The Profiles of Volatile Compounds in Some Domestic And Foreign Olive Oils

Abstract

In recent years, the popularity of olive oil has increased because of to its health benefits and consumer perception. In this respect, it has been a preferred oil in many culinary cultures apart from the Mediterranean diet. In the evaluation of the qualities of olive oils, the sensory analysis is also used as well as the some chemical analysis. Volatile compounds (VC) have a decisive effect on the odor properties olive oils as one of the main parameters for their sensory qualities. In this study, the volatile compound profiles of five different olive oils, two of which are domestic (Domat, Uslu) and three of which are foreign (Arbequina, Taggiasca and Koroneiki), were determined and also principle component analysis (PCA) was applied to the data of these profiles. A total of 44 volatile compounds were identified in the samples. The amounts of most of these compounds in the samples were different from each other (P<0.05). The total contents of C6 and C5 carbon aldehydes and alcohols, which are formed by the lipoxygenase (LOX) enzyme during the processing of olives into oil and also responsible for the characteristic olive oil aroma, were found in higher amounts in Koroneiki olive oil. In particular, (E)-2-hexenal with a typical olive oil flavor was found to be significantly higher in coroneiki oil. In other samples, there was no significant difference between the total contents of the compounds derived LOX pathway. As one of the indicators of processing defect, acetic acid was found only in Taggiasca olive oil. TBA results show that the oils from Domat variety is the most different olive oil in terms of volatile compound profile. This difference was due to the high contents of 3-hexenal, (E)-2-pentenal, 1-pentanol and 2,4-hexanediene in this oil as well as terpene (floral aromas) compounds associated with positive properties. In addition, TBA showed that Arbequina and Taggiasca olive oils had UB compositions that were closer to each other than the other samples. Uslu olive oil was generally separated from other samples due to the lowest contents in terms of most VC. These results revealed that volatile compound contents should also be used in the characterization of olive oils.