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Polyphenol Oxidase from Apple (Malus domestica Borkh. cv Bramley's Seedling): Purification Strategies and Characterization
Author(s) -
Ni Eidhin Deirdre M.,
Murphy Eileen,
O'Beirne David
Publication year - 2006
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.2006.tb12388.x
Subject(s) - polyphenol oxidase , sodium metabisulfite , chemistry , pyrogallol , catechol oxidase , ascorbic acid , ion chromatography , ammonium sulfate precipitation , polyacrylamide gel electrophoresis , catechol , malus , chromatography , polyphenol , sodium dodecyl sulfate , size exclusion chromatography , biochemistry , food science , enzyme , antioxidant , botany , biology , peroxidase
Polyphenol oxidase (PPO) was isolated from Bramley's Seedling apples with 75.7‐fold purification and 26.5% recovery by ammonium sulfate precipitation, phenyl sepharose chromatography, ion exchange chromatography, and hydroxyapatite chromatography. Molecular weight was estimated to be about 45 kDa by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS PAGE). Optimum PPO activity was at pH 6.5 and greater than 50% activity was retained during storage for 72 h at pH 5.5 to 6.5. Optimum temperature for activity was 30 °C and the enzyme had residual activity of greater than 50% during storage for 72 h at 20 °C to 30 °C and for 24 h at 40 °C to 50 °C. Of the substrates tested, activity was greatest with 4‐methylcatechol followed by catechol, pyrogallol, and (−)epicatechin. The most effective inhibitors tested were sodium metabisulfite and ascorbic acid.