How do I specify a natural carotenoid for formulation: assay, carrier, form and stability?
Start with a closed specification that fixes the active assay as % total carotenoids and the active isomer or ester distribution, names the carrier and physical form, and sets a minimum assay after storage. Commonly available commercial grades include about 2.5% to 10% astaxanthin, 5% to 20% lutein
How do I specify a natural carotenoid for formulation: assay, carrier, form and stability?
Start with a closed specification that fixes the active assay as % total carotenoids and the active isomer or ester distribution, names the carrier and physical form, and sets a minimum assay after storage. Commonly available commercial grades include about 2.5% to 10% astaxanthin, 5% to 20% lutein esters and 1% to 30% beta-carotene, but exact values must come from the manufacturer’s certificate of analysis and stability data. For EU colour use, confirm the correct number: astaxanthin is E 161j, lutein E 161b, zeaxanthin E 161h, lycopene E 160d and beta-carotene E 160a. If you are buying astaxanthin from Haematococcus pluvialis for human food in the EU, the oleoresin must also meet the Union-list specification under Regulation (EU) 2015/2283 and Commission Implementing Regulation (EU) 2017/2470 as amended by 2024/1026, including the monoester/diester share and the 9-cis fraction.
Core specification fields for a natural carotenoid purchase
| Parameter | What the buyer should fix in the specification |
|---|---|
| Active assay | Total carotenoid % by UV/Vis or HPLC; plus active isomer, ester share or cis/trans ratio where relevant |
| E-number / CAS | E 161j astaxanthin (CAS 472-61-7), E 161b lutein (CAS 127-40-2), E 161h zeaxanthin (CAS 144-68-3), E 160d lycopene (CAS 502-65-8), E 160a beta-carotene (CAS 7235-40-7) |
| Carrier | Sunflower oil, MCT oil, corn starch, maltodextrin, gum acacia or modified starch; declare the exact carrier on the CoA |
| Physical form | Oleoresin, oil suspension, cold-water-dispersible beadlet, microencapsulated powder or crystalline |
| Solubility/dispersibility | Oil-soluble or water-dispersible; target dispersion clarity at the intended use level in the finished matrix |
| Particle size | D50/D90 in µm for powders and beadlets where dry blending, tableting or dispersion kinetics matter |
| Heavy metals | Compliance with EU 231/2012 food additive purity criteria or USP/NF grade; Pb, As, Cd and Hg by ICP-MS |
| Microbiology | Total plate count, yeast/mould, E. coli and Salmonella; specify limits per gram and method |
| Residual solvents | USP <467> or equivalent; declare extraction and drying solvents |
| Storage | Sealed, nitrogen-flushed, ≤ 25 °C, dry and protected from light |
| Shelf life | Commonly 24 months from manufacture; confirm the minimum assay at expiry |
| Packaging / MOQ | Foil bag, vacuum bag or drum; confirm sample MOQ, production MOQ and lead time |
Assay and isomer profile: specify the active, not just “carotenoid content”
A total carotenoid number alone is not enough. Lutein from marigold is usually supplied as lutein esters, so a specification should separate free lutein from lutein ester equivalents. Astaxanthin requires attention to the monoester, diester and free astaxanthin distribution, and in the EU the 2024/1026 amendment to the novel food specification sets parameters for the monoester/diester share and the 9-cis fraction. Beta-carotene and lycopene should be specified by total content and, where relevant, the cis/trans ratio because light and heat can shift less stable cis isomers.
| Carotenoid | EU colour E-number | CAS | Common commercial presentations |
|---|---|---|---|
| Astaxanthin | E 161j | 472-61-7 | 2.5–10% oleoresin, oil suspension, cold-water-dispersible beadlets |
| Lutein | E 161b | 127-40-2 | 5–20% lutein esters, 5–10% free lutein powder or beadlets |
| Zeaxanthin | E 161h | 144-68-3 | 5–10% beadlets or suspensions, often co-sourced with lutein |
| Lycopene | E 160d | 502-65-8 | 5–20% tomato oleoresin, cold-water-dispersible powder |
| Beta-carotene | E 160a | 7235-40-7 | 1–30% powder, oil suspension or beadlets |
These are examples of common grades, not universal specifications. A purchase specification should always state the method used for assay, whether the result is on an “as-is” or dry basis, and the acceptance window at release and at expiry.
