Catechin Types and How Content Varies

Catechin is a collective term, not a single compound.

In brewed green tea, the proportions run approximately:

Compound	Abbreviation	Share
Epigallocatechin gallate	EGCG	about 59%
Epigallocatechin	EGC	about 19%
Epicatechin gallate	ECG	about 14%
Epicatechin	EC	about 6%

Total catechins account for 8 to 20 percent of dry leaf weight. The range is wide because cultivar, growing method, and harvest timing all move it.

Gallate forms are more astringent

Compounds with gallate in the name — EGCG and ECG — carry an attached gallic acid group. These read as more astringent.

So two teas with identical total catechins can taste different depending on the ratio. Total content alone does not determine flavor.

Cultivation moves the number

Catechin levels respond to light exposure. L-theanine, the savory amino acid, converts into catechins when leaves receive sunlight.

Shaded cultivation slows that conversion. Tencha — the leaf behind matcha — and gyokuro are both grown under cover, so they carry relatively less catechin and more theanine than sencha grown in full sun.

Composition as a quality marker

Research from NARO, Japan's agricultural research organization, reports that higher-priced matcha tends to show higher theanine content, with a distinguishable EGCG-to-EGC ratio.

Composition can function as an objective indicator of grade rather than a matter of impression.

In sweetened products

Catechin content depends on how much of the powder is matcha. A sugar-heavy blend delivers less per 20 g serving.

Few products state catechin figures on the label. The ingredient order gives you the practical estimate.