getpdf

Cyclic Voltammetric Determination of Antioxidant Capacity of Cocoa Powder, Dark Chocolate and Milk Chocolate Samples: Correlation with Spectrophotometric Assays and Individual Phenolic Compounds

Jelena M. Brcanović1, Aleksandra N. Pavlović1*, Snežana S. Mitić1, Gordana S. Stojanović1, Dragan D. Manojlović2, Biljana M. Kaličanin3 and Jovana N. Veljković1


1
University of Niš, Faculty of Sciences and Mathematics, Department of Chemistry, Višegradska 33, RS-18000 Niš, Serbia

2
University of Belgrade, Faculty of Chemistry, Department of Analytical Chemistry, Studentski trg 12–16, RS-11000 Belgrade, Serbia

3
University of Niš, Faculty of Medicine, Department of Pharmacy, Blvd. Dr Zorana Đinđića 81, RS-18000 Niš, Serbia

Article history
:
Received February 11, 2013
Accepted July 22, 2013

Key words:

cocoa powder and chocolates, cyclic voltammetry, antioxidant capacity, spectrophotometric assays, catechins, procyanidins

Summary:

Phenolic antioxidants in cocoa powder, dark chocolate and milk chocolate samples are quantified electrochemically using cyclic voltammetry with a glassy carbon electrode. Cyclic voltammograms were recorded from 0 to 800 mV at a scan rate of 100 mV/s. Phenolics with an ortho-diphenol group show the first oxidation peak in the potential range between 370 and 460 mV (vs. Ag/AgCl) in 0.1 mol/L of the acetate buffer, pH=4. The first and third anodic current peaks, close to 670 mV, can be ascribed to the first and second oxidation of the catechin-type flavonoids that are present at a high concentration in samples. The second peak at around 560 mV can be ascribed to phenolic acids. Procyanidins B1, B2, B3 and B4 did not have any visible waves. Strong positive correlation was established between antioxidant activities deduced from cyclic voltammograms with those determined using spectrophotometric assays. HPLC method was used for the quantification of individual phenolic compounds.


*Corresponding author:      aleksandra.pavlovic@pmf.edu.rs
                                           ++381 18 533 015
                                           ++381 18 533 014

Search FTB


Follow us


 facebook 1 twitter bird_icon LI In Bug

 

QR Code


qrcode

We use cookies to improve our website and your experience when using it. Cookies used for the essential operation of the site have already been set. To find out more about the cookies we use and how to delete them, see our privacy policy.

I accept cookies from this site.

EU Cookie Directive Module Information