Degradation kinetics of anthocyanins in blackberry juice and concentrate

Thermal and storage stabilities of anthocyanins in blackberry (Rubus fruticosus L.) juice and concentrate were studied over the temperature range 60–90 °C and 5–37 °C. Results indicate that the thermal degradation of anthocyanins followed first-order reaction kinetics. The temperature-dependent degradation was adequately modeled on the Arrhenius equation. The activation energy value for the degradation of blackberry anthocyanins during heating was 58.95 kJ/mol for the 8.90°Brix blackberry juice. During storage, antocyanins in the 65.0°Brix blackberry juice concentrate degraded more rapidly than that in 8.90°Brix blackberry juice, with the activation energies of 65.06 kJ/mol and 75.5 kJ/mol, respectively.