Degradation kinetics of anthocyanins in blood orange juice and concentrate

Thermal and storage stabilities of anthocyanins in blood orange juice and concentrate were studied over the temperature range 70–90 °C and 5–37 °C. Analysis of kinetic data suggested a first-order reaction for the degradation of blood orange anthocyanins with the half-lives of 6.3 to 1.5, 3.4 to 0.7 and 2.0 to 0.4 h for 11.2, 45 and 69°Brix samples between 70 and 90 °C, respectively. At 5, 20 and 37 °C, the half-lives were between 55.7 and 2.1, and 115.7 and 3.1 days for 45 and 69 °Brix samples, respectively. Activation energies for solid content of 11.2–69 °Brix ranged from 73.2 to 89.5 kJ mol−1.