Characterization, purification, and temperature/pressure stability of polyphenol oxidase extracted from plums ( Prunus domestica )

Extraction, purification and processing stability of peroxidase from plums (Prunus domestica)

“…In this manner, the substrate specificity of each oxidative enzyme was assessed with different compounds, providing the possibility to identify them based on their catalytic behavior toward different specific substrates. In accordance with the specific enzymatic activity values, the results suggested the presence of both enzymes, PPO [8] and POD, corresponding to the two protein bands separated by SDS-PAGE. Taken into consideration the specific enzymatic activities and also the catalytic behavior, we estimated that the second protein band corresponds to POD.…”

“…The extraction and purification procedure was performed according to the method proposed by Ioniţǎ et al. [8] To purify the enzyme, three purification phases were taken into account, namely ammonium sulfate precipitation, hydrophobic interaction chromatography (HIC), and ion exchange chromatography (IEC). The crude enzyme extract was subjected to two stages of precipitation with ammonium sulfate 30% and 90%.…”

“…As expected for the oxidative enzymes, the inactivation of POD induced by thermal treatment was described by a first-order kinetic model. The equations used for modeling the inactivation kinetics were previously reported by Ioniţă et al [8] Stability at high pressure The high-pressure stability was determined as stipulated by Ioniţă et al [8] with a RESATO FPU 100-2000 food processor equipment (Resato International B.V., Netherlands). The partially purified extract was loaded into Eppendorf tubes and treated at a pressure range between 300 and 700 MPa, for 20 min, at 10°C, 30°C, and 50°C.…”

Comparison of biochemical properties and thermal inactivation of membrane‐bound polyphenol oxidase from three apple cultivars (Malus domestica Borkh)

“…The thermal inactivation of mPPOs was studied at temperatures between 45 and 75 °C according to the method of Ioniţă et al . (). For the experiment, 2 mL of crude mPPO mixture was poured into a water bath at different temperatures (45, 55, 65 and 75 °C) and for different periods (10, 20, 30, 40, 50 and 60 min).…”

“…The enzymatic activity of mPPO was determined through the method described by Ioniţă et al . () with some modifications. The reaction mixture, which consisted of 0.5 mL of mPPO extract and 2.5 mL of substrate solution (0.2 m catechol in 0.05 m phosphate buffer, pH 6.8), was incubated at 20 °C for 10 min.…”