## 2 Results and Discussion  
### SPME-GC/MS: Chemical Volatile Composition of the Spices  
Aroma is an important characteristic of the flavor and quality of pepper fruit and is closely related to the VOCs present in the sample [9; 10]. However, as reported by a previous study conducted on 147 samples of dried peppers, the compositional profile (variability between components and their levels) can vary significantly among different _Capsicum_ varieties [11]. In fact, the VOC content was investigated by [PERSON] et al. [12] in two pepper varieties, _C. chinenses_ and _C. annuum_, by using the HS-SPME technique. Twenty-nine VOCs were identified, which were mainly esters, aldehydes, alcohols and hydrocarbons, but with _C. chinenses_ having much higher VOC levels. In another work, a gas chromatography-olfactometry-mass spectrometry analysis was performed on _C. chinense_ JT-1\({}^{\prime}\) pepper fruits harvested from 1 to 7 weeks after flowering. The results of the investigation revealed a variable concentration of VOCs depending on the different harvest periods [13]. The VOC levels in fresh _C. annuum_ spices, chili flakes, and industrial and traditional spices were analyzed by SPME-GC/MS. The results demonstrated that thermal process, moisture content and time are critical parameters in determining the VOC profile during the production stage of pepper [14]. In addition, the geographical origin, cultivar and ripening process also influence pepper aroma type [15]. Generally, the main VOCs detected in pepper are esters and terpen. Other compounds present in trace amounts include phenolic derivatives, alcohols and other hydrocarbons and nitrogen-sulfur compounds [16; 17]. Pepper is known to be a natural source of carotenoids, and most of the works in the literature investigate this chemical class of compounds [18; 19]. A recent study described the content in terms of carotenoids, phenolic compounds, steroids and capsaicinoids in the hydro-methanolic seed extract of _C. ammonium_ from Tunisia [20]; nevertheless, on the other hand, data on the volatile fraction are more scarce. In the present work, we aimed to provide more information on the less investigated volatile composition of this matrix. In particular, to the best of our knowledge, the present study is the first to use SPME-GC/MS and PTR-ToF-MS techniques to determine the volatilome of _Capsicum amum_ L. collected in Tunisia. The analyses conducted by SPME-GC/MS allowed us to identify 31 Volatile Organic Compounds (VOCs), listed in Table 1.  
The obtained results highlighted, for the two spices, an almost overlapping chemical composition from a qualitative point of view. Both peppers were rich in sequiterpene compounds, which represented 65.4% (Paprika) and 65.4% (Baklouti) of the total composition. As regards Paprika pepper, its compositional profile was predominantly characterized by \(\alpha\)-curcumene (16.0%), \(\beta\)-sesquiphellandrene (14.7%) and \(\beta\)-bisabolene (13.0%). On the other hand, Baklouti showed I-zingiberene (25.5%) as the most abundant component followed by \(\alpha\)-curcumene (19.7%), \(\beta\)-sesquiphellandrene (13.8%) and \(\beta\)-bisabolene (10.7%). In addition to I-zingiberene, for some compounds such as limonene, linalool, (-)-carvone and \(\beta\)-carophyllene, the quantitative differences detectable between the two spices were more evident. Other minor compounds, whose relative quantities ranged from 0.1 to 0.9%, such as camphor, \(\alpha\)-limonene diepoxide and _trans_-\(\beta\)-farnesene, were present in Paprika pepper, while anothele, isobornyl acetate, carvacrol, eugenol, \(\beta\)-copaene, transgeranylacetone, _trans_-calamenene and \(\alpha\)-calacorene (ranging from 0.1 to 1.0%) were found only in Baklouti pepper. The sesquiterpene hydrocarbon zingiberene, found in the dried rhizomes of Indonesian ginger, _Zingiber officinalis_, has been shown to have a considerable spectrum of biological activity such as antiviral and antiulcer [21].