Abstract: In this paper, the effects of pH and temperature on the stability and thermal degradation kinetic characteristics of polyphenols from the whole plant of Geum japonicum Thunb variant were explored. Results indicated that the concentration of  polyphenols was increased with increasing pH but decreased with increasing temperature. The thermal degradation of polyphenols from G.japonicum was a first-order kinetic model with an excellent linear relationship. The rate constants of thermal degradation reaction at 30, 40, 50, 60 ℃ and 70 ℃ were 0.0096, 0.0115, 0.0153, 0.0175 h-1 and 0.02 h-1, respectively. Its apparent activation energy was 15.6952 kJ/mol.

Key words: Geum japonicum Thunb variant, polyphenol, stability, thermal degradation kinetics