GC-O结合OAV鉴定陇南初榨橄榄油关键香气成分

选取甘肃陇南代表性品种莱星和鄂植8号初榨橄榄油及消费口碑良好的特级混合初榨橄榄油为研究对象，通过气相色谱-质谱（gas chromatography-mass spectrometry，GC-MS）检测比较3 种初榨橄榄油的挥发性物质组成，同时采用气相色谱-嗅闻（gas chromatography-olfactometry，GC-O）技术筛选其香气活性物质，最后结合香气活性值（odor activity value，OAV）分析各呈香组成对橄榄油香气轮廓呈现的贡献性，从而鉴定出3 种橄榄油各自的关键香气成分。结果表明：采用GC-MS在莱星、特级混合及鄂植8号初榨橄榄油中各检测出35、30 种及25 种挥发性成分，其中己醇、3-己烯-1-醇、(E)-2-己烯-1-醇和(E)-2-己烯醛的含量丰富。采用GC-O在3 种初榨橄榄油中各筛选出13、15 种和12 种香气活性成分，包含具有青草特征的C6化合物、呈现油脂香气的庚醛和(E,E)-2,4-癸二烯醛以及表现其他气味信息的香气物质。OAV分析发现3 个样品各有12、13 种及11 种关键香气成分（OAV≥1），以1-辛烯-3-醇、芳樟醇、(E)-2-己烯醛和(E,E)-2,4-癸二烯醛为代表的OAV较高，对初榨橄榄油呈香品质具有重要作用。本研究筛选出3 种初榨橄榄油的关键香气成分，结果可为提升初榨橄榄油风味品质提供理论基础。

Identification of Key Aroma Compounds in Virgin Olive Oils from Varieties Grown in Longnan by Gas Chromatography-Olfactometry Coupled with Odor Activity Value

The volatile components of virgin olive oils from the representative varieties (Laixing and Ezhi 8) grown in Longnan, Gansu province and a mixed extra virgin olive oil popular with consumer were comparatively analyzed by gas chromatography-mass spectrometry (GC-MS). In addition, their aroma compounds were identified by gas chromatography-olfactometry (GC-O), and the contribution of these aroma compounds to the flavor profile of olive oil was analyzed by OAV in order to identify the key aroma-active compounds in each sample. Totally 35, 30 and 25 volatile components were identified in Laixing, Ezhi 8 and mixed virgin olive oils, respectively. The contents of hexanol, 3-hexen-1-ol, (E)-2-hexen-1-ol and (E)-2-hexenal were the highest in all samples. In addition, 13, 15 and 12 aroma compounds were identified in the three samples, including C6 compounds with grassy notes, and heptanal and (E,E)-2,4-decadienal with fatty aroma notes. In total, 12, 13 and 11 compounds whose OAV were higher than or equal to 1 were identified as the key aroma-active compounds in the three samples. The OAVs of 1-octen-3-ol, linalool, (E)-2-hexenal and (E,E)-2,4-decadienal were higher, indicating that these compounds were important to the flavor quality. The results of this study can provide a theoretical basis for improving the flavor quality of virgin olive oil.