Thermostability of the visual color and anthocyanins from Rio-Grande-Cherry (Eugenia involucrata DC)

Abstract The extract of Rio-Grande-Cherry (Eugenia involucrata DC), pure and with stevia addition (0.75% and 1.5%) and sucrose addition (20% and 40%), was subjected to heat treatment at 10 °C, 25 °C and between 50 °C and 90 °C. Anthocyanins and the color parameters C* and TCD (total color difference) followed first-order reaction kinetics while h° followed a zero order kinetic model, under all conditions. The addition of sweeteners, through the reduction of water activity, influenced the thermal stability of the anthocyanins and of the color parameters C*, h° and TCD was the most pronounced effect in the latter. The lower the temperatures, the most relevant was the effect of the sweeteners on increasing half-life. Thermodynamically, the degradation reaction of anthocyanins was defined as endothermic, as well as non-spontaneous and transition state of the molecules more structurally organized than the reactants.