Kinetics of thermal degradation of ascorbic acid in lulo juice (Solanum Quitoense Lam.)

The kinetics of thermal degradation of ascorbic acid was study in the lulo juice (Solanum quitoense Lam.), in the temperature range of 65 to 95 degrees celsius at 0, 5, 10, 15 and 20 minutes. The ascorbic acid was determined with the iodine titration method. A reduction of 66,7% and 80,0% ascorbic acid was observed and its degradation follows a kinetic of order one with a speed constant (k) of 0.0511 - 0.0813 min^-1, an R²> 0.9715 and an activation energy (Ea) of 16.42 kJ.mol-1 (3.93 kcal.mol^-1). The obtained results are for reference purposes for the design, improvement and optimization of processes related to lulo. (author)