Types of Curcumin Extract: 7 Grades by Process, Assay and Use
A purchase order that says “curcumin 95%” is not a complete specification. The number may refer to total curcuminoids, curcumin alone, or a colourant assay measured by a different method. It also does not tell you whether the material is a natural extract, a purified single compound, a formulated powder or a feed ingredient. Those differences affect COA comparisons, active-content calculations and whether the ingredient fits the finished product.[1][3]
Use the guide below to compare seven commercial forms by assay, chromatographic profile, process and intended use. The categories are a practical sourcing framework—not seven official pharmacopoeial grades—and some describe different dimensions of a product.
Start with the finished product
For capsules and tablets
Start by evaluating a natural standardized curcuminoid extract. Confirm whether the assay is total curcuminoids, request curcumin, DMC and BDMC separately, and check the calculation basis.
For drinks and water-based formulas
Evaluate a water-dispersible formulation, not just a high-assay extract. Check the active content in the finished powder, carrier and allergens, plus dispersion and stability in your actual formula.
For single-compound research
Specify single-peak curcumin and the required assay. It may come from further purification of a natural extract or from synthesis, so source must be declared separately.
For colour-sensitive formulations
Tetrahydrocurcumin (THCu) is a different, much less yellow compound—not a higher grade of curcumin. Confirm its own assay, impurity profile and suitability for the intended market.
Synthetic three-peak blends, feed-grade materials and turmeric residues are more specialised cases. Verify the exact process, batch profile and intended-use status before specifying them; a similar chromatogram or a low price does not establish source or suitability.
01 · At a glance
Seven Commercial Forms: What Actually Differs?
Compare the specification, not just the product name. Trade ranges below are examples, not universal standards. The HPLC descriptions assume a suitable method that resolves the compounds in question; peak count alone cannot prove natural or synthetic origin.
| Commercial form | Typical assay or definition | HPLC profile | Appearance | Process or key distinction | Typical fit | Critical purchasing check |
|---|---|---|---|---|---|---|
| 1. Natural standardized curcuminoid extract | ≥95% total curcuminoids is a common high-assay specification; USP defines its own component ranges. | Usually three principal peaks: curcumin, DMC and BDMC. Quantify each if the ratio matters. | Orange-yellow powder | Turmeric rhizome extraction, concentration and further purification or crystallization. | Capsules, tablets and supplement blends. | Assay method and basis; individual curcuminoids; residual solvents and relevant contaminants. |
| 2. Water-dispersible formulated curcumin | About 10–40% curcuminoids is a trade range seen in some products, not a universal standard. | Assay should quantify curcuminoids in the finished powder; carriers are not counted as curcuminoids. | Usually yellow powder; dispersion may be cloudy or clear depending on the system. | Extract combined with a carrier or emulsifier; spray-drying is one possible process. | Beverages, drink powders and effervescent formulas when validated. | Final-powder assay; carrier and allergens; dispersion in the target formula; stability. |
| 3. Tetrahydrocurcumin (THCu) | 95–98% THCu appears in some commercial specifications; confirm the actual grade. | Requires a THCu-specific assay and reference standard; it is not total curcuminoids. | White to off-white | Hydrogenation of curcumin followed by purification; routes can vary. | Colour-sensitive cosmetic or other formulas where suitable and permitted. | THCu identity and assay; related compounds; residual catalyst metals; local-use status. |
| 4. High-purity single-peak curcumin | ≥98% curcumin is a commercial claim; method and basis still matter. | One dominant curcumin peak under the stated method; this does not prove source. | Orange-yellow powder | Further purification of a natural extract or chemical synthesis. | Research standards and applications requiring a defined single compound. | Natural or synthetic source declaration; impurity profile; reference standard and traceability. |
| 5. Synthetic or reconstituted three-peak blend | Specified by total assay and, where relevant, a target ratio; no universal grade applies. | Three peaks can resemble a natural profile; routine HPLC alone cannot authenticate origin. | Orange-yellow powder | Curcuminoids are produced separately and blended to a defined profile, where offered. | Specialist applications requiring a repeatable multi-component ratio. | Exact component ratios; process and origin evidence; target-market regulatory status. |
