FlavScents AInsights Entry for 2-Pentenal (CAS: 764-39-6)

1. Identity & Chemical Information

2-Pentenal, also known as pent-2-enal, is a volatile organic compound with the CAS number 764-39-6. It is a single chemical compound with the molecular formula C5H8O and a molecular weight of 84.12 g/mol. The compound features an aldehyde functional group, which is crucial for its characteristic odor profile. The presence of the double bond in its structure contributes to its reactivity and sensory attributes. While a specific FEMA number for 2-pentenal is not readily available, it is recognized in various chemical databases for its applications in flavor and fragrance industries.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Pentenal is characterized by a pungent, green, and slightly fruity odor, often described as reminiscent of cut grass or green apple. Its intensity is moderate, and it serves as an impact note in formulations, providing freshness and a green character. The odor threshold for 2-pentenal is relatively low, making it effective even at minimal concentrations. It is typically used to impart a fresh, natural quality to both flavors and fragrances.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Pentenal is naturally found in various fruits and vegetables, contributing to their fresh, green aroma. It can be formed through the enzymatic degradation of unsaturated fatty acids, a process common in plant tissues. This compound is relevant to the designation of "natural flavor" due to its occurrence in nature and its formation through natural biochemical pathways.

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

4. Use in Flavors

In flavor applications, 2-pentenal is used to enhance the freshness and authenticity of fruit and vegetable flavors. It is commonly employed in apple, pear, and green vegetable flavor profiles. Typical use levels in finished food products range from 0.1 to 5 ppm, depending on the desired intensity and the complexity of the flavor system. It is relatively stable under acidic conditions but may degrade under high heat or oxidative environments, necessitating careful formulation considerations.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

2-Pentenal is utilized in fragrance compositions to impart a fresh, green note, often used in floral and fruity fragrance families. It acts as a modifier, enhancing the naturalness and complexity of the scent. Typical concentration ranges in fragrance formulations are from trace amounts up to 0.5%, depending on the desired effect. Due to its volatility, it contributes primarily to the top notes of a fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, 2-pentenal is generally recognized as safe (GRAS) for use in flavors by FEMA. In the European Union, it is regulated under Regulation (EC) No 1334/2008, with specific use conditions. The UK follows similar regulations post-Brexit. In Asia, regulatory frameworks vary, with Japan and China having specific guidelines for flavor and fragrance materials. In Latin America, countries like Brazil and members of MERCOSUR have their own regulatory standards, often aligning with international norms.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 2-pentenal is considered safe at typical flavor use levels, with no specific ADI established but falling under the threshold of toxicological concern (TTC). Dermal exposure in fragrance applications is generally safe, with low potential for irritation or sensitization, as per IFRA guidelines. Inhalation exposure is minimal due to its low volatility and typical use concentrations. Overall, the risk profiles for food and fragrance applications are similar, with no significant safety concerns at standard use levels.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-Pentenal is valued for its ability to impart a fresh, green note, enhancing the authenticity of both flavors and fragrances. It synergizes well with other aldehydes and green notes, but formulators should be cautious of its reactivity, which can lead to degradation in certain conditions. It is often under-used in complex formulations where its impact can be overshadowed by more dominant notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-pentenal is well-established, with consistent sensory and regulatory information available. While industry practices are well-documented, some variability in natural occurrence data exists due to differences in plant sources and processing methods. No significant data gaps or regulatory ambiguities are noted.

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 2026-07-10 16:20:28 GMT (p2)