FlavScents 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: 3090
• Other Identifiers: FL No. 07.008
• Molecular Formula: C9H14O
• Molecular Weight: 138.21 g/mol
• Functional Groups and Structure–Odor Relevance: (E,E)-2,4-Nonadienal is an unsaturated aldehyde characterized by its conjugated double bonds, which contribute to its potent odor profile. The aldehyde group is crucial for its reactivity and sensory impact, often associated with fatty, green, and cucumber-like notes.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: (E,E)-2,4-Nonadienal is known for its strong, penetrating odor reminiscent of cucumber, fatty, and green notes. It is often described as having a fresh, slightly metallic character with a high intensity and good diffusion.
• Taste and/or Odor Thresholds: The odor threshold is typically low, around 0.1 ppb in water, making it a powerful impact compound even at trace levels.
• Typical Sensory Role: It serves as an impact note in flavor compositions, providing freshness and authenticity to cucumber and melon profiles, and is used to enhance the realism of green and fatty notes in various applications.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: (E,E)-2,4-Nonadienal is naturally found in cucumbers, melons, and certain fish oils. It is also present in the volatile profiles of some fruits and vegetables.
• Formation Pathways: It can be formed through the oxidative degradation of polyunsaturated fatty acids, particularly linoleic acid, during lipid oxidation processes.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Its presence in natural sources allows it to be used in formulations labeled as containing natural flavors or fragrances, provided it is derived from these sources.

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

4. Use in Flavors

• Flavor Categories and Applications: Commonly used in fruit, vegetable, and seafood flavors, particularly in cucumber, melon, and fish profiles.
• Functional Role in Flavor Systems: Acts as an impact compound, providing authenticity and enhancing freshness in flavor compositions.
• Typical Use Levels: Documented use levels range from 0.01 to 0.1 ppm in finished food products, with higher concentrations potentially leading to overpowering effects.
• Stability Considerations: It is relatively stable under acidic conditions but can degrade under high heat and oxidative environments, necessitating careful formulation to maintain its sensory impact.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: Utilized in green, fresh, and marine fragrance families, often in personal care products and household cleaners.
• Functional Role: Provides trace realism and acts as a modifier to enhance the freshness and naturalness of fragrance compositions.
• Typical Concentration Ranges: Generally used at trace levels, often below 0.1% in fragrance formulations, due to its potent odor.
• Volatility and Top/Middle/Base Contribution: It is a top note due to its high volatility, contributing to the initial impression of freshness in a fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Recognized as GRAS for flavor use by FEMA.
• European Union (Reg. (EC) No 1334/2008; FL Number Status): Approved for use in food flavorings, listed under FL No. 07.008.
• United Kingdom (Post-Brexit Alignment or Divergence): Follows EU regulations, with no significant divergence reported.
• Asia (Japan, China, ASEAN): Generally permitted in flavor applications, subject to specific regional regulations.
• Latin America (e.g., Brazil, MERCOSUR): Permitted in food flavorings, with harmonized regulations across MERCOSUR countries.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Considered safe for use in food flavors at typical use levels, with a high margin of safety due to its low concentration in finished products.
• Dermal Exposure: Generally non-irritating at typical fragrance use levels, but IFRA guidelines should be consulted for specific product applications.
• Inhalation Exposure: Low volatility reduces inhalation risk, but occupational exposure should be managed to prevent sensitization.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: Its potent, fresh, and green notes make it indispensable for creating authentic cucumber and melon flavors.
• Typical Synergies: Works well with other green and fruity notes, enhancing the overall freshness and realism of the composition.
• Common Formulation Pitfalls: Overuse can lead to an overpowering and metallic character; balance is crucial.
• Situations Where It is Frequently Over- or Under-Used: Often under-used in complex formulations where its impact can be masked by other strong notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Comprehensive sensory and regulatory data are available, supporting its safe use in flavors and fragrances.
• Industry-Typical but Undocumented Practices: Use levels and synergies are often based on industry experience rather than formal studies.
• Known Data Gaps or Regulatory Ambiguities: Limited data on long-term exposure effects, though current use levels are considered safe.

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 14:07:12 GMT (p2)