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Purification and some properties of polyphenoloxidase in eggplant ( Solanum melongena )
Author(s) -
Fujita Shuji,
Tono Tetsuzo
Publication year - 1988
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740460111
Subject(s) - chemistry , chlorogenic acid , chromatography , enzyme , solanum , sephadex , sodium , ammonium , potassium cyanide , enzyme assay , size exclusion chromatography , melongena , cyanide , biochemistry , botany , organic chemistry , biology
Polyphenoloxidase (EC 1.10.3.1) in eggplant ( Solatium melongena L) was purified by ammonium sulphate fractionation, DEAE‐Cellulofine and DEAE‐Toyopearl chromatography and Sephadex G‐100 gel filtration. The enzyme was purified about 110‐fold with a recovery of 5%. The purified enzyme more quickly oxidised chlorogenic acid (5‐caffeoylquinic acid, IUPAC) than 10 other substrates used. The K m value for the enzyme was found to be 0·50 mM with respect to chlorogenic acid; the optimum pH of the enzyme was about 4 with enzyme stability between pH 5 and 8. The enzyme was completely inactivated after heat treatment at 75°C for 30 min or 80°C for 5 min. Sodium metabisulphite, potassium cyanide and sodium fluoride markedly inhibited the enzyme activity.