Kinetic and Thermodynamic Parameters for Degradation of Anthocyanins from Red Currant and Sour Cherry Juices by Hydrogen Peroxide in the Presence of Cu(II)

Abstract

The kinetics of anthocyanins degradation in the red currant and sour cherry juices by hydrogen peroxide at pH 3.5 was investigated. The reaction was catalyzed by the trace of Cu (II), and it was followed spectrophotometrically at 520 nm by applying the initial-rate method. The reaction kinetic parameters are reported, and the rate equation is suggested. From the dependence of the rate constants on the temperature, the activation energy was calculated: 25.76 and 30.59 kJ mol-1 for the red currant and sour cherry juices, respectively. The thermodynamic functions of activation (ΔG*, ΔH* and ΔS*) have been determined to understand red currant and sour cherry juice anthocyanins degradation.