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Properties of polyphenol oxidase in mango ( Mangifera indica ) kernel
Author(s) -
Arogba S S,
Ajiboye O L,
Ugboko L A,
Essienette S Y,
Afolabi P O
Publication year - 1998
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/(sici)1097-0010(199808)77:4<459::aid-jsfa61>3.0.co;2-o
Subject(s) - mangifera , polyphenol oxidase , catechol , chemistry , substrate (aquarium) , catechol oxidase , polyphenol , anacardiaceae , food science , enzyme , kernel (algebra) , nuclear chemistry , botany , horticulture , biochemistry , peroxidase , biology , antioxidant , mathematics , ecology , combinatorics
Polyphenol oxidase (PPO) activity of filtered extract of ground mango kernel suspension (400 g litre −1 ) was studied spectrophotometrically at 420 nm using catechol as substrate. The enzyme was most active at pH 6·0 and 25°C. Activity was reduced by 50% at pH values of 5·0 and 7·1, and also at temperatures of 14°C and 30°C. The calculated activation energy and the Michaelis constant ( K m ) were 21·4 kcal mol −1 °C −1 and 24·6 m M , respectively. The V max value was 2·14 units g −1 mango kernel. The time to heat inactivate PPO decreased rapidly to < 10 min with increasing temperature of ⩾ 70°C at 50% activity. © 1998 SCI.