A Dynamic Test for Kinetic Models of Chemical Changes During Processing: Ascorbic Acid Degradation in Dehydration of Potatoes

A method was developed for kinetic-model parameter estimation using data obtained from processes with known dynamic stress paths. The utility of the method was demonstrated for the case of modeling of ascorbic acid degradation during air drying of potatoes. Potato discs were dried under a variety of conditions using a laboratory-scale tray-dryer with wet- and dry-bulb temperature control. Ascorbic acid concentration was monitored as a function of time along with average moisture content and temperature. These data obtained under dynamic conditions were used to estimate optimal parameters in a kinetic model describing the rate of degradation of ascorbic acid as a function of temperature, moisture content, time, and ascorbic acid concentration.