## 3 Results and Discussion  
### Bioactive Compound Analysis in Propolis Residue  
The analysis of propolis residue, derived from raw propolis processing, reveals a rich composition of bioactive phenolic compounds, crucial for valorizing this biomass in sustainable applications. Phenolic compounds contribute to sustainability being derived from natural sources, offering a natural alternative to synthetic antioxidants in various applications [30], reducing reliance on chemical processes and enhancing biodegradability [23; 24; 31]. Utilizing HPLC-ESI-MS/MS, a diverse array of phenolic compounds was quantified (Table 1) (Figure 1), underscoring the potential of propolis residue as a source of natural antioxidants. \begin{table}
\begin{tabular}{c c} \hline \hline
**Compounds** & **Propolis Residue [2; 3]** \\ \hline Gallic acid & 7.49 \(\pm\) 0.89 \({}^{\mathrm{a}}\) \\ Neochlorogenic acid & 207.67 \(\pm\) 19.32 \({}^{\mathrm{b}}\) \\ Delphinidin 3-galactosidase & n.d. 1 \\ Catechin & n.d. \\ Procyanidin B2 & n.d. \\ Chlorogenic acid & 497.93 \(\pm\) 28.33 \({}^{\mathrm{c}}\) \\
4-Hydroxybenzoic acid & 14.37 \(\pm\) 1.05 \({}^{\mathrm{a}}\) \\ Epicatechin & n.d. \\ Cyanidin-3-glucose & 0.14 \(\pm\) 0.01\({}^{\mathrm{a}}\) \\ Petunidin-3-glucose & n.d. \\
3-Hydroxy benzoic acid & n.d. \\ Caffeic acid & 115.11 \(\pm\) 6.51 \({}^{\mathrm{a}}\) \\ Vanillic acid & 2.69 \(\pm\) 0.08 \({}^{\mathrm{a}}\) \\ Pelargonidin-3-glucoside & n.d. \\ Pelargonidin-3-rutinoside & n.d. \\ Malvidin-3-galactoside & n.d. \\ Syringic acid & n.d. \\ Procyanidin A2 & n.d. \\ \(P\)-Coumaric acid & 637.80 \(\pm\) 27.35 \({}^{\mathrm{d}}\) \\ Ferulic acid & n.d. \\ Rutin & 5.59 \(\pm\) 0.47 \({}^{\mathrm{a}}\) \\ Hyperoside & 104.16 \(\pm\) 5.61 \({}^{\mathrm{a}}\) \\ Isoquercitrin & 34.75 \(\pm\) 2.30 \({}^{\mathrm{a}}\) \\ Delphindin 3,5 diglucoside & 34.56 \(\pm\) 3.17 \({}^{\mathrm{a}}\) \\ Phloridzin & n.d. \\ Naringin & n.d. \\ Quercitrin & 0.82 \(\pm\) 0.04 \({}^{\mathrm{a}}\) \\ Myricetin & n.d. \\ Kaempferol-3-glucoside & 5.70 \(\pm\) 0.32 \({}^{\mathrm{a}}\) \\ Hesperidin & n.d. \\ Ellagic acid & 23.29 \(\pm\) 2.40 \({}^{\mathrm{a}}\) \\ _Trans_-cinnamic acid & 17.13 \(\pm\) 0.80 \({}^{\mathrm{a}}\) \\ Quercetin & 31.21 \(\pm\) 29.94 \({}^{\mathrm{a}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Contents of the bioactive phenolic compounds (mg/kg dry weight) determined by HPLC-MS/MS in propolis residue, including Artepillin-C quantified using HPLC-DAD. The study identified significant quantities of \(p\)-coumaric acid (637.80 \(\pm\) 27.35 mg/kg), chlorogenic acid (497.93 \(\pm\) 28.33 mg/kg), and kaempfer (295.82 \(\pm\) 11.67 mg/kg) as the predominant compounds, alongside notable concentrations of neochlorogenic acid (207.67 \(\pm\) 19.32 mg/kg). Several studies reported that propolis contains bioactive compounds such as phenolic compounds, flavonoids, and antioxidant compounds [32; 33; 34]. Moreover, caffeic acid (115.11 \(\pm\) 6.51 mg/kg) was also detected in considerable amounts, further emphasizing the complexity and richness of propolis residue in bioactive compounds. The total quantified bioactive compounds by HPLC-ESI-MS/MS amounted to 2041.34 mg/kg dry weight, showcasing the substantial phenolic content present in propolis-lis residue. Also, Artepillin-C, a prenylated phenolic compound primarily found in Brazilian green propolisis, known for its potent antioxidant, anti-inflammatory, and anticancer properties, contributing to the overall bioactivity of propolisis, was identified by HPLC-DAD (56.56 \(\pm\) 1.75 mg/kg) in a good concentration. These findings are consistent with those of [35; 36] who noted the antimicrobial and anti-inflammatory properties of propolisis. Similarly, [37], emphasized its health-promoting applications. And according also, with the work of [38], who confirmed the superior antioxidant efficacy of propolis residues compared to other natural sources, including fruits and vegetables known for their health-promoting properties.