Beta-Ionone

SyntheticAROMA CHEMICALSfloral · violet · woody

HeartPyramid

4/5Strength

—Tenacity

—Origins

Specimen

Definition

Beta-ionone is a ketone of 13 carbon atoms and an important fragrance chemical used in perfumery. Its odour is warm, woody, dry and fruity, and violet-like upon dilution.

FLORAL SWEET WOODY POWDERY FRUITY

Irisone

Type: Ingredient
Olfactive family: Florals
Subfamily: Powdery florals
Cluster: Iris-violet powdery florals
Source: synthetic molecule
Chemical class: ketone (ionone)

Instruments

Pyramid

TTop

HHeart

BBase

4/5Strength

High

odour strength

Scent

Beta-ionone is warm, dry and reminiscent of cedar wood, and violet-like upon dilution. In a very dilute alcoholic solution the odour resembles that of violets.

In PREMIEREPEAU

DISCOVERY SET7 × 2 ml →EXTRAIT DE PARFUMThe seven extraits →

The Full Story

What it is

Beta-ionone is a C13 norisoprenoid formed by cleavage of carotenoids. The name ionone comes from the Greek for violet, which refers to the violet odour, and from ketone, which refers to the structure of the molecule. Its EINECS number is 238-969-9.

Chemistry

Alpha-ionone and beta-ionone are 3-buten-2-ones substituted at position 4 by a 2,6,6-trimethyl-2-cyclohexen-1-yl group and a 2,6,6-trimethyl-1-cyclohexen-1-yl group respectively. The systematic name of beta-ionone is 4-(2,6,6-trimethylcyclohexen-1-yl)but-3-en-2-one. Beta-ionone is soluble in alcohol, most fixed oils and propylene glycol, and insoluble in glycerin. Its solubility in water is 169 mg/L at 25 °C.

Occurrence

Beta-ionone is a significant contributor to the aroma of roses, despite its relatively low concentration. It is a common aromatic volatile found in many plant species, for example in the essential oil of Osmanthus fragrans, in petunia and in Rosa bourboniana. It is also found in fruits and vegetables including carrot, tomato, melon, raspberry, apricot, plum, apple and fig. It is an essential contributor to fragrance in the flowers of Boronia megastigma. Sweet osmanthus has beta-ionone as a major aromatic component.

Volume

Today the global usage of alpha-ionone and beta-ionone is approximately between 100 and 1000 metric tons yearly.

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Related: Alpha Ionone · Alpha Isomethyl Ionone · Boisiris · Iris · Iris Butter · Iris Pallida · Orris Absolute

Did You Know?

In tea, the enzymatic oxidation of catechins causes the oxidation of beta-carotene and so the formation of beta-ionone, which can be responsible for woody and floral odour in tea. A single-nucleotide polymorphism in the OR5A1 receptor makes people with at least one G allele sensitive to beta-ionone, perceiving a pleasant floral scent, while people homozygous for AA are about 100 times less sensitive and at higher concentrations perceive a pungent sour or vinegar odour.

Extraction & Chemistry

Extraction method

Ionone can be synthesised from citral and acetone. Citral and acetone are condensed in an alkaline medium to give pseudoionone, which is then cyclised to ionone under acidic conditions. The type and concentration of the acid used decides the ratio of alpha-ionone to beta-ionone formed. Concentrated sulfuric acid preferentially yields beta-ionone, while phosphoric, fumaric and other weaker acids mainly yield alpha-ionone. In plants, a carotenoid cleavage dioxygenase (CCD1) catalyses the oxidative cleavage of carotenoids at the 9,10 and 9′,10′ positions, which gives beta-ionone.

Formula: C₁₃H₂₀O
CAS: 14901-07-6
Appearance: Pale yellow to yellow liquid
Odour strength: strong
Synonyms: Irisone

IFRA status

See note

No IFRA Standard for the material itself (51st Amendment)

Physical properties

Boiling point: 126 to 128 °C at 12 mmHg
Flash point: > 113 °C (> 235 °F), closed cup
Specific gravity: 0.942 - 0.946 (density, g/ml, 20 °C)
Refractive index: 1.518 - 1.522 at 20 °C

In Perfumery

The combination of alpha-ionone and beta-ionone is characteristic of the scent of violets and is used with other components in perfumery and flavouring to recreate their scent. Beta-ionone is often used in personal care, cosmetics, laundry care and home care applications.

Role in the formula

01signature note

02blender

03diffusion

Available as

synthetic