Sourcing Green Tea Extract: Origin, Raw Material & Supplier Qualification

Origin: India's Tea-Growing Regions

India is one of the world's largest tea producers, which gives extract manufacturers a deep, traceable raw-material base. Camellia sinensis leaf for extraction is drawn principally from:

• Assam - low-elevation, high-yield gardens; robust leaf well suited to bulk extraction.
• The Nilgiris (South India) - high-grown, year-round plucking; clean catechin profile.
• Darjeeling & Kangra - cooler, high-elevation leaf often used for premium and organic grades.

Sourcing under Good Agricultural and Collection Practices (GACP) with garden-level traceability is the baseline a serious buyer should expect.

Why Post-Harvest Processing Decides Catechin Content

Green tea's value rests on its native catechins. The moment leaf is plucked, its own polyphenol-oxidase enzymes begin oxidising those catechins into theaflavins (the path that produces black tea). To preserve catechins, leaf must be steamed or pan-fired soon after harvest to deactivate those enzymes. A supplier that cannot describe its de-enzyming step and time-to-processing window is a risk to your EGCG yield.

Contaminant Control Specific to Tea

Tea carries category-specific contaminant risks that buyers should test against explicitly:

Risk	Why it applies to tea	Control
Pesticide residues	Tea is an intensively cultivated crop	Screen against EU MRL (EC 396/2005); request the residue panel
Heavy metals	The tea plant can accumulate lead and aluminium from soil	ICP-MS with defined Pb/As/Cd/Hg limits
Residual solvents	From extraction / decaffeination	USP <467> compliance on the CoA
Microbial load	Leaf is a natural agricultural material	Full micro panel; pathogen absence

Supplier Qualification Checklist

• WHO-GMP and ISO 22000 certification, with audit reports available.
• HPLC identity and assay capability in-house (catechin/EGCG), not just UV polyphenols.
• Documented GACP sourcing and garden-level traceability.
• Batch-specific CoA, MSDS, allergen, BSE/TSE, Non-GMO, Country of Origin and Phytosanitary certificates.
• Organic, Halal and Kosher certification where your market requires it.
• Demonstrated batch-to-batch consistency across at least three CoAs.

Once a supplier is qualified, use our buyer's guide to lock the exact specification, and the standardisation guide to interpret the assay numbers correctly.