Epigallocatechin (EGC)

Ureda Naturals manufactures green tea–derived Epigallocatechin (EGC), CAS No. 970-74-1, in two standardized grades: EGC90 and EGC98.

Both grades are supplied as an off-white to light pink powder with caffeine controlled at ≤0.1%. Grade selection should be based on the target EGC dose, dosage format, caffeine limit and finished-product recovery—not assay percentage alone.

Specification at a Glance

Item	EGC90	EGC98
Product name	Epigallocatechin (EGC)	Epigallocatechin (EGC)
Botanical source	Green tea	Green tea
CAS No.	970-74-1	970-74-1
Appearance	Off-white to light pink powder	Off-white to light pink powder
EGC content	≥90%	≥98%
Caffeine	≤0.1%	≤0.1%

Which Grade Should You Start With?

Customer requirement	Recommended starting point	Reason
Low-dose capsule or tablet	EGC98	Lower material mass for the same EGC target
Formula with a wider dosage window	EGC90	More flexibility in total addition mass
Strict EGC standardization	EGC98	Smaller correction between target dose and weighed material
Heated or long-hold beverage	Compare both grades	Select by post-process recovery and appearance stability
Formula containing several tea ingredients	Either grade	Select after total caffeine mass-balance review
Pilot blend with uncertain filling behavior	Compare both grades	Select by blend uniformity and transfer recovery

EGC90 and EGC98 should not be treated as automatically interchangeable. A higher assay reduces the amount of material required, but it does not by itself prove better dispersion, flow, compression or stability in the finished formula.

EGC90 and EGC98: Dose Correction

The grade assay changes the quantity of raw material required to deliver a defined EGC amount.

Required material = Target EGC amount ÷ Assay fraction

Target EGC in finished product	EGC90 addition	EGC98 addition
100 mg	111.1 mg	102.0 mg
500 mg	555.6 mg	510.2 mg
1 g	1.111 g	1.020 g

For low-dose products, EGC98 can reduce the material burden in a capsule, tablet or sachet. For pilot blends or formulas with a wider active-loading range, EGC90 may provide more flexibility.

The calculation should be based on the agreed minimum assay during formulation locking. This prevents under-dosing when the assay is close to the grade limit.

Caffeine Mass Balance

Caffeine is controlled separately from EGC content.

• For a 100 mg EGC target, EGC90 requires approximately 111.1 mg of material and may contribute up to approximately 0.111 mg caffeine at the 0.1% limit.
• For the same target, EGC98 requires approximately 102.0 mg of material and may contribute up to approximately 0.102 mg caffeine at the same limit.

When other green tea ingredients are present, their caffeine contributions must be calculated separately and then combined. The finished-product caffeine level should not be calculated from the EGC target alone.

EGC Is Not Total Tea Polyphenols

A general green tea extract or total tea-polyphenol ingredient does not define the actual EGC input.

Ingredient	Abbreviation	Quality distinction
Epigallocatechin	EGC	Target compound in this product
Epigallocatechin gallate	EGCG	Different gallated catechin
Epicatechin gallate	ECG	Different gallated catechin
Epicatechin	EC	Different non-gallated catechin
Total tea polyphenols	—	Composite value, not an EGC-specific assay

A formula can meet a total tea-polyphenol target while containing a different ratio of EGC, EGCG, ECG and EC. For an EGC-specific product claim or release specification, the analytical method must identify and quantify EGC separately.

How EGC Quality Affects Customer Manufacturing

Manufacturing step	EGC-specific issue	Observable risk	Verification action
Incoming release	Wrong grade or incorrect assay basis	Incorrect active calculation	Confirm EGC grade, assay and caffeine
Weighing	Addition based on nominal mass instead of assay	Under-dosing	Apply assay correction before batching
Pre-blending	Low-dose distribution	Blend non-uniformity	Compare samples from different blender locations
Transfer and filling	Segregation or equipment hold-up	First, middle and last units differ	Test staged filling samples
Beverage dispersion	Matrix-dependent physical behavior	Haze, sediment or incomplete dispersion	Test the actual formula, not water alone
Heating and holding	EGC recovery and catechin stability	Assay decrease or color change	Compare pre-process and post-process samples
Storage	Assay or appearance drift	Finished product moves outside target	Test the final package at defined time points

Beverage and Aqueous Formulation

EGC assay and powder appearance do not determine final beverage clarity, dispersion time or storage performance.

