Thermal degradation kinetics study of curcumin with nonlinear methods

Food Chem. 2014 Jul 15;155:81-6. doi: 10.1016/j.foodchem.2014.01.034. Epub 2014 Jan 23.

Abstract

The results of TG/DTG when curcumin was used as the food colouring agent indicated that the processing temperature of the food should not exceed 190°C. The decomposition process of curcumin involved two stages. The results of Eα values, determined by an advanced isoconversional method, showed that the two stages were both single-step processes. The most probable mechanisms of the two stages were estimated by using comparative and nonlinear model-fitting methods. The mechanisms obtained from the two methods are the same, which are the assumed random nucleation and its subsequent growth for stage I and one-dimensional diffusion for stage II, respectively. The values of pre-exponential factor A for both stages were obtained on the basis of Ea and g(α). Besides, some thermodynamic functions (ΔS(≠), ΔH(≠) and ΔG(≠)) of the transition state complexes for the two stages were also calculated.

Keywords: Activation energy; Advanced isoconversional method; Curcumin; Kinetic analysis; Thermogravimetric analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cooking
  • Curcumin / chemistry*
  • Food Coloring Agents / chemistry*
  • Hot Temperature
  • Kinetics
  • Thermodynamics

Substances

  • Food Coloring Agents
  • Curcumin