FlavScents AInsights Entry for 2-Hexenoic Acid (CAS: 1191-04-4)

1. Identity & Chemical Information

• Common Name(s): 2-Hexenoic acid
• IUPAC Name: Hex-2-enoic acid
• CAS Number: 1191-04-4
• FEMA Number: Not available
• Other Identifiers: Not available
• Molecular Formula: C6H10O2
• Molecular Weight: 114.14 g/mol

2-Hexenoic acid is an unsaturated carboxylic acid characterized by a double bond between the second and third carbon atoms in its six-carbon chain. This structural feature contributes to its reactivity and influences its sensory properties. The presence of the carboxylic acid group is crucial for its solubility and interaction with other compounds in formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Hexenoic acid is known for its sharp, pungent odor with a hint of sourness, often described as reminiscent of fatty acids. Its intensity is moderate, making it suitable as a background note in formulations. The compound can impart a tangy, slightly acidic flavor profile, which can be used to enhance the realism of certain flavor compositions. Specific odor and taste thresholds are not well-documented, but its sensory role is typically as a modifier or enhancer in complex blends.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Hexenoic acid is not commonly found in nature but can be formed through the oxidation of hexanal or the enzymatic degradation of certain fatty acids. It is not typically associated with "natural flavor" or "natural fragrance" designations due to its synthetic origins in most commercial applications. However, it can be a minor component in some fermented products where lipid oxidation occurs.

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

4. Use in Flavors

2-Hexenoic acid is used in flavor formulations to add complexity and depth, particularly in savory and dairy applications. It can enhance the tangy notes in cheese flavors or provide a subtle acidic background in sauces. Typical use levels in finished food products range from 0.1 to 5 ppm, with higher concentrations potentially leading to overpowering sourness. Its stability is generally good under typical food processing conditions, though it may degrade under extreme heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, 2-hexenoic acid is used sparingly due to its potent odor. It can contribute to the authenticity of green or herbal notes and is sometimes used in trace amounts to add realism to complex fragrance compositions. Its volatility is moderate, allowing it to function as a middle note in fragrance pyramids. Typical concentrations in fragrance products are low, often below 0.1%.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Not explicitly listed as FEMA GRAS; usage should comply with general safety standards.
• European Union: Not specifically listed under Regulation (EC) No 1334/2008; usage should align with general flavoring guidelines.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Limited specific data; general compliance with local flavor and fragrance regulations is advised.
• Latin America: Usage should adhere to MERCOSUR and local regulations, though specific listings are not available.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Data not found for specific ADI or MSDI values; general safety practices for carboxylic acids apply.
• Dermal Exposure: Potential for mild irritation; IFRA guidelines should be consulted for fragrance use.
• Inhalation Exposure: Volatility suggests low risk at typical use levels, but occupational exposure should be minimized.

The risk profile for 2-hexenoic acid does not significantly differ between food and fragrance applications, though dermal exposure considerations are more relevant in fragrance contexts.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-Hexenoic acid is valued for its ability to enhance tangy and sour notes in flavor formulations. It synergizes well with other fatty acids and can be used to balance sweetness in complex blends. Formulators should be cautious of its intensity, as overuse can lead to undesirable sourness. It is often under-utilized in fragrance applications due to its potent odor, but when used judiciously, it can add authenticity to green and herbal notes.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-hexenoic acid is well-established in terms of its chemical identity and sensory characteristics. However, specific regulatory listings and toxicological data are less comprehensive, requiring formulators to rely on general industry practices and safety guidelines. Known data gaps include precise sensory thresholds and detailed regional regulatory approvals.

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 2026-01-28 07:10:45 GMT (p2)