## 2 Results and Discussion
### Effect of Germination on the Volatile Profile of IWG
#### 2.2.3 MHE Optimization
The limit of quantitation (LOQ) was determined as the lowest concentration that provided a detectable signal when subjected to MHE. The LOQ varied from 0.21 to 0.54 mg/kg. Intraday and interday precision were evaluated, and the results were expressed as the relative standard deviation. Precision was adequate (less than 20%), in compliance with SANTE 1312/2021 guidelines [42] (Table 5). The main compounds identified in the IWG samples were aldehydes (\(\sim\)49%), hydrocarbons (\(\sim\)27%), alcohols (12%), terpenes (5%), esters (3%), organic acids (3%), and ketones (1%) (Figure 5). The ungerminated samples showed a higher concentration of aldehydes compared to the germinated ones. Among the aldehydes, hexanal and nonanal were predominant in all the samples evaluated. Increasing the germination temperature resulted in a diversification of volatiles, with an increase in acid and ester content and a reduction in alde \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**RT** & **Compounds** & **Odor Descriptors A** & **RI** & **RI Tab** & \(\Delta\) & **Identification** & \(\beta\) \\ \hline  & & & & & & & \\ \hline
7.74 & 2-pinene & Resin-like & 947 & 939 & 8 & RI, MS & 0.90 \\
8.39 & Dehydroasbiene & - & 966 & 957 & 9 & RI, MS & 0.90 \\
10.25 & 3-carene & Terpene-like & 1022 & 1017 & 5 & RI, MS & 0.90 \\
10.82 & p-cymene & Petrol-like & 1038 & 1030 & 8 & RI, MS & 0.90 \\
10.98 & Limonene & Citrus-like & 1042 & 1032 & 10 & RI, MS, STD & 0.88 \\
24.91 & trans-\(\alpha\)-bergamotene & Woody-like & 1444 & 1441 & 3 & RI, MS & 0.88 \\ \hline  & & & & & & & \\ \hline
5.63 & Ethylbenzene & Petrol-like B & 874 & 868 & 6 & RI, MS & 0.90 \\
6.47 & Styrene & Balsam-like & 906 & 895 & 11 & RI, MS & 0.90 \\
7.42 & (1-methylethyl)-benzene & Petrol-like B & 937 & 929 & 8 & RI, MS, STD & 0.90 \\
9.63 & 2-pentylfuran & Vegetable-like & 1004 & 1010 & \(-6\) & RI, MS & 0.90 \\
15.89 & 2-methyl-undecane & - & 1178 & 1167 & 11 & RI, MS & 0.64 \\
16.11 & 3-methyl-undecane & - & 1184 & 1171 & 13 & RI, MS & 0.64 \\
16.49 & Naphthalene & Smoky & 1195 & 1196 & \(-1\) & RI, MS, STD & 0.64 \\
16.86 & 1-dodecene & - & 1205 & 1192 & 13 & RI, MS & 0.64 \\
22.06 & Heptyclohexane & - & 1356 & 1345 & 11 & RI, MS & 0.64 \\
26.83 & 1-pentadecene & - & 1504 & 1494 & 10 & RI, MS & 0.90 \\
29.17 & 3-methyl-pentadecane & - & 1582 & 1566 & 16 & RI, MS & 0.90 \\ \hline  & & & & & & & \\ \hline \hline \end{tabular} RT: retention time, RI: retention index calculated, RI tab: retention index reported in the literature, MS: mass spectra, STD: identification using standard. Odor descriptors were collected from TUM (A) odorant database [40] or PubChem [41] (B).  
\end{table} 
Table 4: _Cont._ \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Compounds** & \begin{tabular}{c} **LOQ** \\ **(mg\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Linear Range** \\ **(mg\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & **Equation** & **R\({}^{2}\)** &
\begin{tabular}{c} **Precision** \\ **Intraday** \\ \end{tabular} \\ \hline
2-Heptanol & 0.54 & 0.54–16.0 & y = 920,915x \(-\) 219,377 & 0.993 & 18.0 & 14.1 \\ Cumene & 0.49 & 0.49–14.79 & y = 46,063x \(+\) 155,054 & 0.999 & 5.9 & 6.0 \\
1-Octen-3-ol & 0.48 & 0.48–14.86 & y = 700,623x \(-\) 223,938 & 0.991 & 15.1 & 9.9 \\ Octanal & 0.45 & 0.45–17.66 & y = 46,063x \(+\) 155,054 & 0.999 & 7.9 & 5.3 \\ Limonene & 0.21 & 0.21–15.06 & y = 46,801x \(+\) 127,215 & 0.991 & 12.5 & 9.0 \\ Trans-2-Octenal & 0.40 & 0.40–15.35 & y = 140,548x \(+\) 31,426 & 0.992 & 14.4 & 8.8 \\ Acetophenone & 0.41 & 0.41–14.76 & y = 671,632x \(+\) 103,442 & 0.998 & 13.1 & 7.4 \\ Naphthalene & 0.44 & 0.44–14.92 & y = 1,730,517x \(-\) 194,167 & 0.992 & 8.1 & 4.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Validation parameters for the MHE-SPME and GC-MS method. Nonanal and hexanal have also been reported in germinated chickpea, lentil, and yellow pea flours [17]. These compounds might be formed via lipoxygenase through the oxidation of FAs.