Modelling the kinetics of peroxidase inactivation and colour changes of seedless guava (Psidium guajava L.) during thermal treatments

• Main Authors: Ganjloo, Ali, Abdul Rahman, Russly, Bakar, Jamilah, Osman, Azizah, Bimakr, Mandana
• Format: Article
• Language: English
• Published: IDOSI Publications 2009
• Online Access: http://psasir.upm.edu.my/id/eprint/15678/1/15678.pdf; http://psasir.upm.edu.my/id/eprint/15678/; https://www.idosi.org/wasj/wasj7(1)2009.htm

The kinetics of thermal inactivation of peroxidase and colour changes in seedless guava (Psidium guajava L.) due to hot water blanching were studied in the temperature range of 80-95°C. Peroxidase inactivation kinetics followed a first-order Arrhenius model, where the activation energy and rate of the reaction at a reference temperature of 87.5°C were 101.27±3 kJ mol-1 and 0.023±4×10-3s-1, respectively. Colour was quantified using the L, a, b in Hunter system. The results indicated that colour system parameters (L, a, b) followed a first-order Arrhenius kinetics model with activation energies (Ea) of 120.43±3, 86.45±5 and a 100.03±2, kJmol-1, respectively. The zero-order kinetic model was applied to total colour difference (TCD) resulting in activation energies of 111.65±5 kJmol-1. Good agreement was found between estimated and experimental data in all cases (R2>0.91).