Green tea is a type of tea that is made from Camellia sinensis leaves and buds that have not undergone the same withering and oxidation process used to make oolong teas and black teas. Green tea originated in China, and since then its production and manufacture has spread to other countries in East Asia.
Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6H2(OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. It is a white solid, although samples are typically brown owing to partial oxidation. Salts and esters of gallic acid are termed "gallates".
Flavonoids are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Flavan-3-ols are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2H-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of compounds, such as catechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins, thearubigins. They are found in most plants and have a role in plant defense.
Polyphenols are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids.
Polyphenon is a series of high grade green tea polyphenol extracts manufactured by the Mitsui Norin Co., Ltd. of Japan. The extracts are in part the result of a water based extraction method which begins with green tea leaves, and then involves successive steps which concentrate the catechins thought to be responsible for the health benefits of green tea.
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of tannins.
Thearubigins are polymeric polyphenols that are formed during the enzymatic oxidation and condensation of two gallocatechins with the participation of polyphenol oxidases during the fermentation reactions in black tea. Thearubigins are red in colour and are responsible for much of the staining effect of tea. Therefore, a black tea often appears red while a green or white tea has a much clearer appearance. The colour of a black tea, however, is affected by many other factors as well, such as the amount of theaflavins, another oxidized form of polyphenols.
Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin.
Gallocatechol or gallocatechin (GC) is a flavan-3-ol, a type of chemical compound including catechin, with the gallate residue being in an isomeric trans position.
Theaflavin digallate (TFDG) is an antioxidant natural phenol found in black tea, and a theaflavin derivative.
The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers (catechins) and flavanol polymers (proanthocyanidins). This large group of natural phenols can be broadly separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color and mouthfeel of the wine. The non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids.
Matcha is finely ground powder of specially grown and processed green tea leaves, traditionally consumed in East Asia. The green tea plants used for matcha are shade-grown for three to four weeks before harvest; the stems and veins are removed during processing. During shaded growth, the plant Camellia sinensis produces more theanine and caffeine. The powdered form of matcha is consumed differently from tea leaves or tea bags, as it is suspended in a liquid, typically water or milk.
Prodelphinidin is a name for the polymeric tannins composed of gallocatechin. It yields delphinidin during depolymerisation under oxidative conditions.
The molecular formula C22H18O11 (molar mass: 458.37 g/mol, exact mass: 458.084911) may refer to:
Epicatechin gallate (ECG) is a flavan-3-ol, a type of flavonoid, present in green tea. It is also reported in buckwheat and in grape.
Prorobinetidins are a type of condensed tannins formed from robinetinidol. They form robinetinidin when depolymerized under oxidative conditions.
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel of tea. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids.
