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.