Partially Purification and Characterization of Polyphenol Oxidase of Quince

نویسندگان

  • Hülya YAĞAR
  • Ayten SAĞIROĞLU
چکیده

In fruits and vegetables, browning occurs due to the oxidation of polyphenols. Oxidative browning is catalysed by polyphenol oxidase (PPO; monophenol, dihydroxyphenyl alanine:oxygen oxidoreductase; EC.1.14.18.1). When fresh products are damaged oxidative browning occurs, and this is an economic problem for producers and consumers. Polyphenoloxidase, which is a copper-containing enzyme, catalyses the aerobic regioselective oxidation of monophenols to o-diphenols followed by dehydrogenation to o-quinons. PPO is widely distributed in plants and microorganisms and many researchers are interested in the PPO isolated from various sources such as the banana, Amasya apple, kiwi fruit, edible burdock, head lettuce , pear, palmito, cocoa bean and oil bean. However, there are only a few articles about quince PPO . The purpose of this study was to isolate PPO from quince and determine some of its enzymatic properties. In the study, the characteristics of the enzyme were investigated at different pH levels and temperatures. Substrate and inhibitor effects were also studied. The assays of PPO activity were carried out in the presence of air oxygen.

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تاریخ انتشار 2002