## 3 Results and Discussions
### Analysis of Volatile Compounds of Biscuit Samples
Therefore, the  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Volatile Compounds**} & **RT (Retention** & \multicolumn{4}{c}{**Biscuit Samples \({}^{\star}\)**} & \multirow{2}{*}{**Aroma Characteristics \({}^{\star\star}\)**} \\ \cline{3-3} \cline{5-6}  & **Time, min)** & & & & & \\ \hline \multicolumn{6}{c}{Alcohols} \\ \hline Phenol & 15.65 & 1.83 \(\pm\) 0.03 b  & 1.8 \(\pm\) 0.02 b  & 1.13 \(\pm\) 0.03 a  & 3.63 \(\pm\) 0.04 c  & Phenol \\ \hline \multicolumn{6}{c}{Aldehydes} \\ \hline Hexanal & 6.07 & 18.39 \(\pm\) 0.05 c  & 14.76 \(\pm\) 0.12 a  & 15.35 \(\pm\) 0.22 a  & 16.36 \(\pm\) 0.03 b  & Grass, fallow, fat \\ Heptanal & 11.926 & 0.63 \(\pm\) 0.02 b  & 0.19 \(\pm\) 0.02 a  & 0.98 \(\pm\) 0.04 c  & 1.12 \(\pm\) 0.07 c  & Fat, citrus \\ \multicolumn{6}{c}{Catanal} & 16.506 & 0.97 \(\pm\) 0.03 a  & 0.87 \(\pm\) 0.06 a  & 1.20 \(\pm\) 0.05 b  & 1.46 \(\pm\) 0.04 c  & Lemon, green \\ \multicolumn{6}{c}{Lemon, green} \\ Nonanal & 19.74 & 5.13 \(\pm\) 0.22 c  & 3.12 \(\pm\) 0.11 b  & 1.69 \(\pm\) 0.05 a  & 2.99 \(\pm\) 0.03 b  & Fat, citrus, green \\ \multicolumn{6}{c}{Benzaldehyde} & 14.744 & 2.40 \(\pm\) 0.03 a  & 5.08 \(\pm\) 0.21 b  & 7.18 \(\pm\) 0.33 c  & 8.82 \(\pm\) 0.03 c  & Almond, burnt sugar \\ \multicolumn{6}{c}{Decanal} & 22.412 & 0.59 \(\pm\) 0.04 b  & 0.45 \(\pm\) 0.02 a  & 0.62 \(\pm\) 0.03 b  & 0.90 \(\pm\) 0.02 c  & Orange peel, tallow \\ \hline \hline \multicolumn{6}{c}{Ketones} \\ \hline Heptan-2-one & 11.167 & 0.89 \(\pm\) 0.04 a  & 1.13 \(\pm\) 0.02 a  & 3.82 \(\pm\) 0.06 b  & 4.22 \(\pm\) 0.08 b  & green banana, with a \\ \multicolumn{6}{c}{Acetophenone} & 18.524 & 2.50 \(\pm\) 0.03 a  & 5.02 \(\pm\) 0.02 b  & 8.69 \(\pm\) 0.06 c  & 10.98 \(\pm\) 0.02 d  & Must, flower, almond \\ \multicolumn{6}{c}{Nonan-2-one} & 19.341 & 1.59 \(\pm\) 0.02 b  & 1.44 \(\pm\) 0.03 b  & 0.53 \(\pm\) 0.05 a  & 1.70 \(\pm\) 0.04 b  & Freuity, sweet, waxy, \\ \multicolumn{6}{c}{Benzophenone} & 31.223 & 1.26 \(\pm\) 0.04 c  & 0.72 \(\pm\) 0.06 b  & 0.91 \(\pm\) 0.03 b  & 0.44 \(\pm\) 0.05 a  & Balsamic \\ \hline \multicolumn{6}{c}{Terpenes and terpenoids} \\ \hline \(\beta\)-Myrcene & 15.951 & 8.99 \(\pm\) 0.17 a  & 10.77 \(\pm\) 0.23 a  & 12.79 \(\pm\) 0.31 b  & 15.65 \(\pm\) 0.22 c  & Balsamic, must, spice \\ \multicolumn{6}{c}{D-Limonene} & 17.323 & 2.47 \(\pm\) 0.03 a  & 4.28 \(\pm\) 0.04 b  & 6.14 \(\pm\) 0.07 c  & 8.48 \(\pm\) 0.03 d  & Citrus, mint \\ \hline \multicolumn{6}{c}{Acids} \\ \hline Benzoic acid & 21.232 & 9.62 \(\pm\) 0.02 c  & 5.91 \(\pm\) 0.03 b  & 7.15 \(\pm\) 0.07 b  & 3.02 \(\pm\) 0.03 a  & Balsamic \\ \multicolumn{6}{c}{Dodecanoic acid} & 29.711 & 2.47 \(\pm\significant differences (\(p<0.05\)) between benzaldehyde sample amounts, could be justified by the chemical composition of flaxseed and by lipid oxidation. It is worth nothing that non-enzymatic Maillard reactions such as the Strecker degradation process could lead to the formation of aldehydes as a result of the reaction of aminoacids with dehydrodetotones [54]. Overall, the increased RFSF percentages during biscuits manufacturing, led to significant differences (\(p<0.05\)) between aroma volatile compounds, mainly due to the rich chemical composition in lipids, protein, aminoacids, phenols and chemical reactions such as Maillard and lipid oxidation.