Antioxidant properties were studied by determining the ability to deactivate stable two chromogen radicals - 1,1-dipheny-2-picrylhydrazyl (DPPH.), [2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS•+) as well as inhibition of reactions that yield peroxides in emulsions of linoleic acid and chelation of iron. The study demonstrated the influence of technological processing on changes in antioxidant properties of cocoa processed products. Cocoa beans were characterised by the highest whereas cocoa butter by the lowest content of polyphenols. This study demonstrated that the products under investigation exhibited antioxidant properties in relation to ABTS•+ and DPPH•. Extracts were more effective in scavenging ABTS^•+ than DPPH•. Extracts from cocoa beans, cocoa mass as well as dark chocolate were characterised by very high capacity (at 100% level) to inhibit the formation of peroxides in emulsion systems. Dilution of extracts had an impact on the antioxidant properties of the products under investigation. Correlations were found between the total content of polyphenols in cocoa products and the ability of extracts to scavenge ABTS^•+ and DPPH• as well as to chelate iron and inhibit peroxide production in emulsion systems.