## 3 Results and Discussion
### Antioxidant Properties of Fish Burgers  
Thanks to their safety and efficiency, much recent interest has been paid to the considerable role of fortified foods with bioactive substances usually derived from plants and microalgae in the cure of many human disorders. In order to estimate the effect of the three microalgae on the burgers' antioxidant capacities, two different methods were used: the DPPH free radical scavenging assay and the ferric reducing antioxidant power (FRAP) assay (Table 6).  
\begin{table}
\begin{tabular}{l c c c c} \hline  & **Control** & **1\%** & **1\%** & **1\%** \\  & **Burger** & _Isochrysis_ & _Picochlorum_ & _Chlorella_ **Burger** \\  & & **Burger** & **Burger** & \\ \hline L* & 46.75 \(\pm\) 0.335 & 41.1 \(\pm\) 0.95 a & 41.26 \(\pm\) 0.9 a & 43.7 \(\pm\) 0.7 a \\ a* & 10.65 \(\pm\) 0.22 & 4.22 \(\pm\) 0.135 a & 4.93 \(\pm\) 0.05 a & 4.71 \(\pm\) 0.03 a \\ b* & 11.4 \(\pm\) 0.71 & 9.55 \(\pm\) 0.3 a & 8.48 \(\pm\) 0.55 a & 7.88 \(\pm\) 0.48 a \\ Chroma (C*) & 15.6 \(\pm\) 0.3 & 10.4 \(\pm\) 0.1 a & 9.8 \(\pm\) 0.2 a & 9.18 \(\pm\) 0.2 a \\ Hue (H*) & 47\(\pm\) 0.2 & 66 \(\pm\) 0.4 a & 60 \(\pm\) 0.4 a & 60 \(\pm\) 0.2 a \\ \hline \end{tabular} Control burgers vs. microalgae-fortified burgers: a \(p<0.001\).  
\end{table}
Table 5: Color analysis of control burgers and microalgae-fortified burgers.  
The chlorophyll, carotenoid, and phycocyanin contents of burgers were also measured (Table 6). Compared to the control treatment, results show that treatments containing 1% _Chlorella minutissima_, 1% _Isochrysis galhana_, and 1% _Picochlorum_ sp. significantly increased the levels of chlorophylls (_p_ < 0.001), carotenoids (_p_ < 0.001), and phycocyanin (_p_ < 0.001) (Table 6). In addition, they enhanced the scavenging (_p_ < 0.001) and reducing power (_p_ < 0.001) activities (Table 6). In a sample concentration of 10 mg/mL, carp burgers containing 1% _Chlorella minutissima_, 1% _Picochlorum_ sp., and 1% _Isochrysis galhana_ had considerably higher DPPH scavenging activities (95.2%, 83.8%, and 65.6%, respectively) than control burgers (56.2%) (_p_ < 0.001) (Table 6). Furthermore, a comparable tendency was also noticed for the FRAP method. At a sample concentration of 10 mg/mL, the ferric reducing activities of unfortified and fortified carp burgers with 1% _Chlorella minutissima_, 1% _Isochrysis galhana_, and 1% _Picochlorum_ sp. were equal to 0.35, 0.5, 0.75, and 0.46 (_p_ < 0.001), respectively, (Table 6). Similar previous studies have postulated that the antioxidant activity of food products was increased by the presence of algae. In a comparative study, [PERSON] et al. [35] noted the high antioxidant activity from seafood products containing _Fucus vesicusus_ powder (brown algae). The rise in scavenging of free radicals could be attributed to an increase in pigment [32] and polysaccharide [36; 37] content, which plays an important role in the protection of the body's cells and molecules from oxidative stress and in cancer chemopre. For example, _Chlorella_ species are known to contain several types of polysaccharides, including \(\beta\)-1,3-glucan, an active free-radical scavenger [38]. In addition, many previous studies found that _Isochrysis galhana_ was rich in polysaccharides, with content up to 25% (dry cell weight) [36]. These polysaccharides were shown to have high scavenging activities against superoxide and hydroxyl radicals as well as moderate reductive power in a concentration-dependent manner [36]. Generally, these results indicate that fish burger transformation did not have a negative effect on the efficiency of the antioxidant components.