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: 2764
• Other Identifiers: FL No. 02.062
• Molecular Formula: C9H16O
• Molecular Weight: 140.23 g/mol

(E)-2-nonenal is an unsaturated aldehyde characterized by a linear chain with a double bond at the second carbon. This structural feature contributes to its distinctive odor profile, often described as fatty, green, and cucumber-like. The presence of the aldehyde group is crucial for its reactivity and sensory impact.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

(E)-2-nonenal is known for its potent odor, often described as green, cucumber-like, and slightly fatty. It is a high-impact compound with a low odor threshold, making it a powerful note in both flavors and fragrances. Its intensity can be overwhelming if not used judiciously, typically serving as an impact note or modifier in formulations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

(E)-2-nonenal is naturally found in various plant sources, including cucumbers and certain types of melons. It can also form through the oxidative degradation of unsaturated fatty acids, such as linoleic acid, during food processing or storage. This compound is relevant to "natural flavor" designations when derived from natural sources or processes.

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

4. Use in Flavors

In flavor applications, (E)-2-nonenal is used to impart fresh, green, and cucumber-like notes. It is commonly employed in fruit and vegetable flavor profiles, particularly in cucumber, melon, and certain citrus flavors. Typical use levels in finished food products range from 0.1 to 1 ppm, with higher concentrations potentially leading to overpowering effects. It is relatively stable under neutral pH but can degrade under acidic or high-temperature conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

(E)-2-nonenal is utilized in fragrance formulations to provide fresh, green, and aldehydic notes. It is often found in the top notes of perfumes, contributing to the initial impression of freshness and naturalness. Typical concentrations in fragrance products range from trace amounts to 0.5%, depending on the desired intensity and product type. Its volatility makes it suitable for top note applications.

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. 02.062.
• United Kingdom: Aligns with EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific restrictions in certain 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)-2-nonenal is considered safe at typical flavor use levels, with an established ADI not clearly reported but generally recognized as safe under FEMA GRAS. Dermal exposure in fragrance applications may pose a risk of irritation or sensitization, particularly at higher concentrations, necessitating adherence to IFRA guidelines. Inhalation exposure is generally low risk due to its rapid volatilization, but occupational exposure should be monitored.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

(E)-2-nonenal is valued for its ability to impart fresh, green notes, enhancing the realism of fruit and vegetable flavors. It synergizes well with other aldehydes and green notes but can easily dominate a formulation if overused. Formulators should be cautious of its low odor threshold and potential for oxidation, which can alter its sensory profile.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on (E)-2-nonenal is well-established, particularly regarding its sensory characteristics and regulatory status. However, specific numeric safety thresholds such as ADI are not always clearly reported, requiring formulators to rely on industry-typical practices and 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

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 2026-02-08 18:31:37 GMT (p2)