Assessing antioxidant activities of phenolic compounds of common Turkish food and drinks on in vitro low-density lipoprotein oxidation

The total phenol concentrations of solid (9 types of vegetables and 6 types of fruits) and liquid (10 different types of drinks) foods were determined by the Folin-Ciocalteu colorimetric method. Oxidized low-density lipoprotein (LDL) was formed in in vitro conditions, and the effects of the phenolic compound extracts were measured on the inhibition of LDL oxidation. The phenol concentration for the 50% inhibition of LDL oxidation (IC50) and the phenol antioxidant index (PAOXI) were calculated. Walnut (7052 mg/kg) and Turkish coffee (2389 mg/L) had the highest total phenol concentrations. Green pepper and orange nectar had the lowest IC50 values, whereas walnut and red wine had the highest PAOXI values.