| 摘要: | 黑葉荔枝(Litchi chinensis Sonn.var Hei Yeh; Lychee)原產於中國南方，主要分佈於亞熱帶區域，為最早引進台灣的荔枝品種，盛產期集中於6至7月上旬，每逢適時修枝後所剪下的葉子會選擇丟棄，雖屬於廢棄物，但仍棄之可惜。因此，本研究將黑葉荔枝修剪後之葉子，使用水蒸氣蒸餾法(HD)及無溶劑微波萃取法(SFME)做精油萃取，並將荔枝葉精油做抗菌、抗發炎、抗氧化、美白的活性評估，賦予其經濟價值。 將荔枝葉子清洗、陰乾、剪碎後行水蒸氣蒸餾法(HD)及無溶劑微波萃取法(SFME)來萃取精油，利用氣相層析質譜法(GC-MS)進行荔枝葉之精油成分分析，再將精油進行抗菌、抗發炎、抗氧化、美白的活性評估並比較兩者萃取法之差異。荔枝葉精油平均產率，在HD精油為0.88g/Kg；SFME精油為0.35g/Kg。經GC-MS分析成分，HD主成分為α-Curcumene (27.815%)、β-Bisabolene(27.198%)、(-)-α-zingiberene (19.385%)；SFME主成分為α-Curcumene(41.100%)、β-Bisabolene (28.214%)，兩種萃取法皆以α-Curcumene成分的含量最高。在抗發炎試驗中，抑制5-Lipoxygenase能力測定的部分，SFME精油效果較HD精油佳；在NO自由基清除能力測定的部分， SFME精油效果較HD精油佳。在抗氧化試驗中，清除DPPH自由基能力測定的部分，為SFME精油效果較HD精油佳；抑制β-Carotene氧化的能力為HD精油效果較SFME精油佳。在酪胺酸梅抑制能力的部分，以SFME精油效果較HD精油佳。在抗菌活性方面，抑制P.acnes、P.ovale、E.coli及S.aureus的MIC皆為SFME精油優於HD精油；而抑制C.albicans、P.aeruginosa的MIC為HD精油優於SFME精油。
Hei Yeh lychee (Litchi chinensis) was originated in Southern China. Now this fruit distributes in subtropical areas, and was the first kind of lychee introduced into Taiwan. The harvest season of Hei Yeh lychee is June to early July. In appropriate seasons, the lychee is pruned, and the cut leaves are thrown away. However, it seems a shame to throw away these leaves. Thus, this study employed hydrodistillation (HD) and solvent-free microwave extraction (SFME) to extract lychee-leaf essential oil from the pruned leaves of Hei Yeh lychee. To endow the oil with economic value, the oil’s activity was examined to evaluate its anti-bacterial, anti-inflammatory, antioxidant, and whitening characteristics. Before HD and SFME were employed to extract the essential oil, lychee leaves were cleaned, washed, dried in shade, and shredded. Gas chromatography–mass spectrometry (GC-MS) was adopted to analyze the components of the lychee-leaf essential oil, and the oil was also examined to evaluate its anti-bacterial, anti-inflammatory, antioxidant, and whitening characteristics. Finally, the two extraction methods were compared. The average yield of the lychee-leaf essential oil was 0.88 g/kg using HD, and 0.35 g/kg using SFME. The GC-MS analysis results indicated that the major components extracted by HD were α-Curcumene (27.815%), β-Bisabolene (27.198%), and (-)-α-zingiberene (19.385%), and were α-Curcumene (41.100%) and β-Bisabolene (28.214%) using SFME. α-Curcumene was the primary element extracted by both the two extraction methods. In the anti-inflammatory test, the essential oil extracted by SFME was superior in inhibiting 5-Lipoxygenase to that by HD; and the essential oil extracted by SFME was superior in removing NO free radicals to that by HD. In the antioxidant test, the essential oil extracted SFME was superior in removing DPPH free radicals to that by HD; the essential oil extracted by SFME was superior in inhibiting β-Carotene oxidation to that by HD; and the essential oil extracted by SFME was superior in inhibiting tyrosinase to that by HD. In the anti-bacteria activity test, the essential oil extracted by SFME was superior in the minimum inhibitory concentration (MIC) of P.acnes, P.ovale, E.coli, and S.aureus to that by HD; and the essential oil extracted by HD was superior in the minimum inhibitory concentration (MIC) of C.albicans and P.aeruginosa to that by SFME. |
