Development and characterization of red propolis powders obtained by complex coacervation and spray drying: application in isomalt-based hard candy

Abstract Red propolis ethanolic extract is a phenolic-rich ingredient whose application in food systems is limited by intense sensory attributes and handling difficulties. This study comparatively characterized red propolis powders obtained by different microencapsulation routes, focusing on key physicochemical and functional properties relevant to powder quality and stability. Red propolis microcapsules were produced by complex coacervation using gelatin and gum Arabic, applying either direct coacervation (DC) or coacervation preceded by emulsification (CE), followed by spray drying, with whey protein isolate (WPI) used as an additional carrier. Encapsulation efficiency after spray drying was significantly higher for the DC method (≥ 62%) than for the CE method (~ 15%), with statistically significant differences ( p < 0.05). All powders exhibited low water activity (~ 0.23), moisture content (~ 6.5%), and hygroscopicity (~ 10%), indicating adequate stability for low-moisture food applications. The highest formononetin content (~ 15 mg/g) was observed in DC powders without WPI. During storage at 25 °C for 60 days, WPI improved total phenolic retention in CE-based powders, whereas no significant effect was observed for DC-based powders. The encapsulated powders were incorporated into an isomalt-based hard candy as a model low-moisture system to evaluate phenolic release in simulated salivary fluid. Candies containing free or encapsulated extract showed similar release profiles, indicating that encapsulation did not hinder compound release. Overall, the results demonstrate that encapsulation route and carrier composition significantly influence powder properties and phenolic stability, supporting informed process selection for phenolic-rich food ingredients.