# Repurposing Olive Oil Mill Wastewater into a Valuable Ingredi for Functional Bread Production
## 2 Materials and Methods
### Quality Characteristics of Final Breads
These data highlighted the production of OOMW breads with unacceptable quality characteristics, particularly in relation to their compactness and very limited alveolation (Figure 2a). In the \(B\) process, OOMW reduced the peak height and specific volume (3.50 to 2.50 cm\({}^{3}\)/g) of the ciabatta bread, while increasing baking weight loss. However, commercial yeast improved leavening. Therefore, the biga-like developed with the help of _Saccharomyces cerevisiae_, allowing for better leavening compared to that obtained with only sourdough. Color parameters were significantly affected, with lower lightness in CTR\({}_{B}\) breads and notable a\({}^{*}\) parameter differences in the crumb (\(p<0.05\)). Image analysis of \begin{table}
\begin{tabular}{c c c c c} \hline \multicolumn{5}{c}{S Process Breads} \\ \hline \multirow{2}{*}{**Attributes**} & \multicolumn{3}{c}{**Samples**} & \multirow{2}{*}{\(p\)**Value**} \\ \cline{2-2} \cline{5-5}  & \(\mathbf{CTR_{S}}\) & & \(\mathbf{EXP_{S}\text{-}1}\) & & \(\mathbf{EXP_{S}\text{-}2}\) \\ \hline Weight loss (\%) & 14.09 \(\pm\) 0.75 \({}^{\text{a}}\) & 13.67 \(\pm\) 1.11 \({}^{\text{a}}\) & 13.27 \(\pm\) 2.15 \({}^{\text{a}}\) & 0.797 \\ Specific volume (cm\({}^{3}\)/g bread) & 2.67 \(\pm\) 0.81 \({}^{\text{a}}\) & 2.35 \(\pm\) 0.1 \({}^{\text{a}}\) & 2.16 \(\pm\) 0.25 \({}^{\text{a}}\) & 0.484 \\ Hardness (N/mm\({}^{2}\)) & 0.050 \(\pm\) 0.005 \({}^{\text{a}}\) & 0.094 \(\pm\) 0.037 \({}^{\text{a}}\) & 0.103 \(\pm\) 0.009 \({}^{\text{a}}\) & 0.055 \\ Crust & & & & \\ Lightness (L*) & 70.29 \(\pm\) 5.77 \({}^{\text{a}}\) & 71.31 \(\pm\) 1.53 \({}^{\text{a}}\) & 74.29 \(\pm\) 8.79 \({}^{\text{a}}\) & 0.721 \\ Redness (a*) & 16.11 \(\pm\) 1.92 \({}^{\text{b}}\) & 7.68 \(\pm\) 3.58 \({}^{\text{b}}\) & 3.69 \(\pm\) 0.71 \({}^{\text{a}}\) & 0.002 \\ Yellowness (b*) & 32.16 \(\pm\) 2.88 \({}^{\text{a}}\) & 28.89 \(\pm\) 1.32 \({}^{\text{a}}\) & 26.42 \(\pm\) 4.09 \({}^{\text{a}}\) & 0.139 \\ Crumb & & & & \\ Lightness (L*) & 71.31 \(\pm\) 1.54 \({}^{\text{a}}\) & 73.57 \(\pm\) 3.17 \({}^{\text{a}}\) & 74.84 \(\pm\) 2.83 \({}^{\text{a}}\) & 0.315 \\ Redness (a*) & \(-\)1.83 \(\pm\) 0.19 \({}^{\text{c}}\) & 1.30 \(\pm\) 0.31 \({}^{\text{b}}\) & 2.77 \(\pm\) 0.35 \({}^{\text{a}}\) & \textless{}0.0001 \\ Yellowness (b*) & 20.81 \(\pm\) 0.93 \({}^{\text{a}}\) & 20.28 \(\pm\) 0.96 \({}^{\text{a}}\) & 19.06 \(\pm\) 1.21 \({}^{\text{a}}\) & 0.189 \\ Void fraction (\%) & 32.55 \(\pm\) 6.40 \({}^{\text{b}}\) & 42.44 \(\pm\) 2.92 \({}^{\text{ab}}\) & 44.65 \(\pm\) 4.66 \({}^{\text{a}}\) & 0.044 \\ Cell density (n/cm\({}^{2}\)) & 121.8 \(\pm\) 63.41 \({}^{\text{a}}\) & 198.87 \(\pm\) 38.47 \({}^{\text{a}}\) & 240.33 \(\pm\) 35.86 \({}^{\text{a}}\) & 0.057 \\ Mean cell area (mm\({}^{2}\)) & 0.30 \(\pm\) 0.14 \({}^{\text{a}}\) & 0.21 \(\pm\) 0.069 \({}^{\text{a}}\) & 0.16 \(\pm\) 0.037 \({}^{\text{a}}\) & 0.250 \\ \hline \multicolumn{5}{c}{\(B\) Process Breads} \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Weight loss (\%) \\ Specific volume (cm\({}^{3}\)/g bread) \\ Hardness (N/mm\({}^{2}\)) \\ Crust \\ Lightness (L*) \\ Redness (a*) \\ Yellowness (b*) \\ Yellowness (b*) \\ Lightness (L*) \\ Yellowness (b*) \\ Lightness (b*) \\ Lightness (L*) \\ Yellowness (a*) \\ Yellowness (b*) \\ Yellowness (b*) \\ Void fraction (\%) \\ Cell density (n/cm\({}^{2}\)) \\ Cell density (n/cm\({}^{2}\)) \\ Mean cell area (mm\({}^{2}\)) \\ 0.42 \(\pm\) 0.25 \({}^{\text{a}}\) & 0.30 \(\pm\) 0.90 \({}^{\text{a}}\) & 0.27 \(\pm\) 0.061 \({}^{\text{a}}\) & 0.938 \\ \hline \end{tabular}
\end{table} 
Table 5: Quality of breads. the central slices of the breads revealed differences between the CTR\({}_{B}\) breads and those containing OOMW across all three alveolation-related parameters. This analysis showed higher void fraction and alveolar area in \(B\) process breads due to yeast (Figure 2b). Given the better quality in the \(B\) process breads, further analyses focused on CTR\({}_{B}\), EXP\({}_{B}\)-1, and EXP\({}_{B}\)-2 breads.