## 4 Discussion  
### Nutritional Profile  
Octopus is a good source of essential nutrients with a genuine sensorial profile. In this study, we focused on common octopus (_Octopus vulgaris_) captured by the Portuguese small-scale fishing fleet of the Algarve. The obtained proximal composition of octopus agrees with other authors [32,33]. This cephalopod has a high protein content (16-17 g/100 g) and an excellent profile of amino acids, with glutamic acid (>2 g/100 g) being the most abundant. When considering the origin of the octopus, windward vs. leeward, respectively, significant differences in the content of sodium (0.35-0.5 g/100 g), salt (0.9-1.2 g/100 g), and energetic value (75.5 to \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Vitamins and Minerals** & \begin{tabular}{c} **Nutrient Reference** \\ **Value (NRV)** \\ \end{tabular} & \begin{tabular}{c} **Significant Amount** \\ **15\%/100 g/mL** \\ \end{tabular} & \begin{tabular}{c} **Significant** \\ **Amount 30\%** \\ \end{tabular} & \
\begin{tabular}{c} **Octopus** \\ **Windward** \\ \end{tabular} &
\begin{tabular}{c} **Octopus** \\ **Leeward** \\ \end{tabular} \\ \hline \multicolumn{5}{c}{**Rich In**} & **High Content In** & **Average** & **Average** \\ \hline Thiamin-B1 (mg) & 1.1 & 0.165 & 0.33 & \textless{}0.015 & \textless{}0.015 \\ Riboflavin-B2 (mg) & 1.4 & 0.21 & 0.42 & 0.03 & 0.03 \\ Niacin-B3 (mg) & 16 & 2.4 & 4.8 & 1.74 & 1.56 \\ Piridoxin-B6 (mg) & 1.4 & 0.21 & 0.42 & 0.07 & 0.06 \\ Biotin-B8 (\(\upmu\)g) & 50 & 7.5 & 15 & 8.15 & 6.63 \\ Folic acid-B9 (\(\upmu\)g) & 200 & 30 & 60 & \textless{}5 & \textless{}5 \\ Cyanocobalamin-B12 (\(\upmu\)g) & 2.5 & 0.375 & 0.75 & 1.20 & 1.05 \\ Pantothenic acid-B5 (mg) & 6 & 0.9 & 1.8 & 0.39 & 0.31 \\ Vitamin E (mg) & 12 & 1.8 & 3.6 & 1.5 & 1.05 \\ Magnesium (mg) & 375 & 56.25 & 112.5 & 59 & 67 \\ Zinc (mg) & 10 & 1.5 & 3 & 1.47 & 1.33 \\ Copper (mg) & 1 & 0.15 & 0.3 & 0.37 & 0.22 \\ Selenium (\(\upmu\)g) & 55 & 8.25 & 16.5 & 26 & 26 \\ Ca (mg) & 800 & 120 & 240 & 18 & 18.5 \\ Iodine (micro) & 150 & 22.5 & 45 & 9.5 & 8.15 \\ Potassium (mg) & 2000 & 300 & 600 & 277 & 263 \\ Phosphorus (mg) & 700 & 105 & 210 & 164 & 158 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Results of minerals or vitamins obtained in windward and leeward common octopus (_Octopus vulgaris_); the nutrient reference value (NRV); the value calculated to be able to label as “rich in” and as “high content in”. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Octopus vulgaris** & \multicolumn{2}{c}{**Windward**} & \multicolumn{2}{c}{**Leeward**} \\ \hline
**Minerals and Vitamins** & **Average** & **SEM** & **Average** & **SEM** \\ \hline Se (mg/kg) & 0.26 & 0.01 & 0.26 & 0.02 \\ K (mg/100 g) & 262.7 & 17.1 & 277.0 & 17.2 \\ Zn (mg/kg) & 13.3 & 0.38 & 14.7 & 0.35 \\ P (mg/100 g) & 157.7 & 12.99 & 164.0 & 11.9 \\ Mg (mg/kg) & 673.3 & 60.1 & 590.7 & 6.36 \\ Ca (mg/100 g) & 18.5 & 2.5 & 18.0 & 1.0 \\ I (mg/kg) & 0.08 & 0.02 & 0.1 & 0.001 \\ Cu (mg/kg) & 2.17 & 0.35 & 3.73 & 0.55 \\ Thiamin-B1 (mg) & \textless{}0.015 & 0.0 & \textless{}0.015 & 0.0 \\ Riboflavin-B2 (mg) & 0.03 & 0.0 & 0.03 & 0.0 \\ Niacin-B3 (mg) & 1.56 & 0.17 & 1.74 & 0.05 \\ Pantothenic acid-B5 (mg) & 0.31 & 0.0 & 0.39 & 0.0 \\ Piridoxin-B6 (mg) & 0.06 & 0.0 & 0.07 & 0.0 \\ Biotin-B8 (\(\upmu\)g) & 6.63 & 3.08 & 8.15 & 0.61 \\ Folic acid-B9 (\(\upmu\)g) & \textless{}5 & 0.0 & \textless{}5 & 0.0 \\ Cyanocobalalmin-B12 (\(\upmu\)g) & 1.05 & 0.3 & 1.20 & 0.26 \\ Vitamin E (mg) & 1.05 & 0.35 & 1.50 & 0.40 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Results of vitamins and minerals analyzed in leeward and downward common octopus (_Octopus vulgaris_). Average \(\pm\) SEM (_n_ = 2/3 samples). 64.7 Kcal/100 g) were found. This result is probably due to the different habitats in which the octopuses live, two geographically distinct areas. Indeed, the leeward region of the Algarve is predominantly composed of sandy substrates, and the windward region of the Algarve is dominated by erosional landforms [34].