Enzymatic Properties of Polyphenol Oxidase in Artemisia carvifolia

The study was performed to explore the effects of temperature,pH,substrate concentration,activator,and inhibitor on PPO activity of Artemisia apiacea.Experimental results showed that the optimal pH and temperature for PPO activity were 40 °C and 6.8,respectively.The Michaelis constant(Km) was 0.015 4 mol/L and Vmax was 125 U/min,which was increased along with an increase in substrate concentration in a certain range.As compared with the control,MgCI2 and SDS activated PPO activity by 30.3%and 45.3%when added at a concentration of 0.9 and 8 mmol/L,respectively.VC,citric acid and PVP inhibited the enzyme activity by 70.4%,83.7%and 77.6%when used at a concentration of 0.03,1.2 and20g/L,respectively.The inhibition of NaHSO3 on PPO activity rose slowly with increasing concentration from 0.01 to 0.08 mmol/L.