## 3 Results and Discussion
### Antioxidant Properties  
The antioxidant properties of the formulations are shown in Table 3. Despite reports that red cactus pear has higher total phenolic content (TPC) in the pulp than in the peel and seeds [62], the results in terms of phenolic compounds were higher (\(p<0.05\)) in GL, followed by GM. The TPC in the red cactus pear formulations (RM and RL) did not differ significantly; however, [PERSON] et al. reported that yellow varieties of whole cactus pear fruit have higher contents of phenolic compounds in the pericarp and epicarp than in the pulp [63]. Regarding antioxidant activity by DPPH, the radical inhibition of the red formulations was higher (24%) when compared to the green tablets (20%). Differences in antioxidant activity between green and red cactus pear residues were also found by [PERSON] et al., where seeds from green cactus pear showed greater antioxidant activity than the red variety [64]. These differences in antioxidant capacity could be linked to the antioxidants of lipophilic nature associated with different cactus pear varieties, for instance, lipophilic compounds such as tocopherols may increase the antioxidant activity measured by DPPH [33]. The antioxidant activity by ABTS was similar (\(p>0.05\)) among all the tablets. Finally, the RM formulation exhibited higher FRAP values (\(p<0.05\)). Although studies on the antioxidant properties of tablets with added fruit wastes are limited, a study on effervescent tablets made with tangerine peel reported a 141 mg GAE/100 g total phenolic content and 27% DPPH inhibition percentage [65], which are lower and slightly higher, respectively, than the cactus pear residue tablets These results are interesting and are in accord with the study by [PERSON] et al. ; cactus pear by-products have the potential to be used in the development of food products because their high dietary fiber and antioxidant content can prevent the damage caused by \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **GM** & **GL** & **RM** & **RL** \\ \hline \(L^{*}\) & 49 \(\pm\) 0 \({}^{\circ}\) & 48 \(\pm\) 1 \({}^{\circ}\) & 40 \(\pm\) 1 \({}^{\circ}\) & 41 \(\pm\) 0 \({}^{\circ}\) \\ \(a^{*}\) & \(-\)2 \(\pm\) 0 \({}^{\circ}\) & \(-\)2 \(\pm\) 0 \({}^{\circ}\) & 7 \(\pm\) 0 \({}^{\circ}\) & 9 \(\pm\) 0 \({}^{\circ}\) \\ \(b^{*}\) & 16 \(\pm\) 0 \({}^{\circ}\) & 15 \(\pm\) 0 \({}^{\circ}\) & 4 \(\pm\) 0 \({}^{\circ}\) & 4 \(\pm\) 0 \({}^{\circ}\) \\ h\({}^{\circ}\) & 97 \(\pm\) 0 \({}^{\circ}\) & 98 \(\pm\) 0 \({}^{\circ}\) & 31 \(\pm\) 1 \({}^{\circ}\) & 25 \(\pm\) 0 \({}^{\circ}\) \\ C\({}^{*}\) & 16 \(\pm\) 0 \({}^{\circ}\) & 15 \(\pm\) 0 \({}^{\circ}\) & 9 \(\pm\) 0 \({}^{\circ}\) & 11 \(\pm\) 0 \({}^{\circ}\) \\ \hline \hline \end{tabular} Mean values \(\pm\) standard deviations (\(n=3\)). \({}^{a+}\) Superscript letters indicate significant differences (\(p<0.05\)) between tablet formulations. GM: green cactus pear residue with microcrystalline cellulose; GL: green cactus pear residue with lactose; RM: red cactus pear residue with microcrystalline cellulose; RL: red cactus pear residue with lactose. \(L^{*}\) values of 0 and 100 indicate black and white, respectively, \(a^{*}\) is the axis of chromaticity between green (\(-\)) and red (\(+\)), \(b^{*}\) is the axis between blue (\(-\)) and yellow (\(+\)), h\({}^{\circ}\) indicate Hue angle and C\({}^{*}\) indicate chroma parameters.  
\end{table} 
Table 2: Color parameters of the cactus pear residue tablet formulations. free radicals [53]. The measures of antioxidant status help to determine why a diet high in antioxidants is often more beneficial, since dietary antioxidants have the ability to inhibit the formation of both reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can adversely affect normal cellular processes and physiological functions.