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]

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 (PPO) is a copper-containing phenolase discovered in most animals, plants (not found in Arabidopsis thaliana, Brassica napus, and green algae), and microorganisms [1,2,3]. In plants, PPO is encoded by multiple genes from the nuclear genome.

Polyphenol oxidase (PPO) is a copper containing enzyme widely occurred in many plants, animals, bacteria and some fungi. Polyphenol oxidase has wide applications in the field of biosensor formation, food industry, medicine and waste water treatment.

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.

2025年1月1日 · The role of polyphenol oxidase (PPO) induction in plant defense against biotic stimuli (living organisms) has been extensively studied. Here, we explore the complex relationship between PPO activity, pathogen resistance, and the potential mechanisms involved.

Polyphenol oxidase (PPO) -catalyzed browning reactions are of significant importance in the fruit and vegetable industry. These reactions proceeding in many foods of plant origin cause deterioration and loss of food quality. A better knowledge of the factors that influence the action of PPO is imperative in order

2023年2月25日 · PPO has an important role in plant stress resistance and physiological metabolism. However, the enzymatic browning reaction induced by PPO is a major problem in the production, processing, and storage of fruits and vegetables.

2008年9月12日 · Polyphenol oxidase, a copper-containing metalloprotein, catalyzes the oxidation of phenolic compounds to quinones, which produce brown pigments in wounded tissues. This enzymatic mechanism causes post harvest losses and mainly affects tropical fruits.

2021年1月1日 · Polyphenol oxidases (PPOs) catalyse the oxidation of phenols to highly reactive o-quinones, after which non-enzymatic secondary reactions result in the formation of melanin polymers and cross-linked polymers with protein functional groups.