Identification of Trace Volatile and Phenolic Compounds in Olive Oils with Trees Growing in Different Area Conditions: Using SPME/GC-MS

This research work was performed on olive orchards (Olea europaea L., cv. Chemlali) of different origin areas of olive trees exposed to atmospheric contamination and those growing in a relatively clean area, during two successive years (2015/2016 and 2016/2017). Volatile profile of olive oil samples was carried out by headspace solid-phase micro-extraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC/MS). A total of 93 volatile compounds, belonging to several classes of compounds, such as hydrocarbons, aldehydes, ketones, alcohols, terpenoids, and esters, were identified. Indeed, the analysis of phenols was performed by high-performance liquid chromatography with absorbance and fluorometric detection. Discriminant analysis confirmed that the pattern of volatile compounds includes enough information to predict sample variety amongst discrete monovarietal olive oil. The results indicate that climatic factors strongly effect volatile formation and phenolic composition and are supposed to be suitable markers of the geographic origin.