## 3 Results and Discussion
### Phenolic Compounds of C. pepo Seed Extract  
Phenolic compounds are a group of non-enzymatic antioxidants that have the ability to combat free radicals, which, when in excess, may lead to increased oxidative stress and consequently to cell aging. The phenolic composition of the _C. pepo_ extracts is summarized in Table 3.  
MAE condition 2 achieved the highest concentration of phenolic compounds (20.34 mg/g DW), followed by MAE condition 1 (17.01 mg/g DW), UAE condition 1 (12.51 mg/g DW) and UAE condition 2 (9.15 mg/g DW). The lower concentration of phenolic compounds in the UAE extracts may be explained by the partial degradation of phenolic \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multicolumn{2}{c}{**UAE (mg/g DW)**} & \multicolumn{2}{c}{**MAE (mg/g DW)**} \\ \cline{2-5}  & **Condition 1** & **Condition 2** & **Condition 1** & **Condition 2** \\ \hline \multicolumn{5}{l}{**Alkaloids**} \\ \hline Caffe & 2.401 \(\pm\) 0.120 & 1.147 \(\pm\) 0.057 & 1.483 \(\pm\) 0.074 & 2.373 \(\pm\) 0.119 \\ \hline \multicolumn{5}{l}{**Chalconoids**} \\ \hline Phloridzin & ND & ND & 1.502 \(\pm\) 0.075 & 2.062 \(\pm\) 0.103 \\ \hline \multicolumn{5}{l}{**Flavanols**} \\ \hline Catechin & 5.634 \(\pm\) 0.282 & 4.567 \(\pm\) 0.228 & 5.753 \(\pm\) 0.288 & 7.354 \(\pm\) 0.368 \\ Epicatechin & 0.278 \(\pm\) 0.014 & \textless{LOD} & 0.549 \(\pm\) 0.027 & 0.654 \(\pm\) 0.033 \\ \hline \multicolumn{5}{l}{**Flavanones**} \\ \hline Naringin & 0.016 \(\pm\) 0.001 & 0.072 \(\pm\) 0.004 & 0.102 \(\pm\) 0.005 & 0.116 \(\pm\) 0.006 \\ \hline \multicolumn{5}{l}{**Flavonols**} \\ \hline Rutin & ND & ND & 0.045 \(\pm\) 0.002 & 0.054 \(\pm\) 0.003 \\ Myricetin & 0.299 \(\pm\) 0.015 & ND & 0.392 \(\pm\) 0.020 & \textless{LCOQ} \\ \hline \multicolumn{5}{l}{**Phenolic acids**} \\ \hline Gallic acid & 1.337 \(\pm\) 0.067 & 0.945 \(\pm\) 0.047 & 1.061 \(\pm\) 0.053 & 1.236 \(\pm\) 0.062 \\ Protocatechuic acid & 0.378 \(\pm\) 0.019 & 0.712 \(\pm\) 0.036 & 1.989 \(\pm\) 0.099 & 1.970 \(\pm\) 0.098 \\ Neochlorogenic acid & 0.224 \(\pm\) 0.011 & \textless{LOD} & 0.106 \(\pm\) 0.005 & \textless{LCOQ} \\ Caftaric acid & 0.174 \(\pm\) 0.009 & 0.176 \(\pm\) 0.009 & 0.090 \(\pm\) 0.005 & 0.081 \(\pm\) 0.004 \\ Chlorogenic acid & 0.079 \(\pm\) 0.004 & 0.111 \(\pm\) 0.006 & 1.490 \(\pm\) 0.074 & 1.419 \(\pm\) 0.071 \\
4-O-caffeytoplasmic acid & 0.396 \(\pm\) 0.018 & 0.369 \(\pm\) 0.018 & 0.399 \(\pm\) 0.020 & 0.533 \(\pm\) 0.0267 \\ Vanillic acid & 0.224 \(\pm\) 0.011 & 0.269 \(\pm\) 0.013 & 0.531 \(\pm\) 0.027 & 0.835 \(\pm\) 0.042 \\ Caffe acid & 0.050 \(\pm\) 0.002 & 0.032 \(\pm\) 0.002 & 0.152 \(\pm\) 0.008 & 0.184 \(\pm\) 0.009 \\ Syringic acid & 0.047 \(\pm\) 0.002 & 0.083 \(\pm\) 0.004 & 0.183 \(\pm\) 0.009 & 0.197 \(\pm\) 0.010 \\ \(p\)-Coumaric acid & 0.123 \(\pm\) 0.006 & 0.142 \(\pm\) 0.007 & 0.257 \(\pm\) 0.013 & 0.303 \(\pm\) 0.015 \\ trans-Ferulic acid & 0.061 \(\pm\) 0.003 & 0.044 \(\pm\) 0.002 & 0.080 \(\pm\) 0.004 & 0.132 \(\pm\) 0.007 \\ Sinapic acid & 0.155 \(\pm\) 0.080 & 0.093 \(\pm\) 0.005 & 0.062 \(\pm\) 0.003 & ND \\
4,5-di-O-caffeytoplasmic acid & 0.555 \(\pm\) 0.028 & 0.336 \(\pm\) 0.017 & 0.693 \(\pm\) 0.035 & 0.840 \(\pm\) 0.042 \\ \hline \multicolumn{5}{l}{**Stilbenoids**} \\ \hline trans-polydatin & 0.072 \(\pm\) 0.004 & 0.055 \(\pm\) 0.003 & 0.090 \(\pm\) 0.004 & \textless{LCOQ} \\ \hline
**Total** & 12.511 & 9.154 & 17.006 & 20.340 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Identification and quantification (mg/g DW) of the phenolic compounds present in _C. pepo_ seed extracts obtained by UAE and MAE at different extraction conditions through HPLC-PDA analysis. Results are expressed as mean \(\pm\) standard deviations (_n_ = 3). acids by ultrasonic waves and the creation of highly reactive hydroxyl radicals during the UAE process, which has been reported by several authors [92; 93; 94]. In all extracts, the phenolic compound present in the highest quantity was catechin.