Enhancing gelatin matrices with propolis and royal jelly: antioxidant, physico-chemical, techno-functional, and physico-mechanical properties

This study evaluated the effects of incorporating propolis and royal jelly into gelatin matrices (solution, powder, and film) to enhance their stability and functionality. Both bee products significantly modified the physicochemical and techno-functional properties of gelatin. Propolis reduced conductivity (1205 to 890 μS/cm), osmolarity (195 to 130 mOsm/kg), and zeta potential (−51 to −42 mV), while royal jelly increased them (conductivity to 1390 μS/cm, osmolarity to 256 mOsm/kg, zeta potential to −60 mV). Viscosity decreased with propolis but increased with royal jelly. Antioxidant activity improved significantly with both additives (p < 0.05), especially propolis. Techno-functional properties such as emulsification activity (55.6 % to 66.8 %) and oil-holding capacity (2.14 to 3.25 g/g) were enhanced. Mechanical testing showed decreased tensile strength (from 48 to 35 MPa) and increased flexibility in films. Water-binding capacity was reduced by propolis and increased by royal jelly. These findings suggest that gelatin matrices enriched with bee products can serve as multifunctional delivery systems for food and pharmaceutical applications.