Characterization of polyphenol oxidase during three ripening stages of an eggplant (Solanum melongena L.) fruit: a local type in northeast Anatolia [Patlıcan (Solanum melongena L.) meyvesinin polifenol oksidazının üç olgunlaşma safhası boyunca karakteriza
ABSTRACT Objective: A relatively new local type of eggplant, Solanum melongena L. ‘Kadife’ is widely consumed in Turkey because of its economic availability and good nutritional qualities. However, the high polyphenol content of eggplant renders it susceptible to unattractive oxidative browning catalyzed by polyphenol oxides (PPOs). Therefore, the main aim of this study was to characterize PPO in this eggplant cultivar at three stages of its development. Methods: In this study, we determined substrate specificity, optimum pH and temperature, and optimum substrate concentration of the partial purified eggplant fruits PPO during ripening. Results: L-DOPA was proved to be the preferred PPO substrate in all three stages of ripening. Optimum activity was observed at pH 7.0 for PPO in extracts of ripening and overly-ripe eggplant, while activity in extracts of immature eggplant exhibited a broad pH optimum between, pH 5.0 and 7.0. In general, at all ripening stages, PPO was most active at 30°C and was most sensitive to inhibition by sodium metabisulphite and ascorbic acid. The metal ions (Hg2+, Mn2+, Fe3+ and Co2+) mostly inhibited PPO activities. Conclusion: These data regarding the properties of PPO should enhance understanding of the browning reaction in eggplant and lead to the development of techniques for controlling this undesirable process.
Hülya TORUN Yakup KOLCUOĞLU Faik Ahmet AYAZ Ahmet ÇOLAK Robert Hayes GLEW
Hülya Torun, Yakup Kolcuoğlu, Faik Ahmet Ayaz, Ahmet Çolak, Robert Hayes Glew
Anahtar Kelimeler : Browning, eggplant, polyphenol oxidase, ripening, Solanum melongena,Esmerleşme, patlıcan, polifenol oksidaz, olgunlaşma, Solanum melongena
Dönem : 2015 | Cilt : 40 | Seri : 1 | Sayfalar : 44-50 | Doi : 10.5505/tjb.2015.27146
Okuma : 14 | İndirme : 13 | Yayınlama :