# Enzymatic Degradation of _Gracilariopsis lemaneiformis_
## 2 Results and Discussion
### Orthogonal Optimization Experiment and Verification Test
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & \multirow{2}{*}{\begin{tabular}{c} **A** \\ **(Temperature)\({}^{\prime}\)/C** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **B** \\ **(pH)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **C** \\ **(Enzyme** \\ **Dosse/U \(\&^{1}\))** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Hydrooxyl** \\ **Radical** \\ **Scavenging** \\ **Rate/\%** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **DPPH** \\ **Radical** \\ **Calcity** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Reducing** \\ **Concacity** \\ **Calcity** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Total** \\ **Concacity** \\ **Calcity** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Comprehensive** \\ **Score** \\ \end{tabular} } \\ \hline
1 & 1(30) & 1(4.4) & 1(250,000) & 48.33 \(\pm\) 0.26 & 29.60 \(\pm\) 0.38 & 0.096 \(\pm\) 0.002 & 0.322 \(\pm\) 0.002 & 19.59 \\
2 & 1(30) & 2(5.0) & 2(300,000) & 44.22 \(\pm\) 0.85 & 28.42 \(\pm\) 0.14 & 0.108 \(\pm\) 0.002 & 0.329 \(\pm\) 0.001 & 18.27 \\
3 & 1(30) & 3(5.6) & 3(350,000) & 35.65 \(\pm\) 0.64 & 28.79 \(\pm\) 0.38 & 0.104 \(\pm\) 0.001 & 0.320 \(\pm\) 0.001 & 16.22 \\
4 & 2(40) & 1(4.4) & 2(300,000) & 43.39 \(\pm\) 1.43 & 19.65 \(\pm\) 1.08 & 0.109 \(\pm\) 0.004 & 0.324 \(\pm\) 0.001 & 15.87 \\
5 & 2(40) & 2(5.0) & 3(350,000) & 40.27 \(\pm\) 2.71 & 20.74 \(\pm\) 0.05 & 0.118 \(\pm\) 0.004 & 0.326 \(\pm\) 0.001 & 15.36 \\
6 & 2(40) & 3(5.6) & 1(250,000) & 38.92 \(\pm\) 0.17 & 22.45 \(\pm\) 0.35 & 0.117 \(\pm\) 0.001 & 0.324 \(\pm\) 0.001 & 15.45 \\
7 & 3(50) & 1(4.4) & 3(350,000) & 37.12 \(\pm\) 1.13 & 22.23 \(\pm\) 0.11 & 0.124 \(\pm\) 0.003 & 0.322 \(\pm\) 0.001 & 14.95 \\
8 & 3(50) & 2(5.0) & 1(250,000) & 41.94 \(\pm\) 0.16 & 17.69 \(\pm\) 0.53 & 0.117 \(\pm\) 0.003 & 0.322 \(\pm\) 0.001 & 15.02 \\
9 & 3(50) & 3(5.6) & 2(300,000) & 39.30 \(\pm\) 0.61 & 15.92 \(\pm\) 0.14 & 0.124 \(\pm\) 0.006 & 0.322 \(\pm\) 0.001 & 13.92 \\ \hline Hydroxyl & K\({}_{1}\) & 42.73 & 42.95 & 43.06 & & & \\ radical & K\({}_{2}\) & 40.86 & 42.14 & 42.30 & & & \\ scavenging & K\({}_{3}\) & 39.45 & 37.96 & 37.68 & & & \\ rate/\% & R & 3.28 & 4.99 & 5.38 & & \\ \hline \multirow{2}{*}{DPPH radical scavenging rate/\%} & K\({}_{1}\) & 28.94 & 23.83 & 23.25 & & & \\ \cline{2-2} DPPH radical & K\({}_{2}\) & 20.95 & 22.28 & 21.33 & & & \\ \cline{2-2} scavenging & K\({}_{3}\) & 18.61 & 22.39 & 23.92 & & & \\ rate/\% & R & 10.32 & 1.54 & 2.59 & & & \\ \hline \multirow{2}{*}{Reducing capacity} & K\({}_{1}\) & 0.103 & 0.110 & 0.110 & & & \\ \cline{2-2} Reducing capacity & K\({}_{2}\) & 0.115 & 0.114 & 0.114 & & & \\ \cline{2-2} Reducing capacity & K\({}_{3}\) & 0.122 & 0.115 & 0.115 & & & \\ \cline{2-2} Reducing capacity & K\({}_{1}\) & 0.019 & 0.005 & 0.005 & & & \\ \hline \multirow{2}{*}{Total antioxidant capacity} & K\({}_{1}\) & 0.324 & 0.323 & 0.323 & & & \\ \cline{2-2} Reducing capacity & K\({}_{2}\) & 0.325 & 0.326 & 0.325 & & & \\ \cline{2-2} Reducing capacity & K\({}_{3}\) & 0.322 & 0.322 & 0.323 & & & \\ \cline{2-2} R & 0.003 & 0.004 & 0.002 & & & & \\ \hline \multirow{2}{*}{Comprehensive score} & K\({}_{1}\) & 18.03 & 16.80 & 16.69 & & & \\ \cline{2-2} Reducing capacity & K\({}_{2}\) & 15.56 & 16.22 & 16.02 & & & \\ \cline{2-2} \(\&\) & 14.63 & 15.20 & 15.51 & & & \\ \cline{2-2} R & 3.40 & 1.61 & 1.18 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Design and corresponding results of orthogonal experiment L\({}_{9}\)(3\({}^{3}\)) based on the antioxidant capacities of the GLP hydrolyses. The verification experiments were further carried out with 1 mg/mL of GDPs, and the results were shown in Table 4. GDP3 showed the strongest hydroxyl radical scavenging ability (61.99%) (Table 4), which was higher than that of degradation products obtained by chemical degradation of GLP [39]. GDP2, prepared under the conditions of 30 \({}^{\circ}\)C, pH 4.4, and 350,000 U/g, exhibited the highest DPPH radical scavenging activity (32.68%; Table 4).