## 3 Results
### DPPH Radical Scavenging Activity  
The enzyme and the hydrolysis time used had significant effects (\(P<0.05\)) on the DPPH radical scavenging activity of the porcine liver protein hydrolysates (Table 2). For the same hydrolysis time, alcalase was the enzyme that displayed the highest activity, reaching values of 562 ug Trolox/g. In contrast, samples hydrolyzed with papain showed the lowest outcomes, with an activity that in some cases was half of the values shown by the other two enzymes used (145 vs. 344 and 477 ug Trolox/g for papain vs. bromelain and alcalase, respectively). Except for the results found in the samples extracted with bromelain, the activity of porcine liver protein hydrolysates increased with the hydrolysis time. \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **g/100 g*** \\ \hline Moisture & 74.1 \(\pm\) 0.12 \\ Protein & 19.0 \(\pm\) 0.25 \\ Fat & 3.56 \(\pm\) 0.100 \\ Ash & 1.40 \(\pm\) 0.010 \\ Carbohydrate & 1.97 \(\pm\) 0.270 \\ \hline \hline \end{tabular} \({}^{*}\) Mean values presented are the results of liver analysis (n = 6).  
\end{table} 
Table 1: Chemical composition of porcine liver. Results expressed as mean \(\pm\) standard error. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Enzyme** & \multicolumn{3}{c}{**Papain**} & \multicolumn{3}{c}{**Bromelain**} & \multicolumn{3}{c}{**Alcalase**} & \multicolumn{3}{c}{**Enzyme Sig. **} \\ \hline
**Hydrolysis Time** & **4 h** & **8 h** & **Sig. ** & **4 h** & **8 h** & **Sig. ** & **4 h** & **8 h** & **Sig. ** & **4 h** & **8 h** \\ \hline
**MWCO** & & & & & & & & & & & \\
5 kDa & \(249\pm 2.2^{\rm\,av}\) & \(304\pm 4.6^{\rm\,A\,\alpha}\) & *** & 341 \(\pm\) 6.1\({}^{\rm\,ba}\) & 322 \(\pm\) 3.9\({}^{\rm\,la\alpha}\) & ns & 372 \(\pm\) 3.7\({}^{\rm\,ca}\) & 443 \(\pm\) 7.1\({}^{\rm\,ba}\) & *** & *** & *** \\
10 kDa & \(228\pm 4.1^{\rm\,b}\) & \(325\pm 3.2^{\rm\,A\,\beta}\) & *** & 427 \(\pm\) 3.4\({}^{\rm\,c\,\beta}\) & 379 \(\pm\) 5.2\({}^{\rm\,ga}\) & ** & 408 \(\pm\) 2.0\({}^{\rm\,b\,\beta}\) & 542 \(\pm\) 2.7\({}^{\rm\,Cb}\) & *** & *** & *** \\
30 kDa & \(145\pm 5.4^{\rm\,a\,\alpha}\) & \(309\pm 3.9^{\rm\,a\,\alpha}\) & *** & 342 \(\pm\) 26\({}^{\rm\,ba}\) & 376 \(\pm\) 4.1\({}^{\rm\,b\,\beta}\) & ** & 477 \(\pm\) 3.9\({}^{\rm\,c\,\beta}\) & 562 \(\pm\) 4.5\({}^{\rm\,c\,\gamma}\) & *** & *** & *** \\ Sig. & *** & * & * & *** & *** & *** & *** & *** & *** & \\
5 kDa & \(277\pm 1.9^{\rm\,b\,\beta}\) & \(352\pm 4.9^{\rm\,ba}\) & *** & 346 \(\pm\) 10.3\({}^{\rm\,b\,\beta}\) & 284 \(\pm\) 5.7\({}^{\rm\,ca}\) & ** & 754 \(\pm\) 8.2\({}^{\rm\,ca}\) & 815 \(\pm\) 6.7\({}^{\rm\,Cb}\) & ** & *** & *** \\
10 kDa & \(264\pm 5.1^{\rm\,a\,\alpha}\) & \(368\pm 5.1^{\rm\,ba}\) & 392 \(\pm\) 6.7\({}^{\rm\,b\,\gamma}\) & 335 \(\pm\) 54.6\({}^{\rm\,a\,\alpha}\) & ** & 791 \(\pm\) 7.2\({}^{\rm\,c\,\beta}\) & 1068 \(\pm\) 6.1\({}^{\rm\,c\,\gamma}\) & *** & *** & *** \\
30 kDa & \(335\pm 1.9^{\rm\,b\,\gamma}\) & \(416\pm 1.9^{\rm\,b\,\gamma}\) & *** & 281 \(\pm\) 1.5\({}^{\rm\,a\,\alpha}\) & 280 \(\pm\) 2.9\({}^{\rm\,a\,\alpha}\) & ns & 936 \(\pm\) 4.6 \({}^{\rm\,c\,\gamma}\) & 761 \(\pm\) 8.7\({}^{\rm\,Ca}\) & *** & *** & *** \\ Sig. & *** & *** & *** & *** & *** & *** & *** & *** & *** \\ \hline \multicolumn{10}{c}{FRAP (umol Fe\({}^{\rm\,2}\)/100 j)} \\
5 kDa & \(24.3\pm 0.72^{\rm\,za}\) & \(46.2\pm 2.47^{\rm\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,za\,zaza\,za\,zaza\,zaza\,zaza\,The filtration process also had a significant effect (\(P<0.05\)) on DPPH. However, the behavior depended on the enzymatic hydrolysis carried out. In the case of alcalase, the results showed that DPPH activity increased when the pore size of the membrane was larger. In this way, when the hydrolysis time was 8 h, values of 562, 542, and 443 ug Trolox/g for 30, 10, and 5 kDa were found, respectively; while the capacity decreased at low hydrolysis time, with values of 477, 408, and 372 ug Trolox/g for 30, 10, and 5 kDa, respectively.