## 3 Results
### Nutritional Composition and Bioactivity
#### 3.4.2 Total Phenolic Compounds and Antioxidant Activity  
In recent years, there has been a growing interest in phenolic compounds derived from algae due to their antioxidant, antimicrobial, and immunomodulatory properties [38; 62; 63; 64]. [PERSON] et al. [4] demonstrated their potential in addressing cardiovascular disease and diabetes, while [PERSON] et al. [65] emphasised their antioxidant potential. Despite these promising results, it is important to assess the biological activity of the phenolic compounds within the food matrix and evaluate their stability during baking. In this study, the addition of microalgae to bread formulations significantly increased (\(p<0.05\)) the total phenolic compounds (TPC) and antioxidant capacity (FRAP and DPPH) (Figure 4). _T. chuii_ bread presented the highest phenolic content (38.52 ug GAE/g), followed by _P. tricornutum_ (32.38 ug GAE/g) and _C. vulgaris_ (17.94 ug GAE/g) (Figure 4a). These results are consistent with the findings of [PERSON] et al. [26], who characterised the nutritional profile and bioactivity of _C. vulgaris_ and _T. chuii_ biomasses used in the present study, indicating the exceptionally high phenolic content of the _T. chuii_ biomass. In a study conducted by [PERSON] et al. [22], a comparable trend was identified, indicating that, upon incorporation into gluten-free bread, _T. chuii_ exhibited a greater phenolic content than _C. vulgaris_. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & \multicolumn{5}{c}{**Major Minerals (mg/100 g)**} \\ \cline{2-6}  & **Na** & **K** & **Ca** & **Mg** & **P** & **S** \\ \hline Control & 166.40 \(\pm\) 0.45 d  & 111.97 \(\pm\) 0.61 d  & 9.56 \(\pm\) 0.07 d  & 12.27 \(\pm\) 0.24 d  & 60.63 \(\pm\) 0.87 d  & 58.27 \(\pm\) 0.27 d  \\ Cv & 208.36 \(\pm\) 1.31 c  & 132.73 \(\pm\) 1.91 c  & 11.07 \(\pm\) 0.30 c  & 14.05 \(\pm\) 0.06 c  & 74.28 \(\pm\) 1.24 a  & 72.50 \(\pm\) 1.08 c  \\ Pt & 281.18 \(\pm\) 2.19 a  & 186.62 \(\pm\) 1.05 a  & 18.33 \(\pm\) 0.65 b  & 25.10 \(\pm\) 0.44 a  & 66.82 \(\pm\) 0.67 b  & 112.53 \(\pm\) 1.41 a  \\ Tc & 260.05 \(\pm\) 1.28 b  & 141.01 \(\pm\) 1.62 b  & 40.61 \(\pm\) 0.32 a  & 24.89 \(\pm\) 0.11 b  & 61.78 \(\pm\) 0.20 c  & 84.82 \(\pm\) 0.38 b  \\
15\% RDV & Nd & 300.0 & 120.0 & 56.3 & 105.0 & Nd \\ (mg/100 g) & & & & & \\ \hline \multicolumn{6}{c}{Trace Minerals (mg/100 g)} \\ \cline{2-6}  & Fe & Cu & Zn & Mn \\ \hline Control & 0.93 \(\pm\) 0.04 b  & 0.06 \(\pm\) 0.00 b  & 0.37 \(\pm\) 0.00 c  \\ Cv & 1.14 \(\pm\) 0.09 a  & 0.09 \(\pm\) 0.01 a  & 0.71 \(\pm\) 0.00 a  & 0.43 \(\pm\) 0.00 b  \\ Pt & 0.93 \(\pm\) 0.00 b  & 0.07 \(\pm\) 0.00 ab  & 0.71 \(\pm\) 0.02 a  & 0.50 \(\pm\) 0.00 a  \\ Tc & 0.96 \(\pm\) 0.00 b  & 0.08 \(\pm\) 0.00 ab  & 0.68 \(\pm\) 0.01 b  & 0.41 \(\pm\) 0.00 b  \\
15\% RDV & 2.1 & 0.2 & 1.5 & 0.3 \\ (mg/100 g) & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Minerals content (mg/100 g) of bread samples. Control: Without microalgae; _Chlorella vulgaris_ (Cv), _Pluoadedylum tricornutum_ (Pt) and _Tetraselmis chuii_ (Tc). Different letters in the same parameter show significant differences (\(p<0.05\), Tukey test). Nd—non determined. The antioxidant capacity of the bread samples was assessed using the FRAP and DPPH assays, which revealed a positive relation between the total phenolic content and antioxidant capacity (Figure 4b,c). Results indicate that _T. chuii_-enriched bread displayed the highest antioxidant capacity, with a FRAP value of 592.0 ug TEAC/g, followed by _P. tricornutum_ (420.9 ug TEAC/g) and _C. vulgaris_ (331.7 ug TEAC/g). Similarly, the DPPH assay showed values of 160.3 ug TEAC/g for bread containing _C. vulgaris_, 236.4 ug TEAC/g for _T. chuii_, and 192.0 ug TEAC/g for _P. tricornutum_. A similar trend was observed in a study conducted by [PERSON] et al. [66] where the addition of Spirulina to bread formulation resulted in high antioxidant capacity. Additionally, an increase in antioxidant capacity was observed when microalgae were added to other staple foods, such as pasta [67] and broccoli soup [7].