FlavScents AInsights Entry for (E)-2-nonenal (CAS: 18829-56-6)

1. Identity & Chemical Information

• Common Name(s): (E)-2-nonenal
• IUPAC Name: (E)-non-2-enal
• CAS Number: 18829-56-6
• FEMA Number: Data not found
• Other Identifiers: FL number not clearly reported; CoE number not available; IFRA reference not specified
• Molecular Formula: C9H16O
• Molecular Weight: 140.23 g/mol
• Functional Groups and Structure–Odor Relevance: (E)-2-nonenal is an unsaturated aldehyde characterized by a double bond in the trans configuration. This structural feature contributes to its distinctive odor profile, often described as fatty, green, and cucumber-like, which is significant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: (E)-2-nonenal is known for its strong, penetrating odor reminiscent of aged paper, cucumber, and fatty nuances. It is often described as having a green, waxy, and slightly citrusy character.
• Taste and/or Odor Thresholds: The odor threshold is reported to be extremely low, around 0.1 ppb in air, making it a potent odorant even at minimal concentrations.
• Typical Sensory Role: In formulations, (E)-2-nonenal serves as an impact note, providing a realistic and fresh quality to green and cucumber-like profiles. It is also used as a modifier to enhance the authenticity of complex fragrance and flavor compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: (E)-2-nonenal is naturally found in various plant sources, including cucumbers and certain types of melons. It is also a component of aged beer and some wines.
• Formation Pathways: This compound can form through the oxidative degradation of unsaturated fatty acids, such as linoleic acid, during storage or processing of food products.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Due to its presence in natural sources, (E)-2-nonenal can be labeled as a natural flavor or fragrance component, depending on its method of extraction and processing.

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

4. Use in Flavors

• Flavor Categories and Applications: (E)-2-nonenal is primarily used in green, cucumber, and melon flavor profiles. It is also employed in creating realistic vegetable and fruit flavors.
• Functional Role in Flavor Systems: It acts as an impact note, providing freshness and authenticity to flavor compositions.
• Typical Use Levels: Documented use levels in finished food products range from 0.01 to 0.1 ppm, with industry-typical levels often around 0.05 ppm.
• Stability Considerations: (E)-2-nonenal is relatively stable under neutral pH conditions but can degrade under acidic or highly oxidative environments, which may affect its sensory impact.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: This compound is utilized in green, citrus, and aquatic fragrance families. It is commonly found in personal care products, including soaps and shampoos.
• Functional Role: (E)-2-nonenal serves as a trace realism enhancer and a modifier, adding a fresh, green note to fragrance compositions.
• Typical Concentration Ranges: It is typically used at concentrations ranging from 0.01% to 0.1% in fragrance formulations.
• Volatility and Top/Middle/Base Contribution: Due to its volatility, (E)-2-nonenal contributes primarily to the top notes of a fragrance, imparting an initial fresh and green impression.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Not explicitly listed as GRAS by FEMA; usage is subject to general safety and regulatory compliance.
• European Union (Reg. (EC) No 1334/2008; FL Number Status): Not specifically listed; usage must comply with general flavoring regulations.
• United Kingdom (Post-Brexit Alignment or Divergence): Follows EU regulations; no specific divergence reported.
• Asia (Japan, China, ASEAN): Data not clearly reported; usage typically follows international safety standards.
• Latin America (e.g., Brazil, MERCOSUR): High-level data not available; generally aligns with international practices.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: No specific ADI or MSDI established; usage should be guided by general safety assessments and industry practices.
• Dermal Exposure: Limited data on irritation or sensitization; IFRA guidelines should be consulted for safe use in fragrances.
• Inhalation Exposure: Due to its volatility, inhalation exposure should be minimized in occupational settings; adequate ventilation is recommended.
• Risk Profiles: Generally considered safe at typical use levels in both food and fragrance applications, though care should be taken to avoid excessive exposure.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: (E)-2-nonenal is prized for its ability to impart a fresh, green note that enhances the realism of both flavor and fragrance compositions.
• Typical Synergies: It blends well with other green and citrus notes, enhancing the overall freshness and complexity of formulations.
• Common Formulation Pitfalls: Overuse can lead to an overpowering and unpleasant fatty odor; careful dosing is essential.
• Situations Where It is Frequently Over- or Under-used: Often under-used in complex formulations where its subtle impact can be easily overshadowed by more dominant notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Sensory characteristics and natural occurrence are well-documented.
• Industry-Typical but Undocumented Practices: Use levels and stability considerations are often based on industry experience rather than formal studies.
• Known Data Gaps or Regulatory Ambiguities: Specific regulatory approvals and toxicological data are limited, necessitating reliance on general safety guidelines.

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 2026-08-13 20:08:46 GMT (p2)