Polyphenols extraction from black chokeberry wastes

Polyphenols are secondary metabolites of plants and are broadly distributed in fruits and vegetables. It is demonstrated that these compounds act as strong antioxidants which determines a variety of their medicinal properties. Wastes of black chokeberry after juice recovery were used to investigate the optimal conditions for maximal yield of polyphenols applying solid-liquid extraction. Parameters such as temperature, medium acidity and type of solvent were varied. Total polyphenol content was assayed according to the Folin-Ciocalteu colorimetric reaction method. The results obtained demonstrated that water and water-ethanol mixtures were suitable for polyphenols extraction from black chokeberry wastes. The increase in temperature, regardless of the solvent, led to increasing polyphenol content in the extracts, reaching 7700 mg/L GAE with 50 % ethanol at ebullition, while acidity had clearly less effect on polyphenols extraction.