## 3 Results
### Volatiles Bouquet in the Headspace Emissions of the Cooked Breads  
A total of 58 volatiles were identified among those spontaneously emitted by the bread samples, whole and sliced, accounting for 95.9-99.9% of total emission (data shown in the Supplementary Material, Table S1). Volatiles were classified into four main chemical classes, among which non-terpene derivatives clearly prevailed (88.3-99.1%). Nitrogen derivatives, pyrroles, and pyrazines were mainly emitted when the highest percentage of flaxseed cake was added. As a result of their high percentages, non-terpene derivatives were further divided into chemical subclasses. Carboxylic acids, in particular acetic acid, characterized the emission of sourdough samples, mainly when flaxseed cake was absent or in small percentages. Conversely, non-terpene alcohol/ethers were emitted by brewer's yeast samples. Even if with more marked differences, a similar behavior was observed for non-terpene esters. Non-terpene aldehydes/ketones were detected in quite high percentages in all the samples, while non-terpene hydrocarbons were always present in smaller amounts. For the volatile aroma compounds, it is clearly apparent from the HCA dendrogram (Figure 3) that the breads made only from wheat flour are placed in two different clusters on the basis of the adopted leavening agent used (brewer's yeast or sourdough), indicating that the type of leavening agent had a strong influence on the aroma. This is true for both the whole bread and the corresponding sliced samples. \begin{table} \begin{tabular}{c c c c c c c c c c} \hline \hline  & \(p\)-Value1  & SEM & \(SB0\) & \(SB5\) & \(SB7.5\) & \(SB10\) & YB0 & YB5 & YB7.5 & YB10 \\ \hline
**Total phenols** & \({}^{\star}\)/SSS/T11  & 0.073 & _0.481_  & _0.671_  & _0.032_  & _1.041_  & 0.301  & 0.586  & 0.833  & 1.212  \\
**(mg CAE/g dm)** & \({}^{\star}\)/SSS/T11  & 0.039 & _0.083_  & _0.165_  & _0.216_  & _0.241_  & 0.075  & 0.183  & 0.226  & 0.303  \\
**DPPII** & \({}^{\star}\)/SSS/n.s. & 0.186 & _0.505_ & _1.734_ & _2.329_ & _2.826_ & 0.361 & 1.657 & 2.283 & 2.710 \\
**TEAC** & n.s/SSS/T1  & 0.087 & _0.259_  & _0.760_  & _1.258_  & _1.522_  & 0.348  & 0.606  & 1.242  & 1.545  \\
**(g/100 g of fatty acids)** & \({}^{\star}\)/SSS/T1  & 0.81 & _20.46_  & 17.43  & 17.74  & 13.66  & 20.01  & 18.74  & 18.58  & 16.06  \\
**MMEA (g/100 g fatty acids)** & n.s/SSS/T11  & 1.00 & _10.57_  & _10.40_  & _15.26_  & 16.41  & 8.43  & 11.76  & 13.61  & 23.24  \\
**PUFA n-6 (g/100 g of fatty acids)** & n.s/SSS/N.s. & 1.54 & 63.32 & 57.63 & 48.27 & 45.23 & 67.03 & 57.26 & 50.07 & 37.73 \\ PUFA n-3 (g/100 g of fatty acids)** & \({}^{\star}\)/SSS/T11  & 0.50 & 3.79  & _19.18_  & _18.12_  & 23.98  & 3.80  & 11.33  & 17.21  & 22.34  \\
**PUFA/SFA** & n.s/s./s./n.s. & 0.56 & _3.28_ & _4.41_ & _3.74_ & _5.07_ & 3.54 & 3.66 & 3.62 & 3.74 \\
**n-6/n-3** & n.s/SSS/N.s. & 0.48 & _16.81_ & _3.01_ & _2.66_ & _1.89_ & 17.64 & 5.05 & 2.94 & 1.69 \\ \hline \hline \end{tabular}   
* Notes: 1 Significance level \({}^{\star}\)/SSS/T11  1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] & _1.001_  1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] 1: footnotemark: [ENDFOOTNOTE] & _1.00_ [FOOTNOTE:1]FootnoteThe adding of flaxseed cake to the dough permitted grouping the samples, within each subgroup, on the basis of the percentage adopted, regardless of whether whole or sliced bread was considered. In this discussion, the only exceptions are represented by breads produced with baker's yeasts and 5% or 7.5% flaxseed cake in the recipe. In these conditions, indeed, the whole and the sliced samples cluster differently, regardless of the flaxseed cake percentage.