## 2 Results
### Volatile Organic Compounds  
#### 2.2.1 Buffalo Milk  
Table 3 shows the headspace concentrations, sensory descriptors, and relative changes of volatile compounds identified in milk samples obtained from buffaloes fed mycorrhizal and nonmycorrhizal maize silage. An increase in ketones, aldehydes, and short and medium free fatty acid concentrations was found in M + m compared to M samples. In particular, the M + m buffalo milk sample showed more 2-heptanone, 2-nonanone, nonanal, decanal, butanoic, octanoic, and decanoic acids in M + m compared to M samples. Finally, acetone and ethyl acetate showed an important decrease in the M + m buffalo milk. From a sensory point of view, 2-heptanone is mainly characterized by cheesy and spicy odors, and 2-nonanone by hot milk, smoked cheese, fruity, and floral odors (Table 3). Based on the concentration data, the odors of 2-heptanone and 2-nonanone increased in M + m milk by about \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Fatty Acids** & **S** & **sd** & **S + m** & **sd** & **Change (\%) \({}^{\text{a}}\) S+/S-** \\ \hline C4:0 & Butyric acid & 5.53 & 0.86 & 7.69 & 0.96 & +39 & \({}^{\text{a}}\) \\ C6:0 & Caproic acid & 3.40 & 0.44 & 4.35 & 0.04 & +28 & \({}^{\text{a}}\) \\ C8:0 & Caprylic acid & 1.95 & 0.28 & 2.16 & 0.03 & +11 & \\ C10:0 & Capric acid & 4.25 & 0.64 & 4.17 & 0.48 & \(-\)2 & \\ C11:0 & Undecanoic acid & 0.11 & 0.04 & 0.09 & 0.02 & \(-\)17 & \\ C12:0 & Lauric acid & 4.79 & 0.71 & 4.64 & 0.39 & \(-\)2 & \\ C13:0 & Tridecylic acid & 0.17 & 0.04 & 0.17 & 0.01 & \(-\)3 & \\ C 14:0 & Myristic acid & 14.10 & 0.35 & 14.52 & 0.21 & +3 & \\ C15:0 & Pentadecylic acid & 1.43 & 0.11 & 1.43 & 0.00 & 0 & \\ C16:0 & Palmitic acid & 37.94 & 0.76 & 38.78 & 0.99 & +2 & \\ C17:0 & Margaric acid & 0.50 & 0.02 & 0.43 & 0.06 & \(-\)14 & \\ C18:0 & Stearic acid & 5.82 & 0.86 & 4.86 & 0.52 & \(-\)16 & \\ C24:0 & Lignoecric acid & 0.06 & 0.00 & 0.05 & 0.01 & \(-\)8 & \\
**SFA** & & **80.06** & **1.90** & **83.34** & **0.69** & +4 & \({}^{\text{a}}\) \\ C14:ln9 & Myristoleic acid & 1.94 & 0.14 & 1.78 & 0.08 & \(-\)8 & \\ C16:ln9 & Palmitoleic acid & 1.88 & 0.17 & 2.34 & 0.58 & +25 & \\ C 17:1 & Heptadecenoic acid & 0.27 & 0.02 & 0.25 & 0.02 & \(-\)9 & \\ C18:ln9 & Elaidic acid & 0.93 & 0.37 & 0.66 & 0.04 & \(-\)29 & \\ C18:ln9 & Oleic acid & 11.66 & 1.43 & 9.31 & 0.53 & \(-\)20 & \\ C18:ln7 & Vaccenic acid & 0.16 & 0.02 & 0.15 & 0.03 & \(-\)6 & \\ C22:ln9 & Erucic acid & 0.06 & 0.01 & 0.04 & 0.01 & \(-\)24 & \\ C24:1 & Nervonic acid & 0.06 & 0.01 & 0.04 & 0.01 & \(-\)51 & \({}^{\text{a}}\) \\
**MUFA** & & **16.95** & **1.47** & **14.56** & **0.14** & \(-\)14 & \({}^{\text{a}}\) \\ C18:2n6c+ct & Trans-linoleic acid & 0.27 & 0.07 & 0.19 & 0.07 & \(-\)29 & \\ C18:2n6c & Linoleic acid & 1.73 & 0.20 & 1.17 & 0.29 & \(-\)32 & \\ CLA & Conjugated linoleic acid & 0.40 & 0.09 & 0.28 & 0.04 & \(-\)31 & \\ C20:3n6 & Homo-\(\gamma\)-linoleic acid & 0.10 & 0.03 & 0.28 & 0.04 & \(+\)21 & \\ C22:2n6 & Docsadiene acid & 0.05 & 0.00 & 0.05 & 0.00 & \(-\)8 & \\
**PUFA n-6** & & **2.55** & **0.35** & **1.81** & **0.40** & \(-\)29 & \\ C18:3n3 & \(\alpha\)-Linolenic acid & 0.35 & 0.07 & 0.23 & 0.13 & \(-\)32 & \\ C20:5n3 & EPA & 0.02 & 0.00 & 0.01 & 0.00 & \(-\)35 & \\ C22:6n3 & DHA & 0.07 & 0.01 & 0.04 & 0.01 & \(-\)44 & \({}^{\text{a}}\) \\
**PUFA n-3** & & **0.44** & **0.08** & **0.29** & **0.14** & \(-\)34 & \\
**ouf/u3** & & **5.88** & **0.26** & **7.49** & **3.31** & +27 & \\ \hline \hline \end{tabular} \({}^{\text{a}}\) Asterisks indicate significantly different values between milk samples obtained from cows fed on mycorrhizal and nonmycorrhizal sorghum silage (\({}^{\text{a}}\)\(p<\) 0.05). \({}^{\text{a}}\) Relative difference. The total saturated fatty acids (SFA), monomusaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFAs) and the ratio \(\omega\)6/\(\omega\)3 are shown in bold.  
\end{table}