Characterization and immobilization of purified polyphenol oxidase extracted from banana peel

Abstract

This study was undertaken to obtain a crude extract of polyphenol oxidase (PPO) from banana peel in addition to purification and characterization to determining the optimal temperature, pH, the storage periods , number of used times and dyes decolrization. A partial purified polyphenol oxidase from banana peel was immobilized by agarose and Calcium Alginates. The entrapment of PPO by the Calcium alginate showed the best method for the immobilization. The immobilized and free PPO enzyme properties were studied. The results of study showed the optimal pH of free and immobilized PPO enzyme activities from banana peel were 7.0; the optimal pH of free PPO enzyme stability ranged from 6.0 - 7.0. The optimal pH of immobilized PPO enzyme stability ranged between7 - 8. The optimal temperatures of free and immobilized PPO activity extracted from banana peel were 35^ᴼC and the free enzyme was stabilized in temperature 35 ᵒC then the enzyme activity began to decrease and it was lost at 60^ᵒC; the immobilized enzyme remained stable in temperature ranged 35-55 ^ᵒC. The immobilized PPO activity which incubated for more times with catechol decreased after ninth time of using, the experiment showed that the activity of immobilized enzyme decreased with long storage period. The neutral red, acridine and toluidine were decolorized and showed a change in their absorbance values after the immobilized PPO incubate for a time while no analysis occurred for other dyes.