| 6. Feed-grade turmeric extract or curcuminoids | No universal feed-grade assay. 5–10% products are trade examples; some evaluated feed extracts have much higher assays. | Depends on the underlying material. Dilution lowers finished-product concentration but need not change the active fraction's ratio. | Yellow to orange-yellow | Extract or concentrate supplied under a feed-specific specification and regulatory framework. | Animal feed only for the species, function and conditions covered by applicable documents. | Species and intended function; jurisdiction and authorization; use level; feed-specific quality documents. |
| 7. Turmeric residues and spent oleoresin | Batch-dependent. One spent-oleoresin study reported 15 ± 2.0% total curcuminoids; an enriched fraction reached 39 ± 1.2%.[10] | Component ratios may shift after extraction or crystallization; test the actual batch. | Yellow-orange to brownish, depending on the stream. | Spent rhizome after extraction and mother-liquor residue after crystallization are different materials. | Potential recovery or other specifically permitted uses; do not assume human-food or feed suitability. | Exact residue stream and process history; assay; residual solvents and contaminants; intended-use status. |
Source (natural or synthetic), assay (total curcuminoids or curcumin alone), formulation (such as water-dispersible), and intended use (human food or feed) answer different questions. They are not a single ladder of quality. Lower-assay extracts and oleoresin are discussed in the process section because assay level and processing stage do not, by themselves, define a separate chemical identity.
02 · Read the specification
What Does “Curcumin 95%” Actually Mean?
In supplier documents, curcumin is sometimes used loosely for both the individual molecule and the group of related pigments known as curcuminoids. That shorthand can make technically different products look comparable when they are not.
Curcumin and total curcuminoids are different assay claims
Curcuminoids commonly refers to curcumin, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC). The USP-NF Curcuminoids monograph defines a partially purified natural complex containing not less than 95.0% total curcuminoids on a dried basis, with curcumin at 70–80%, DMC at 15–25% and BDMC at 2.5–6.5%. These are monograph requirements for the material defined by USP—not proof that every product advertised as “95%” complies with that monograph.[1]
Two batches can therefore both report 95% total curcuminoids and still differ in the proportion of curcumin itself. If the individual ratio matters to your formulation, request separate HPLC results for all three compounds rather than relying on one total number.
Dry basis, as-is basis and test method matter
An assay calculated on a dried basis is not identical to a result calculated on the powder as received. Moisture can change the apparent percentage. Method matters too: HPLC can separate and quantify individual curcuminoids, while the EU E 100 colourant specification defines its minimum as 90% total colouring matters measured under that specification. A multi-laboratory HPLC-DAD study of turmeric dietary supplements is another reason to identify the exact analytical method and reference standards in a COA rather than comparing supplier percentages without context.[4] That colourant figure should not be compared directly with an HPLC total-curcuminoid result as if both were the same measurement.[3][6]
Before comparing “95% total curcuminoids,” “98% curcumin” and “90% total colouring matters,” ask what is being measured, which method and reference standard were used, and whether the result is reported on an as-is or dried basis.
03 · Process and composition
How Standard 95% Curcuminoid Extract Is Made
Natural curcuminoid extract starts with the dried rhizome of Curcuma longa. The plant is milled, extracted with a suitable solvent and concentrated. The process may stop at an oleoresin stage, or continue through purification and crystallization to produce a concentrated powder. A 2014 review reports that dried turmeric can contain around 2–9% curcuminoids depending on origin and growing conditions; JECFA describes the first-pass oleoresin as containing roughly 25–35% colouring matter. Those figures refer to different materials and analytical descriptions, so they are not directly interchangeable assay values.[5][14]
| Published figure | What it refers to | How to interpret it |
|---|---|---|
| 2–9% | Curcuminoids reported in dried turmeric rhizome in a review. | Natural raw-material content varies; it is not the assay of an extract powder. |
| 25–35% | Colouring matter in first-pass oleoresin described in the JECFA technical assessment. | Oleoresin also contains oils, resins and other extractives. |
| ≥90% | Total colouring matters under the EU E 100 curcumin colourant specification. | This is a colourant specification and measurement basis, not a blanket threshold for every supplement extract. |
| About 60% | Curcuminoids recovered from the oleoresin in one patented conventional crystallization process. | A process-specific yield example, not a universal recovery rate for all manufacturers. |
Step 1: Dry and mill the rhizome
Grinding improves solvent access to the plant material, but raw-material quality and preparation still influence the starting composition. Curcuminoid content varies by source, and a raw-rhizome figure should not be used to predict the assay of the final extract without process-specific data.
