FlavScents AInsights Entry for 3-Mercaptoisobutyric Acid (CAS: 26473-47-2)
1. Identity & Chemical Information
- Common Name(s): 3-Mercaptoisobutyric acid
- IUPAC Name: 3-sulfanyl-2-methylpropanoic acid
- CAS Number: 26473-47-2
- FEMA Number: Not available
- Other Identifiers: FL number not available; CoE number not available; IFRA reference not available
- Molecular Formula: C4H8O2S
- Molecular Weight: 120.17 g/mol
3-Mercaptoisobutyric acid is characterized by the presence of a thiol group, which is known to contribute to its distinctive odor profile. The thiol group is often associated with sulfurous, pungent odors, which can be impactful even at low concentrations. The carboxylic acid group may also influence its solubility and reactivity in formulations.
Citation hooks: FlavScents; PubChem; FEMA
2. Sensory Profile
3-Mercaptoisobutyric acid is known for its potent sulfurous odor, which can be described as pungent and reminiscent of garlic or cooked cabbage. The intensity of the odor is high, and it can diffuse rapidly in the air. This compound is typically used as an impact note in flavor formulations, providing a realistic sulfurous character that can enhance the authenticity of savory profiles.
Taste and odor thresholds for 3-mercaptoisobutyric acid are not clearly reported in the literature. However, due to its strong odor, it is generally used at low concentrations to avoid overpowering the overall sensory profile.
Citation hooks: FlavScents; peer-reviewed sensory literature
3. Natural Occurrence & Formation
3-Mercaptoisobutyric acid is not commonly found in nature and is primarily synthesized for use in flavor and fragrance applications. It may be formed through chemical synthesis involving the introduction of a thiol group to a suitable precursor molecule. Its role in natural flavor or fragrance designations is limited due to its synthetic origin.
Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs
4. Use in Flavors
3-Mercaptoisobutyric acid is utilized in flavor formulations to impart a sulfurous, savory note, often used in meat, garlic, and onion flavors. It serves as an impact note, providing depth and authenticity to these profiles. Typical use levels in finished food products are not well-documented, but industry practice suggests concentrations in the low ppm range to achieve the desired effect without overwhelming the flavor system.
Stability considerations include sensitivity to oxidation, which can diminish its sulfurous character over time. It is generally stable under acidic conditions but may degrade at high temperatures.
Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature
5. Use in Fragrances
In fragrance applications, 3-mercaptoisobutyric acid is used sparingly due to its potent odor. It can be employed in trace amounts to add realism to sulfurous or earthy fragrance profiles. Its volatility contributes to its role as a top note, providing an initial impact that can enhance the complexity of a fragrance composition.
Typical concentration ranges are qualitative, with usage often dictated by the desired intensity and character of the fragrance.
Citation hooks: FlavScents; IFRA; fragrance chemistry texts
6. Regulatory Status (Regional Overview)
- United States: Not explicitly listed as FEMA GRAS; usage in flavors may be subject to general safety evaluations.
- European Union: Not specifically listed under Regulation (EC) No 1334/2008; usage may be governed by general safety and labeling requirements.
- United Kingdom: Post-Brexit regulations align closely with EU standards; specific status not reported.
- Asia: Specific regulatory status in Japan, China, and ASEAN countries not clearly documented; general safety assessments likely apply.
- Latin America: Regulatory status in Brazil and MERCOSUR not explicitly detailed; harmonized safety evaluations may be applicable.
Citation hooks: FEMA; EFSA; national authority publications
7. Toxicology, Safety & Exposure Considerations
- Oral Exposure: Data on acceptable daily intake (ADI) or threshold of toxicological concern (TTC) for 3-mercaptoisobutyric acid is not found. Formulators should ensure usage levels are consistent with general safety practices for sulfur-containing compounds.
- Dermal Exposure: Potential for irritation or sensitization is not well-documented; caution is advised in fragrance applications.
- Inhalation Exposure: Due to its volatility, inhalation exposure should be minimized in occupational settings to prevent respiratory irritation.
Risk profiles may differ between food and fragrance applications, with fragrance use requiring careful consideration of dermal and inhalation exposure.
Citation hooks: EFSA; FEMA; PubChem; toxicology literature
8. Practical Insights for Formulators
3-Mercaptoisobutyric acid is valued for its ability to impart a realistic sulfurous note, enhancing the authenticity of savory flavors. It synergizes well with other sulfur-containing compounds and can be used to create complex, layered profiles. Common pitfalls include overuse, leading to an overpowering and unpleasant odor. It is often under-used in applications where a subtle sulfurous note could enhance the overall profile.
Citation hooks: FlavScents; industry practice
9. Confidence & Data Quality Notes
The data on 3-mercaptoisobutyric acid is well-established in terms of its sensory characteristics and functional roles. However, specific regulatory and toxicological data are less documented, requiring formulators to rely on industry-typical practices and safety assessments. Known data gaps include precise usage levels and comprehensive safety evaluations.
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 2026-04-29 01:28:28 GMT (p2)