## 3 Results and Discussion
### Analysis of Volatile Compounds
\begin{tabular}{c c c c c c c c} \hline  & **MISCELANEOUS** & & & & & & & \\ \multirow{-2}{*}{69} & 2-Pently-furan & 3777-69-3 & earthly been vegetable metallic & 6 & 22.82 \(\pm\) 1.11 * & 59.05 \(\pm\) 9.20 * & 54.47 \(\pm\) 6.62 * & 46.31 \(\pm\) 6.37 * \\  & & & sweet woody almond & & & & & \\ \multirow{-2}{*}{70} & \multirow{-2}{*}{71} & \multirow{-2}{*}{72} & \multirow{-2}{*}{98-01-1} & sweet woody almond & & & & & \\  & & fragment baked bread & na & 6.20 \(\pm\) 3.68 * & 6.45 \(\pm\) 0.91 * & nd & 19.55 \(\pm\) 8.56 * \\  & & & & & & & \\ \multirow{-2}{*}{71} & \multirow{-2}{*}{dihydrophalence (TION)} & \multirow{-2}{*}{30364-38-6} & \multirow{-2}{*}{licorice} & na & nd & 43.95 \(\pm\) 16.26 * & nd & 196.29 \(\pm\) 34.35 * \\  & & & & & & & & \\ \multirow{-2}{*}{72} & \multirow{-2}{*}{4-Ethylguanicol} & \multirow{-2}{*}{2785-89-9} & \multirow{-2}{*}{spicy smy backon phenolic clove} & & & & & \\  & & swerb baslan & & & & & \\ \multirow{-2}{*}{73} & \multirow{-2}{*}{Styrene} & \multirow{-2}{*}{100-42-5} & sweet basalan & & & & & \\  & & floral plastic & & & & & \\ \multirow{-2}{*}{74} & \multirow{-2}{*}{\(\gamma\)-Nonalactone} & \multirow{-2}{*}{104-61-0} & coconut creamy wavy sweet battery alloy & na & nd & nd & 15.80 \(\pm\) 7.79 * & 15.10 \(\pm\) 4.86 * \\ \cline{2-2}  & \multicolumn{2}{c}{TOTAL MSCIELANEOUS} & & & & & & \\ \hline  & & & & & & & & \\ \end{tabular} 
\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 & & & & & \\ \multirow{-2}{*}{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 & 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  & & & & & & & \\ \multirow{-2}{*}{60} & \multirow{-2}{*}{\(\alpha\)-Teripolence} & \multirow{-2}{*}{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 * \\  & & & earthy woody & na & nd & nd & 44.88 \(\pm\) 5.60 \\
62 & (E,E)-Famesyl acetate & 4128-17-0 & oily wavy & na & nd & nd & 44.88 \(\pm\) 5.60 \\
63 & dihydroxymethylenol & 18479-58-8 & fresh citrus lime & na & 2.32 \(\pm\) 0.13 & nd & nd \\
64 & Bomylene & 464-17-5 & - & na & nd & nd & 37.11 \(\pm\) 6.92 & nd \\
65 & d-Nerolidolid & 142-50-7 & mild floral & na & nd & nd & 13.66 \(\pm\) 2.01 \\
66 & DL-Limonene & 138-86-3 & terpene camphor & 10 & 5.39 \(\pm\) 1.06 * & 9.43 \(\pm\)Octanoic acid was also found in SBC and BC samples, and its production is related to yeast [24]. Control breads with and without sourdough (SBC and BC) presented no significant differences in organic acid concentration (\(p<0.05\)). Furthermore, SBC and BC breads had the highest concentration of acetic acid (143.83 \(\pm\) 1.63 and 132.04 \(\pm\) 0.06 mg/kg, respectively). In fact, acetic acid is one of the main organic acids responsible form microbiological shelf-life extension since it also possesses antiripeness and antimold activity [20; 30]. Moreover, acetic acid is thought to inhibit yeast growth [25], which can be related to the lower yeast cell density obtained in SBC and BC breads (Figure 2). Alcohols are mainly produced during fermentation from flour amino acids via the Ehrlich pathway in yeast cells but may be also a product of lipid oxidation [20]. SBC showed the highest concentration of alcohols (\(p<0.05\)). The dominant alcohols in all bread samples were phenethyl alcohol and isoamyl alcohol. Phenethyl alcohol is derived from the fermentation of phenylalanine by yeast, and it has been reported that prolonged fermentations increase its concentration [20; 31].