Step 2: Extract and concentrate to oleoresin
Published extraction methods use solvents including ethanol, acetone, ethyl acetate, methanol and hexane, among others. Some studies report improved extraction at 60–80 °C, but temperature and solvent choice are process-dependent, not a universal manufacturing recipe.[14] For EU E 100, the applicable specification lists permitted solvents and residue limits; for example, the cited consolidated specification sets ethyl acetate residues at no more than 50 mg/kg, singly or in combination, and dichloromethane at no more than 10 mg/kg. Always check the current rule and the destination market before setting a purchase specification.[6]
Oleoresin is a complex intermediate rather than a synonym for purified 95% curcuminoids. It can retain volatile turmeric oils and resinous constituents, and its composition depends on the raw material and extraction process.
Step 3: Purify and crystallize the curcuminoids
Crystallization enriches the curcuminoids, but it can also change the relative amounts of the three principal compounds. In one patent describing a particular process, the curcuminoid profile of the oleoresin was reported as approximately 50–70% curcumin, 10–30% DMC and 10–30% BDMC. The crystallized powder in that process had a different profile: about 65–85% curcumin, 10–30% DMC and 5–15% BDMC. The same patent reported a yield of about 60% of the curcuminoids initially present in the oleoresin for that crystallization step.[13]
These are figures from a specific patent process, not guaranteed industry-wide ranges. They illustrate a real purchasing point: two products can meet the same total-curcuminoid assay while having different component ratios. If the ratio matters, ask the supplier for curcumin, DMC and BDMC as separate results.
Step 4: Dry, mill and test the finished powder
After purification, the material is dried and sized to the required physical form. The finished lot should be tested against the agreed specification. Depending on the product and destination market, this may include individual curcuminoids, moisture or loss on drying, residual solvents, relevant contaminants, microbiology and process-specific impurities. Not every test belongs on every COA; the correct panel follows the actual process and intended use.
Where lower-assay natural grades fit
Products sold at 10%, 20%, 40–60% or other lower assays can be made by stopping purification earlier or by standardizing a concentrated extract with a carrier. These routes do not produce identical compositions. A partially purified extract may retain more oils and resins, while a carrier-standardized powder contains a higher proportion of added excipient per gram of finished product. A separate USP monograph for Powdered Turmeric Extract defines a product containing not less than 20% curcuminoids on a dried basis and permits other added substances; that formal definition should not be assumed to apply to every product sold as turmeric extract.[2] Ask which route applies, what the carrier is, and whether the stated assay is measured in the finished powder.
For available grades and batch-specific specifications, see our turmeric root extract specifications, including HPLC assay, carrier options and supporting documentation.
04 · Formulated ingredients
Water-Dispersible Curcumin: The Carrier Is Part of the Specification
Curcumin is practically insoluble in water at acidic and neutral pH. A water-dispersible ingredient is therefore usually a formulated system, not simply a 95% extract that has become water-soluble. Published approaches include γ-cyclodextrin inclusion, phospholipid complexes such as lecithin-based systems, gum-based colloidal dispersions and surfactant or micellar systems that may use polysorbates.[5][11] One published study cites a curcumin solubility estimate of about 11 ng/mL in aqueous buffer at pH 5.0; treat that as a condition-specific literature value, not a universal solubility constant for every curcumin material or test method.[16]
The carrier is not an irrelevant filler. It affects the finished powder’s active percentage, how the powder behaves in water, the appearance of the drink, label declarations and sometimes allergen management. A lecithin-based system raises different formulation and labelling questions from a cyclodextrin, modified-starch or gum-based system. That is why a “20–40% water-soluble curcumin” claim is incomplete without the carrier composition and test conditions.