Carrier, form and solubility: match the matrix, not just the colour
The same active can behave very differently depending on carrier and form. An oil-soluble oleoresin is suitable for oil-filled capsules, oil-based dressings or colouring fats, but it will not disperse evenly in a clear beverage. A cold-water-dispersible beadlet or microencapsulated powder is designed for aqueous systems, dry blends, tablets and sports drinks. Powders can be spray-dried, adsorbed onto starch or silica, or physically blended; each route affects dusting, flowability, particle size and protection from oxygen.
The carrier must be declared because it becomes part of the formulation and the label. Sunflower oil and MCT are common for oleoresins and oil suspensions. Maltodextrin, gum acacia and modified starch are typical beadlet wall materials. Ask for the full quantitative composition, not only the carotenoid assay, and request an allergen statement for the carrier system.
Stability: minimum assay at expiry, not just release assay
Carotenoids are sensitive to oxygen, light, heat and acidic pH. A robust specification therefore includes storage and a guaranteed assay at the end of shelf life. Many suppliers provide 24 months from manufacture for sealed beadlets or powders stored at ≤ 25 °C away from light, but this must be confirmed for the specific carrier and form.
Request real-time and accelerated stability data, including assay retention, colour shift and physical changes such as caking or dispersion failure. In formulation work, the relevant measure is usually not only the ingredient assay but also the finished-product colour or target value after processing and storage. Starting use levels are formulation-specific; ask the supplier for a recommended dosing range by matrix rather than applying a single use level across all applications.
Fermentation, botanical and algal routes: what changes in the specification
Fermentation-derived carotenoids can offer a tighter isomer profile and less dependence on seasonal crop supply than botanical extraction, but they do not change the legal identity of the colour additive. The E-number and purity criteria still apply to the chemical substance. Botanical sources such as marigold for lutein, tomato for lycopene and palm or carrot for beta-carotene are well established, but they introduce crop variability, extraction-solvent documentation and, for some grades, pesticide or PAH questions. Algal astaxanthin from H. pluvialis is the source named in the EU novel food listing, and its oleoresin has a defined monoester/diester and 9-cis specification.
| Route | Source examples | Specification consequence | Supply and cost consideration | Regulatory angle |
|---|---|---|---|---|
| Fermentation | Yeast, fungal or bacterial carotenoid strains | Potentially tighter isomer control, no crop seasonality | More controlled batch-to-batch production; cost depends on titre and downstream form | E-number still applies; EU novel food status must be checked for human food use |
| Botanical extraction | Marigold, tomato, palm, carrot | Lutein mostly as esters; extraction solvent and crop residues must be documented | Subject to crop cycles, raw material prices and acreage risk | Established route; must meet extraction solvent and purity criteria |
| Algal cultivation | Haematococcus pluvialis for astaxanthin | Oleoresin with specified monoester/diester share and 9-cis fraction | Higher production cost; weather and contamination risk | EU novel food Union list; colour E 161j |
| Synthetic astaxanthin | Chemical synthesis | Different production route | Published 2021 peer-reviewed anchor around USD 1,000/kg | Not permitted in EU food under Reg (EC) No 1925/2006; no US GRAS status |
For astaxanthin specifically, published 2021 peer-reviewed anchor prices are around USD 1,000/kg for synthetic, USD 2,500/kg for Phaffia yeast-derived astaxanthin and USD 7,000/kg for H. pluvialis algal astaxanthin. Treat these as indicative order-of-magnitude anchors only; actual prices depend on assay, form, volume and market.
