## 3 Results and Discussion
### Free Amino Acids and Ummi Flavor in Frozen and Freeze-Dried Materials  
FAAs give rise to different flavors such as umami, sourness, bitterness, and sweetness. In Figure 3, the FAAs content in both frozen and freeze-dried samples are grouped corresponding to their respective flavors [13; 37; 38; 39]. Glutamic acid had the highest concentration of FAAs in the 'umami/sour' group, followed by aspartic acid in both frozen and freeze-dried samples. Glutamic and aspartic acids are thought to impart a sour flavor, and contribute to the umami flavor in the presence of sodium salts like monosodium glutamate [40; 41]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{3}{c}{**Total Amino Acids**} & \multicolumn{3}{c}{**Free Amino Acids**} \\ \hline
**Amino Acids** & **g/100 g Dry Weight** & **g/100 g Dry Weight** & **mg/100 g Dry Weight** & **mg/100 g Dry Weight** \\  & **Frozen** & **Freeze-Dried** & **Frozen** & **Freeze-Dried** \\ \hline Alanine & 2.76 \(\pm\) 1.36 & 1.94 \(\pm\) 0.35 & 13.0 \(\pm\) 4.2 & 42.9 \(\pm\) 10.6 * \\ Asparagine & -0.01 & \textless{}0.01 & 1.0 \(\pm\) 0.6 & 3.5 \(\pm\) 3.0 * \\ Asparatic acid & 5.08 \(\pm\) 2.21 & 3.60 \(\pm\) 0.73 & 10.8 \(\pm\) 1.6 & 11.2 \(\pm\) 3.4 \\ Glutamic acid & 6.79 \(\pm\) 3.14 & 4.50 \(\pm\) 1.08 & 139.2 \(\pm\) 31.4 & 414.2 \(\pm\) 48.1 * \\ Glutamine & 0.04 \(\pm\) 0.02 * & \textless{}0.01 & 9.5 \(\pm\) 4.4 & 32.2 \(\pm\) 7.1 * \\ Glycine/Arginine & 6.07 \(\pm\) 3.02 & 8.45 \(\pm\) 2.04 & 45.8 \(\pm\) 12.4 & 257.6 \(\pm\) 57.7 * \\ Histidine & 0.48 \(\pm\) 0.21 & 0.37 \(\pm\) 0.07 & 1.8 \(\pm\) 1.0 & 9.1 \(\pm\) 2.5 * \\ Isoleucine & 1.35 \(\pm\) 0.58 & 1.00 \(\pm\) 0.25 & \textless{}1 & 1.3 \(\pm\) 0.3 * \\ Leucine & 2.65 \(\pm\) 1.16 & 1.83 \(\pm\) 0.41 & 2.0 \(\pm\) 0.9 & 3.4 \(\pm\) 0.3 * \\ Lysine & 1.81 \(\pm\) 0.80 & 1.31 \(\pm\) 0.30 & 11.8 \(\pm\) 3.3 & 36.5 \(\pm\) 12.2 * \\ Methionine & 0.72 \(\pm\) 0.34 * & 0.45 \(\pm\) 0.16 & \textless{}1 & 1.2 \(\pm\) 0.2 * \\ Phenyalalanine & 1.55 \(\pm\) 0.65 & 1.17 \(\pm\) 0.24 & 1.0 \(\pm\) 0.5 & 2.3 \(\pm\) 0.2 * \\ Serine & 2.57 \(\pm\) 1.21 * & 1.58 \(\pm\) 0.46 & 1.8 \(\pm\) 0.5 & 8.8 \(\pm\) 2.5 * \\ Threonine & 2.63 \(\pm\) 1.16 & 1.86 \(\pm\) 0.42 & 1.4 \(\pm\) 1.2 & 9.1 \(\pm\) 2.5 * \\ Tyrosine & 1.33 \(\pm\) 0.56 & 0.94 \(\pm\) 0.19 & 1.1 \(\pm\) 0.6 & 3.0 \(\pm\) 0.3 * \\ Valine & 1.82 \(\pm\) 0.78 & 1.38 \(\pm\) 0.31 & 1.6 \(\pm\) 0.9 & 2.6 \(\pm\) 0.6 * \\ \hline \hline \end{tabular}
\begin{tabular}{c c c c} \hline \hline
**TAAs** & \multicolumn{3}{c}{Tryptonian is destroyed during acid hydrolysis and is thus not detected. Cysteine, proline, and taurine are not detected in this method. Arginine/Glycine could not be separated in this method. Asparagine and glutamine are deaminated during acid hydrolysis and are therefore included in the aspartic acid and glutamic acid. * Denotes statistically significant differences of total amino acids or free amino acids between frozen and freeze-dried samples (\(p<0.05\)), using SPSS version 29.0.1.0 with independent-samples \(t\)-test (\(p<0.05\)) analysis. \\ \hline \hline \end{tabular}
\begin{tabular}{c c c c} \hline \hline
**TAAs** & \multicolumn{3}{c}{Tryptonian is destroyed during acid hydrolysis and is thus not detected. Cysteine, proline, and taurine are not detected in this method. Arginine/Glycine could not be separated in this method. Asparagine and glutamine are deaminated during acid hydrolysis and are therefore included in the aspartic acid and glutamic acid. * Denotes statistically significant differences of total amino acids or free amino acids between frozen and freeze-dried samples (\(p<0.05\)), using SPSS version 29.0.1.0 with independent-samples \(t\)-test (\(p<0.05\)) analysis. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Total amino acids (TAAs) (g/100 g dry weight) and free amino acids (FAAs) (mg/100 g dry weight) content in both frozen and freeze-dried red sea cucumber (_Parastichopus tremlus_). The frozen samples have theoretically been calculated from wet weight to dry weight.