Water-dispersible does not necessarily mean molecularly water-soluble. A product may form a cloudy dispersion, emulsion or micellar system rather than a true molecular solution. To compare suppliers, test the ingredient in the intended liquid at the target concentration and pH, using a defined mixing procedure. Record wetting, clumping, dispersion appearance, sedimentation over a specified time and changes during the intended shelf life. A clear result in a beaker of water does not guarantee performance in an acidic beverage, protein drink or effervescent system.
Improved dispersion and improved oral bioavailability are also separate claims. The latter requires evidence for the specific formulation and relevant comparator; it cannot be inferred from the words “water-soluble,” “micellar” or “phytosome.” For a deeper comparison of delivery approaches, see our curcumin bioavailability guide.
05 · A different molecule
Tetrahydrocurcumin (THCu): The Colourless Derivative
Tetrahydrocurcumin is produced by hydrogenating curcumin’s conjugated double bonds. The change in structure removes the intense yellow colour associated with curcumin, which is why THCu is sometimes called “white curcumin.” It is a different compound, not a higher or lower purity grade of ordinary curcumin; research or specifications for curcumin should not automatically be applied to THCu.[12]
One patent example dissolves curcumin in acetone, reduces it with hydrogen using activated Raney-nickel catalyst, then filters the catalyst and purifies the product by silica-gel chromatography. Other routes and specifications may differ, so this is an example rather than a universal manufacturing description.[15] Where a process uses a metal catalyst, residual catalyst metals and incompletely hydrogenated related compounds are sensible process-specific checks.
THCu may be considered for colour-sensitive cosmetic or other formulations where a colourless derivative is appropriate, but application suitability and legal status must be checked separately for each market and product type.
What to request: THCu assay against a THCu reference standard, identity confirmation, related-substance profile, residual solvents and any catalyst-metal testing relevant to the actual manufacturing route. Do not accept a “95% curcuminoids” COA as a substitute for a THCu-specific specification.
06 · Origin and chromatogram
Single-Peak and Three-Peak Curcumin: What the Chromatogram Shows
A high-purity single-compound product may be obtained by further purification of a natural extract or by chemical synthesis. A chromatogram with one dominant curcumin peak supports a composition claim under the stated method, but it does not establish how the material was made. The source and manufacturing route must be documented separately.
A synthetic or reconstituted three-peak blend may combine curcumin, DMC and BDMC to a target ratio. One synthetic route described in the FDA response to GRAS Notice 000822 starts with vanillin and 2,4-pentanedione, forms a curcumin–boron complex using tri-n-butyl borate and n-butylamine, then hydrolyses the complex; the notifier reported a product specification of approximately 99% purity. That is one manufacturer’s route and specification, not a universal description of synthetic curcumin.[9] Its chromatogram can resemble that of a natural extract because routine HPLC identifies and quantifies the compounds, not necessarily the botanical origin of each molecule. Do not assume every supplier offers a synthetic or reconstituted three-peak blend as a standard commodity grade; where it is offered, ask for the actual route, blend specification and intended-market status.
| Evidence | What it can support | What it cannot prove alone |
|---|---|---|
| HPLC profile | Identity and relative or absolute amounts of compounds separated by the stated method. | Natural origin, botanical traceability or legal suitability for a market. |
| Batch COA and traceability | Recorded lot results, manufacturer and declared source. | Authenticity beyond the scope of the tests and records provided. |
| Carbon-14 analysis | Can help distinguish modern biogenic carbon from fossil-derived carbon in appropriate cases. | Every possible manufacturing route or blend without considering the method’s scope. |
| Stable isotope ratios | May provide additional evidence for source authentication; a 2023 study examined carbon and hydrogen isotope patterns in natural and synthetic curcuminoids. | A universal pass/fail rule for all origins, laboratories and adulteration levels. |
Carbon-14 testing is described in the literature as an effective authentication approach, although it can be expensive. A 2023 study reported that stable carbon and hydrogen isotope ratios may also help identify synthetic curcuminoids or additions, but the study’s proposed indicators should not be treated as universal acceptance limits for every supply chain.[8] If “natural origin” is a contractual or label requirement, put the expected evidence into the specification before placing the order.
