Department of Basic Sciences, University of Horticulture and Forestry, Solan-173 230 (H.P.)
A crude preparation of polyphenol oxidase (PPO) from ‘Elberta’ peaches showed a shift from a single pH optimum at 7.0 to two optima at 6.6 and 7.4 during ripening. The PPO activity and the number of isoenzymes increased in ripe peaches. New isoenzymes of PPO are synthesized in ripe peaches as the result of shift in pH optimum. The temperature optimum was 37°C and Km was 25 × 10-2 when catechol was used as substrate.
