AInsights Entry for (E,Z)-2,6-Nonadienal (CAS: 557-48-2)

1. Identity & Chemical Information

• Common Name(s): (E,Z)-2,6-Nonadienal
• IUPAC Name: (2E,6Z)-nona-2,6-dienal
• CAS Number: 557-48-2
• FEMA Number: 2789
• Other Identifiers: FL No. 05.061
• Molecular Formula: C9H14O
• Molecular Weight: 138.21 g/mol

(E,Z)-2,6-Nonadienal is an unsaturated aldehyde characterized by its conjugated double bonds, which contribute to its potent odor profile. The presence of the aldehyde group is crucial for its reactivity and sensory properties, often associated with green, cucumber-like aromas.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

(E,Z)-2,6-Nonadienal is renowned for its distinctive green, cucumber-like odor, often described as fresh and slightly fatty. It is a high-impact aroma compound with a low odor threshold, making it effective even at minimal concentrations. This compound is typically used as an impact note in formulations, providing a fresh, green character that enhances the realism of natural profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

(E,Z)-2,6-Nonadienal naturally occurs in cucumbers and melons, contributing to their characteristic fresh aroma. It is formed through the enzymatic degradation of linolenic acid, a common fatty acid in plant tissues. This compound is often used to impart a "natural flavor" designation due to its presence in these natural sources.

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

4. Use in Flavors

(E,Z)-2,6-Nonadienal is utilized across various flavor categories, including fruit, vegetable, and herbal profiles. It serves as a functional impact note, enhancing the freshness and authenticity of flavor systems. Typical use levels range from 0.1 to 2 ppm in finished food products, with higher concentrations potentially leading to overpowering effects. It is relatively stable under neutral pH but can degrade under acidic or high-heat conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, (E,Z)-2,6-Nonadienal is used in green and fresh fragrance families, often in personal care products and household cleaners. It acts as a modifier or impact note, contributing to the top notes with its volatile and fresh character. Typical concentrations range from trace amounts to 0.5% in formulations, depending on the desired intensity.

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. 05.061.
• United Kingdom: Aligns with EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted under MERCOSUR regulations, with country-specific variations.

Explicit approvals are well-documented, though some regional differences in concentration limits may exist.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, (E,Z)-2,6-Nonadienal is considered safe at typical flavor use levels, with an established ADI by FEMA. Dermal exposure in fragrance applications is generally safe, though IFRA guidelines should be consulted to avoid sensitization. Inhalation exposure is minimal due to its low volatility, but occupational safety measures should be observed in manufacturing settings.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

(E,Z)-2,6-Nonadienal is valued for its ability to impart a fresh, green note, enhancing the authenticity of natural profiles. It synergizes well with other green and citrus notes but can be overpowering if overused. Formulators should be cautious of its stability under acidic conditions and high temperatures.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on (E,Z)-2,6-Nonadienal is well-established, with comprehensive sensory and regulatory information available. While industry practices are well-documented, some regional regulatory nuances may require further 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 2026-10-23 21:04:47 GMT (p2)