Cis-3-hexenyl Acetate
Cis-3-hexenyl acetate is the acetate ester of leaf alcohol, systematically (Z)-hex-3-enyl acetate, and it carries the fresh green odour of its parent alcohol with a fruity, banana and pear like character laid over it. It occurs naturally in many fruits and in leaf material, including apple, kiwi, tomato leaf and green tea, and it is one of the standard building blocks for green top notes.
The material is a colourless to very pale yellow mobile liquid boiling near one hundred and sixty eight degrees. It is practically insoluble in water and freely soluble in ethanol and in oils, so it partitions strongly into the fat phase of an emulsion and is dosed through an ethanol or triacetin dilution rather than added neat. Compared with cis-3-hexenol it is softer, less aggressive and more diffusive, which is why formulators often use the two together to spread the green effect across the top and middle of a profile.
Stability depends on the ester bond and the double bond. The ester hydrolyses slowly in acidic aqueous systems back to the alcohol and acetic acid, and the cis double bond isomerises under acid and heat, so the compound performs best in neutral and oil continuous products.
We source bulk Cis-3-hexenyl Acetate from top China manufacturers for our partners. The manufacturers are in Beijing and Jiangxi. A smaller requirement can ship in a combined container with other ingredients.
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- Function
- Flavours and Aromas
Specifications
| Item | Specification |
|---|---|
| Appearance | Colourless to pale yellow clear liquid |
| Odour | Fresh green, fruity, banana and pear character |
| Assay by Gas Chromatography | Not less than 98.0% |
| Free Cis-3-Hexenol | Not more than 1.0% |
| Trans Isomer Content | Not more than 1.0% |
| Refractive Index at 20 C | 1.427 to 1.433 |
| Relative Density at 20 C | 0.895 to 0.903 |
| Acid Value | Not more than 1.0 mg KOH per g |
| Ester Content as Acetate | Not less than 98.0% |
| Solubility | Clear solution in four volumes of 70% ethanol |
| Heavy Metals as Lead | Not more than 10 mg/kg |
| Lead | Not more than 1.0 mg/kg |
| Arsenic | Not more than 0.5 mg/kg |
Common Markets Grades
Trade is dominated by synthetic material at ninety seven to ninety nine percent by gas chromatography, specified on free acid, on residual cis-3-hexenol from incomplete esterification, and on trans isomer content, since each of those shifts the odour away from the clean green fruity target. Flavour grade and fragrance grade differ mainly in documentation and in the control of residual solvent and catalyst rather than in the assay figure.
Natural grade is produced by esterifying natural cis-3-hexenol, or by lipase catalysed esterification, and trades at a substantial premium with isotope ratio evidence of origin. The material ships as the neat liquid in lined drums and in smaller lacquered tins, and working dilutions at one or ten percent in ethanol, triacetin or propylene glycol are commonly bought by flavour houses that dose small quantities.
Applications
- Apple and pear flavours, where the ester supplies both the green leaf and the fruity ester character in a single addition
- Kiwi, melon and green grape flavours, in which it is a genuine natural constituent
- Banana flavours, contributing an unripe green edge that keeps the profile from reading as confectionery
- Tomato and vegetable flavours, reproducing the note of tomato leaf and vine rather than of the fruit
- Green tea and herbal beverage flavours, giving fresh leaf lift over a brewed base
- Berry flavours, where a trace sharpens the top note of strawberry and raspberry compounds
- Chewing gum and confectionery flavours, where the neutral pH and fat phase suit the ester
- Fragrance compounds for fabric care, shampoo and fine perfumery, as a diffusive green fruity top note
- Dilution products and flavour bases sold to compounders as ready made green accords
China Manufacturers of Cis-3-hexenyl Acetate
Top Cis-3-hexenyl Acetate manufacturers in China.
Beijing Zoteq Co., Ltd.10 ingredients in the directory
Jiangxi Shamhai Bio-technology Co., Ltd.5 ingredients in the directory
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
Regulatory Status
Cis-3-hexenyl acetate is an approved flavouring substance in the major markets. In the United States it holds FEMA GRAS status, and the Food and Drug Administration listing of synthetic flavouring substances and adjuvants permitted for use in food covers it. In the European Union it appears on the Union list of authorised flavouring substances with its own FLAVIS number, which is the operative clearance; flavourings are outside the food additive framework, so no E number applies.
JECFA has assessed the substance as part of its group evaluation of aliphatic primary alcohols, aldehydes, acids, acetals and esters and concluded that there is no safety concern at current levels of intake as a flavouring. Material destined for perfumery is additionally subject to the fragrance industry standards for cosmetic use, which sit alongside rather than within food law.
Manufacturing Process
The ester is made by acetylation of cis-3-hexenol. The alcohol is charged with acetic anhydride, or with acetic acid and an acid catalyst, and the mixture is held at moderate temperature under agitation. Acetic anhydride is generally preferred at scale because it drives the reaction to completion without the water of esterification that promotes isomerisation of the cis double bond, and it allows a lower reaction temperature. Where a natural label is required, the same alcohol is esterified enzymatically with a lipase, which runs under mild conditions and avoids acid catalysis altogether.
The reaction mass is quenched and washed with water and then with dilute alkali to remove acetic acid and any residual anhydride, and the organic layer is separated and dried. Fractional distillation under vacuum removes unreacted alcohol, high boiling residues and the trans isomer, and the heart cut is polished through a filter and blanketed with nitrogen before packing. The recovered alcohol fraction is returned to the next esterification batch.
