## 3 Results and Discussion
### Monitoring the Volatile Compound Profiles in Seaweed Fermentation  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Concentration (ug/L)**} \\ \cline{2-7}  & **Unferenced** & **BS** & **SC** & **LA** & **LB** & **LC** \\ \hline
6-Methyl-5-hepten-2-one & 23.07 \(\pm\) 3.21 \({}^{\circ}\) & 47.32 \(\pm\) 4.38 \({}^{\circ}\) & nd & 114.31 \(\pm\) 7.44 \({}^{\circ}\) & 62.84 \(\pm\) 2.52 \({}^{\circ}\) & 47.43 \(\pm\) 2.14 \({}^{\circ}\) \\ \hline
3,5-Trimethyl-2-cyclohexen-1-one & 31.33 \(\pm\) 2.60 \({}^{\circ}\) & 4.57 \(\pm\) 0.08 \({}^{\circ}\) & 5.92 \(\pm\) 0.13 \({}^{\circ}\) & 7.55 \(\pm\) 1.15 \({}^{\circ}\) & 5.33 \(\pm\)0.27 \({}^{\circ}\) & 5.68 \(\pm\) 0.11 \({}^{\circ}\) \\ \hline
3,5-Octation-2-one & 47.78 \(\pm\) 1.12 \({}^{\circ}\) & 34.12 \(\pm\) 0.37 \({}^{\circ}\) & 77.71 \(\pm\) 3.92 \({}^{\circ}\) & 147.08 \(\pm\) 5.40 \({}^{\circ}\) & 48.77 \(\pm\) 3.48 \({}^{\circ}\) & 61.86 \(\pm\) 10.29 \({}^{\circ}\) \\ \hline
6-Methyl-3,5-hepten4-one & 31.68 \(\pm\) 3.58 \({}^{\circ}\) & 50.78 \(\pm\) 5.93 \({}^{\circ}\) & 33.91 \(\pm\) 1.21 \({}^{\circ}\) & 69.67 \(\pm\) 3.29 \({}^{\circ}\) & 46.88 \(\pm\) 0.57 \({}^{\circ}\) & 60.75 \(\pm\) 1.35 \({}^{\circ}\) \\ \hline
4-Ketoisophorone & 19.68 \(\pm\) 1.48 \({}^{\circ}\) & 1.08 \(\pm\) 0.22 \({}^{\circ}\) & 56.07 \(\pm\) 3.39 \({}^{\circ}\) & 11.94 \(\pm\) 2.77 \({}^{\circ}\) & nd & nd \\ \hline Propiophene & 61.68 \(\pm\) 1.12 \({}^{\circ}\) & 33.20 \(\pm\) 0.50 \({}^{\circ}\) & 61.16 \(\pm\) 3.09 \({}^{\circ}\) & nd & nd & nd \\ \hline
5-Ethyl-2(5H)-furanone & 15.33 \(\pm\) 0.33 \({}^{\circ}\) & 7.34 \(\pm\) 0.34 \({}^{\circ}\) & 18.09 \(\pm\) 0.32 \({}^{\circ}\) & 12.96 \(\pm\) 1.12 \({}^{\circ}\) & 5.81 \(\pm\) 0.28 \({}^{\circ}\) & 6.42 \(\pm\) 1.22 \({}^{\circ}\) \\ \hline trans-\(\beta\)-Ionone & nd & 36.35 \(\pm\) 0.32 & nd & nd & nd & nd \\ \hline \(\beta\)-Ionone & 211.59 \(\pm\) 3.93 \({}^{\circ}\) & 149.52 \(\pm\) 2.60 \({}^{\circ}\) & 201.70 \(\pm\) 6.00 \({}^{\circ}\) & 183.55 \(\pm\) 1.56 \({}^{\circ}\) & 147.39 \(\pm\) 3.51 \({}^{\circ}\) & 223.88 \(\pm\) 8.74 \({}^{\circ}\) \\ \hline
