## 1 Introduction  
Extra-virgin olive oil (EVOO) is a kind of high-grade edible vegetable oil obtained by cold mechanical extraction from fresh olives (_Olea europaea_) without use of solvents or refining methods [1]. It can be consumed in original form without refining, possessing good stability as well as nutritional and healthy features with respect to other vegetable oils [2]. Thanks to its excellent nutritional and organoleptic properties, EVOO has become one of the most popular oils in the world. The demand for it has increased rapidly in the past decade. In 2014, 3.05 million tons of olive oil was produced worldwide, and the production of olives increased to 19.27 million tons in 2016 [3]. Aroma is an important criterion for EVOO. Its characteristic flavor is one of the main f distinguishing it from the other edible vegetable oils [4]. Meanwhile, the identification of the compounds contributing to the aroma is considered to be a key for quality and authentication control. The aroma compounds of EVOO derive from the enzymatic reactions and autoxidation of unsaturated fatty acids; they occur by the lipoxygenase (LOX) pathway comprising mainly the actuation of LOX and hydroperoxide-lyase enzymes [5] after crushing and during malaxation, a basic step of EVOO extraction process, aimed to improve oil yield and quality [6; 7]. From the qualitative and quantitative results, C6 aldehydes and alcohols and the corresponding esters are considered to be the most crucial aroma compounds of EVOO [8; 9]. Reasonable amounts of various classes of C5 compounds are also contained in the aroma of EVOO [10]. Aroma of EVOO consists of a complex mixture of volatile compounds, which includes mainly aldehydes, alcohol, ketones, and esters [2; 11; 12]. (_E_)-2-Hexenal is the most important compound in olive oil, followed by hexanal and (_E_)-2-heptenal using the extraction methods of headspace SPME, purge and trap (P&T), simultaneous distillation and extraction (SDE), and headspace (HS) [2; 11; 13; 14]. According to the flavor dilution (FD) factor, the most potent aromatic active compound is hexanal (FD = 512) in Fakhari olive oil, (FD = 256) in Touffehi oils, and (FD = 128) in Jemri olive oil [12]. (_E_)-2-Hexenal, (_E_)-2-hexen-1-enol, (_Z_)-3-hexen-1-ol, and 1-hexanol were also identified in the virgin olive oils from Greece and Tunisia of Koroneiki variety using SPME-GC/MS [8]. Although the percentage of C6 alcohols [hexan-1-ol, (E)-2-hexen-1-ol, and (E)-3-hexen-1-ol] were higher than that of C6 aldehydes [hexanal and (E)-2-hexenal], C6 aldehydes contributed to the virgin olive oil from four cultivars greatly grown in southern of Tunisia with the lower thresholds [15]. C6 and C5 volatile compounds were considered to be the potent odorants in most studies previously, but there were some differences of varieties and content of the compounds because of the different extraction methods [2; 11; 13; 14; 16]. The selective adsorption coating of SPME results in the incomplete extraction of aroma compounds. The high temperature of SDE affects the accuracy during the extraction process. Solvent-assisted flavor evaporation (SAFE) has become a preferred method because of the low extraction temperature and high vacuum characteristics (about \(10^{-5}\) Pa), which can extract more low-boiling compounds. SAFE allows the fast and careful isolation of volatiles from either solvent extracts of foods, oil samples, or even fruit pulps. Application of SAFE to model solutions of selected aroma compounds resulted in higher yield from both solvent extracts and fatty matrices (50% fat) compared to previously used techniques. Besides its efficiency in aroma isolation, the use of the equipment saves time and reduces costs due to the stability of the compact distillation unit [17]. The volatile profiles of pomelo flower, leaf, peel, and juice were comparatively analyzed using HS-SPME and SAFE [18]. To our knowledge, SAFE has not been applied to the aroma extraction of EVOO until now.