## 3 Results and Discussion
### Effect of the Incorporation of the Valorized Pomace Ingredient in Dry-Cured Sausages
In line with our results, sliced dry-cured loin manufactured with nitrites presented lower values of carbonyls with respect to that free of nitrites [11]. Figure 2 displays the results of the sensory analysis of dry-cured sausages from different batches. There were no statistically significant differences in the attributes assessed by the panel for the addition of the RPG ingredient, except for the lean and fat color. Appearance descriptors showed higher scores regarding the intensity of lean color in the PC group compared to the NC group, while RGP (LL and HL) showed the highest lean color intensity. In addition, PC presented significant differences in fat color, since the yellowness of fat was lower than in the other groups. These results are consistent with the instrumental color differences (Table 5). On the other hand, the spicy taste was lower in PC than in other groups, although no explanation has been found for these results. Nitrites act as antioxidants and modulate the aroma and taste formation in dry-cured products [14]. Some panelists noticed an excess of spicy taste in the product, which could be modulated by the inclusion of nitrites. Therefore, the use of nitrites produced a positive effect at the sensory level which was not achieved by the addition of pomace. It is important to highlight that the use of the RPG ingredient did not negatively affect the texture and aroma characteristics in the sensory analysis of the sausages. The tasters did not find any unpleasant texture, odor, or flavor/taste in any of the groups, regardless of the recipe used. This is particularly important in the case of the groups prepared with RPG ingredients (LL and HL), which provide a significant content of polyphenols (Table 1). A parallel study with white grape pomace [31], produced by the same methodology, which was added into burgers, found that high levels of the ingredient reduced the acceptability of burgers due to problems with the texture, since the pomace was perceived during chewing. In the current study, pomace was more intensely ground, and the mentioned texture problems have been solved (\(p\)-value for texture >0.05). But, this has led to a significant reduction of phenolic compounds in the ingredient (Table 1). Furthermore, this fact may have reduced the bioactivity of the ingredient, since as mentioned, the antioxidant effect on salchichon was not intense. Dry-cured sausages from different groups presented significant differences in 15 of the 49 volatile compounds isolated (Table 6). Volatile compounds were grouped into sulfur compounds (9 compounds), terpen (19 compounds), alcohols (8 compounds), aldehydes (4 compounds), ketones (3 compounds), lineal hydrocarbons (3 compounds), and aromatic hydrocarbons (3 compounds). Terpenes and sulfur compounds were the most abundant groups of the volatile compounds isolated. Terpenes represented between 43-51%, while sulfur compounds represented between 32-36% with respect to the total compounds. The highest percentages were found in the PC group (51 and 36%), while the NC and the groups with pomace presented similar levels. On the other hand, the rest of the chemical groups represented minor compounds, such as alcohols (4-10%), ketones (4-5%), aldehydes (2-3%), lineal hydrocarbons (2-11%), or aromatic hydrocarbons (1%). Despite the difficulties in establishing the origin of some volatile compounds, they could be grouped according to their most probable origin. In dry-cured sausages, most volatile compounds, like terpenes and sulfur, could be derived from the seasoning (in this case, garlic, pepper, and nutmeg) added during the manufacturing process. The second group would be the lipid-derived compounds, like some aldehydes, ketones, and alcohols. In addition, some volatile compounds would be originated from the Maillard reaction, such as Strecker aldehydes and hydroxyketones. In fermented dry-cured meat products, microorganisms also participate in the fermentation and in the degradation of amino acids, like some sulfur compounds.