# Changes in the Volatile Profile of Wheat Sourdough Produced with the Addition of Cava [PERSON]
## 2 Results
### Analysis of Volatile Compounds in Different Sourdough Samples
#### 2.2.4 Esters
\begin{tabular}{c c c c c c c c c} \hline \hline  & **Compound** & **CAS Num.** & **Odor 1** & **ODT 2** & **Cava Lees** & \multicolumn{4}{c}{**Soundough**} \\ \cline{6-10}  & 9 & Acetic acid & 64-19-7 & pungent, sour & na & 32.58 \(\pm\) 1.24 & 66.08 \(\pm\) 9.99 \({}^{\circ}\) & 13.21 \(\pm\) 4.61 \({}^{\circ}\) & 168.78 \(\pm\) 7.84 \({}^{\circ}\) & 246.10 \(\pm\) 1.64 \({}^{\circ}\) \\
10 & Butanoic acid & 107-92.6 & sewed, rancid & 240 & nd & 269.41 \(\pm\) 9.36 \({}^{\circ}\) & 80.43 \(\pm\) 14.13 \({}^{\circ}\) & 29.55 \(\pm\) 2.46 \({}^{\circ}\) & 4 \\
11 & Pentranco acid & 109-52-4 & - & 3000 & nd & 61.88 \(\pm\) 2.04 & nd & nd & nd \\
12 & Hexanoic acid & 142-62-1 & - & 3000 & nd & 55.56 \(\pm\) 2.09 \({}^{\circ}\) & 31.60 \(\pm\) 9.88 \({}^{\circ}\) & 32.39 \(\pm\) 3.08 \({}^{\circ}\) & 41.73 \(\pm\) 5.97 \({}^{\circ}\) \\
13 & Heptonic acid & 111-14-8 & 3000 & nd & 8.28 \(\pm\) 1.23 \({}^{\circ}\) & nd & & & \\
14 & Octanoic acid & 124-07-2 & old, rancid & 3000 & 49.45 \(\pm\) 4.98 & 8.72 \(\pm\) 3.18 \({}^{\circ}\) & 48.00 \(\pm\) 22.33 \({}^{\circ}\) & 135.98 \(\pm\) 3.91 \({}^{\circ}\) & 253.58 \(\pm\) 2.26 \({}^{\circ}\) \\
15 & Nonanoic acid & 112-05-0 & fatty, mid, rancid & 3000 & 49.38 \(\pm\) 4.98 & 8.72 \(\pm\) 3.18 \({}^{\circ}\) & 48.00 \(\pm\) 22.33 \({}^{\circ}\) & 135.98 \(\pm\) 3.91 \({}^{\circ}\) & 253.68 \(\pm\) 2.26 \({}^{\circ}\) \\
16 & Decanoic acid & 112-05-0 & fatty, mid, rancid & 3000 & 49.38 \(\pm\) 3.08 \({}^{\circ}\) & 17.78 \(\pm\) 3.17 \({}^{\circ}\) & 28.21 \(\pm\) 5.18 \({}^{\circ}\) & 40.99 \(\pm\) 1.93 \({}^{\circ}\) \\
16 & Decanoic acid & 334-85-5 & sour, fatty & 10,000 & 31.68 \(\pm\) 5.84 & nd & 23.27 \(\pm\) 1.14 \({}^{\circ}\) & 85.70 \(\pm\) 11.43 \({}^{\circ}\) & 209.27 \(\pm\) 4.98 \({}^{\circ}\) \\
17 & Benzoic acid & 1863-63-6 & n & nd & 1.33 \(\pm\) 0.05 \({}^{\circ}\) & 6.61 \(\pm\) 0.33 \({}^{\circ}\) & 1.50 \(\pm\) 0.02 \({}^{\circ}\) & 25.16 \(\pm\) 0.04 \({}^{\circ}\) \\
18 & Tetrafaceonic acid & 544-63-8 & waxy, oility, faint & 10,000 & nd & 5.55 \(\pm\) 0.17 \({}^{\circ}\) & nd & 11.37 \(\pm\) 1.36 \({}^{\circ}\) & 29.36 \(\pm\) 4.98 \({}^{\circ}\) \\
19 & Headacanoic acid & 57-10-3 & - & 10,000 & 29.62 \(\pm\) 2.39 & 8.57 \(\pm\) 5.82 \({}^{\circ}\) & 52.63 \(\pm\) 3.13 \({}^{\circ}\) & 74.79 \(\pm\) 1.20 \({}^{\circ}\) & 164.35 \(\pm\) 1.07 \({}^{\circ}\) \\
20 & Octadecanot & 57-11-4 & - & 20,000 & 49.62 \(\pm\) 2.39 & 8.57 \(\pm\) 5.82 \({}^{\circ}\) & 52.63 \(\pm\) 3.13 \({}^{\circ}\) & 74.79 \(\pm\) 1.20 \({}^{\circ}\) & 164.35 \(\pm\) 1.07 \({}^{\circ}\) \\ \hline \hline \end{tabular}   
* From [25], \({}^{\circ}\)OT: Older Detection Threshold (in water) from [24], Expressed a mg/kg, Values are mean \  
The results obtained were subjected to a PCA to group the different sourdoughs produced based on their similarities or differences in the volatile fraction. Figure 4 shows the result of a previous correlation analysis and Figure 5 presents the PCA biplot obtained. It can be observed that, in general, most compounds had a positive correlation between them, except for the SCFAs (butanoic, pentanoic and hexanoic acids) and heptanoic acid (Figure 4). These compounds were also the ones that characterized the control sourdoughs (Figure 5). Indeed, samples were grouped according to the concentration of Cava lees added to the formulation. The PC1 and PC2 explained 84.40% of the total variability. The first principal component (PC1) explained 75.26% of the samples variances while the second one (PC2) explained 9.15%. All volatile compounds were found on the positive side of PC1, except for butanoic, pentanoic, hexanoic, and heptanoic acids (short- and medium-chain fatty acids), and 2-undecanone (ketone) and (E)-2-Octenal (aldehyde). These compounds were considered to characterize the control and 0.5% Cava lees sourdoughs. On the other hand, it can be observed that the sourdoughs with 1% and 2% Cava lees had the highest concentrations of all volatile compounds, especially esters.