title: Thermal degradation kinetics study of curcumin with nonlinear methods.
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.
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China. Electronic address: liaosen@gxu.edu.cn.
authors.forename: Sen
authors.initials: S
authors.lastname: Liao
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China; School of Materials Science and Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Yingheng
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: He
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Zhangfa
authors.initials: Z
authors.lastname: Tong
authors.affiliation: Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
mesh_terms: D003296:Cooking; D003474:Curcumin / Q000737:chemistry*; D005505:Food Coloring Agents / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D013816:Thermodynamics
chemical_list: D005505:Food Coloring Agents; D003474:Curcumin
keywords: Activation energy; Advanced isoconversional method; Curcumin; Kinetic analysis; Thermogravimetric analysis