The polyphenol oxidase (PPO) enzyme tends to catalyze the oxidation of one particular phenol or phenolic compound more readily than others. It comprises of catechol oxidase and laccase. The activities of these enzymes are important with regard to  plant defense mechanism against pests and diseases and use of plant products. It can be isolate from  vegetables like Potato, Brinjal, mushroom etc.To get a crude enzyme preparation,  acetone with 2.5mL of 0.2M citrate phosphate buffer (pH 6.0), 1mL of 1% Triton X-100, 6.5mL of water and 500mg polyamide. Shake for 1h and filter. Use the filtrate as enzyme source.

Thanks Deepmala Katiyar  for your answer

you need to purchase kits, its contain procedure and equation

Thanks brother, Actually one of my friend need this procedure.I will ask him

Regards

The answer from Deepmala has cleared. Good luck