橘汁发酵过程中柑橘香气及其贡献化合物的分析

柑橘香气是柑橘果酒重要香气属性之一。为研究柑橘果酒加工过程中柑橘香气形成及影响机制，采用固相萃取法和正向硅胶色谱法结合气相色谱嗅闻仪、气相色谱质谱仪和感官评价对柑橘香气及其贡献化合物和异味物质在橘汁发酵中的变化趋势进行分析。结果表明，从橘汁中共鉴定出29种关键香气物质，主要为果香气、柑橘香气、花香气、清香气和乳脂香气化合物，其中月桂烯、庚醛、柠檬烯、γ-松油烯、癸醇、辛醛、辛醇、香茅醇和橙花醇被鉴定为柑橘香气重要贡献化合物。在橘汁发酵前4 d，柑橘香气强度呈显著增加的趋势，随后显著减弱。Pearson相关性分析显示，柑橘香气强度的变化与柠檬烯、γ-松油烯、辛醇和橙花醇含量增减密切相关(P＜0.05)。伴随着柑橘香气化合物含量降低，异丁酸、丁酸、2-甲基丁酸、戊酸、己酸、庚酸和辛酸等酸败刺激性气味物质含量显著增加，这些异味物质对柑橘香气的形成具有显著的遮盖作用。研究结果可为今后柑橘果酒工艺改进及香气品质提升提供一定的理论依据。

Analysis of Orange Characteristic Aroma and Its Potent Odorants during Orange Juice Fermentation

Orange characteristic aroma is one of the important aroma properties of orange wine. In order to study the formation and influence mechanism of orange characteristic aroma during the production of orange wine， the changing trend of orange characteristic aroma， its potent odorants and off-odorants during orange juice fermentation were analyzed using solid phase extraction (SPE) and forward silica gel chromatography combined with gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). The results showed that a total of 29 compounds were identified as the key aroma compounds in orange juice， which were mainly composed of fruity， orange-like， floral， green/grassy， and creamy aroma compounds. Among them， myrcene， heptanal， limonene γ-terpinene， decanol， octanal， octanol， citronellol and nerol were identified as the important contributor for orange characteristic aroma attribute. The orange-like aroma intensity increased significantly during fermentation for 1-4 days， and then decreased significantly， which were closely related to the contents of limonene γ-terpinene， octanol and nerol (P < 0.05). In addition， with the decrease of the content of orange characteristic aroma compounds， the content of isobutyric acid， butyric acid， 2-methyl butyric acid， valeric acid， caproic acid， heptanoic acid and caprylic acid with rancidity irritant odor increased significantly， which can significantly cover the orange characteristic aroma. The results would provide a theoretical basis for the improvement of citrus wine technology and aroma quality in the future.