大道至简-一线可以定乾坤.doc

不同溫度乾燥洛神葵揮發性成分之萃取，鑑定與分析Extraction, Identification and Analysis of the Volitile Components in Roselle Dried by Different Temperature研究生：陳世煌 Chen, Shyh-Hung指導教授：蔡碧仁 Pi-Jen Tsai【摘要】洛神葵豔麗的紅色係以花青素為主，然其色素很不穩定，容易失去豔麗的紅色，故一般學者對洛神葵的研究，多以色澤為探討重點。但是對於洛神葵特殊風味或揮短桲痔w的相關報告則不多見。只有Jirovetz等(1992)曾對洛神葵種子油脂中的揮發性成分物質作過鑑定分析。由於洛神葵在進行加工或熱風乾燥時，能散發出濃郁的香味，卻在洛真掑u製品中缺乏獨特的香氣。因此若能設法萃取出其主要揮發性成分加以鑑定，並找出具代表性之揮發性成分，未來再設法合成或調製、回添，當有助於其商品價值的提升。在不同溫度(25冷風、50、75及85熱風) 乾燥之乾燥洛神葵，以蒸氣蒸餾溶劑萃取(L-N裝置)及短徑熱脫附系統(TD-3裝置)萃取其揮發性成分，再以GC及GC-MS分析鑑定。結果L-N萃取方式鑑定出37個成分，TD-3萃取方式則可鑑定出43個成分，並依其來源可大致分為脂肪酸衍生物、糖類衍生物、酚類衍生物、terpene化合物等四大類。其中脂肪酸衍生物以直鏈六碳之醛、醇為主，糖類衍生物以furfural為主，酚類衍生物以丁香酚為主，terpene化合物以linalool，limonene，linalool oxide及-terpineol為主。在直鏈六碳醛、醇類及terpene化合物中的linalool及limonene等成分，以TD-3萃取方式所得揮發性成分比例較L-N方式高；而furfural及其他terpene類如linalool oxide、-terpineol及eugenol等則以L-N萃取方式所得之成分比例比TD-3萃取方式為高。在比較不同溫度乾燥的洛神葵揮發性成分，脂肪酸衍生物方面，未乾燥之洛神葵樣品其含量高於乾燥洛神葵樣品；furfural的含量以乾燥洛神葵中含量較高於，並且隨著樣品乾燥溫度之提升furfural的含量也之增加。而terpene類中的linalool及limonene則隨乾燥溫度的上升而減少。酚類衍生物的丁香酚在不同溫度乾燥之洛神葵樣品及未乾燥洛神葵樣品中其含量並沒有太大之異。這些鑑定出之揮發性成分，經主成分分析法分析，其結果在L-N萃取方式部分，第一主成分正相為terpene類成分為主，負相為furfural及5-methyl-2-furaldehyde；第二主成分正相部分為linalool及octanal等成分，負相則為hexanol成分。TD-3萃取方式部分，第一主成分正相以terpene類為主，負相為furfural；第二主成分正相則是以limonene、linalool及hexanal等成分為主，而第一、二主成分之負相交集部分則分佈有furfural。關鍵字：洛神葵 揮發性成分 熱脫附 主成分分析 主成分迴歸 【Abstract】Liken-Nickerson steam distillation (L-N) and short path thermal desorption system (TD-3) were used to extract the volatiles of roselle dried by different temperature, including cold-air dried (25) and hot-air dried (50, 75and 85). Volatiles were analyzed and identified by GC and GC-MS. At least 37 and 43 compounds were characterized by L-N and TD-3 methods, respectively and were classified into four groups: fatty acid derivatives, sugar derivatives, phenolic derivatives and terpene components. As compared with L-N extraction, volatiles extracted by TD-3 apparently had more quantity in compounds of the aliphatic C6 components (hexanal, (E)-2-hexenal etc.) and terpene (especially in linalool and limonene). But thermal generated volatile such as furfural, terpene derivatives(linalool oxide, -terpineol) and eugenol, has much less amount in comparison. Volatiles gave different tendency in the samples dried by different temperature. In the undried sample, the quantity of fatty acid derivatives were much higher when compared with the dried ones. Furfural (sugar derivatives) increased with increasing drying temperature, while linalool and limonene (terpene components) decreased. No obvious change in eugenol (phenolic derivatives) from all samples was found. All the volatiles were further analyzed by principal component analysis (PCA) to elucidate the causative compound of the volatiles in roselle. Along the positive and negative directions of the factor 1 axis were terpene and sugar derivatives (furfural), respectively. Therefore, roselle volatile might come from a combination of volatiles mainly with terpene and