Regulatory status depends on the use and destination. The US FDA’s response to GRAS Notice 000822 stated that it had no questions about the notifier’s conclusion under the stated conditions of use, but it also made clear that the response was not an approval for use as a colour additive. The EU E 100 definition specifies curcumin obtained by solvent extraction of turmeric. Neither reference should be read as blanket authorization for every synthetic product or every application.[6][9]
07 · Intended use
Feed-Grade Curcumin and Turmeric Residues Need Separate Checks
“Feed grade” is not a fixed curcuminoid percentage. EFSA assessed a specific turmeric extract for use as a sensory additive in feed and water for drinking; the evaluated product contained at least 90% curcuminoids and the opinion concluded it was safe at the proposed maximum use level of 15 mg/kg complete feed. That assessment applies to the evaluated preparation and its stated use, not to every low-assay product sold for feed or to every colouring function.[7]
Low-assay 5% or 10% curcuminoid materials may be sold for dosing convenience in premixes, but those percentages are commercial examples, not a legal definition of feed grade. The authorization or documentation must match the intended species, function, dose and jurisdiction. EFSA’s opinion assessed the named preparations as sensory additives, including flavouring uses; that assessment should not automatically be treated as approval for a different colouring function, such as pigmenting egg yolks or broiler skin, without checking the applicable feed-additive category and authorization.
“Turmeric residue” also covers different process streams. Spent plant material left after extraction is not the same as spent turmeric oleoresin or mother liquor remaining after crystallization. A published study reported 15 ± 2.0% total curcuminoids in its spent turmeric oleoresin sample; after removing non-antioxidant constituents, the enriched fraction contained 39 ± 1.2%.[10] A separate patent’s analysed crystallization residues contained about 13.4–17.9% curcuminoids by weight, with one reported residue profile close to 40:25:35 for curcumin:DMC:BDMC. In that patent’s process description, the residue retained a substantial share of the starting curcuminoids, but its low overall colouring strength reflected the oils, flavour compounds and other material still present.[13] These are results for particular samples and processes, not specifications for all residues or proof that any residue is suitable for a particular end use.
If a supplier offers a residue-derived material, ask for its exact process origin, batch-specific assay, contaminant results, traceability and documentation for the proposed use. Do not assume it is suitable for human food, supplements or animal feed simply because it comes from turmeric.
08 · Buyer checklist
How to Read a Curcumin COA Before Comparing Quotes
A COA is useful when it answers the specification you actually ordered. Before comparing quotations, check that both suppliers are reporting the same material, the same analyte and a comparable calculation basis.
| COA item | What to check | Why it matters |
|---|---|---|
| Product identity | Natural curcuminoids, single-compound curcumin, formulated curcumin, THCu, oleoresin or residue. | Similar product names can refer to different chemical materials. |
| Assay definition | Total curcuminoids, curcumin alone, total colouring matters or THCu. | The numbers are not interchangeable. |
| Method and basis | HPLC/UPLC or colourimetric method; as-is or dried basis; moisture/LOD where relevant. | Method and moisture can change the apparent result. |
| Individual profile | Curcumin, DMC and BDMC separately when buying a curcuminoid complex. | Total assay can conceal different component ratios. |
| Carriers and excipients | Names and proportions of maltodextrin, modified starch, gums, phospholipids or other carriers. | These affect active content, allergen management, labelling and formulation performance. |
| Process-related impurities | Residual solvents; catalyst metals or related compounds where relevant to the process. | The appropriate test panel depends on how the material was made. |
| Contaminants and microbiology | Applicable heavy metals, pesticide residues and microbiological criteria. | Requirements depend on product category and destination market. |
| Origin and traceability | Botanical source, manufacturing site, batch number and source evidence if required. | HPLC alone does not prove botanical origin. |
| Performance in the formula | Dispersion, sedimentation, colour or stability test under defined conditions. | A high assay does not guarantee the behaviour of a finished formulation. |
Not every item is mandatory for every product. The correct panel follows the ingredient, process and intended use. Agree the specification before ordering rather than assuming a generic COA covers every buyer requirement.
