Abstract:

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 ℃ 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, MgCl2 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 and
20 g/L, respectively. The inhibition of NaHSO3 on PPO activity rose slowly with increasing concentration from 0.01 to 0.08 mmol/L.

Key words: Artemisia apiacea, polyphenol oxidase, enzymatic kinetics