## 3 Results and Discussion
### Volatile Compounds
#### 3.2.1 LOX-Derived Volatile Compounds  
Table 3 shows the results for the most representative C5 and C6 LOX volatile compounds affected by the organic production, the harvesting method, and/or the harvesting time. Those compounds were among the most abundant ones in the Verdial de Badajoz olive oil headspace, as it was previously reported for the oil from this cultivar [30] and others [3; 4; 10]. Most of those compounds have low odour-thresholds [3] and, therefore, could take part in oil flavour. In fact, C5 and C6 LOX compounds seem to contribute to the positive traits of olive oil [3; 10]. The most abundant LOX compounds were \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **Week 1** & **Week 2** & **Week 3** & **Week 4** & **Week 5** & **Week 6** \\ \hline \multirow{2}{*}{Heptanal} & Organic & 1.90b & 1.41 & 1.62 & 2.45 ab & 2.36 & 2.69 \\  & Conventional & 1.81b & 2.34 & 1.77 & 2.23b & 2.31 & 2.81 \\  & Ground & 3.66a & 2.48 & 3.80 & 4.38a & 4.14 & 3.05 \\ \hline \multirow{2}{*}{Hexa-2,4-dienal} & Organic & A4.95a & BC3.68a & D1.52b & AB4.28a & D1.20b & C2.83a \\  & Conventional & B3.44 ab & B3.33a & A5.20a & A5.34a & B3.13a & B3.04a \\  & Ground & AB2.02b & ABC1.16b & A2.33b & A2.11b & C0.60b & BC0.81b \\ \hline \multirow{2}{*}{(E)-Hept-2-enal} & Organic & AB6.64b & AB6.54b & D2.60c & A7.96b & C4.40b & BC5.91b \\  & Conventional & A9.16 ab & B6.62b & AB7.96b & A8.87b & AB7.69a & AB8.56a \\  & Ground & B11.69a & C9.62a & B12.54a & A14.92a & D4.97b & C9.43a \\ \hline \multirow{2}{*}{Octanal} & Organic & 2.52b & 1.66 & 2.09c & 3.09 & 2.51b & 3.91 \\  & Conventional & 2.02b & 4.31 & 3.27b & 2.77 & 2.29b & 3.14 \\  & Ground & 4.94a & 3.14 & 4.54a & 4.49 & 6.43a & 4.65 \\ \hline \multirow{2}{*}{(E)-Oct-2-enal} & Organic & 0.79 & 0.65 & 0.40c & 0.85b & 0.69 & 0.69b \\  & Conventional & 0.92 & 1.27 & 1.00b & 0.76b & 0.90 & 0.83b \\  & Ground & 1.23 & 1.16 & 1.42a & 1.53a & 1.03 & 1.50a \\ \hline \multirow{2}{*}{Nonanal} & Organic & 8.75b & 6.90 & 7.90 & 10.52 & 11.86 & 13.04 \\  & Conventional & 10.44b & 15.90 & 9.14 & 12.88 & 10.73 & 16.36 \\  & Ground & 20.33a & 12.45 & 12.61 & 15.34 & 16.57 & 15.60 \\ \hline \multirow{2}{*}{Nona-2,4-dienal} & Organic & 0.84b & 0.95 & 0.35b & 1.06a & 0.72b & 0.91b \\  & Conventional & 1.10a & 1.11 & 1.32a & 1.29a & 1.15a & 1.45a \\ \multicolumn{2}{c}{} & Ground & 0.45c & 0.27 & 0.11b & 0.12b & 0.13c & 0.03c \\ \hline \multicolumn{2}{c}{\({}^{\star}\) Different letters in the same row (A–C) or the same column (a–c) indicate statistical differences (Tukey test’s \(p<0.05\)). Results are expressed as AU \(\times\) 10\({}^{-6}\).} \\ \end{tabular}
\end{table} 
Table 5: Results (means and significance \({}^{\star}\)) for the most representative oxidation compounds of the Verdial de Badajoz oil headspace significantly affected by the organic production, harvesting method and/or harvesting time according to Table 2.  
(E)-hex-2-enal and (Z)-hex-3-en-1-ol, followed by hexan-1-ol and hexanal. It should be noted that hexanal, besides the LOX pathway, can be generated through oxidation reactions on linoleic acid [3], being involved in the rancid note of food when it appears at high concentrations. According to the ANOVA results (Table 2), the organic production affected eight out of the 13 LOX compounds included in Table 3, the harvesting method 12 out of 13 (all except hexanal), and the harvesting time 12 out of 13 (all except hexan-1-ol). Some LOX compounds were not significantly affected by any factors, such as pentan-2-one and 3-pentanol (Table 2). Effect of the Organic Production (Organic vs. Conventional)  
The effect of the organic production was significant on four out of the six C5 compounds included in Table 3, and on four out of the seven C6 ones, according to the ANOVA results (Table 2). The effect was stronger than expected taking into account the relatively slight influence on the quality parameters (Table 1).