Encapsulated bee propolis powder: Drying process optimization and physicochemical characterization
Kirty Pant, Mamta Thakur, Harish Kumar Chopra, Vikas Nanda
Abstract
The current study was aimed to produce the encapsulated vacuum dried propolis powder. The RSM (Box-Behnken modelling) experimental design comprised the following process variables: propolis ethanolic extract (PEE) (40–70%), temperature (30–50ᵒC), and pressure (15–25 in Hg) for evaluating their impact on physical characteristics and total phenolic content (TPC) of prepared powder. The outcomes showed higher TPC (20.98–30.91 mg GAEg−1) with increase in propolis extract concentration and pressure whereas, bulk density (414–612 kg m−3) was intensified with higher propolis amount while contrary effect was shown in case of hygroscopicity (9.12–15.41%). The whiteness (66.13–74.85) of powder was decreased by increasing propolis extract concentration and temperature. The optimum conditions for encapsulated propolis powder were 52.3% PEE concentration, 39.2ᵒC temperature, and 21.7 in Hg pressure. Further, the encapsulation efficiency, antioxidant activity, FTIR spectroscopy, TGA and morphological analysis of optimized powder sample underlined the existence of polyphenolic compounds with effective encapsulation. This study herein will open the gateway for valorization of vacuum-dried propolis powder in formulation of several value-added and functional food products.