## 3 Results and Discussion
### The Total Polyphenol and Flavonoid Content of GV Extracts  
Phenolic compounds found in vegetables, fruits, grains, and seaweed consist of one or more aromatic rings and at least one hydroxyl (-OH) group [46]. These compounds  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**Foodborne Bacteria**} & \multicolumn{3}{c}{**Cultivation Conditions**} \\ \cline{3-4}  & & **Culture Medium** & **Culture Temperature** \\ \hline \multirow{3}{*}{**Gram-positive**} & _Bacillus cereus_ & Nutrient broth & 30 \({}^{\circ}\)C \\  & _Staphylococcus aureus_ & Nutrient broth & 37 \({}^{\circ}\)C \\  & _Listeria monocytogenes_ & Brain heart infusion broth & 37 \({}^{\circ}\)C \\ \hline \multirow{3}{*}{**Gram-negative**} & _Escherichia coli_ & Nutrient broth & 37 \({}^{\circ}\)C \\  & _Salmonella typhimurium_ & Nutrient broth & 30 \({}^{\circ}\)C \\  & _Vibrio parahaemolyticus_ & Nutrient broth & 37 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table}
Table 1: Culture conditions of the foodborne bacteria used for the evaluation of the antibacterial activity of the GV extracts.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Extracts** & **GVE** & **GVM** & **GVW** \\ \hline Yield (\%) & \(3.3\pm 0.3\)b & 1.3 \(\pm\) 0.2b & 43.4 \(\pm\) 1.7a \\ \hline GVE, _G. vermiculos_ ethanol extract; GVM, _G. vermiculos_ methanol extract; GVM, _G. vermiculos_ water extract. Different letters (a–b) indicate significant differences (\(p<0.05\)).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Extracts** & **GVE** & **GVM** & **GVW** \\ \hline Yield (\%) & \(3.3\pm 0.3\)b & 1.3 \(\pm\) 0.2b & 43.4 \(\pm\) 1.7a \\ \hline \hline \end{tabular}
\end{table}
Table 2: Yield of _Gracilaria verrucosa_ extracts.  
are categorized into phenolic acids, flavonoids, stilbenes, and lignins and are known for their effective antioxidant activities, which are attributed to their free radical-scavenging ability [47; 48]. The total polyphenol content of GV extracts using different extraction solvents varied from 0.8 to 4.0 mg TA/g, with the GVM exhibiting the highest content at 3.74 \(\pm\) 0.14 mg TA/g (Figure 1a). Regarding the flavonoid contents, the GV extracts ranged from 0.2 to 0.9 mg QC/g, with the GVE and GVM displaying higher contents of 0.86 \(\pm\) 0.01 and 0.64 \(\pm\) 0.12 mg QC/g, respectively, than the GVW (Figure 1b). GVM and GVE had the highest total polyphenol and flavonoid contents, respectively, whereas GVW had the lowest.  
[PERSON] et al. [49] observed that methanol extracts of GV, _Sargassum_ sp., and _Caulerpa recemosa_ had the highest polyphenol content, followed by ethanol and acetone extracts. Similarly, [PERSON] et al. [50] indicated that organic solvents are more efficacious than water for polyphenol extraction. The solubility of polyphenols is influenced by factors such as molecular size, the presence of hydroxyl groups, and hydrocarbon chain length [51]. These findings suggest that organic solvents such as methanol and ethanol are more effective than water for extracting polyphenol compounds from GV. However, comparisons of the yields of polyphenic compounds based on extraction conditions such as temperature and solvent ratios, excluding extraction solvents, show considerable variability owing to factors such as the type of seaweed and the variability of standard reagents (such as gallic acid and tannic acid).