## 3 Results and Discussion
### Effect of Breed and Finishing Diet on Volatile Compounds
#### 3.2.1 Hydrocarbons: Lineal, Branched and Cyclic
**} \\ \cline{3-10}  & & & **D1** & **D2** & **D1** & **D2** & **SEM** & **B** & **D** & **B** \(\times\)**D** \\ \hline \multirow{2}{*}{Propanal} & 499 & 58 & 9.70 b  & 5.42 a  & 10.29 b  & 11.74 b  & 0.531 & *** & ns & ** ** \\
2-Propynal & 537 & 53 & 7.47 a  & 7.41 a  & 13.43 b  & 12.60 b  & 0.583 & *** & ns & ns \\ Pentanal & 714 & 57 & 15.66 b  & 8.05 a  & 11.07 a  & 15.28 b  & 0.802 ns & ns & *** \\ Hexanal & 853 & 56 & 294.0 c  & 140.0 a  & 207.1 b  & 198.4 b  & 13.513 & ns & *** & ** \\ Heptanal & 963 & 70 & 7.83 b  & 2.07 a  & 8.91 b  & 3.78 a  & 0.517 & * & *** & ns \\
2-Heptension & 1029 & 83 & 6.70 c  & 3.29 a  & 4.27 ab  & 0.296 ns & ns & ** & *** \\ Octanal & 1057 & 84 & 1.98 c  & 1.98 c  & 1.27 b  & 0.107 ns & ** & ** & ns \\
2-Octanal, (E)- & 1116 & 83 & 2.05 c  & 0.99 a  & 1.88 b  & 1.47 ab  & 0.106 ns & ** & ** & ns \\ Nonanal & 1141 & 98 & 4.21 c  & 1.78 a  & 3.69 bc  & 3.03 b  & 1.98 ns & ** & ** & ** \\
**Total aldehydes** & & & 349.6 c  & 169.9 a  & 262.6 b  & 252.4 b  & 15.017 ns & ** & *** & ** \\ \hline
2,3-Pentanedione & 722 & 100 & 5.28 ab  & 4.08 a  & 5.80 b  & 8.29 c  & 0.309 & *** & ns & *** \\ Acetoin & 776 & 45 & 5.41 a  & 5.74 a  & 9.60 b  & 4.07 a  & 0.438 ns & ** & *** & ** \\
2-Heptanone & 956 & 58 & 3.03 b  & 1.35 a  & 2.73 b  & 1.55 a  & 0.167 ns & ** & ** & ns \\ Butylolactone & 1038 & 86 & 4.49 b  & 3.98 b  & 4.20 b  & 2.95 a  & 0.170 & * & ** & ns \\
5-Hexen-3-one & 1075 & 69 & 0.55 b  & 0.41 b  & 0.87 c  & 0.22 a  & 0.039 ns & ** & *** & *** \\
3-Octen-2-one & 1099 & 111 & 2.34 b  & 1.30 a  & 2.05 b  & 1.73 ab  & 0.122 ns & ** & ns & ** & ns \\
**Total ketones** & & & 221.10 b  & 16.86 a  & 25.26 c  & 18.80 ab  & 0.696 & ** & ** & ns \\ \hline \multirow{2}{*}{Dibutyl sulphate} & 525 & 56 & 1.65 a  & 3.35 b  & 2.91 b  & 0.163 & *** & ns & ns \\ Vinyl butyrate & 1041 & 71 & b  & 60.71 a  & 77.90 a  & 3.717 ns & ** & ** & ** \\ Caprovic acid, vinyl ester & 1041 & 99 & 115.3 b  & 61.33 a  & 93.08 b  & 89.63 b  & 5.121 ns & ** & ** & ** \\ Glycerol 1,2-diacetate & 1333 & 145 & 0.37 b  & 0.26 a  & 0.34 ab [FOOTNOTE:b]Footnote b: footnotemark: [ENDFOdodecane, recording the highest (\(p\) < 0.001) content in JN foals (0.31 _vs._ 0.14 AU \(\times\) 10\({}^{4}\)/g fresh meat, respectively). Regarding branched hydrocarbons, the majority compound, pentane, 3-methyl, reported significantly greater (\(p\) < 0.001) values in BU foals compared to JN ones (3.48 _vs._ 1.81 AU \(\times\) 10\({}^{4}\)/g fresh meat, respectively); whereas, bicyclo[3.2.0]hepta-2,6-diene represented not only the most abundant cyclic hydrocarbon, but also the majority compound within the entire hydrocarbon family. BU foals, also in this case, displayed the highest (\(p\) < 0.01) values of bicyclo[3.2.0]hepta-2,6-diene compared to the JN group (2887 _vs._ 2432 AU \(\times\) 10\({}^{4}\)/g fresh meat, respectively). Therefore, considering the contribution of hydrocarbons over the total volatile compounds, this group represented the first most plentiful family in both breeds, as a total percentage of 70.41% in BU foals and 70.03% in the JN group was obtained (Figure 1). This trend disagrees with results obtained by other researchers, who found that esters represented the most abundant volatile compounds in raw steaks from GM \(\times\) HB [25; 27] and GM [26] horses. In addition, statistical analysis showed that the total content of hydrocarbons was significantly affected also by the type of finishing diet (\(p\) < 0.05). In fact, the D1 group reported the highest values compared with D2 foals (2832 _vs._ 2484 \(\times\) 10\({}^{4}\)/g fresh meat, respectively) (data not shown). Moreover, D1 animals produced significantly higher amounts of total lineal (\(p\) < 0.001; 4.45 _vs._ 3.48 AU \(\times\) 10\({}^{4}\)/g fresh meat, respectively) and cyclic hydrocarbons (\(p\) < 0.05; 2824 _vs._ 2477 AU \(\times\) 10\({}^{4}\)/g fresh meat, respectively); whereas, both groups reported similar values of total branched hydrocarbons (\(p\) > 0.05).