## 3 Results and Discussion
### Analysis of Volatile Compounds
** & **Odor 1** & **ODT 2** & **SBC** & **SB+L** & **BC** & **B+L** \\ \hline \multicolumn{2}{c}{**ALDEHYDES**} & & & & & & & \\
27 (F)-2-Heptenal & 18829-5  
In general, B+L had the highest concentration and number of different volatile compounds (_p_ < 0.05), especially in acids (660.46 \(\pm\) 135.75 mg/kg), esters (1804.88 \(\pm\) 274.08 mg/kg) and terpen (215.74 \(\pm\) 27.95 mg/kg). Oppositely, controls (SDC and BC) were richer in alcohols (611.27 \(\pm\) 80.37 and 488.17 \(\pm\) 72.70 mg/kg, respectively). Although it would be expected that sourdough bread had a richer aroma profile [29], in the present study we obtained less abundance of volatile compounds in SB+L and SBC breads. In that regard, sourdough is generally added at less than 50% of the flour content (Table 2) and afterwards there is a baking process, so volatile compounds from sourdough might be diluted in the end product [24]. Acids are a product of the fermentation process and are responsible for the acidification of the dough [24; 30]. Nevertheless, organic acid production during sourdough and bread-making depends on several variables, including microbial composition as well as process parameters (dough yield, fermentation time and temperature and NaCl concentration) [16; 24; 30]. In B+L samples, the dominant acids were dodecanoic acid (240.41 \(\pm\) 83.22 mg/kg) and octanoic acid (173.53 \(\pm\) 11.96 mg/kg). In fact, octanoic acid along with decanoic acid, were the major organic acids found in Cava lees (Table S1). \begin{table} \begin{tabular}{c c c c c c c c} \hline  & **Compound** & **CAS-Num.** & **Odor1** & **ODT2** & **SBC** & **SB+L** & **BC** & **B+L** \\ \hline
57 & Ethyl octanoate & 106-32-1 & fruity wine wavy sweet apricot banana & na & nd & nd & 28.72 \(\pm\) 4.55 * & 965.31 \(\pm\) 167.18 * \\  & & & brandy pear & & & & & \\
58 & Phenethyl isobutyrate & 103-48-0 & floral fruity rose tea rose peach ystery & na & nd & nd & 14.22 \(\pm\) 2.49 \\
59 & Ethyl myristate & 124-06-1 & sweet wavy violet orts & na & nd & nd & nd & 10.75 \(\pm\) 7.36 \\ \hline  & & TOTAL ESTERS & & & 75.43 \(\pm\)8.76 * & 139.14 \(\pm\)15.71 * & 47.36 \(\pm\)8.33 * & 1804.88 \(\pm\)274.08 * \\ \hline  & & & & & & & \\
60 & _a_-Teripolence & 586-62-9 & fresh woody sweet pine citrus & 20 & nd & 8.71 \(\pm\) 1.25 & nd & nd \\
61 & Vitispirane & 6696-94-4 & floral fruity & na & nd & 7.73 \(\pm\) 0.43 * & nd & 25.03 \(\pm\) 3.08 * \\
62 & (E,E)-Famesyl acetate & 4128-17-0 & oily wavy & na & nd & nd & nd & 44.88 \(\pm\) 5.60 \\
63 & dihydroxymethylenol & 18479-58-8 & fresh citrus lime & na & 2.32 \(\pm\) 0.13 & nd & nd & nd \\
64 & Bomylene & 464-17-5 & - & na & nd & nd & 37.11 \(\pm\) 6.92 & nd \\
65 & d-Nerolidid & 142-50-7 & mild floral & na & nd & nd & nd & 13.66 \(\pm\) 2.01 \\
66 & DL-Limonene & 138-86-3 & terpene camphor & 10 & 5.39 \(\pm\) 1.06 * & 9.43 \(\pm\) 4.22 * & 23.34 \(\pm\) 14.40 * & 34.02 \(\pm\) 2.30 * \\
67 & Farnesol & 4602-84-0 & mild fresh sweet indien floral angelicia & 2 & nd & nd & nd & 24.84 \(\pm\) 6.21 \\
68 & Nerolidol & 7212-44-4 & floral green wavy citrus woody & na & nd & nd & nd & 73.31 \(\pm\) 8.75 \\  & & TOTAL TERPENES & & & & & & \\ \hline  & & & & & & & & \\ \hline  & & & & & & & & \\ \end{tabular}  \