Compare cost per gram of active—not only price per kilogram
When two products report the same assay basis, calculate the approximate cost of the measured active fraction before comparing quotations.
Cost per kg of assayed curcuminoids = price per kg of ingredient ÷ curcuminoid mass fraction. A 95% product at US$20/kg gives US$20 ÷ 0.95 = about US$21.05 per kg of assayed curcuminoids. A 20% formulated powder at US$8/kg gives US$8 ÷ 0.20 = US$40 per kg of assayed curcuminoids.
This is a screening calculation, not a final value judgement. It assumes comparable assay methods and bases, and does not account for the function of a carrier, dispersion, stability, processing losses, regulatory fit or performance. Do not compare total curcuminoids with curcumin alone—or a colourant assay with an HPLC assay—as if the figures were interchangeable.
09 · Application fit
Which Curcumin Form Should You Investigate?
Start with the finished product, not the highest percentage in a catalogue. This table gives a starting point for technical discussion; it is not a substitute for formulation testing or regulatory review.
| Application or need | Forms to investigate | Specification priorities |
|---|---|---|
| Supplement capsules or tablets | Natural standardized curcuminoid extract. | Total and individual HPLC results, calculation basis, contaminants, residual solvents and relevant quality documents. |
| Food colourant | Material that meets the applicable curcumin colourant specification. | Regulatory identity, total colouring matters where specified, permitted solvents and purity criteria. |
| Water-based beverage or drink powder | Water-dispersible or other validated formulated system. | Active content in the final powder, carrier declaration, dispersion and stability in the target beverage. |
| Single-compound research or dosing | High-purity curcumin with a clearly defined assay. | Identity, reference standard, impurity profile and source declaration where relevant. |
| Colour-sensitive cosmetic | THCu may be considered if suitable for the intended formula. | THCu-specific assay, related compounds, process impurities and local regulatory review. |
| Animal feed | Only a material documented for the intended feed function. | Species, function, dose, authorization and feed-specific quality documentation. |
For EU projects, distinguish curcumin used as the food colour E 100 from a turmeric-derived ingredient being considered for a supplement or another purpose. The regulatory pathway and evidence required are not automatically the same. Our guide to curcumin in the EU: E 100 and Novel Food considerations explains this boundary in more detail.
11 · Questions
Frequently Asked Questions
Is 95% curcuminoids the same as 95% curcumin?
No. Total curcuminoids generally combines curcumin, DMC and BDMC. A 95% curcumin claim should refer to curcumin itself. Ask for the assay definition and individual HPLC results.
Is 98% curcumin always better than 95% curcuminoids?
No. The numbers may refer to different analytes and the products may serve different purposes. Compare identity, assay, component profile, source, carriers and intended use.
Does a three-peak HPLC profile prove that curcumin is natural?
No. A three-peak profile can be consistent with a natural extract, but a blend can be formulated to contain the same principal compounds. Source authentication needs appropriate traceability and, where required, additional analytical evidence.
Does water-dispersible curcumin dissolve completely in water?
Not necessarily. Some products form dispersions, emulsions or micellar systems rather than true molecular solutions. Evaluate the product at the target concentration, pH and storage conditions.
What should a curcumin COA include?
It should identify the material, assay target, method and calculation basis. For a curcuminoid complex, request total and individual curcumin, DMC and BDMC results. Add carrier, solvent, contaminant, traceability and performance requirements according to the product and market.
Can feed-grade curcumin be used in a human supplement?
Do not assume so. Feed-grade status and supporting documents relate to the intended animal-feed use. Human food or supplement use needs a separate quality and regulatory assessment.
Is tetrahydrocurcumin the same ingredient as curcumin?
No. THCu is a hydrogenated derivative with a different chemical structure and its own assay requirements. It should be identified and assessed separately from ordinary curcumin.
