risk of combustion and explosion, in addition, organic solvents will remain in the extract, and further separation processes will increase the cost of the experiment. Supercritical fluid extraction (SFE) has been a popular method for essential oil extraction in recent years, especially using carbon dioxide as a solvent, which has many advantages such as non-toxic, non-flammable, easy to obtain, recyclable, etc., which greatly reduces the risk and cost of experiments. The carbon dioxide in the supercritical phase is a non-polar solvent. Its high diffusivity and low viscosity are very suitable for the extraction of low molecular weight compounds. It is relatively easy to achieve supercritical conditions and uses relatively little energy.
The experiment uses supercritical carbon dioxide oven equipment to extract Australian tea tree, and the yield of essential oils were investigated through the changes of pressure and temperature. First, the crude fat rate of tea tree was obtained by Soxhlet extraction method as a reference for the yield of SFE, The experiment adopts a three-level two-factor design, the pressure is set to 2000psi, 3000psi and 4000psi, and the temperature is set to 40℃, 50℃ and 60℃. Semi-flow extraction is carried out with dynamic and static phase equilibrium equipment, and the yield obtained is compared to whether the crude fat rate is too different. The experimental results were analyzed by ANOVA and second-order regression to examine the experimental conditions of the best yield and the significance of the interaction between various factors, and to predict the maximum yield that can be obtained by the two factors. |
