Immobilization of Chaga extract in alginate beads for modified release: simplicity meets efficiency

Abstract

Chaga (Inonotus obliquus) is a parasitic fungus, which has been used in traditional medicine in Russia and other northern European countries in the treatment of cancer, gastrointestinal andliver diseases. It has been a subject of intensive researchrecently, confirming many of its health-beneficial effects. In order to obtain a product that would allow modified and prolonged release of the Chaga's active metabolites, hot water Chaga extract was immobilized using calcium - alginate. The extract, which was predominantly composed of carbohydrates (57 %), also contained a relatively high amount of antioxidants/phenolic compounds (130 mg gallic acid equivalents per g of dry extract) and exhibited pronounced radical scavenging activity. It showed significant antibacterial activity as well, inhibiting growth of tested bacterial strains at concentrations of 1.25-20 mg/mL. Entrapment efficiency was about 80 %, and the extract-alginate system showed pH-dependant extract release; there was negligible release at pH 1.75 (gastric pH), and the release gradually increased with the increase in pH, reaching similar to 43 % of immobilized extract at pH 8.5 after 90 min. Such a product could be used as a dietary supplement, adjuvant in therapy of gastrointestinal diseases or as a food additive.