## 2 Results and Discussion
### Volatile Compounds  
Table 2 shows the volatile compounds identified in the samples clustered according to their breeding (non Iberian and Iberian), while Figure 1 displays the chromatograms of three dry-cured hams. The formation of these volatiles is caused by the intense degradation processes that happen in lipids and proteins during the processing of dry-cured hams. Most of the volatiles identified (hydrocarbons, aldehydes, alcohols, ketones, esters, carboxylic acids, _etc._) derive from lipid oxidation that is probably the main source of ham volatiles as in almost all fat products [16]. Other volatiles, such as 3-methylbutanol and benzaldehyde, derive from reactions between amino acids and reducing  
sugars referred to as the Maillard reaction [16]. An intense proteolysis, and hence a larger release of amino acids in hams, promotes the Strecker degradation, and is the implication of reactive carbonyls in the Strecker degradation of free amino acids, which would explain the concentrations of the branched aldehydes (e.g., 2-methylbutanal derived from isoleucine) quantified in dry-cured hams. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Code** & **Compound** & **Non Iberian**\({}^{\text{a}}\) & **Iberian**\({}^{\text{a}}\) & \(p\) \\ \hline A1 & Tryptophan & \(23\pm 1\) & \(21\pm 1\) & 0.30 \\ A2 & Phenylalanine & \(252\pm 55\) & \(286\pm 67\) & \(<\)0.01 \\ A3 & Tyrosine & \(103\pm 3\) & \(150\pm 11\) & \(<\)0.01 \\ A4 & Tyramine & \(12\pm 2\) & \(2\pm 1\) & 0.02 \\ A5 & Isoleucine & \(300\pm 8\) & \(391\pm 10\) & \(<\)0.01 \\ A6 & Leucine & \(267\pm 7\) & \(353\pm 11\) & \(<\)0.01 \\ A7 & Methionine & \(157\pm 1\) & \(209\pm 1\) & \(<\)0.01 \\ A8 & Valine & \(316\pm 1\) & \(402\pm 1\) & \(<\)0.01 \\ A9 & Creatine & \(1637\pm 19\) & \(118\pm 23\) & \(<\)0.01 \\ A10 & Proline & \(146\pm 4\) & \(197\pm 6\) & \(<\)0.01 \\ A11 & Creatinine & \(29\pm 1\) & \(36\pm 1\) & \(<\)0.01 \\ A12 & Glutamic acid & \(543\pm 162\) & \(739\pm 25\) & \(<\)0.01 \\ A13 & Arginine & \(195\pm 6\) & \(301\pm 9\) & \(<\)0.01 \\ A14 & Asparagine & \(185\pm 50\) & \(195\pm 15\) & 0.50 \\ A15 & Taurine & \(57\pm 1\) & \(86\pm 8\) & \(<\)0.01 \\ A16 & Histidine & \(165\pm 5\) & \(226\pm 6\) & \(<\)0.01 \\ A17 & Serine & \(181\pm 7\) & \(255\pm 5\) & \(<\)0.01 \\ A18 & Glycine & \(92\pm 3\) & \(119\pm 2\) & \(<\)0.01 \\ A19 & Lysine & \(686\pm 22\) & \(966\pm 29\) & \(<\)0.01 \\ \hline \end{tabular} Note: \({}^{\text{a}}\) mean \(\pm\) standard deviation.  
\end{table} 
Table 1: Amino acids and related compounds (mg/100 g) determined in non Iberian and Iberian hams. Column with _p_-value lower than 0.05 indicates amino acids distinguish between hams. Values are expressed as the mean and the standard error of the mean. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Code** & **Rt** & **Volatile compound** & **Non Iberian**\({}^{\text{a}}\) & **Iberian**\({}^{\text{a}}\) & \(p\) & **OT** & **GC-O** \\ \hline V1 & 0.16 & Hexane & \(0.36\pm 0.03\) & \(0.29\pm 0.03\) & 0.20 & 1.50 & Spicy \\ V2 & 0.17 & Heptane & \(0.22\pm 0.03\) & \(0.23\pm 0.03\) & 0.85 & 0.67 & Sweety, alkane \\ V3 & 0.20 & Octane & \(2.23\pm 0.42\) & \(3.00\pm 0.41\) & 0.35 & 0.94 & Sweety, alkane \\ V4 & 0.21 & 2-Propanone & \(1.72\pm 0.13\) & \(2.21\pm 0.32\) & 0.10 & 500 & Fruity, apple, cooked meat \\ V5 & 0.27 & 2-Butanone & \(0.34\pm 0.04\) & \(0.20\pm 0.02\) & 0.03 & 40 & Ethereal \\ V6 & 0.29 & 3-Methylbutanal & \(0.13\pm 0.02\) & \(0.38\pm 0.06\) & \(<\)0.01 & 0.08 & Acorn, fruity, cheesy, salty \\ V7 & 0.31 & 2-Propanol & \(0.07\pm 0.01\) & \(0.07\pm 0.01\) & 0.95 & 26 & Alcoholic, dry, buttery-taste \\ V8 & 0.32 & Ethanol & \(1.31\pm 0.20\) & \(1.52\pm 0.26\) & 0.61 & 30 & Alcohol, sweet \\ \hline \end{tabular} Note: \({}^{\text{a}}\) mean \(\pm\) standard deviation.  
\end{table}