Antioxidant capacity of cocoa products from Serbia market

Abstract

Introduction: Cocoa is gaining importance as a source of biologically active substances. Cocoa flavonoids have received considerable attention because of their physiological functions including antioxidant, antimicrobial, antimutagenic and anti-inflammatory activities. Objectives: The aim of this study was to evaluate the correlation of declared cocoa content with the antioxidant activity of analyzed cocoa products. Objectives: The aim of this study was to evaluate the correlation of declared cocoa content with the antioxidant activity of analyzed cocoa products. Method / Design: Different kinds of cocoa products from Serbia market were analyzed regarding total polyphenol, flavonoid and proanthocyanidin content using spectrophotometric methods. DPPH, FRAP, ABTS and ORAC assays were applied for measuring antioxidant capacity. The average of all four antioxidant tests for each cocoa product was used for calculating antioxidant potency composite index (ACI). Results: The total polyphenol and flavonoid content was the highest in cocoa powder samples (35.35 mg GAE/g and 63.3 μmol CE/g, respectively). The content of flavonoids followed the content of total polyphenols in all samples. Total polyphenol content was 3 and 13 times lower in dark and milk chocolates than in cocoa powders and this decrease did not follow declared cocoa content in products. The content of proanthocyanidins in chocolate/cocoa extracts varied between 0.69 mg CyE/g in milk chocolates and 7.07 mg CyE/g in cocoa powders. Cocoa powders had average ACI value of 88.3%, dark chocolates 29.1%, while average ACI value for milk chocolates was only 7.3%. Conclusions: Obtained results for all four assays have shown that antioxidant capacity of analyzed chocolate/cocoa extracts followed cocoa, polyphenol, flavonoid, and proanthocyanidin contents. In addition, correlation between antioxidant potency composite index and declared percentage of cocoa was high (R 2=0.798, p<0.05) and indicated that declared cocoa content was a reliable indication for antioxidant capacity of chocolates produced in Serbia.