AInsights Entry for (E,E)-2,4-Nonadienal (CAS: 5910-87-2)

1. Identity & Chemical Information

• Common Name(s): (E,E)-2,4-Nonadienal
• IUPAC Name: (2E,4E)-nona-2,4-dienal
• CAS Number: 5910-87-2
• FEMA Number: 2764
• Other Identifiers: FL No. 05.073
• Molecular Formula: C9H14O
• Molecular Weight: 138.21 g/mol

(E,E)-2,4-Nonadienal is an unsaturated aldehyde characterized by its conjugated double bonds, which contribute to its potent odor profile. The presence of these functional groups is crucial for its sensory attributes, often described as fatty, green, and cucumber-like.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

(E,E)-2,4-Nonadienal is known for its distinctive odor, often described as fatty, green, and reminiscent of cucumber or melon. It has a strong intensity and is considered an impact note in flavor and fragrance formulations. The compound's odor threshold is relatively low, making it effective even at minimal concentrations. Its role is typically as a characterizing note, providing freshness and realism to compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

(E,E)-2,4-Nonadienal naturally occurs in various foodstuffs, including cucumbers, melons, and certain fish oils. It is formed through the oxidative degradation of polyunsaturated fatty acids, a process that can occur during food processing or storage. This compound is relevant for "natural flavor" designations when derived from natural sources through approved processes.

Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs

4. Use in Flavors

(E,E)-2,4-Nonadienal is utilized in flavor formulations for its ability to impart a fresh, green, and cucumber-like note. It is commonly used in fruit, vegetable, and seafood flavors. Typical use levels in finished food products range from 0.1 to 2 ppm, depending on the desired intensity and application. It is relatively stable under acidic conditions but can degrade under high heat or oxidative environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, (E,E)-2,4-Nonadienal is valued for its fresh, green aroma, contributing to the top notes of compositions. It is used in various fragrance families, including green, aquatic, and citrus. Concentration levels typically range from trace amounts to 0.5% in the final product, depending on the formulation. Its volatility makes it a prominent top note, providing an initial burst of freshness.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Recognized as GRAS by FEMA for flavor use.
• European Union: Listed under Regulation (EC) No 1334/2008 with FL No. 05.073.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific restrictions in some ASEAN countries.
• Latin America: Generally accepted, with specific regulations in Brazil and MERCOSUR countries.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, (E,E)-2,4-Nonadienal is considered safe at typical use levels, with an acceptable daily intake (ADI) not specifically established but implied through GRAS status. Dermal exposure in fragrances is generally safe, though it may cause irritation in sensitive individuals. Inhalation exposure is minimal due to its low volatility at typical use concentrations. The risk profiles are similar for both food and fragrance applications.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

(E,E)-2,4-Nonadienal is prized for its ability to impart a fresh, green note, enhancing the realism of flavors and fragrances. It synergizes well with other green and citrus notes but can overpower formulations if used excessively. Formulators should be cautious of its stability under heat and oxidative conditions, which can lead to degradation and off-notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on (E,E)-2,4-Nonadienal is well-established, with comprehensive sensory and regulatory information available. While industry practices are well-documented, some variability in natural occurrence and formation pathways may exist, necessitating careful sourcing and verification.

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 2026-09-01 11:04:17 GMT (p2)