Evaluation of Thermal Degradation Kinetic Order of Anthocyanins Extracted from Garcinia Mangostana L. rind

Abstract

Garcinia Mangostana L. rind is well-known for its natural occurrence anthocyanins red pigment. It has been extensively sought nowadays due to its abundant health benefited values. This study aimed to evaluate thermal degradation kinetic of anthocyanins extracted from Garcinia Mangostana L. rind at elevated storage temperatures. Total monomeric anthocyanins (TMA) of Garcinia Mangostana L. rind extract was quantified using pH differential method. Graphical integrated rate laws of zero-, first-, and second-order were used to evaluate the best fit of experimental data. Temperature dependency of anthocyanins was further investigated using natural logarithm Arrhenius plots. Results showed that TMA values were degraded significantly by 14.84%, 19.44%, 23.97%, and 29.61% when storing at temperatures of 25°C, 40°C, 55°C and 70°C, respectively, but merely 7.04% degraded at 10°C. This result indicated that 10°C storage condition is ideal for long term storage whereas 25°C storage condition is suitable for short term. Arrhenius plot with the highest R² value of 0.9761 has identified that second-order was the best model to describe anthocyanin thermal degradation from 10°C to 70°C. Activation energy (Ea) of anthocyanin thermal degradation was 22.54kJ/mol and half-lives were from 44.16 to 8.91 hour in temperature range from 10 to 70°C.