## 3 Results and Discussion
### Volatile Compounds Profile  
The volatile composition from fresh and dried _S. ramossissima_ was studied by GC-MS. For the identification, the mass spectra comparison with the mass spectra bank, the retention time, and the Linear Retention Index (LRI) were determined. Compounds were classified by their chemical classes and odor descriptions according to the literature (Appendix A, Table A1). In order to compare contents, the percentage of the area of peaks compared to the total area of the chromatogram was measured. Many chemical classes of compounds were identified in both the dried and fresh _S. ramossissima_, such as alcohols, aldehydes, carboxylic acids, esteres, furans, hydrocarbons, ketones, pyrazines, and terpen, as summarized in Figure 2.  
Figure 2: Pie charts showing the chemical classes profile of volatile compounds of the _S. ramossissima_. (**a**) Volatile compounds profile of fresh plant; (**b**) volatile compounds profile of oven-dried plant; and (**c**) volatile compounds profile of freeze-dried plant. In the fresh _S. ramossissima_ samples, two peaks of high intensity were identified, which corresponded to 3-hexen-1-ol (47.95%) and 1-hexanol (47.82%). Both alcohols are known to be responsible for green-type odors and 3-hexen-1-ol has also been described as a seaweed odor [50; 51]. In addition, hexanal (0.26%), ethyl tiglate (1.51%), 3-hexen-1-ol acetate (0.33%), and methyl and ethyl benzoate (0.54% and 0.21%, respectively) are responsible for odors such as green, herbal, fruity, and floral [52; 53]. For the oven-dried _S. ramossissima_, the main volatile compounds detected were hexanal (34.16%), 3-hexen-1-ol (1.80%), 2-methylbutanoic acid (7.84%), heptanal (5.14%), 1-octen-3-ol (3.0%), 6-methyl-5-hepten-2-one (3.92%), _p_-cymene (3.08%), limonene (10.18%), 3,4-dimethylcyclohexanol (7.31%), \(\beta\)-cyclocitral (1.97%), and 3,5-ocatadien-2-one (1.19%). In general, linear and branched chain aldehydes contribute with herbaceous and grassygen aromas [54], namely hexanal, which is responsible for herbal and grassy-green odors [52; 53]. Compounds such as 2-methylbutanoic acid, heptanal, 1-octen-3-ol, and 3,5-ocatadien-2-one are described as responsible for some off-odors including sour, penetrating oil-like, mushroom-like, and marine odors, respectively, but their contribution to the aroma depends on their limit of detection [50; 53; 55; 56]. The major compounds identified in the freeze-dried _S. ramossissima_ include \(\beta\)-myrcene (2.26%), \(\alpha\)-phellandrene (8.45%), \(p\)-cymene (8.80%), 1,8-cineole (38.73%), \(\beta\)-thujone (7.21%), \(\alpha\)-thujone (2.31%), camphor (4.80%), and isobornyl acetate (8.17%). These terpen and esters are responsible for odors described as herbaceous, fresh, and green [57; 58; 59; 60; 61], specifically 1,8-cineole that has an odor description of eucalyptus, spicy, and pepper. In addition, (Z,Z)-3,6-nonadien-1-ol was identified in the freeze-dried _S. ramossissima_ (0.30%), which has been described as contributing to the odor of marine and seaweed of _Mertensia martiima_ L. [50]. Both drying methods induced changes in the volatile profile compared to the fresh _S. ramossissima_. For the oven-dried plant, a loss of compounds such as esters, terpen, and alcohols was observed and has been justified by the effect of the temperature [62]. Additionally, the formation of lactones, pyrazines, and ketones, and the increase of hydrocarbons and lactones, was observed. Pyrazines and ketones can be produced during the oven-drying process from free amino acids and monosaccharides by the Maillard reaction through Strecker degradation, and they contribute to the roast-like aroma and buttery flavor [63]. Conversely, lactones can be generated by the degradation of phenolic acids during the oven-drying, such as chlorogenic acids [64]. The oven-drying process significantly decreased the contribution of terpen (17.02%) and increased aldehydes (12.77%) compared to the freeze-drying process.