## 3 Discussion
From a general point of view on volatiles in the SC samples, some particular and unusual molecules (both in high and low relative amounts) were identified, e.g., (7Z)-tetradecene, (2E)-tridecen-1-ol, ethyl esters [of 9-C\({}_{101}\), (9Z)-C\({}_{141}\), (9Z)-C\({}_{161}\), (9Z)-C\({}_{171}\), (9Z)-C\({}_{181}\), (9Z,12Z,15Z)-C\({}_{183}\), (9Z,12Z)-C\({}_{182}\), and C\({}_{180}\)], \(\beta\)-phenethyl acetate, \(m\)-tolualdehyde, 5-methyl-2-hexanone, 2-methylbutanoic acid, etc. Some of them [(7Z)-tetradecene, (2E)-tridecen-1-ol, ethyl 9-decenoate (C\({}_{101}\)), and ethyl (9Z)-tetradecenoate (C\({}_{141}\))] are recorded  
Figure 6: Comparison of the types of compounds identified in the volatile fractions (by SDE and HS-SPME) of the RM samples (average values of the relative amounts). for the first time as constituents of a dairy product (or fermented sour creams), but others have been found in other dairy products (goat cheese: ethyl 9-decenoate; goat cheese/mozzarella/camembert: \(\beta\)-phenethyl acetate; Spanish artisanal cheese: ethyl (9Z)-hexadecenoate, ethyl (9Z)-tetradecenoate, ethyl linoleicate, and ethyl oleate) and in plants, which could be food sources for animals during grazing; likewise, sesquiterpenes (\(\beta\)-caryophyllene, \(\alpha\)-humulene, etc.) and monoterpenes (limonene, \(\alpha\)-pinene, \(p\)-cymene, etc.) found in the SC samples could come from this type of source [56; 57; 58; 59; 60]. When consulting the scientific literature on the volatiles of SC, only the report by [PERSON] et al. [19] described the volatile profiles (by HS-SPME/GC-MS) of seven SC samples prepared at laboratory (four samples) and production (three samples) scales from isolated native starter cultures (_L. plantarum, S. infuntarius_, and _L. lactis_). However, no report was found on the chemical composition of the volatile fraction of SC by SDE/GC-MS; therefore, this is the first report on the complete volatilome of this Colombian artisanal food product considering that the SPME technique alone is not sufficient to determine the volatile constituents of the SC, as mentioned above. Comparison between the volatiles identified in SC samples by [PERSON] et al. [19] with those of this study showed differences and some similarities. That is, the authors reported for each sample 1-2 alcohols (hexanol, 1,4-butanediol), 1-2 methyl alkoxyl ketones (acetoin, acetol), 1-2 SCFAs (C\({}_{2:0}\), C\({}_{4:0}\)), 1 FA (C\({}_{1:0}\)), 2-5 aldehydes (acetaldehyde, nonanal, etc. ), and 2-3 other components (dimethylsulfide, etc. ), for a total of 18 compounds for all samples, with varying relative amounts (0.01-18%); of these volatiles, only acetoin, C\({}_{2:0}\), C\({}_{4:0}\), C\({}_{10:0}\), and nonanal were identified in this research. Furthermore, esters (including lactones), ethanol, fatty (iso-C\({}_{4}\)-C\({}_{9}\) and C\({}_{10:1}\)-C\({}_{16}\)) and aromatic acids, methyl alkyl ketones, terpenes (C\({}_{10}\) and C\({}_{15}\)), and hydrocarbons were not identified in any of the SC samples in the study by [PERSON] et al. [19]; these notable compositional differences could be related to both the inoculation (strains and time) and the manufacturing processes used for SC production. Additionally, some comparisons were made with science reports of products with similar physicochemical characteristics to those of SC and related to the fermentation process of cow's milk (sour cream). Thus, [PERSON] et al. [61] characterized the profiles of volatiles produced during milk fermentation by _Streptococcus thermophilus_ and _Lactobacillus helveticus_); the authors reported 56 constituents, belonging mainly to aldehyde, ketone, acid, alcohol, and ester type compounds. Among them, 2,3-butanedione, acetoin, 2,3-pentanedione, C\({}_{6:0}\), C\({}_{2:0}\), acetaldehyde, and C\({}_{4:0}\) were identified as discriminating molecules between different time points and fermented milk samples. While [PERSON] et al.