## 3 Results and Discussion
### Effect of Breed and Finishing Diet on Volatile Compounds
#### 3.2.3 Alcohols  
Table 3 shows the effect of breed and finishing diet on alcohols identified in the _longsismus thoracis et lumborum muscle_ of foals. Fourteen compounds belonging to this family were detected both in JN and BU foals and their total content resulted to be unaffected by breed (\(p>0.05\)). On the other hand, six of the alcohols detected showed significant differences among groups (\(p<0.05\)). This could be explained by the fact that some alcohols have metabolic origin [56], as a consequence, genetic factors such as breed can influence their synthesis. In addition, other alcohols can also derive from lipid oxidation, since they are associated to the degradation of their homologous aldehydes [22; 29]. Among them, 1-hexanol, showing higher (\(p<0.01\)) values in BU foals, is associated to the reduction of hexanal [57] and the oxidation of the oleic acid [29]. Indeed, as can be seen in Table 2, the BU group reported greater concentrations of this fatty acid, though not significantly (\(p>0.05\)). On the other hand, 1-octen-3-ol, being more abundant (\(p<0.05\)) in JN foals, is considered to be a product of the autoxidation of linoleic and other polyunsaturated fatty acids [22] and it is distinguished by a mushroom-like grassy odor [58; 59]. BU foals, in fact, showed significantly (\(p<0.001\)) lower values of C18:2\(n\)-6 in comparison with JN ones (Table 2). These compounds were also identified in GM \(\times\) HB foals [27], but their total contents were much greater than ours. Regarding the contribution of alcohols on the volatile content, this family was the fifth most plentiful, representing 3.64 and 4.59% of the volatile profile for BU and JN foals, respectively. On the other hand, the type of finishing diet remarkably influenced the total alcohol content, where the D1 group reported the highest (\(p<0.001\)) values. The same tendency was observed in each compound belonging to this family, reporting significant (\(p<0.05\)) differences among groups, except for three alcohols (cyclobutametethanol, prepol and cis-2-pentenol). In particular, the alcohol found in the highest quantity was 1-octen-3-ol for both foal groups (91.33 _vs._ 70.35 AU \(\times\) 10\({}^{4}\)/g fresh meat for D1 and D2 foals, respectively), followed by 1-pentanol (41.55 _vs._ 28.03 AU \(\times\) 10\({}^{4}\)/g fresh meat for D1 and D2 foals, respectively). Our outcomes are consistent with those published by some authors, who observed higher contents of these alcohols in animals fed with concentrates [54]. In particular, these compounds are described as products of lipid oxidation, especially of linoleic acid [22; 29], typically found in high amounts in concentrates. Table 1, in fact, showed that concentrates employed in both diets reported relevant amounts of this fatty acid; however, considering the lipid profile of D1 and D2 foals (Table 2), similar values were recorded in both groups (\(p>0.05\)). Furthermore, 1-hexanol, 1-heptanol and 1-octanol are described as typical volatile compounds of oxidizing oleic acid [29]. These alcohols were generated in higher (\(p<0.001\)) amounts by D1 foals, which in fact also showed the greatest values of C18:1\(n\)-9 (Table 2). Corresponding with us, other authors observed the presence of 1-hexanol [27; 60], 1-heptanol [60] and 1-octen-3-ol in raw meat from foals and heifers fed with concentrates. Nevertheless, our values were lower than those detected by [PERSON] et al. [27]. Moreover, among these alcohols, 1-octen-3-ol odor, as commented above, is described as \"fungus\" [59], but other compounds play a major role in the final aroma of meat. This is the case mainly of 1-pentanol, characterized by its pleasant, sweet or fruity odor, and 1-hexanol, which has a positive aroma described as herbal and with fatty notes [22; 58; 61]. Despite this, alcohols are characterized by a high odor threshold and their contribution to volatile flavor is minor compared to other volatile substances,such as aldehydes [22; 62].