Determination of biochemical properties of polyphenol oxidase from domat olive

This research was undertaken to determine some of the biochemical properties (substrate specificity, optimum pH, optimum temperature, heat inactivation, and effect of inhibitors) of polyphenol oxidase (PPO) which was isolated from Domat olives grown in Çukurova region and partially purified.4-methylcatechol was used as substrate and Km dand Vm values of the enzyme were found to be 14.52 mM and 1.73 Abs/dk, respectively. The optimum pH and temperature for PPO activity was found to be 4.5 and 30°C, respectively. After the optimum pH enzyme activity declined rapidly. The enzyme had more than 70% activity between 20-50°C. Energy of activation (Ea) and Z values were found to be 121 kj.mol-1 (r²=0.9496) and 18.55°C (r²=0.9532), respectively. Of the inhibitors tested, ascorbic asid was the least effective inhibitor.