There is a factor of roughly two sitting inside every lutein quotation, and whether you notice it depends entirely on one word that many specifications omit. It is the cleanest example in the ingredient trade of a number that means two different things depending on a basis nobody states.
Lutein in Marigold Is an Ester
In the Tagetes erecta flower, lutein does not occur free. It occurs almost entirely as fatty acid esters — principally lutein dipalmitate and related forms, where lutein is bound to two fatty acid chains.
So an oleoresin extracted from the flower is naturally an ester product. That is not a processing choice; it is what the plant makes.
Why That Creates a Factor of Two
The ester molecule includes the fatty acids. They contribute weight but they are not lutein.
An ester figure is roughly twice the free-lutein figure it corresponds to. Converting ester content to free-lutein equivalent uses a factor of approximately one half. So "20% lutein esters" carries roughly the free lutein of a "10% free lutein" material — not of a 20% one.
A buyer comparing two quotations without checking the basis can therefore be wrong by nearly a factor of two on the thing they are actually paying for. That is not a rounding difference; it is the whole commercial comparison.
The Three Ways It Bites
1. Quotation comparison
Supplier A quotes 20% (esters). Supplier B quotes 20% (free lutein). B's material carries roughly twice the lutein and should cost accordingly. On a spreadsheet listing "20%" against both, A looks cheaper.
2. Label claims
If your finished-product label declares a lutein quantity, that figure must rest on the correct basis. A claim calculated from an ester figure as though it were free lutein overstates the lutein content of the product. This is a compliance exposure, not just a commercial one.
3. Third-party testing disputes
Send material to a laboratory that reports free lutein, against a certificate stating esters, and the result appears to show a large shortfall. Nothing is wrong — the two numbers were never comparable. This dispute is entirely avoidable by instructing the laboratory which basis to report.
Saponified Grades
Saponification hydrolyses the esters, releasing free lutein. The resulting material assays higher on a like-for-like basis and is the form most supplement specifications are written around, since dosing and labelling are usually done on free lutein.
| Unsaponified (ester) | Saponified (free lutein) | |
|---|---|---|
| Natural form | Yes | Processed further |
| Assay basis | Lutein esters | Free lutein |
| Typical use | Feed pigmentation, food colour | Supplements |
| Compare directly? | Only after converting to a common basis | |
Do Not Forget Zeaxanthin
Marigold carries zeaxanthin alongside lutein at a much lower level, and many eye-health formulations are built to a defined lutein-to-zeaxanthin ratio rather than a lutein figure alone.
A material can meet your lutein specification and still miss your intended ratio. If your product's positioning or claim substantiation rests on a ratio, put it on the specification and require it reported per batch.
Feed Grade Is a Different Product
Feed-grade marigold is specified for pigmentation performance — how well it colours egg yolk or broiler skin — and is documented for the animal feed route, which has its own regulatory framework. Supplement grade is specified for lutein content on a stated basis for food and supplement use.
Comparing the two on a single assay number is a category error, and the cheaper number usually belongs to the material that cannot go where you need it.
What to Put on Your Specification
- Lutein content with the basis named — "as lutein esters" or "as free lutein";
- Free-lutein equivalent, with the conversion basis stated;
- Zeaxanthin and the lutein : zeaxanthin ratio;
- Saponification status;
- Carrier and antioxidant with inclusion levels — carotenoids oxidise, and protection systems matter for clean-label review;
- Intended route — food, supplement or feed, since the grade and documentation differ;
- Solvent named, residual level by GC.
One Instruction for Your Laboratory
When commissioning third-party testing, state the basis you want reported. It removes the most common false alarm in this trade at zero cost.
SV Botanica states the lutein basis, reports the free-lutein equivalent with the conversion named, and declares the zeaxanthin ratio on every batch. Tell us your basis and application or see the full specification.
Source Basis-Declared Marigold Oleoresin from India
Lutein basis stated · free-lutein equivalent reported · zeaxanthin ratio declared · saponified grades available · CoA-backed · samples for qualified buyers