FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




The antioxidant properties of polyphenol preparations obtained from black, pink, and white bean seed coats (Phaseolus)


The objective of this work was to study antioxidative properties of the preparations obtained from the seed coats of black, pink and white beans. To make the preparations, polyphenols were extracted using a 0.5% HCl solution (HCL in methanol), condensed under the vacuum conditions, and, finally, they underwent a lyophilization procedure. In order to provide a chemical profile of the preparations obtained, the contents of condensed tannins and anthocyanins were determined. Furthermore, the chelating capacity of the polyphenols and their effect on Fe(II) ions were determined. The antioxidative properties were determined in the presence of hydroxyl and ABTS radicals. It was stated that polyphenols under investigation developed an antioxidative activity in the presence of both the ABTS radicals (from 18% to 28.5%) and the hydroxyl radicals (from 25% to 95%). The preparations extracted from the black and pink bean coats developed the strongest antioxidative activity, whereas the preparation extracted from the white bean coats had the weakest antioxidant effect. This fact could be attributed to the higher contents of condensed tannins in the preparations made of colour bean coats.


polyphenols, antioxidant properties, ABTS+· radicals, hydroxyl radicals