Amino Acid Profile of Matcha
Matcha contains 30–40mg of free amino acids per gram, with L-theanine comprising ~45% of the total. Shade-growing suppresses photosynthetic conversion of theanine to catechins, elevating all free amino acids by 3–4× compared to sun-grown tea.
| Measure | Value | Unit | Notes |
|---|---|---|---|
| Total free amino acids per gram of matcha | 30–40 | mg/g | First-flush ceremonial grade; varies significantly by cultivar and shade period |
| L-theanine share of total free amino acids | ~45 | % | Unique to tea; not found in other plants at this concentration |
| Glutamic acid share | ~25 | % | Primary contributor to umami taste perception |
| Arginine share | ~10 | % | Converted to theanine via γ-glutamylmethylamide pathway in roots |
| GABA content (shade-grown matcha) | 1–2 | mg/g | Higher in anaerobic-processed GABA tea; normal matcha is lower |
| Amino acid increase from shading (vs. sun-grown) | 3–4× | Across all free amino acids |
Matcha’s amino acid profile is among the richest of any plant-based food — a direct consequence of the shade-growing protocol applied before harvest. While most of the attention focuses on L-theanine, matcha contains a suite of free amino acids that collectively determine its umami character and nutritional profile.
How Shade-Growing Elevates Amino Acids
The biosynthetic pathway is key: L-theanine is synthesized in tea plant roots (from ethylamine and glutamate) and transported to leaves. In leaves with adequate sunlight, L-theanine is enzymatically converted to catechins (polyphenols) via the phenylpropanoid pathway. When sunlight is reduced by 70–90%, this conversion is suppressed, and L-theanine accumulates along with other precursor amino acids.
Glutamic Acid and Umami
Glutamic acid (the ionized form: glutamate) is the fundamental umami compound — the same molecule added as MSG. Its elevated concentration in shade-grown matcha explains why high-quality matcha tastes savory and sweet rather than astringent and bitter. This is a key quality differentiator: good matcha should have forward umami notes before any bitterness.
GABA in Matcha
GABA (γ-aminobutyric acid) is present in small amounts in normal matcha (~1–2mg/g). Specialized “GABA tea” (produced by anaerobic processing) contains much higher GABA levels, but this is a distinct product category. Standard matcha’s GABA content is insufficient to cross the blood-brain barrier in significant quantities and is unlikely to produce pharmacological sedative effects at typical consumption doses.
Arginine’s Role
Arginine is a precursor to L-theanine synthesis via the γ-glutamylmethylamide pathway in tea roots. Its presence in the leaf reflects incomplete enzymatic processing. Arginine also contributes mild sweetness to the taste profile.