The most commonly studied polyphenols are procyanidins, quercetin, isoflavones and catechins.

Also, certain yams contain an enzyme called polyphenol oxidase, which speeds up oxidation when the yam is cut, further deepening the colour change.

Enzymes like polyphenol oxidase speed things up, quickly clumping the polyphenols inside -- like our four catechins -- into bigger, reddish brown pigments such as thearubigins and theaflavins.

In particular, green tea contains catechins and caffeine. These may help promote weight loss by increasing the number of calories you burn daily (energy expenditure) and boosting fat oxidation ...

Feeding with tea catechins for 1 month significantly increased acyl-CoA oxidase and medium chain acyl-CoA dehydrogenase mRNA expression as well as β-oxidation activity in the liver.

When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors ...

In apples, this oxidation of polyphenolic compounds in presence of oxygen (in air) is catalysed by some enzymes called polyphenol oxidase or tyrosinase. Enzymes have a coiled structure and when an an ...

This process stops chemical reactions driven by the enzyme polyphenol oxidase that would otherwise oxidise coloured chemicals such as polyphenols (catechins).

Research Paper For A Support System Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans.