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

Peroxidase (POD) was extracted from Prunus domestica and partially purified by three methods: ammonium sulfate precipitation, hydrophobic interaction chromatography, and ion exchange chromatography, respectively. The selected procedure allowed a 26.33-fold purification, and the molecular mass estimated by SDS-PAGE was 58 kDa. The purified enzyme presented enzymatic activity toward guaiacol, pyrogallol, catechol, and showed no activity toward ferulic, caffeic, and p-coumaric acids. In terms of optimum parameters for activity, the pH was 6.5, whereas the temperature was 25 degrees C. The enzyme exhibited high stability in the pH range of 5.0-7.0 and in the temperature range of 25-70 degrees C. The most potent inhibitors of POD were L-cysteine and sodium metabisulfite. The thermal inactivation displayed a first-order kinetic model, with an activation energy of E(a)84.79 +/- 2.2kJ/mol. POD extracted from plums exhibited high stability at high-pressure treatment, maintaining over 50% of the initial activity even at 700 MPa.