啤酒是世界上最受歡迎的酒精飲料之一，在世界各地皆有自己的獨特風味。它是由麥芽汁與啤酒花發酵而成，在發酵的過程中產生豐富的口味跟香味。香氣為啤酒中最重要且最具代表性的特色，因此想探討啤酒的風味就必須分析其內的成分。根據文獻回顧，Flavour Dilution (FD) factor，跟Odour Activity Value (OAV) 可以顯示一個芳香化合物對啤酒香味的貢獻。因此，本研究以十種在啤酒中FD質與OAV較高的化合物作為目標，建立一個分析方法。研究中探討了有機溶劑萃取的選擇，發現乙醚跟二氯甲烷相對之下，乙醚能夠有效的萃取目標化合物也能夠減少目標化合物在減壓濃縮中的流失。設下的分析方法也顧及到各個目標化合物在減壓濃縮中不同程度的流失，在計算中以各個化合物的揮發性做調整，確保分析方法的準確性。借由以上的方法，本研究利用GC-MS分析了臺灣菸酒公司十八天生啤酒的芳香化合物，發現結果在一般啤酒的正常範圍內。此外，該研究也探討了這十種芳香化合物經過存放的變化，發現各個化合物都有減低的現象，尤其在第十八天之後。

Beer is one of the most widely consumed beverages in the world. It is derived from the alcoholic fermentation of malt and hops extract, giving rise to its distinct flavour and aroma. The aroma profile of beer is made up of various compounds existing in a delicate balance to give beer its characteristic aroma. As beer aroma is one of its defining traits and therefore of great importance, this study focuses on the establishment of a protocol to quantitate compounds which contribute greatly to the aroma profile. Flavour dilution (FD) factor and odour activity value (OAV) are generally recognized as a reliable indicator of a compound’s contribution to aroma. Therefore, 10 aroma compounds which were commonly observed to have high OAV and FD factors in beer were chosen to be the target analytes from which a protocol for their analysis could be established. Diethyl ether was found to be a suitable choice of solvent for the extraction of the target analytes in beer and also minimising analyte loss during solvent removal compared to dichloromethane. The volatilities of the target analytes were also studied and compared, thus allowing for the quantitation protocol to take into account the difference in analyte loss during solvent removal. Using this method, 18 day draft beer from Taiwan Tobacco and Liquor Corporation was analysed using Gas Chromatography – Mass Spectrometry (GCMS) and the concentrations of the target analytes were found to be within the range of that typical in beers. The change in these aroma compounds were tracked over and beyond the mandated shelf life of 18 day draft beer and it was found that their concentrations decreased over time, especially once past the 18 day mark.