Turmeric Extract / Curcumin 95%

Curcumin 95% is the purified curcuminoid concentrate obtained by solvent extraction of the ground rhizome of Curcuma longa L. (Curcuma domestica Valeton), family Zingiberaceae, followed by crystallisation. It is a step beyond turmeric oleoresin: the volatile oil and most of the resinous matter are removed, leaving the three colouring principles. The USP Curcuminoids monograph sets NLT 95.0% total curcuminoids on the dried basis, with curcumin at 70.0–80.0%, desmethoxycurcumin at 15.0–25.0% and bisdesmethoxycurcumin at 2.5–6.5%. The JECFA food-additive monograph for curcumin, INS 100(i), takes a different route and requires NLT 90% total colouring matters by absorbance at 425 nm using a specific absorbance of 1607. Thovek states which method a batch was assayed by, because a spectrophotometric 95% and an HPLC 95% are not the same number. Curcumin itself is 1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione, CAS 458-37-7, C21H20O6, MW 368.39. The two minor curcuminoids are demethoxycurcumin (CAS 33171-16-3, C20H18O5) and bisdemethoxycurcumin (CAS 33171-05-0, C19H16O4). The material is an orange-yellow crystalline powder, insoluble in water and diethyl ether and soluble in ethanol and glacial acetic acid. That water insolubility is the practical constraint for most buyers, and separate water-dispersible, phospholipid-complexed and colloidal grades are offered rather than being represented as the same article. Only acetone, methanol, ethanol, isopropanol, hexane and ethyl acetate may be used in extraction and purification under the JECFA monograph, with supercritical carbon dioxide also permitted; residual solvent limits are set at NMT 30 mg/kg acetone, NMT 25 mg/kg hexane and NMT 50 mg/kg each for the remaining four, with lead at NMT 2 mg/kg. Thovek tests to those limits and can supply solvent-free scCO2 material where a clean-label declaration is required. The powder is plant-derived, vegan and vegetarian, non-GMO, and free of milk, egg, soy, fish, crustacean, mollusc, peanut, tree nut, sesame, mustard, celery, lupin and gluten. Curcumin is light-sensitive and stains readily, so it ships in opaque liners and should be handled in dedicated equipment.