FlavScents AInsights Entry for 2,4-Undecadienal (CAS: 13162-46-4)
1. Identity & Chemical Information
- Common Name(s): 2,4-Undecadienal
- IUPAC Name: Undeca-2,4-dienal
- CAS Number: 13162-46-4
- FEMA Number: 3422
- Other Identifiers: FL No. 02.084
- Molecular Formula: C11H18O
- Molecular Weight: 166.26 g/mol
2,4-Undecadienal is an unsaturated aldehyde characterized by its conjugated diene system. This structural feature is crucial for its potent odor profile, contributing to its use in both flavor and fragrance applications. The presence of the aldehyde group is significant for its reactivity and sensory impact, often imparting a fatty, citrus-like aroma.
Citation hooks: FlavScents; PubChem; FEMA
2. Sensory Profile
2,4-Undecadienal is known for its strong, fatty, citrus-like odor, often described as reminiscent of tangerine or grapefruit. It has a high odor intensity and is typically used as an impact note in formulations. The compound's diffusion is moderate, allowing it to blend well with other citrus and fruity notes. While specific taste and odor thresholds are not widely reported, its potent aroma suggests a low threshold, making it effective even at minimal concentrations.
Citation hooks: FlavScents; peer-reviewed sensory literature
3. Natural Occurrence & Formation
2,4-Undecadienal occurs naturally in various citrus oils and is a product of lipid oxidation in certain foodstuffs. It can form through the degradation of linoleic acid, a common fatty acid in many plant oils, via enzymatic or oxidative pathways. This compound's presence in natural sources supports its designation as a "natural flavor" in regulatory contexts, provided it is derived from natural processes.
Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs
4. Use in Flavors
2,4-Undecadienal is utilized in flavor formulations to impart citrus, fatty, and green notes. It is commonly found in citrus-flavored beverages, confectionery, and savory products. Typical use levels in finished products range from 0.1 to 1 ppm, with higher concentrations potentially leading to overpowering effects. The compound is relatively stable under acidic conditions but may degrade under high heat or oxidative environments, necessitating careful formulation considerations.
Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature
5. Use in Fragrances
In fragrance applications, 2,4-undecadienal is valued for its ability to enhance citrus and green notes, often used in perfumes, soaps, and household products. It serves as a top note due to its volatility, contributing freshness and realism to fragrance compositions. Typical concentrations range from trace amounts to 0.5% in finished products, depending on the desired intensity and product type.
Citation hooks: FlavScents; IFRA; fragrance chemistry texts
6. Regulatory Status (Regional Overview)
- United States: Recognized as GRAS by FEMA for flavor use.
- European Union: Approved under Regulation (EC) No 1334/2008 with FL No. 02.084.
- United Kingdom: Aligns with EU regulations post-Brexit.
- Asia: Approved for use in Japan and China, with specific limits varying by country.
- Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.
Explicit approvals and harmonized assumptions are common, though formulators should verify specific country requirements due to potential variability.
Citation hooks: FEMA; EFSA; national authority publications
7. Toxicology, Safety & Exposure Considerations
For oral exposure, 2,4-undecadienal is considered safe at typical flavor use levels, with no specific ADI established but covered under general GRAS status. Dermal exposure in fragrance applications is generally safe, though IFRA guidelines should be consulted to avoid irritation or sensitization. Inhalation exposure is minimal due to low volatility, but occupational safety measures should be in place to limit prolonged exposure.
Citation hooks: EFSA; FEMA; PubChem; toxicology literature
8. Practical Insights for Formulators
2,4-Undecadienal is prized for its ability to impart fresh, citrus-like notes, enhancing both flavor and fragrance profiles. It synergizes well with other citrus and green notes but can dominate if overused. Formulators should be cautious of its reactivity, particularly in oxidative environments, and consider encapsulation or antioxidants to preserve its integrity.
Citation hooks: FlavScents; industry practice
9. Confidence & Data Quality Notes
Data on 2,4-undecadienal is well-established, particularly regarding its sensory characteristics and regulatory status. While specific numeric thresholds are not always available, industry practices provide reliable guidance. Known data gaps include detailed toxicological profiles, which are typically extrapolated from similar compounds.
Citation hooks: FlavScents
QA Check
- All required sections 1–9 are present
- "Citation hooks:" line is present under each section
- Flavor section includes ppm ranges
- Toxicology section covers oral, dermal, inhalation
- Regulatory section mentions US, EU, UK, Asia, Latin America
- No section 5a required as this is a single compound
About FlavScents AInsights (Disclosure)
FlavScents AInsights integrates information from authoritative government, scientific, academic, and industry sources to provide applied, exposure-aware insight into flavor and fragrance materials. Data are drawn from regulatory bodies, expert safety panels, peer-reviewed literature, public chemical databases, and long-standing professional practice within the flavor and fragrance community. Where explicit published values exist, they are reported directly; where gaps remain, AInsights reflects widely accepted industry-typical practice derived from convergent sensory behavior, historical commercial use, regulatory non-objection, and expert consensus. All such information is clearly labeled to distinguish documented data from professional guidance or informed estimation, with the goal of offering transparent, practical, and scientifically responsible context for researchers, formulators, and regulatory specialists. This section is generated using advanced computational language modeling to synthesize and structure information from established scientific and regulatory knowledge bases, with the intent of supporting—not replacing—expert review and judgment.
Generated 2026-02-09 18:09:02 GMT (p2)