Polyphenol oxidase - Wikipedia
Polyphenol oxidase (PPO; also polyphenol oxidase i, chloroplastic), an enzyme involved in fruit browning, is a tetramer that contains four atoms of copper per molecule. [1] PPO may accept monophenols and/or o -diphenols as substrates. [2] .
多酚氧化酶 - 百度百科
多酚氧化酶（,PPO）是自然界中分布极广的一种 金属蛋白酶，普遍存在于植物、真菌、昆虫的质体中，甚至在土壤中腐烂的植物残渣上都可以检测到多酚氧化酶的活性。 由于其检测方便，是被最早研究的几类酶之一。 自1883年Yoghid发现日本漆树液汁变硬可能和某种活性物质相关，1938年Keilin D.和Mann G.研究了蘑菇多酚氧化酶的提取和纯化，得到多酚氧化酶并将这类酶称为polyphenol oxidase。 多酚氧化酶又称 儿茶酚 氧化酶， 酪氨酸酶，苯酚酶，甲酚酶， 邻苯二 …
Polyphenol Oxidases in Crops: Biochemical, Physiological and …
Polyphenol oxidases (PPOs) are a group of Cu-containing enzymes that catalyse the oxidation of several phenols to o -quinones [,]. In turn, o -quinones are highly reactive molecules that can undergo non-enzymatic secondary reactions to form brown complex polymers known as melanins and cross-linked polymers with protein functional groups [,,,].
Polyphenol Oxidase - an overview | ScienceDirect Topics
Polyphenol oxidases or tyrosinases (PPO) are enzymes with a dinuclear copper centre, which are able to insert oxygen in a position ortho- to an existing hydroxyl group in an aromatic ring, followed by the oxidation of the diphenol to the corresponding quinone. You might find these chapters and articles relevant to this topic.
Beyond brown: polyphenol oxidases as enzymes of plant …
Most cloned and/or characterized plant polyphenol oxidases (PPOs) have catechol oxidase activity (i.e., they oxidize o -diphenols to o -quinones) and are localized or predicted to be localized to plastids. As a class, they have broad substrate specificity and are associated with browning of produce and other plant materials.
Enzymatic browning and polyphenol oxidase control strategies
2023年6月1日 · Polyphenol oxidase (PPO) is the key enzyme involved in the enzymatic browning. In the past decades, various methods have been developed to inhibit browning of various fresh produce items. However, for most fresh horticultural produce, ideal measures accepted by industries and consumers are still scarce.
Polyphenol Oxidase - SpringerLink
PPOs are copper metalloproteins catalyzing the o - hydroxylation of a monophenol, followed by its oxidation to the o -diquinone (cresolase activity), or the oxidation of an o -dihydroxyphenol to the o -diquinone (catecholase activity). The quinonoid reaction products formed by PPO are familiar to anyone who has homogenized plant tissues.
Polyphenol oxidases in plants and fungi: Going places? A review
2006年11月1日 · Polyphenol oxidases or tyrosinases (PPO) are enzymes with a dinuclear copper centre, which are able to insert oxygen in a position ortho - to an existing hydroxyl group in an aromatic ring, followed by the oxidation of the diphenol to the corresponding quinone. Molecular oxygen is used in the reaction.
Polyphenoloxidase (PPO): Effect, Current Determination and Inhibition ...
2021年8月25日 · Knowledge about PPO action, determination and inhibition processes applied to minimally processed fruit and vegetables. Fresh-cut produce are quite popular among consumers due to their eating ease, high quality and functional content.
Polyphenol Oxidase - SpringerLink
Polyphenol oxidase (1,2-benzenediol:oxygen oxidoreductase; EC 1.10.3.1), also known as tyrosinase, phenolase, catechol oxidase, monophenol oxidase, creso-lase, and catecholase, was first discovered in 1856 by Schoenbein (1856) in mushrooms. He noted that something in mushrooms catalyzed the aerobic oxidation of certain compounds in plants.