Effect of culture,storage and variety on polyphenol oxidase and peroxidase activities in potatoes

The Viking potato variety was found to possess the highest activities for polyphenol oxidase and peroxidase, among the five varieties tested. The Norland and Pontiac varieties possessed the lowest polyphenol oxidase activity. There was a direct positive correlation between storage temperature and peroxidase activity (r = 0.66). The application of fertilizer potassium was shown to be a significant factor determining polyphenol oxidase activity in the tubers (p = 0.025), appearing in interactions with storage temperature and variety.