The kinetics of the thermaldegradation of vitaminC of marula, mango and guava pulp at different heat treatments at temperature ranging from 80 to 150 °C were investigated. For temperatures lower than 125 °C, the ascorbic acid in marula pulp was about 15 fold more stable to heat than the ascorbic acid in mango and guava pulp. The results showed that a simple first order degradation model could not describe the vitaminCdegradation as biphasic behaviour was observed. Therefore the model was transformed in a two-fraction model in which the vitaminC content is divided in relatively stable and instable fractions. Marula had a low kd1,100°C of 7.2 × 10-3 min-1compared to kd1,100°C of 1.2 × 10-1 min-1 for guava and 1.3 × 10-1 min-1 for mango. Guava had the highest activation energy, Ea of 58 kJ/mol, followed by mango with 39 kJ/mol and then marula with 29 kJ/mol.
|Journal||Food Science and Technology = Lebensmittel-Wissenschaft und Technologie|
|Publication status||Published - 2012|