Abstract:

The major physico-chemical properties of polyphenol oxidase (PPO) from apricot kernel were studied in this paper.
The results showed that the optimum parameters for determining the PPO activity of apricot kernel were established by using
catechol as the substrate at a concentration of 1.0 mol/L, reaction at 40 ℃ for 3 min in pH 3 buffer solution and detection
at a wavelength of 410 nm. The corresponding Km and Vmax were 20.53 and 1.27 U/min, respectively. The thermostability of
PPO activity from apricot kernel suggested that treatment time had a slight influence on the PPO activity in the temperature
range of 30 – 50 ℃, while the PPO activity decreased sharply with an increase in treatment time at a given temperature of
60 – 100 ℃. The half-life time of PPO activity was 15 and 3 min at the temperature of 60 and 100 ℃, respectively.

Key words: apricot kernel, polyphenol oxidase (PPO), physico-chemical property