Regulatory status: EU, US, Japan and Korea (MFDS)
European Union. Colour use is governed by Regulation (EC) No 1333/2008 and its amendments. The carotenoids named above are authorised as food colours under their E-numbers: astaxanthin E 161j, lutein E 161b, zeaxanthin E 161h, lycopene E 160d and beta-carotene E 160a. E 162 is beetroot red, not astaxanthin. For astaxanthin as a human food ingredient, the astaxanthin-rich oleoresin from Haematococcus pluvialis is listed as a novel food under Regulation (EU) 2015/2283 and Commission Implementing Regulation (EU) 2017/2470 as amended by 2024/1026. EFSA’s NDA Panel indicates a maximum of 4 mg/day from H. pluvialis, equivalent to 0.06 mg/kg bw/day at 70 kg. Nutrition or health claims are made only under the authorised wording of Regulation (EC) No 1924/2006.
United States. Astaxanthin is exempt from certification for salmonid fish feed under 21 CFR 73.35; food and supplement use rests on GRAS notifications. Lutein has no 21 CFR Part 73 listing and moves through the GRAS notification route. Fungal lycopene has no Part 73 listing; tomato-derived lycopene is listed under 21 CFR 73.585. Beta-carotene is listed under 21 CFR 73.95. A GRAS notification is not an FDA colour additive approval, and the intended use must be supported for the specific food category.
Japan. Natural carotenoids may be used if they comply with Japan’s Specifications and Standards for Food Additives. The exact permitted source, extraction solvent, purity and food category must be confirmed against the current Japanese food additive list.
Korea (MFDS). Natural pigments are addressed under the MFDS Food Additives Code. Source, manufacturer and residual-solvent documentation must support the intended food category. If a specific fermentation or botanical grade is not covered by the facts above, confirm the exact jurisdiction and food category before purchase.
Frequently asked questions
Q: Should I specify total carotenoids or the active isomer? A: Specify both. Total carotenoids by spectrophotometric assay gives a broad value, while HPLC gives the active isomer, monoester/diester share or cis/trans ratio. For EU astaxanthin novel food, request the 2024/1026 specification parameters on the CoA.
Q: What is the difference between an oleoresin, an oil suspension, a beadlet and a powder? A: An oleoresin is the concentrated extract. An oil suspension is the extract diluted into a carrier oil. A beadlet is a microencapsulated particle designed to disperse in cold water. A powder may be spray-dried or adsorbed, and the form affects dosing, dusting, stability and label statement.
Q: How do I set shelf life and storage? A: Fix storage at sealed, nitrogen-flushed, ≤ 25 °C and protected from light. Ask for real-time and accelerated stability data, and write a minimum assay at expiry into the supply agreement. Many suppliers state 24 months from manufacture, but this varies by form and carrier.
Q: Is fermentation-derived astaxanthin the same as algal astaxanthin from Haematococcus pluvialis in the EU? A: For colour use, E 161j applies to astaxanthin as a chemical substance subject to purity criteria, but the EU novel food listing for human food is tied to H. pluvialis oleoresin. If a fermentation grade is intended for human food in the EU, verify whether that source has Union-list status for the intended food category; this is market-specific.
Q: Do I need heavy metals, residual solvent and microbiology specifications? A: Yes. Request compliance with EU 231/2012 or USP/NF where relevant, plus routine microbiological limits. For botanical extracts, also ask about extraction solvents and any relevant pesticide or PAH documentation.
Q: How do I get a reliable price for a natural carotenoid? A: Send the target market, food or cosmetic category, requested E-number, assay, carrier, form, annual volume and required documentation. Because price depends on assay, form, volume and market, use indicative anchors only for planning and request a quote for the exact grade.
Conclusion
Specifying a natural carotenoid is a closed-loop exercise: fix the active assay and isomer or ester profile, choose the carrier and physical form for the finished matrix, define storage and minimum assay at expiry, and attach the correct regulatory documentation for the intended market. EarthHue supplies fermentation-derived astaxanthin, lutein, lycopene, beta-carotene and zeaxanthin with full specification sheets, CoA and technical support. For product grades and technical contact, see https://earthhue.net/en/products and https://earthhue.net/en/contact.