本文研究了混合菌株发酵南瓜汁的香气物质。采用固相微萃取技术（SPME）富集、气相色谱-嗅辨-质谱（GC-O-MS）分离检测手段，结合计算机检索技术对分离化合物进行鉴定，应用色谱峰面积归一法测定各成分的相对含量。实验结果表明：新鲜南瓜和南瓜汁中分别分鉴定出58和41个香气化学成分,南瓜汁和新鲜南瓜共有的挥发性成分有19种，南瓜中含量较高的挥发性物质为己醛、3-甲基丁醛、壬醛、戊醛、庚醛、环丁醇等物质。经过乳酸菌、酵母菌和二者混合发酵南瓜汁后挥发性成分分别鉴定出51、36和45种。通过乳酸菌和酵母菌混合发酵的南瓜汁的挥发性成分主要是乙醇、异戊醇、辛酸乙酯、1-庚醇、2, 3-丁二酮和异丁醇。与乳酸菌和酵母菌单独发酵的南瓜汁相比，混合发酵后挥发性成分以醇类居多；相对含量较高的香气成分种类相似，而微量特征香气成分差异较为显著。

The aromatic compounds in the mixed strains fermentation pumpkin juice were discussed in this paper. They were evaluated by solid phase micro-extraction (SPME) combined with gas chromatography mass spectrometry (GC-MS) and gas chromatography olfactometry (GC-O) methods, and the relative contents were determined by area normalization. 58 and 41 compounds were seperated from fresh pumpkin and pumpkin juice, respectively, and 19 common volatile components were detected. The aromatic compounds with higher contents included hexanal, 3-methyl-butanal, nonanal, pentanal, heptanal and cyclobutanol in fresh pumpkin. 51, 36 and 45 aromatic compounds were identified from Lactic acid fermentation, yeast fermentation and mixed fermentation pumpkin juice, respectively. The main aromatic compounds by mixed fermentation pumpkin juice were ethanol, 3-methyl-1-butanol, ethyl caprylate, 1-heptanol, 2,3-butanedione and 2-methyl-1-propanol. Compared with the pumpkin juice fermented by only lactic acid bacteria or yeast, the majority of aromatic compound was ethanol in mixed fermentation pumpkin juice.The three fermentation pumpkin juices had similar major aromatic compounds, but showed significant difference in trace amounts . Therefore, mixed fermentation pumpkin juice was not only similar to those single strain fermentation, also formed unique aroma.

公益性行业（农业）科研专项经费项目(201303112)