Microencapsulation of Lonicera caerulea pomace extract by spray drying: Characterization and stability studies

Abstract

Lonicera caerulea pomace contains abundant polyphenols with health-promoting properties, yet its rough texture limits food applications. In this study, the potential of maltodextrin (MD), whey protein isolation (WPI), soybean protein isolate (SPI) and their combinations as wall materials for microencapsulation of Lonicera caerulea pomace extract was investigated. Three wall materials (MD, SPI and their combination) were evaluated for microencapsulating Lonicera caerulea pomace extract via spray drying. The resulting microcapsules were characterized for physicochemical properties, storage stability, and digestive behavior. Results demonstrated effective encapsulation, with SPI exhibiting superior polyphenol and anthocyanin encapsulation efficiencies (97.27 % and 96.05 %, respectively). The microcapsules displayed favorable characteristics including low hygroscopicity (9.64–10.75 g/100g), low moisture content (5.13 %–5.92 %), and low water activity (0.25–0.30). Thermogravimetric analysis confirmed enhanced thermal stability of encapsulated extracts compared to their unencapsulated counterparts. Storage stability studies revealed over 90 % retention of bioactive compounds after 90 days at 25 °C. During in vitro simulated digestion, SPI-based microcapsules provided superior protection and high bioaccessibility in the gastrointestinal environment, with 90.73 % polyphenol release. This research validates the feasibility of spray-dried microencapsulation for Lonicera caerulea pomace extract, improving its edibility, enhancing extract stability, expanding its potential as a functional food ingredient, and increasing the value of berry processing byproduct.