5,6-Epoxide-\(\beta\)-Ionone & 210.31 \(\pm\) 0.64 \({}^{\circ}\) & 114.60 \(\pm\) 2.73 \({}^{\circ}\) & 189.46 \(\pm\) 3.09 \({}^{\circ}\) & 149.01 \(\pm\) 11.20 \({}^{\circ}\) & 104.40 \(\pm\) 3.81 \({}^{\circ}\) & 143.16 \(\pm\) 11.36 \({}^{\circ}\) \\ \hline Total ketones & 738.05 \(\pm\) 38.28 \({}^{\circ}\) & 1243.98 \(\pm\) 19.14 \({}^{\circ}\) & 751.21 \(\pm\) 16.28 \({}^{\circ}\) & 706.59 \(\pm\) 25.97 \({}^{\circ}\) & 430.11 \(\pm\) 7.18 \({}^{\circ}\) & 556.47 \(\pm\) 26.58 \({}^{\circ}\) \\ \hline \multicolumn{7}{l}{**Aldehydes**} \\ \hline
3-Methylbutanal & 99.47 \(\pm\) 1.69 \({}^{\circ}\) & nd & nd & 34.47 \(\pm\) 3.47 \({}^{\circ}\) & 28.33 \(\pm\) 2.90 \({}^{\circ}\) & nd \\ \hline Hexanal & 234.47 \(\pm\) 4.27 \({}^{\circ}\) & nd & 58.38 \(\pm\) 1.21 \({}^{\circ}\) & 44.98 \(\pm\) 6.08 \({}^{\circ}\) & 20.55 \(\pm\) 1.80 \({}^{\circ}\) & 56.88 \(\pm\) 1.82 \({}^{\circ}\) \\ \hline (_E_)-2-Pentenal & 61.75 \(\pm\) 1.52 \({}^{\circ}\) & nd & 29.38 \(\pm\) 0.06 \({}^{\circ}\) & 23.20 \(\pm\) 1.52 \({}^{\circ}\) & 11.59 \(\pm\) 1.54 \({}^{\circ}\) & 22.48 \(\pm\) 0.66 \({}^{\circ}\) \\ \hline
2-Methyl-2-pentenal & 8.61 \(\pm\) 1.11 \({}^{\circ}\) & nd & nd & nd & 7.14 \(\pm\) 0.91 \({}^{\circ}\) & nd \\ \hline Heptanal & 194.50 \(\pm\) 12.07 \({}^{\circ}\) & nd & nd & 108.34 \(\pm\) 10.39 \({}^{\circ}\) & 52.29 \(\pm\) 4.77 \({}^{\circ}\) & nd \\ \hline (_E_)-2-Hexenal & 63.60 \(\pm\) 5.26 \({}^{\circ}\) & nd & nd & 45.49 \(\pm\) 3.77 \({}^{\circ}\) & 18.09 \(\pm\) 0.11 \({}^{\circ}\) & 20.88 \(\pm\) 2.13 \({}^{\circ}\) \\ \hline Furfurral & 49.72 \(\pm\) 2.77 \({}^{\circ}\) & nd & nd & 51.72 \(\pm\) 3.24 \({}^{\circ}\) & 26.02 \(\pm\) 1.51 \({}^{\circ}\) & 22.69 \(\pm\) 1.37 \({}^{\circ}\) \\ \hline
5-Methylfurfurral & 560.93 \(\pm\) 25.70 \({}^{\circ}\) & nd & 501.50 \(\pm\) 12.66 \({}^{\circ}\) & 405.88 \(\pm\) 7.23 \({}^{\circ}\) & 308.09 \(\pm\) 11.48 \({}^{\circ}\) & 321.86 \(\pm\) 11.53 \({}^{\circ}\) \\ \hline
2.4-Heptadien & 25.02 \(\pm\) 1.78 \({}^{\circ}\) & nd & 16.98 \(\pm\) 0.59 \({}^{\circ}\) & nd & nd & nd \\ \hline Safranal & 43.37 \(\pm\) 4.61 \({}^{\circ}\) & nd & 93.64 \(\pm\) 4.49 \({}^{\circ}\) & 44.26 \(\pm\) 0.76 \({}^{\circ}\) & 6.38 \(\pm\) 0.46 \({}^{\circ}\) & 1.81 \(\pm\) 0.57 \({}^{\circ}\) \\ \hline Total aldehydes & 1341.44 \(\pm\) 30.80 \({}^{\circ}\) & nd & 699.87 \(\pm\) 17.50 \({Ten aldehydes were detected in the unfermented _Ulva_ sp., including linear, branched, or unsaturated aldehydes (Table 1).