Results 241 to 250 of about 58,939 (280)

Preharvest changes in polyphenols, peroxidase, and polyphenol oxidase in sorghum grain

Journal of Agricultural and Food Chemistry, 1981
At various stages of preharvest development. "bird-resistant" sorghum (Sorghum bicolor (I,.) Moench] grain was analyzed for tannin content and polyphenol oxidizing enzymes. Tannins appeared first at the milk stage, reached a maximum at the hard dough stage, and thereafter declined by 25%. Polyphenol oxidase (PPO) and peroxidase activities were detected
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Direct Electrochemistry of Polyphenol Oxidase

2014
The electrochemistry of banana tissues on a carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) is presented. Cyclic voltammetry is applied to investigate the direct electrochemistry of banana tissues i.e. a source of polyphenol oxidase (PPO). A redox couple with an anodic and counterpart cathodic peak is obtained. The influence
Raoof, Jahan Bakhsh, Kiani, Abolfazl, Ojani, Reza, Valiollahi, Roudabeh   +3 more
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[145] Plant tyrosinase (polyphenol oxidase)

1955
Publisher Summary This chapter discusses the determination plant tyrosinase. The darkening of mushrooms, potatoes, apples, and many other plants and plant products on injury to the tissue is the result of the enzymatic oxidation of certain mo/aohydric and o-dihydric phenols.
Charles R. Dawson, Richard J. Magee
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Polyphenol Oxidases from Wine Grapes

2017
Wine is produced from grapes which contain enzymes forming unfavorable dark polymers such as melanin, oxidizing proteins, and phenols which may influence their functions. Here we focus on the class of type-3 copper proteins presenting new insights on the structure, the occurrence during the ripening process and during wine making.
Petra Fronk, Matthias Riebel, Heinz Decker   +2 more
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Polyphenol oxidase of dates

Journal of Agricultural and Food Chemistry, 1980
S, Hasegawa, V P, Maier
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Polyphenol oxidase isoenzymes in avocado

Phytochemistry, 1976
Abstract Avocado polyphenol oxidase (PPO) was precipitated mainly in the 30–90% saturated ammonium sulfate fraction. The 40–75% saturated ammonium sulfate fraction (the partially purified enzyme) had the highest specific activity in the cultivars Lerman, Horeshim and Fuerte. The PPO was active towards o -dihydroxyphenols.
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Physicochemical Properties of Polyphenol Oxidases

2017
The presence of multiple molecular forms of polyphenol oxidases (PPOs) in several plant species is very well established (Yoruk and Marshall 2003). In addition to the differences in number, the properties of PPOs within and outside a particular species also differ significantly.
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Polyphenol Oxidase

1994
John C. Steffens, Eitan Harel, Michelle D. Hunt   +2 more
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Polyphenol Oxidase

2002
Edna Rami√≠rez, John Whitaker, Victoria Virador   +2 more
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Reaction Features of Polyphenol Oxidases

2017
Polyphenol oxidases (PPOs) are dinuclear copper-containing metalloproteins that are present and characterized in several higher plants (Flurkey 1989; van Gelder et al. 1997; Demeke and Morris 2002). PPOs are also known as catechol oxidase, catecholase, diphenol oxidase, o-diphenolase, phenolase, and tyrosinase (Martinez and Whitaker 1995).
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