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Purification and enzymatic characteristics of a novel polyphenol oxidase from lotus seed ( Nelumbo nucifera Gaertn.)
Author(s) -
Cai XiXi,
Hong YongXiang,
Wang ShaoYun,
Zhao LiNa,
Rao PingFan
Publication year - 2015
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/ijfs.12735
Subject(s) - polyphenol oxidase , chemistry , browning , ascorbic acid , citric acid , catechol , catechol oxidase , lotus , urea , sodium , polyphenol , enzyme , nuclear chemistry , chromatography , biochemistry , food science , antioxidant , organic chemistry , botany , peroxidase , biology
Summary A polyphenol oxidase ( PPO ) from lotus seed was purified by the procedures including ammonium sulphate precipitation and affinity chromatography. The apparent molecular mass was 38.6 kD a by SDS ‐ PAGE . Kinetic studies showed that the K m and V max values for catechol were 6.04 m m and 416.67 U, respectively. The PPO performed optimal activity in 20 °C and pH 7.0. The enzymatic activity could be mainly maintained up to 50 °C and pH 4.0–7.0. The activity could be inhibited by various inhibitors including thiourea, urea, sodium hydrogen sulphite, EDTA ·2Na, SDS , citric acid, guanidine hydrochloride, ascorbic acid, sodium sulphite and sodium thiosulphate. The metal ions Ba 2+ , Mg 2+ , Ca 2+ , Mn 2+ , Co 2+ and Zn 2+ could inhibit the activity of PPO , while Cu 2+ performed obvious enhancement. The enzymatic properties of PPO could probably provide practical application in inhibiting the PPO activity and preventing enzymatic browning in the process of picking, transportation, processing and storage of fresh lotus seeds.