12 · Evidence base
References
[1] United States Pharmacopeia (USP). Curcuminoids, USP–NF dietary supplement monograph. Defines a natural curcuminoid complex and its total and individual component ranges. View monograph.
[2] United States Pharmacopeia (USP). Powdered Turmeric Extract, USP–NF dietary supplement monograph. Defines powdered turmeric extract and its minimum curcuminoid content on a dried basis. View monograph.
[3] Kotra VSR, Satyabanta L, Goswami TK. A critical review of analytical methods for determination of curcuminoids in turmeric. Journal of Food Science and Technology. 2019;56(12):5153–5166. Read review.
[4] Mudge EM, Brown PN, Rimmer CA, Phillips MM. Determination of Curcuminoids in Turmeric Dietary Supplements by HPLC-DAD: Multi-laboratory Study Through the NIH-ODS/NIST Quality Assurance Program. Journal of AOAC International. 2020;103(6):1625–1632. Read study.
[5] FAO/WHO Joint Expert Committee on Food Additives (JECFA). Curcumin: Chemical and Technical Assessment. 61st JECFA, 2004. Describes natural curcumin, manufacturing, composition, physical properties and colourant use. Read technical assessment (PDF).
[6] European Commission. Commission Regulation (EU) No 231/2012, specification for food additive E 100 Curcumin (consolidated text cited). Check the current consolidated version applicable to the destination market and date. Read specification (PDF).
[7] EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP). Safety and efficacy of turmeric extract, turmeric oil, turmeric oleoresin and turmeric tincture from Curcuma longa L. rhizome when used as sensory additives in feed for all animal species. EFSA Journal. 2020;18(6):e06146. Read EFSA opinion.
[8] Perini M, Pianezze S, Ziller L, Larcher R, Pace R. Stable Isotope Ratio Analysis for the Authentication of Natural Antioxidant Curcuminoids from Curcuma longa (Turmeric). Antioxidants. 2023;12(2):498. Read study.
[9] U.S. Food and Drug Administration. Response letter to GRAS Notice No. GRN 000822, Curcumin, June 4, 2019. The response notes that the GRAS response is not approval for use as a colour additive. Read FDA letter (PDF).
[10] Nagarajan S, et al. Separation of Curcuminoids Enriched Fraction from Spent Turmeric Oleoresin and Its Antioxidant Potential. Journal of Food Science. 2010. Read study.
[11] Advancements in curcuminoid formulations: An update on bioavailability enhancement strategies. Biology. 2025. Reviews delivery approaches including cyclodextrins, hydrophilic carriers, micelles, liposomes, lipid particles and emulsions. Read review.
[12] Tetrahydrocurcumin as a stable and highly active curcumin derivative: A review of synthesis, bioconversion, detection and application. Food Bioscience. 2023;53:102591. Read review.
[13] Madsen B, Hidalgo Garcia V, Hernandez Vera L. Purification process for improving total yield of curcuminoid colouring agent. U.S. Patent 6,576,273 B2; 2003. The reported ratios and recovery apply to the described process and examples, not to every commercial manufacturer. Read patent.
[14] Priyadarsini KI. The Chemistry of Curcumin: From Extraction to Therapeutic Agent. Molecules. 2014;19(12):20091–20112. Read review.
[15] Method for making tetrahydrocurcumin and a substance containing the antioxidative substance tetrahydrocurcumin. U.S. Patent 5,266,344; 1993. A patent example of catalytic hydrogenation and subsequent purification. Read patent.
[16] Kharat M, Du Z, Zhang G, McClements DJ. Physical and Chemical Stability of Curcumin in Aqueous Solutions and Emulsions: Impact of pH, Temperature, and Molecular Environment. Journal of Agricultural and Food Chemistry. 2017. Read study.
B2B ingredient sourcing
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Discuss your specification →View turmeric extract grades →Disclaimer: This article is intended for ingredient evaluation and B2B sourcing. It does not replace product-specific technical documentation, regulatory advice or validation in the finished formulation. Published specifications and study results apply to the materials and methods described in their sources; they should not be generalized to every commercial product. PhytoVale supplies botanical ingredients as raw materials and makes no medical claims. © 2026 PhytoVale.
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