## 3 Results and Discussion
### Arthospira Plateensis Fermentation
For each volatile compound’s aromatic note, calculated and tabulated linear retention indices (LSIs), references and effect given by treatments, stabilization and fermentation (statistical difference = positive = p; no statistical difference = negative = n; not determinable = nd) are reported. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Chemical Class, Compound** & **Odor Type** & **Calculated LRI** & **Reference LRI** & \begin{tabular}{c} **Identification** \\ **Method** \\ \end{tabular} & **Reference** & \
\begin{tabular}{c} **Effect of** \\ **Stabilization** \\ \end{tabular} &
\begin{tabular}{c} **Effect of** \\ **Fementiation** \\ \end{tabular} \\ \hline _Alcohals_ & & & & & & & \\
1-Pentanol & fermented & 1239 & 1260 & MS + LRI & [55] & p & n \\
1-Hexanol & herbal & 1341 & 1337 & MS + LRI & [61] & p & n \\
1-Octen-3-ol & earthy & 1437 & 1455 & MS + LRI & [55] & p & n \\ Benzyl alcohol & floral & 1882 & 1896 & MS + LRI & [61] & n & n \\ \hline _Fanars_ & & & & & & \\
3-Methylfuran & chocolate & 853 & 876 & MS + LRI & [52] & p & p \\
3-Methylfuran & & 881 & 877 & MS + LRI & [53] & n & n \\
2-Butylfuran & spicy & 1123 & 1140 & MS + LRI & [65] & p & p \\
2-Pentyman & fruity & 1220 & 1232 & MS + LRI & [64] & p & n \\ _Hydrocarbons_ & & & & & & \\
1.2,4-A-Tetramethyllycopmente & & 920 & MS & n & n & n \\
2.4,6-Pententrychlycopmente & & 944 & MS & n & n & n \\
2.4,6-Pententrychlyheptane & & 1119 & 1127 & MS + LRI & [66] & n & n \\ Tridenene & alkane & 1300 & 1300 & MS + LRI & [56] & p & p \\ Tetradecane & wavy/alkane & 1396 & 1400 & MS + LRI & [56] & p & p \\
2.6,10-Trimethylridecane & & 1434 & 1442 & MS + LRI & [53] & n & n \\ Pentadecane & wavy & 1492 & 1500 & MS + LRI & [56] & p & p \\ Hexadecane & alkane & 1590 & 1600 & MS + LRI & [56] & p & p \\ N-acetyl+4(H)-Pyridine & & 1644 & MS & p & p & p \\ Heptedacane & alkane & 1687 & 1700 & MS + LRI & [56] & p & p \\
6-B-Heptedacadiene & & 1743 & & & & & p \\ \hline _Pyrains_ & & & & & & & \\
2-Methylpyrazolezine & nutty & 1267 & 1267 & MS + LRI & [52] & n & n \\
2-S-methylpyrazolezine & chocolate & 1318 & 1321 & MS + LRI & [52] & p & n \\
2-Methyl-5-ethylpyrazolezine & coffee & 1368 & 1406 & MS + LRI & [52] & n & n \\
2-Ethyl-6+methylpyridine & potato & 1383 & 1402 & MS + LRI & [52] & p & p \\ Timmethyl pyrazine & nutty & 1398 & 1401 & MS + LRI & [52] & p & p \\
2-Dimethyl-5-ethylpyrazine & burnt & 1452 & 1460 & MS + LRI & [53] & p & n \\ Tetramethyl pyrazine & nutty & 1468 & 1474 & MS + LRI & [52] & p & n \\ \hline _Salifer_ compounds & & & & & & & \\ Dimethyl disulfide & sulfurous & 1063 & 1073 & MS + LRI & [54] & p & n \\
2-Ethyl-4-methylthiazol & nutty & 1336 & 1322 & MS + LRI & [52] & n & n \\ Dimethyl trisulfide & allianceous & 1369 & 1375 & MS + LRI & [54] & n & n \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cott._Pentadecane, hexadecane and heptadecane are hydrocarbons derived from the decarboxylation of palmitic and stearic acids, respectively [29; 67], and they were the most representative among all of the hydrocarbons identified in this work. In particular, heptadecane was the volatile found in the highest amount in all of the considered samples as observed in a recent study focused on the fermentation of spirulina using _Lacticaseibacillus plantarum_ and _Bacillus subtilis_[30]. The presence of this compound could contribute to the off-flavor of algae associated with crude fish notes, despite the fact that it presents a high odor threshold [29]. Heptadecane was significantly lower in the sterilized samples when compared to the UV-treated ones, despite the fact that the fermentation process seemed to increase its concentration in both cases; indeed, both considered factors, stabilization treatment (\(p<0.001\)) and fermentation (\(p=0.006\)), appeared to influence its release/formation. In other studies considering _L. plantarum_ and _B. subtilis_, the fermentation caused a 27% reduction in the relative content of heptadecane, but no information regarding the actual quantity found in the samples was reported [30].