Anthocyanin Degradation and Colour Kinetics of Cornelian Cherry Concentrate

Aims: The purpose of present study is to analyze the physicochemical properties (pH, total acidity, total monomeric anthocyanin, total phenolics and, total antioxidant activity) and to investigate thermal degradation kinetics of anthocyanins and Hunter colour parameters of cornelian cherry (Cornus mas L.) concentrates at 60, 70 and 80°C.

Methods: Monomeric anthocyanin degradation fitted to a first order reaction kinetics. Hunter L*, a*, b* values were measured to characterize colour; total colour difference (TCD*), lightness (L*), chroma (C*), and hue angle (h*°) were calculated from those values and, fitted to zero-order, first-order and combined kinetics model.

Results: The half-life values for anthocyanin degradation were 5.7, 4.3 and 2.1 h in cornelian cherry concentrate at 60, 70 and 80°C, respectively. Temperature dependence of anthocyanin degradation rate constants was expressed as activation energy, Ea, and Ea was calculated as 48.38 kj/mol between 60-80°C. TCD*, L*, C*, and h*° gave best fits with combined kinetics model.

Conclusion: Cornelian cherry fruits are important source of phenolic compounds and anthocyanins, which are also good source of natural antioxidants. Anthocyanin degradation followed first order reaction kinetics, while changes in L*, C*, h*° and TCD* followed combined kinetic model. The degradation rate increased as temperature increased.