Abstract: 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.

Key words: olive oil; gas chromatography-olfactometry; odor activity value; key aroma compounds