Author(s): A.A. Al-Khalifa and R.M. Mahmoud
Article publication date: 1993-12-01
Vol. 11 No. 3 (yearly), pp. 377-390.
202
Keywords
Saudi Arabia, potato, enzyme
Abstract
Since polyphenol oxidase (PPO) plays the key role in enzymatic browning of potatoes, five potato varieties produced in Al-Kharj region, Kingdom of Saudi Arabia, were evaluated for PPO activity. Wide variations in PPO activities among the different potato varieties were found . Ajax potato variety was very low in PPO. Extensive cultivation of low PPO potato varieties should be encouraged. Characteristics of potato PPO extract were also investigated. The temperature and pH optima for the enzyme we re 30-40°C and pH 7, respectively. Heat stability studies indicated that a complete inactivation of PPO occurred at 800C for 30 min. Regarding the effect of inhibitors on the enzyme. sodium metabisulfite and ascorbic acid were the most effective. whereas sodium chloride and EDTA were the least.