Effects of hot-water blanching on the biological and physicochemical properties of sweet potato slices

Changes in the enzymatic and physicochemical properties of sweet potatoes processed by a combination of pre-heating and high-temperature blanching were investigated. First, the characteristics of the inactivation of peroxidase and pectin methylesterase were analyzed, showing that 112.7 and 119.6 kJ mol−1 of activation energy were required for inactivation, respectively. The result also suggested that a temperature of over 94 °C was better to inactivate peroxidase effectively. Second, the optimum conditions for pre-heating treatment were selected through the consideration of quality attributes. Pre-heating at 60 °C and 65 °C produced a stronger effect of enhancing firmness. However, some adverse effects on nutrients and appearance were noted at temperatures over 65 °C. Eventually, pre-heating at 60 °C for 40 min was selected as the best condition for sweet potato slices.