Kinetic modeling of ascorbic acid loss in baobab drink at pasteurization and storage temperatures.

Abstract

The degradation kinetics of ascorbic acid was determined in baobab drink during pasteurization and storage temperatures at 60-90°C for 3 hours and 0 - 40 o C for 5 weeks respectively. The loss of ascorbic acid at all temperatures followed the first order kinetic model as the coefficient of determination (i.e. R 2 -value) ≥ 0.953. Rate constants of ascorbic acid degradation ranged from 9.72 - 26.31 x10 -3 /minute and 5.266 - 29.95x10 -3 /day during pasteurization and storage respectively. Decimal reduction time (D-value) and half-life ranged between 87.52 - 236.87 and 26.35 - 71.30 minutes and 76.89 - 437.78 and 23.15 - 131.78 days for pasteurization and storage temperatures respectively The temperature dependence of degradation reaction was well described by the Arrhenius relationship. The activation energy, Q10 factor, and Z-value obtained ranged from 24.24 - 58.66 kJ/mol, 1.06 - 1.58 and 4.74 - 7.96 o C for the temperature range within which experiments were carried out.