Material guide: beta-damascenone — the trace heavyweight in rose, and the myth of the lowest threshold

The rose trio (geraniol, citronellol, PEA) builds the rose's body. This article is about the other kind of player: molecules dosed in parts per million that make the whole flower come alive.

What matters

• Beta-damascenone is the star of the rose ketone family; the literature credits it with one of the lowest orthonasal and retronasal detection thresholds of any odorant. High strength, 216 hours; think in ppm when you dose it.
• It is kin to beta-ionone: both are C₁₃ molecules cleaved from carotenoids. Plants dismantle their pigments, and the fragments are smells.
• But "lowest threshold" does not mean "biggest contribution". The same review admits its sensory contribution to most products remains unclear, and a Pinot Noir experiment showed the effect answers to the matrix. A low threshold is an entry ticket, not the lead role.

The record

CAS	23696-85-7
Formula	C₁₃H₁₈O
MW	190.28
Odour	natural, sweet, fruity, rose, plum, grape, raspberry, sugar, woody, earthy, green
Odour family	floral
Strength	high (evaluate at 10% or less)
Substantivity	216 h (neat, on a strip)
Specific gravity	0.946–0.952 (25 °C)
Flash point	> 100 °C
Shelf life	24 months or longer (cool, dark, sealed)
Registers	GRAS, JECFA, CoE, FEMA GRAS, IFRA

Plain reading: CAS is the material's ID number. Look at that row of descriptors — rose, plum, grape, raspberry, sugar, woody, earthy — one molecule setting a whole table. That is what a trace heavyweight typically looks like. The "damascenone" name traces to the Damask rose (Rosa damascena); the family was first named in rose research.

Lowest threshold — then what?

Sefton and colleagues' long 2011 review in the Journal of Agricultural and Food Chemistry tells both halves of the story. First, the source of the fame:

Damascenone stands out among plant-derived odorants for its widespread presence in processed foods and beverages, particularly in wines made from Vitis vinifera grapes. It possesses one of the lowest orthonasal and retronasal detection thresholds of any odorant.

Then the honest half: despite that, its actual sensory contribution to most products remains unclear. The review also traces its origins — acid-catalysed breakdown of the plant's apocarotenoids can generate damascenone, which accounts for its formation in some products but not all; in wine it is also degraded, notably by sulfur dioxide.

"The threshold is so low that it dominates everything" is the most common telling of this molecule, and the primary literature pointedly does not say it. A low threshold means a vanishingly small amount is detectable. How much it contributes inside a complex formula is a separate question that only an experiment can answer.

The matrix decides

In 2021, Tomasino and Bolman ran exactly that experiment: they spiked three different Pinot Noir wine matrixes with varying concentrations of beta-ionone and beta-damascenone, and used triangle tests to see whether assessors could tell:

Results show that β-ionone acts as a significant contributor to aromas in Pinot noir wine, as individuals could differentiate both the low and high concentration wines from the control. How β-ionone impacted wine aroma depends on the wine matrix, with different aroma descriptors affected in different model wines (floral, red berry or dark berry). The effect of β-damascenone on Pinot noir aroma was less clear, as perception seems to be heavily influenced by wine matrix composition.

Head to head, the molecule with the louder threshold legend came out less clear. For perfumery this is a practical reminder: the effect of a trace material has to be verified in your own formula, not read off a threshold table. After adding ppm of it, whether the product got better is for your nose to say; the data sheet cannot.

Smelling it

• High strength; the database says evaluate at 10% or less, and in practice I start at 1% and go down. Neat on a strip it is a strange thing, concentrated jam plus tobacco; diluted, it turns into rose and plum.
• In a rose accord it is the finishing touch: build the trio first, then add under 0.1%, and the flower suddenly turns juicy. Overdose and the whole formula goes candied.
• Smell it beside beta-ionone once: two carotenoid fragments, one walking toward violet, the other toward rose jam.
• 216 hours: even a trace stays to the end. When revising a formula, remember it is still in the room.

The catalogue family

Item	What it is
beta-damascenone (96 suppliers)	the star: rose jam, plum, a tobacco shade
delta-damascone (42 suppliers)	the delta version, fruitier toward apple, brisker
(E)-beta-damascone (41 suppliers)	trans beta-damascone, rose-tea leaning
(E)-alpha-damascone (39 suppliers)	the trans alpha, rose plus apple skin
alpha-damascone (14 suppliers)	the alpha isomer
plum damascone (high alpha) (8 suppliers)	a trade-named blend, drifting toward prune

Damascone and damascenone differ by one double bond, and carry two names and two price tags. Read the ending of the name before ordering; this family tests your eyesight harder than the hexenols.

Regulatory

Listed on GRAS, JECFA, CoE, FEMA GRAS, IFRA. As always, registers carry no limit values. Some members of the rose ketone family have individual IFRA standards; for skin formulae, check the current IFRA Standards for the specific item and the supplier's specification.

Buying it

1. Buy the smallest pack. At ppm doses, even 1 mL lasts; make a 1% dilution and dilute down from there.
2. Check CAS 23696-85-7 and the -enone ending so you don't land on the cheaper damascone family (unless a damascone is what you want).
3. First exercise: make one version of the rose trio, and a second with 0.05% of this added. Compare blind. It is the cheapest lesson in verifying a trace material.

→ Beta-damascenone in the database: full properties, supplier list, suggested pairings. → Delta-damascone | (E)-beta-damascone | Search by odour: try "rose plum" for its neighbours.

References

M. A. Sefton, G. K. Skouroumounis, G. M. Elsey & D. K. Taylor, Occurrence, sensory impact, formation, and fate of damascenone in grapes, wines, and other foods and beverages, Journal of Agricultural and Food Chemistry, 59(18), 9717–9746 (2011). PMID 21866982

E. Tomasino & S. Bolman, The Potential Effect of β-Ionone and β-Damascenone on Sensory Perception of Pinot Noir Wine Aroma, Molecules, 26(5), 1288 (2021). PMID 33673491