FlavScents AInsights Entry for Mesityl Oxide (CAS: 141-79-7)

1. Identity & Chemical Information

• Common Name(s): Mesityl oxide
• IUPAC Name: 4-methylpent-3-en-2-one
• CAS Number: 141-79-7
• FEMA Number: 2745
• Other Identifiers: FL No. 07.191
• Molecular Formula: C6H10O
• Molecular Weight: 98.15 g/mol

Mesityl oxide is a volatile organic compound characterized by a ketone functional group and an unsaturated carbon chain. Its structure contributes to its distinct odor profile, which is often described as sweet and fruity with green and citrus nuances. The presence of the carbonyl group is crucial for its reactivity and sensory properties.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Mesityl oxide is known for its sweet, fruity odor with green and citrus-like characteristics. It is often used as an impact note in flavor compositions due to its strong diffusion and moderate intensity. The compound can impart a fresh, crisp quality to formulations, making it valuable in both flavor and fragrance applications. Specific odor thresholds are not well-documented, but its potent aroma suggests a low threshold.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Mesityl oxide is not commonly found in nature but can be formed through the aldol condensation of acetone. This reaction is a key step in various industrial processes, including the production of synthetic flavors and fragrances. While it is not typically classified as a "natural flavor," its formation from acetone, a naturally occurring compound, allows for its use in certain natural flavor formulations under specific regulatory guidelines.

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

4. Use in Flavors

Mesityl oxide is utilized in a variety of flavor categories, including citrus, fruity, and green profiles. It serves as a functional impact note, enhancing the freshness and authenticity of flavor systems. Typical use levels in finished food or beverages range from 0.1 to 5 ppm, with higher concentrations potentially leading to overpowering effects. It is generally stable under acidic conditions but may degrade under high heat or oxidative environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, mesityl oxide is used across several families, including citrus, green, and floral compositions. It acts as a modifier and impact note, contributing to the top and middle notes of a fragrance. Typical concentration ranges are from trace amounts to 0.5%, depending on the desired intensity and diffusion. Its volatility makes it suitable for top note applications, providing an initial burst of freshness.

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. 07.191.
• United Kingdom: Aligns with EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Explicit approvals and harmonized assumptions are common, though country-specific variability may exist, particularly in Asia and Latin America.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, mesityl oxide is considered safe at typical flavor use levels, with an acceptable daily intake (ADI) not clearly reported but generally recognized as safe under FEMA GRAS. Dermal exposure in fragrance applications may pose irritation risks, necessitating adherence to IFRA guidelines. Inhalation exposure is primarily a concern in occupational settings, where adequate ventilation and protective measures are recommended.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Mesityl oxide is valued for its ability to enhance freshness and authenticity in both flavors and fragrances. It synergizes well with citrus and green notes but can be overpowering if used excessively. Formulators should be cautious of its volatility and potential for degradation under heat and oxidation. It is often under-used in complex formulations where its impact could be beneficial.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on mesityl oxide is well-established, particularly regarding its sensory properties and regulatory status. However, specific numeric values for thresholds and ADI are less documented, requiring formulators to rely on industry-typical practices. Known data gaps include detailed toxicological profiles and comprehensive natural occurrence studies.

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 2026-05-01 12:07:36 GMT (p2)