Catechins (tea polyphenols)

This listing is the catechin fraction of green tea rather than a single-marker EGCG isolate, and it is specified on the sum of the five flavan-3-ols the leaf actually contains. From the young unfermented leaf and leaf bud of Camellia sinensis (L.) Kuntze, family Theaceae, those are (-)-epigallocatechin gallate, C22H18O11, MW 458.37, CAS 989-51-5; (-)-epigallocatechin, C15H14O7, MW 306.27, CAS 970-74-1; (-)-epicatechin-3-O-gallate, C22H18O10, MW 442.40, CAS 1257-08-5; (-)-epicatechin, C15H14O6, MW 290.27, CAS 490-46-0; and (+)-catechin, C15H14O6, MW 290.27, CAS 154-23-4. Each is reported individually on the certificate of analysis as well as in the total, because the ratio between them is what separates a genuine leaf catechin fraction from a re-blended isolate. As an article of commerce the material also carries the extract-level registry number CAS 84650-60-2, tea polyphenols or Camellia sinensis leaf extract - a UVCB number describing a substance of variable composition, not a discrete chemical identity, and it should never be quoted as though it were a purity statement. Three numbers move independently on this product and a purchase order that names only one is incomplete. Total tea polyphenols are measured by the Folin-Ciocalteu procedure as gallic acid equivalents and run from roughly 70% to 98%; total catechins are measured by HPLC calculated as EGCG and run from roughly 50% to 90%; the two will not reconcile on the same powder, and a grade sold as '98% polyphenols' typically carries a materially lower catechin sum. Caffeine is the third axis: native leaf caffeine stays in the extract unless it is deliberately removed, so the figure has to be specified rather than inferred from the catechin assay, and the decaffeination route - hot water, supercritical carbon dioxide or ethyl acetate - is stated with its residual solvent limits. The USP monograph for Powdered Decaffeinated Green Tea Extract gives a useful reference frame even for non-USP grades: a 6:1 to 10:1 plant-to-extract ratio, total catechins not less than 60.0% calculated as EGCG, EGCG not less than 40.0%, caffeine not more than 0.1% on the anhydrous basis, water not more than 6.0% and residue on ignition not more than 0.5%. Process behaviour and market constraints. Catechins epimerise and oxidise with heat and alkaline pH - EGCG converts to gallocatechin gallate and ECG to catechin gallate - so a hot-filled or retorted beverage lot can still pass a total-catechin limit while its profile has shifted underneath the number; agree before qualification whether the epimers are counted in the sum, and formulate on the acid side of neutral in opaque packaging. Lead deserves a line of its own: tea is a lead-accumulating leaf crop, which makes a lead limit a standing requirement for US buyers with California Proposition 65 exposure. In the EU, Commission Regulation (EU) 2022/2340, in force since 21 December 2022, keeps an individual portion of a food below 800 mg of EGCG and requires foods containing green tea extract to declare EGCG per portion and the maximum number of portions per day, with warning statements including that the product should not be taken alongside other green tea products on the same day, nor by pregnant or lactating women or anyone under 18 - a formulation and artwork constraint to settle before purchase. The extract is plant-derived, vegan and vegetarian, with no milk, egg, soy, fish, crustacean, mollusc, peanut, tree nut, sesame or gluten-bearing input and no bovine, porcine or marine material; where a spray-drying carrier is used it is maize-derived maltodextrin, named on the specification. Composition and food-technology function only; no therapeutic or disease claim is made or supported.