Resumen
- Monomeric anthocyanin degradation and nonenzymatic browning (NEB) index have been deter-mined in reconstituted blackberry juice heated at high temperature in a hermetically sealed cell.Statistical analysis demonstrated that, when the temperature range (100-180 C) was divided intotwo subranges (100-140 and 140-180 C) for anthocyanin degradation, reaction kinetics were wellrepresented by two sequential first-order reactions. The activation energy for NEB from 100 to180 C (106 kJ3mol-1) was slightly higher than the anthocyanin value at the lower temperaturerange (92 kJ3mol-1), but was more than twice the value for the higher range (44 kJ3mol-1). Thereaction rate constant at 140 C for anthocyanin degradation (3.5 10-3s-1) was two times that forthe NEB index (1.6 10-3s-1). Hence, anthocyanin degradation was faster than the appearance ofNEB products. The non-isothermal method developed allows estimating kinetic parameters andthereby generating temperature profiles of heat processes that would help preserve the nutritionalproperties of foods during high-temperature processes.