## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & & & & & & \\ \hline
**Volatile Compound** & _m/z_ & **LRI** & **1** & **3** & **6** & **9** & **14** & **SEM** & _p-Value_ \\ \hline Furan, 3-methyl- & 82 & 582 & 34.46 & 27.11 & 19.04 & 29.47 & 21.23 & 2.20 & 0.219 \\ Benzene & 78 & 650 & 122.13 & 122.00 & 68.75 & 80.10 & 86.78 & 9.63 & 0.262 \\ Furan, 2-5-dihydro- & 41 & 670 & 35.15 & 25.35 & 16.94 & 22.09 & 21.62 & 2.11 & 0.118 \\ Furan, 2-ethyl- & 81 & 703 & 338.52 & 287.36 & 119.13 & 156.62 & 178.18 & 27.25 & 0.054 \\ Toluene & 92 & 804 & 121.07 & 80.29 & 116.04 & 141.66 & 119.53 & 9.82 & 0.329 \\ Ethlybenzene & 91 & 917 & 561.00 & 222.73 & 248.60 & 231.58 & 207.55 & 37.81 & 0.019 \\ Benzene, 13-dimethyl- & 106 & 926 & 585.07 & 446.28 & 501.35 & 484.48 & 36.24 & 0.821 \\
2-n-Butyl furan & 81 & 944 & 324.98 & 290.61 & 154.92 & 178.15 & 238.87 & 24.02 & 0.135 \\ p-Xylene & 106 & 958 & 221.17 \({}^{\rm a}\) & 121.76 \({}^{\rm b}\) & 128.72 \({}^{\rm a}\) & 116.05 \({}^{\rm b}\) & 120.83 \({}^{\rm b}\) & 11.49 & 0.024 \\
3-Carene & 136 & 983 & 109.63 & 89.09 & 126.39 & 109.03 & 102.17 & 8.58 & 0.718 \\ Furan, 2-3-dihydro-3-methyl- & 81 & 984 & 94.92 & 46.31 & 102.32 & 84.48 & 54.82 & 15.74 & 0.765 \\ Furan, 2-pentyl- & 81 & 1043 & 102.31 \({}^{\rm a}\) & 8082.13 \({}^{\rm a}\) & 3462.15 \({}^{\rm b}\) & 5171.65 \({}^{\rm a}\) & 5534.13 \({}^{\rm a}\) & 730.69 & 0.032 \\ Total Aromatic Hydrocarbons & & & 12,375.25 \({}^{\rm a}\) & 9838.03 \({}^{\rm a}\) & 5064.81 \({}^{\rm b}\) & 6779.35 \({}^{\rm a}\) & 7173.80 \({}^{\rm a}\) & 813.14 & 0.046 \\ \hline Propanal & 58 & 526 & 580.18 & 809.05 & 596.61 & 651.52 & 870.97 & 50.04 & 0.258 \\ Propanal, 2-methyl- & 72 & 557 & 264.63 \({}^{\rm a}\) & 15.96 \({}^{\rm a}\) & 19.06 \({}^{\rm b}\) & 34.31 \({}^{\rm b}\) & 27.65 \({}^{\rm b}\) & 1.95 & 0.010 \\ Butanal, 72 & 584 & 564.4 \({}^{\rm a}\) & 60.67 \({}^{\rm a}\) & 48.67 \({}^{\rm a}\) & 52.48 \({}^{\rm a}\) & 78.13 \({}^{\rm b}\) & 3.31 & 0.042 \\ Butanal, 3-methyl- & 58 & 659 & 30.03 \({}^{\rm a}\) & 34.61 \({}^{\rm a}\) & 28.29 \({}^{\rm a}\) & 79.21 \({}^{\rm b}\) & 55.48 \({}^{\rm a}\) & 5.62 & 0.011 \\ Butanal, 2-methyl- & 57 & 671 & 45.14 & 62.95 & 45.45 & 108.90 & 87.94 & 8.64 & 0.087 \\ Pentanal & 57 & 728 & 240.28 & 2113.87 & 220.51 & 2820.59 & 2858.49 & 1.89 & 0.335 \\ Hexanal & 56 & 865 & 34,161.17 & 339.59 & 36,215.04 & 35,474.08 & 38,958.15 & 3.31 & 0.732 \\ Furfural & 95 & 933 & 39.37 & 23.43 & 29.28 & 53.39 & 24.28 & 5.62 & 0.111 \\
2-Hexenal, (E)- & 41 & 943 & 31.37 & 39.90 & 41.90 & 40.58 & 43.99 & 8.64 & 0.288 \\ Heptanal & 70 & 974 & 1012.65 & 1437.59 & 109.78 & 1258.64 & 1436.41 & 122.08 & 0.303 \\ Benzaldehyde & 106 & 1045 & 248.02 \({}^{\rm a}\) & 258.45 \({}^{\rm a}\) & 221.45 \({}^{\rm a}\) & 335.76 \({}^{\rm a}\) & 481.34 \({}^{\rm b}\) & 1231.03 & 0.031 \\ Octana1 & 57 & 1086 & 352.34 & 513.19 & 408.50 & 413.44 & 511.60 & 4.18 & 0.506 \\
5-Ethlyclopent-1- & 124 & 1099 & 52.37 \({}^{\rm a}\) & 59.46 \({}^{\rm a}\) & 35.52 \({}^{\rm a}\) & 48.00 \({}^{\rm a}\) & 66.62 \({}^{\rm b}\) & 1.76 & 0.025 \\ Benzeneacetaldehyde & 91 & 1119 & 29.02 \({}^{\rm a}\) & 23.27 \({}^{\rm a}\) & 38.55 \({}^{\rm a}\) & 85.76 \({}^{\rm b}\) & 58.54 \({}^{\rm a}\) & 77.33 & 0.030 \\
2-Octene(E)- & 70 & 1123 & 73.24 \({}^{\rm a}\) & 69.16 \({}^{\rm a}\) & 45.44 \({}^{\rm a}\) & 38.01 \({}^{\rm b}  
Table 3 shows the effect of aging time in the ketones (16 VOCs) content of donkey meat steaks aged for 14 days under vacuum conditions. The total amount of ketones did not show significant differences (\(p>0.05\)). Only 2,3-pentanedione, 2-hexanone and 3-octanone, 2-methyl-, poorly representing in the total amount, showed significative variation during aging (\(p<0.01\)).