Flavor ingredient regulatory record
Cyclotene butyrate
Cyclotene butyrate is an ester in the fruity family, FEMA GRAS under FEMA number 4648 (CAS 68227-51-0). Its odor is sweet, fruity, tropical, creamy, buttery.
- FEMA
- 4648
- CAS
- 68227-51-0
- JECFA
- 2056
- Formula
- C10H14O3
GRAS status: FEMA GRAS, publication 24. Recorded by FDA in the Substances Added to Food inventory under CAS 68227-51-0.
Structure
Identity
Also known as: Butanoic acid, 2-methyl-5-oxo-1-cyclopenten-1-yl ester, Butyric acid, 2-methyl-5-oxo-1-cyclopenten-1-yl ester, 2-Methyl-5-oxo-1-cyclopenten-1-yl butanoate, 2-Methyl-5-oxocyclopent-1-en-1-yl butanoate, 2-Methyl-5-oxocyclopent-1-en-1-yl butyrate, 2-methyl-5-oxo-1-cyclopenten-1-yl butyrate, butanoic acid, 2-methyl-5-oxo-1-cyclopenten-1-yl ester, 3-methyl-2-hydroxy-2-cyclopenten-1-one, butyrate, 2-hydroxy-3-methyl-2-cyclopenten-1-one butyrate, butyric acid, 2-methyl-5-oxo-1-cyclopenten-1-yl ester, 2-methyl-5-oxocyclopent-1-en-1-yl butyrate, 2-methyl-5-oxo-1-cyclopentenyl butyrate.
Can Cyclotene butyrate be labeled natural?
Nature occurrence: Not yet found in nature (provisional).
Nature occurrence has not been settled for this substance, so the natural or artificial class is not stated here. The FEMA GRAS status does not depend on it.
Regulatory status, with citations
United States
Cyclotene butyrate is FEMA GRAS under FEMA number 4648. It is cited in the Code of Federal Regulations at 21 CFR 172.515.
European Union and United Kingdom
No EU FL number is on file for Cyclotene butyrate. That is not a finding either way. The Union List covers defined flavouring substances, so natural complex materials are handled as flavouring preparations under Parts B to F and never receive a number, and substances used as additives sit under Regulation 1333/2008 instead. Confirm the position before EU or UK use.
JECFA (WHO / FAO)
JECFA number 2056, evaluated at the 73rd meeting in 2010. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. Cyclotene butyrate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 68227-51-0, where EPA names it Butanoic acid, 2-methyl-5-oxo-1-cyclopenten-1-yl ester.
Inactive in US commerce
EPA designates this substance inactive, so a Notice of Activity Form B is required before anyone manufactures or processes it again. Being FEMA GRAS does not change that. What active and inactive mean.
EPA publishes no regulatory flags on this listing. What the flags mean.
From the EPA non-confidential TSCA Inventory, July 2026 release. EPA also maintains a confidential portion it does not publish. Search the Inventory by CAS number.
Odor and taste
Odor: Sweet, fruity, tropical, creamy, buttery.
Where it is used
Cyclotene butyrate is used in beverage, confection, dairy and fruit flavors, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to Cyclotene butyrate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Butan-3-one-2-yl butanoate | 3332 | 75% | In nature |
| Ethyl maltol isobutyrate | 4534 | 56% | Not determined |
| Guaiacol isobutyrate | 4608 | 53% | Not determined |
| Guaiacol butyrate | 4607 | 52% | Not determined |
| 4-Acetoxy-2,5-dimethyl-3(2H)furanone | 3797 | 51% | In nature |
More esters in this index
Sodium 2-(4-methoxyphenoxy)propanoate · mono-Menthyl succinate · Ethyl 5-acetoxyoctanoate · Ethyl Caprylate · Ethyl decanoate · Ethyl acrylate
Cyclotene butyrate FAQ
Does cyclotene butyrate have FEMA GRAS status?
Cyclotene butyrate holds FEMA GRAS status under FEMA number 4648. It is also codified at 21 CFR 172.515.
How do I cite cyclotene butyrate by FEMA or CAS number?
Cite cyclotene butyrate as FEMA 4648 or CAS 68227-51-0; both point to the same entry. FEMA files it in the fruity flavor category.
Is cyclotene butyrate approved in the EU?
No EU FL number is on file for cyclotene butyrate. It has a JECFA evaluation (JECFA 2056), which the EU list draws on, but the Union List entry itself should be confirmed before EU use.
Has JECFA evaluated cyclotene butyrate?
Yes. JECFA number 2056, evaluated at the 73rd meeting in 2010. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
What does cyclotene butyrate smell and taste like, and where is it used?
The odor of cyclotene butyrate is sweet, fruity, tropical, creamy, buttery. Typical uses are beverage, confection, dairy and fruit flavors.
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Sources and attribution. The identity and regulatory facts on this page are taken from the FDA Substances Added to Food inventory, a US government record, which lists this substance as CYCLOTENE BUTYRATE under CAS 68227-51-0 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as flavoring agent or adjuvant.
A FEMA GRAS conclusion is reached by the Expert Panel of the Flavor and Extract Manufacturers Association of the United States, and the FEMA number names that conclusion. FEMA publishes its own entry for this substance in the FEMA Flavor Library, which is the authoritative record of what the Panel decided and is worth reading alongside this page.
Ambrose Compliance is not affiliated with, endorsed by, or sponsored by FEMA. FEMA and FEMA GRAS are used here as identifiers for a published regulatory determination, not as marks of any relationship between FEMA and Ambrose.
About this page. Facts come from the FDA Substances Added to Food inventory, the Code of Federal Regulations, the EPA TSCA Inventory, the EU Union List, JECFA and the Ambrose database, with FEMA's published determination cited where it applies; parts of the text are written by Ambrose AI, which can make mistakes. Check the cited source before relying on anything here. This is not regulatory or legal advice.