Valorizing Brazilian Propolis Residue: Comprehensive Characterization for Sustainable Reutilization Strategies

This study presents the first comprehensive characterization of Brazilian propolis residue, revealing its rich content of bioactive compounds, essential nutrients, and volatile substances, showcasing its potential for sustainable utilization. The term "residue" refers to the solid by-product remaining after ethanolic extraction of raw propolis, which is typically discarded, despite retaining significant nutritional value. HPLC-ESI-MS/MS analysis identified significant concentrations of <i>p</i>-coumaric acid (637.80 mg/kg), chlorogenic acid (497.93 mg/kg), kaempferol (295.82 mg/kg), and caffeic acid (115.11 mg/kg); while HPLC-DAD revealed also artepillin-C (56.56 mg/kg), illustrating strong antioxidant properties. Nutritional analyses showed high moisture content (37.08%), protein (12.56%) and dietary fiber (24.2%). Additionally, the mineral profile highlighted potassium (9800 mg/kg), phosphorus (2520 mg/kg), and calcium (2100 mg/kg). Volatile compounds analysis via HS-SPME-GC-MS identified a diverse class of components, predominantly terpenoids such as α-pinene (20.09%) and caryophyllene (9.76%), suggesting potential applications in fragrance and flavor industries. The multifunctional nature of propolis residue aligns with circular economy principles and highlights its value as a resource for diverse applications.