A meaningful trial should use the actual formulation and control EGC concentration, formula pH, water composition, ionic strength, acidulants, sweeteners, flavors, addition order, mixing energy, heating profile, holding time, dissolved oxygen and packaging headspace.

The trial should measure dispersion behavior, visible haze or sediment, color before and after processing, EGC assay before and after processing, caffeine contribution and EGC recovery after holding and storage.

A water-only test cannot reproduce the effects of the customer’s acidulants, salts, flavors, oxygen exposure or thermal history.

Dry Blends, Tablets and Capsules

For solid dosage products, the EGC assay controls active input but does not predict powder-flow behavior or finished-dose uniformity.

The customer should qualify pre-blend uniformity, main-blend distribution, transfer loss, hopper discharge, first/middle/last filled units, finished-product EGC content, caffeine contribution and moisture exposure during storage.

If raw-material assay passes but finished-unit results vary, the likely control point may be segregation, transfer hold-up or insufficient pre-blending rather than a failure of the EGC grade.

Heat-Process and Stability Qualification

For heated or oxygen-exposed products, EGC should be measured across the process instead of only at incoming inspection.

Sampling point	Purpose
Incoming material	Confirm starting EGC and caffeine
Pre-process bulk	Confirm actual formula input
Immediately after heating	Detect early recovery loss
After cooling	Identify precipitation or physical loss
After holding	Measure process-related change
After storage	Confirm retained EGC level and appearance

EGC recovery (%) = Measured EGC after processing ÷ Theoretical EGC input × 100

A lower recovery should be investigated through incorrect dosing, incomplete dispersion, sedimentation, filtration loss, equipment hold-up, thermal or oxidative change and analytical recovery bias before changing the raw-material grade.

Analytical Release Requirements

The analytical procedure should distinguish EGC from EGCG, ECG and EC. Total tea-polyphenol testing cannot replace EGC-specific quantification.

The method should establish EGC identity, separation from related catechins, matrix recovery, repeatability, reporting basis and finished-product applicability.

Quality Documents and Supply

• Grade-specific Certificate of Analysis
• Technical Data Sheet
• Safety Data Sheet
• Product specification
• Packaging and storage information

• MOQ: 1 kg
• Bag options: 1 kg, 5 kg or 10 kg
• Fibre drum options: 5 kg, 10 kg or 25 kg
• Storage: Sealed in a cool, dry environment

 FAQ

What analytical specificity is needed to prevent EGCG, ECG or EC from inflating an EGC result?

The release method must identify and quantify EGC while resolving it from EGCG, ECG and EC. Total tea polyphenols or a non-selective colorimetric result cannot establish EGC content.

The method should demonstrate peak identity, separation from related catechins, matrix recovery, repeatability and a defined reporting basis.

What evidence is required before EGC90 and EGC98 can be treated as process-equivalent?

Assay equivalence alone is insufficient. Both grades should be tested in the same formula and process, comparing EGC recovery, caffeine contribution, blend uniformity, color, turbidity, heat-hold performance, finished-product assay and storage trend.

The grades should only be treated as interchangeable when the finished-product results meet the same predefined acceptance criteria.

How should the caffeine limit be propagated through a formula containing multiple green tea ingredients?

Caffeine must be calculated as a separate mass-balance component:

Maximum caffeine contribution = Ingredient addition × Caffeine limit

The caffeine contribution from EGC must be added to the caffeine contribution of every other tea-derived ingredient. Calculating caffeine only from the EGC target can underestimate the total caffeine level of the finished product.

How can a developer distinguish EGC degradation from analytical recovery bias in a finished beverage?

A lower post-process result does not automatically prove chemical degradation. Compare the incoming material, pre-process bulk, post-process bulk, sediment or filter residue and a matrix-spiked recovery sample using the same validated chromatographic method.

This separates chemical degradation, physical process loss and analytical interference before changing the raw-material grade or manufacturing process.

What changes require requalification of the selected EGC grade?

Requalification should be considered when the selected grade, target EGC dose, formula pH, acidulant system, heating profile, mixing equipment, filtration step, packaging or analytical method changes.

These changes can alter EGC recovery, color, caffeine contribution, finished-product uniformity or stability even when the incoming raw material still meets its original specification.