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, which contributes to its potent odor profile. The presence of the aldehyde group is crucial for its reactivity and sensory characteristics, often imparting a fatty, citrus-like aroma that is highly valued in flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2,4-Undecadienal is renowned for its strong, fatty, citrus-like odor with nuances of orange peel and grapefruit. It is often described as having a fresh, aldehydic character with a high diffusion rate, making it an impactful top note in formulations. The compound's odor threshold is relatively low, allowing it to be effective even at minimal concentrations. Its sensory role is typically as an impact note, providing freshness and lift to both flavor and fragrance compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2,4-Undecadienal is naturally found in various citrus oils and is a product of lipid oxidation in certain foodstuffs. It can also form through the Maillard reaction during the thermal processing of foods. Its presence in natural sources allows it to be designated as a "natural flavor" under certain regulatory frameworks, 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 across a broad spectrum of flavor categories, including citrus, dairy, and savory applications. It serves as a key component in flavor systems to enhance freshness and authenticity. Typical use levels in finished food products range from 0.1 to 2 ppm, with higher concentrations potentially leading to overpowering effects. The compound is relatively stable under acidic conditions but may degrade under prolonged heat exposure.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, 2,4-undecadienal is employed in citrus, floral, and green fragrance families. It acts as a top note, providing a fresh, aldehydic lift that enhances the overall brightness of a composition. Typical concentrations range from trace amounts to 0.5% in the final product, depending on the desired intensity. Its volatility ensures a quick release, contributing to the initial impression of a fragrance.

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 restrictions in ASEAN countries.
• Latin America: Generally accepted, with specific guidelines in Brazil and MERCOSUR countries.

Regulatory frameworks generally support its use in both flavor and fragrance applications, with harmonized assumptions across regions. However, formulators should verify specific country regulations 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 within established use levels, with an acceptable daily intake (ADI) not specifically defined but supported by FEMA GRAS status. Dermal exposure in fragrance applications is generally safe, though IFRA guidelines should be consulted to avoid potential sensitization. Inhalation exposure is typically low risk due to its rapid volatility, but occupational safety measures should be observed in manufacturing settings.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2,4-Undecadienal is valued for its ability to impart freshness and authenticity, particularly in citrus and fatty profiles. It synergizes well with other aldehydes and citrus components. Formulators should be cautious of its potency, as overuse can lead to an overpowering effect. It is often under-utilized in savory applications, where it can enhance fatty and umami notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2,4-undecadienal is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though specific use levels may vary. Some data gaps exist in regional regulatory specifics, necessitating verification for compliance.

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
• If complex natural material: includes section 5a (not applicable here)

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 2026-03-24 13:53:59 GMT (p2)