基于电子鼻、GC-MS和GC-IMS技术分析老香黄发酵期间的挥发性成分变化

利用电子鼻、气相色谱-质谱联用（Gas Chromatography-Mass Spectrometry，GC-MS）和气相离子迁移谱（Gas Chromatography-Ion Mobility Spectrometry，GC-IMS）技术分析老香黄发酵期间的挥发性成分变化，并结合相对风味活度值（Relative odor activity value，ROAV）对老香黄挥发性组分的气味贡献程度进行评价。结果表明，电子鼻PCA有效区分了不同发酵时间的样品，老香黄发酵6个月后挥发性组分开始发生较大变化。GC-MS共鉴定出46种挥发性物质，包括萜烯类、醇类、醛类、酚类、酯类、醚类、杂环化合物和其它共8个种类。α-蒎烯、β-蒎烯、月桂烯、萜品油烯、柠檬烯、异松油烯、1-石竹烯、巴伦西亚橘烯、芳樟醇、α-松油醇、糠醛、麦芽酚、茴香脑、2, 4-二甲基苯乙烯是发酵期间含量较高且相对稳定的14个共有成分。GC-IMS定性检出38 种已知挥发性成分，包括萜烯类、醇类、醛类、酯类、酮类、酚类、酸类、杂环类和其它共9个类别。ROAV表明老香黄的主体香气为柑橘香、木青气息、药草香和焦甜香，对老香黄风味贡献程度最大的5个物质分别是香茅醛、壬醛、异松油烯、反式-β-罗勒烯和柠檬烯。发酵丰富了老香黄的挥发性成分种类，其中反式-橙花叔醇、庚醛、糠醛、己醛、异戊醛、3-羟基-2-丁酮、2-乙基呋喃、呋喃甲醇、2-乙酰基呋喃等挥发性成分是发酵过程中产生的。

Analysis of Volatile Components in Laoxianghuang During Fermentation by Electronic Nose,GC-MS and GC-IMS

The changes of volatile components in Laoxianghuang during fermentation were analyzed by electronic nose, gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS), and their contribution to odor was evaluated by relative odor activity value (ROAV). The results showed that, E-nose PCA could effectively distinguish the samples at different fermentation time, and the volatile components began to change significantly after 6 months of fermentation. GC-MS identified 46 volatile compounds, including terpenes, alcohols, aldehydes, phenols, esters, ethers, heterocyclic compounds and others. α-pinene, β-pinene, myrcene, terpinene, limonene, isoterpinene, 1-caryophyllene, valencia limonene, linalool, α-terpinene, furfural, maltol, anethol and 2, 4-dimethylstyrene were 14 common components at high and relatively stable contents during fermentation. 38 known volatile components were detected by GC-IMS, including terpenes, alcohols, aldehydes, esters, ketones, phenol, acids, heterocycles and other volatile components. The results of ROAV showed that the main aroma of Laoxianghuang were citrus, woody, herbal and burnt sweet, and citronellal, nonanal, isoterpinene, trans-β-ocimene and limonene contributed the most to the flavor of Laoxianghuang. Fermentation could enrich the volatile components of Laoxianghuang and the volatile components such as trans nerolidol, heptanal, furfural, hexanal, isovaleraldehyde, 3-hydroxy-2-butanone, 2-ethyl furan, furan methanol and 2-acetylfuran were produced during fermentation.