Coriander seed extract specifications usually carry one number: a linalool percentage. Few buyers can say what that percentage is a fraction of, how it is measured, or what a supplier could legitimately — or illegitimately — do to hit it. This article unpacks the volatile chemistry, the GC assay, the chiral fingerprint that separates genuine seed linalool from the synthetic compound, and the specification language that closes the gaps.
The Volatile Fraction: Linalool and Its Companions
The aroma and functional identity of coriander seed sit in its volatile oil — a monoterpene fraction that typically makes up a fraction of a percent to nearly two percent of the seed by weight, depending on variety. Within that fraction, one compound dominates.
| Constituent | Typical share of volatile fraction | Character |
|---|---|---|
| Linalool | 60–80% | Citrus-floral; the standardisation marker |
| α-Pinene | 3–10% | Fresh, piney |
| γ-Terpinene | 2–9% | Herbaceous, citrus |
| Camphor | 3–6% | Medicinal; a quality signal at elevated levels |
| Geranyl acetate | 2–5% | Sweet, fruity-floral ester |
| Geraniol, limonene, p-cymene | Minor | Round out the natural profile |
Two things follow from this table. First, when a specification says "linalool 60–70%", it is describing the composition of the volatile fraction — which is why a complete CoA must also report the volatile-oil content of the extract itself. An extract can carry beautifully linalool-rich oil and very little of it. You need both numbers.
Second, the companion terpenes are not noise. They are the natural context in which real coriander linalool always arrives, and their presence in natural proportion is part of the authenticity fingerprint — a point that becomes decisive in the spiking discussion below.
The Chiral Signature: (S)-(+)-Linalool
Linalool is a chiral molecule — it exists as two mirror-image enantiomers — and coriander seed produces it with a strong hand: the seed's linalool is predominantly the (S)-(+) enantiomer, historically named coriandrol after the plant itself. Lavender, by contrast, is dominated by the (R)-(−) form, and synthetic linalool — cheap and produced at industrial scale for the fragrance industry — is racemic, an even 50:50 mix of both.
Why this matters commercially: a conventional GC assay cannot distinguish natural from synthetic linalool — the peak looks the same. A chiral GC column separates the enantiomers, and the ratio between them is a fingerprint the seed writes and a spiker cannot economically fake. Material spiked with synthetic linalool drifts toward 50:50; genuine coriander seed extract shows the strong (S)-(+) excess. If you ever have reason to doubt a lot, enantiomeric analysis is the question that settles it. We make the enantiomeric profile available per batch on request.
How Linalool Is Actually Measured
Terpenes are volatile and thermally robust enough to chromatograph in the gas phase, so the industry-standard assay is gas chromatography — typically GC-FID against a reference standard, with GC-MS used for identity confirmation and profile work. The volatile fraction is recovered (Clevenger-type hydrodistillation for the oil-content figure; direct or headspace injection for profiling), separated on the column, and linalool is quantified as a percentage of the fraction.
Two points of specification hygiene follow:
- Name the method. "Linalool 60–70% of volatile fraction, by GC." A bare percentage with no method line is a claim, not an assay.
- Ask for the chromatogram, not just the number. A real coriander profile shows linalool flanked by its companion terpenes in natural proportion. A profile that is essentially one peak is not a better extract — it is a warning.
Camphor: The Quality Marker Nobody Specifies
Camphor is a legitimate minor constituent of coriander seed oil at roughly 3–6% of the fraction. But it is also the constituent that climbs when things go wrong — poor variety selection, immature seed, or harsh processing all push camphor up and drag the sensory profile toward the medicinal. A camphor figure on the profile is a cheap, informative line to request, and persistent high-camphor batches from a supplier tell you something about their raw-material discipline that the linalool number alone will not.
Extract Ratio vs Marker Standardisation
| Basis | What it declares | What it does not tell you |
|---|---|---|
| Native ratio (10:1) | How much raw seed went into one part of extract | Anything about volatile content — seed quality and processing drive the result |
| Marker standardised (linalool by GC) | A verified aromatic composition, with oil content reported | The non-volatile fraction, unless the CoA covers it |
Neither basis is wrong; they serve different products. A full-spectrum 10:1 is the honest choice for a traditional churna or a tea blend built on the whole seed. A linalool-declared grade is the honest choice for anything dosed or positioned on the aromatic fraction. The dishonest move is selling one as the other — covered in detail in our adulteration and authenticity guide.
Writing a Specification That Cannot Be Gamed
- Name the method. "Linalool 60–70% of the volatile fraction, by GC." No method clause, no assay.
- Require volatile-oil content per batch. This is the line that makes a stripped or exhausted material visible.
- Require the profile, with camphor reported. Companion terpenes in natural proportion are the built-in authenticity check.
- Reserve the right to enantiomeric analysis. One sentence in the specification; a decisive deterrent against synthetic spiking.
- Set an acid-insoluble ash limit. NMT 1.5%. Mineral bulking and soil carry-over show up here and nowhere else.
- State seed-only identity. "Seed (fruit) of Coriandrum sativum L. only" — closes the leaf-material door.
Volatility Makes Storage Part of the Specification
Unlike most botanical markers, linalool can simply leave. It is volatile at ambient temperature, and an extract held in a poorly sealed container, or warm, loses aromatic load steadily — which is why our linalool-standardised grades carry a 24-month shelf life against the 36 months of the ratio grade, and why storage conditions (below 25°C, sealed, dark) are printed on the specification rather than offered as advice. If a lot has sat through a summer in an uncooled warehouse, re-assay before use.
SV Botanica standardises coriander seed extract to linalool 60–70% of the volatile fraction by GC, with identity by TLC, volatile-oil content on every CoA and the full chromatogram and enantiomeric profile available on request. See the coriander extract product specification for the complete parameter list, or the buyer's guide for how to approach the purchase.
Source Standardised Coriander Seed Extract from India
Linalool 60–70% of volatile fraction by GC · high-potency, 10:1 & organic grades · CoA-backed · samples for qualified buyers