## 4 Discussion
Regarding the obtained results of oxidative damage of Spanish chorizo for 125 days, acids, which were practically absent at the start, showed the largest increase among the volatiles during ripening. Carbohydrate metabolism ([PERSON], 2016), lipolysis ([PERSON], 2016), amino acid catabolism ([PERSON], 2016), and smoke ([PERSON], 2016)might account for the formation of these acids. The only alcohol present in all the samples of chorizo was furfurrylalcohol. [PERSON] et al. [PERSON] et al. (2018) reported the presence of this compound as the major alcohol in a smoked dry fermented sausage. Lipid oxidation [PERSON] et al. (2018); [PERSON] et al. (2018); [PERSON] et al. (2019), carbohydrate metabolism [PERSON] (2019), and amino acid catabolism [PERSON] et al. (2019) could be the most important pathways accounting for the production of volatile alcohols in fermented dry sausages. These compounds could also come from smoke, like furfurylalcohol, which is abundant in wood smoke [PERSON] et al. (2018); [PERSON] et al. (2019). A total lack of straight chain aldehydes and ketones, which are typical breakdown products of the hydroperoxides derived from fatty acids [PERSON] et al. (2018), was observed in chorizo unlike other varieties of dry fermented sausage [PERSON] et al. (2019). On the other hand, branched and cyclic carbonyls were detected in greater profusion. The bulk of the carbonyls was formed during ripening, and each of the ketones isolated increased during ripening, whereas the aldehydes did not show a definite evolution. The presence of some cyclo-pentanones and cyclopentanones as volatile constituents of dry fermented sausages has not been previously reported. Nonetheless, these substances are typical of wood smoke [PERSON] et al. (2018); [PERSON] et al. (2019). The presence of methyl-branched aldehydes may be explained by amino acid catabolism [PERSON] et al. (2019) and by ketones (such as diacetyl, acetoin) and hydroxypropanone by carbohydrate metabolism [PERSON] et al. (2019). Large amounts of furfurral and 5-methylfuran-2-carbaldehyde, which are characteristic products of the Maillard reaction, were observed principally in industrial chorizo. Apart from spices and smoke, it is generally accepted that the formation of volatiles during the ripening of dry fermented sausages would be due to the occurrence of a set of reactions between the precursors of flavor, such as carbohydrates, lipids, and proteins, with microbial or endogenous enzymes being involved in many instances. Several low molecular weight compounds isolated from chorizo, i.e., formic, acetic, and propanoic acids, propanol, butan-2,3-diol, diacetyl, 1-hydroxy-2-propanone, acetoin, ethyl acetate, ethyl propionate, propyl acetate, and ethyl butyrate, might derive to a great extent, whether directly or indirectly, from carbohydrate metabolism [PERSON] et al. (2019). There was approximately twice the quantity of these substances in industrial chorizo with regard to the traditional ones. Therefore, a more intense fermentation metabolism in industrial chorizo seemed probable. The production of 2-methylpropanal, 2- and 3-methylbutanal, 2-methylpropanol, 2- and 3-methylbutanol, 2-methylpropanoic, and 2- and 3-methylbutanoic acids from valine, leucine, and isoleucine would be explained by amino acid degradation [PERSON] et al. (2019). The larger total content of these substances in industrial chorizo would imply that major amino acid catabolism developed in this type of chorizo. On the other hand, it appeared that there was a smaller incidence of amino acid degradation as contrasted with carbohydrate fermentation in chorizo. This fact was also reported by [PERSON] et al. [PERSON] et al. (2019). Lipid autooxidation accounts for the appearance of numerous volatile compounds in dry fermented sausage [PERSON] et al. (2019); [PERSON] et al. (2019). However, the absence of key intermediates of autooxidation in the chorizo analyzed implies that the development of lipid oxidation is irrelevant, aromatically speaking. This was also suggested by [PERSON] et al.