Alginate-based encapsulation of polyphenols from Rosa canina L. extract

Abstract

Rosa canina L. (Rosaceae) is frequently employed in traditional medicine, due to its diuretic, anti-inflammatory, anti-allergic, antioxidant and analgesic effects. It is rich in various bioactive compounds, including polyphenols, carotenoids, ascorbic acid, mineral elements and fatty acids. Microencapsulation tehnique is a promising tool for improving R. canina polyphenols' functionality, stability and bioavailability. Еlectrostatic extrusion process was carried out to obtain calcium-alginate beads with encapsulated R. canina extract. In pure extract, total polyphenol content was 103.8±1.9 mg GAE/g, whereas the concentration of flavonoids was 64.2±2.40 mg CE/g. Furthermore, polyphenol and flavonoid contents in extract loaded hydrogel beads were 4.68±0.12 mg GAE/g and 2.93±0.23 mg CE/g, respectively. Thus, determined encapsulation efficiency was 45.04±1.15%. In ABTS test, antioxidant activity of pure extract and extract loaded hydrogel beads was 15.30±2.10 and 2.93±0.23 mg Trolox/g, respectively. In DPPH test, IC50 of pure extract and extract loaded hydrogel beads was 1.07±0.01 and 29.32±2.15 mg/mL, respectively. The size of the produced R. canina extract encapsulated hydrogel particles was 550.30±34.56 µm. In distilled water as a medium, most of polyphenols were released relatively rapidly from alginate beads (in the first 20 min), and the maximum release plateau was reached at 60 min. This study demonstrates the potential of using alginate for encapsulation of R. canina polyphenols, with the aim to improve their functionality, bioavailability and stability in food, cosmetic and pharmaceutical products.