Polyphenolic content, antioxidant activity and metal composition of traditional blackberry products

Abstract

In this study, commercially available traditional blackberry products, namely blackberry wines and blackberry elixirs from Coastal Croatia and Bosnia and Herzegovina, were investigated as sources of bioactive compounds, essential nutrients and metals. Samples were analysed for pH, total polyphenols and monomeric anthocyanins content, individual phenolic acids (gallic acid, chlorogenic acid, caffeic acid and p-coumaric acid), antioxidant activity (DPPH and ABTS), reducing power (RPA), total nitrogen and phosphorus as well as metals (K, Na, Ca, Mg, Fe, Mn, Cu, Zn, Co, Cr, Cd). The results of this study showed that the studied traditional blackberry products are rich sources of polyphenols and their consumption could increase the daily intake of dietary antioxidants in humans. In addition, both groups of traditional blackberry products could be considered safe for health and good additional sources of essential minerals such as manganese and potassium. The concentrations of the analysed undesirable toxic and potentially toxic metals in the studied blackberry products were below the maximum allowable concentrations defined by various regulations for wines and fruit wines.