FlavScents AInsights Entry for 2-Methyl Butyric Acid (CAS: 116-53-0)

1. Identity & Chemical Information

2-Methyl butyric acid, also known as isovaleric acid, is a carboxylic acid with the IUPAC name 2-methylbutanoic acid. It is identified by the CAS number 116-53-0. The FEMA number for 2-methyl butyric acid is 2693. Other identifiers include the FL number 08.005 and CoE number 186. The molecular formula is C5H10O2, and it has a molecular weight of 102.13 g/mol. The compound features a branched-chain structure, which contributes to its distinctive odor profile. The presence of the carboxyl group is crucial for its acidic properties and its role in flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Methyl butyric acid is characterized by a strong, pungent odor reminiscent of cheese and sweat, with a sour, acidic taste. It is often described as having a cheesy, rancid, or sweaty note, which can be quite intense and diffusive. Despite its strong odor, it is used in small quantities to impart a rich, creamy note to flavors, often serving as an impact note or a background realism enhancer. The odor threshold is relatively low, making it effective even at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Methyl butyric acid naturally occurs in various foods, including cheese, beer, and certain fruits. It is formed through the fermentation process, particularly in dairy products, where it contributes to the characteristic aroma of aged cheeses. The compound can also be produced via enzymatic degradation of leucine, an amino acid. Its presence in natural sources allows it to be designated as a "natural flavor" in certain regulatory contexts.

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

4. Use in Flavors

In flavor applications, 2-methyl butyric acid is used to enhance dairy, fruity, and savory profiles. It is commonly found in cheese, butter, and fruit flavors, where it acts as a functional component to provide authenticity and depth. Typical use levels in finished food products range from 0.1 to 5 ppm, depending on the desired intensity and the specific application. It is stable under typical food processing conditions, although it may degrade under extreme heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

2-Methyl butyric acid is utilized in fragrance formulations to impart a naturalistic, animalic note. It is often used in trace amounts to add complexity and realism to compositions, particularly in leather, chypre, and fougère fragrance families. Its volatility allows it to contribute primarily to the top and middle notes of a fragrance. Typical concentration ranges are from 0.01% to 0.1% in the final product.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, 2-methyl butyric acid is recognized as GRAS (Generally Recognized As Safe) by FEMA for use in flavors. In the European Union, it is approved under Regulation (EC) No 1334/2008 and assigned the FL number 08.005. The United Kingdom follows similar regulations post-Brexit. In Asia, it is permitted in Japan and China, with specific use conditions. In Latin America, countries like Brazil and those in MERCOSUR generally align with international standards, though specific regulations may vary.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 2-methyl butyric acid is considered safe at typical flavor use levels, with an acceptable daily intake (ADI) not specifically established but generally recognized as safe under FEMA GRAS. Dermal exposure in fragrances may cause irritation or sensitization in sensitive individuals, and it is subject to IFRA guidelines. Inhalation exposure is minimal due to its low volatility in typical use concentrations, but occupational exposure should be managed to prevent irritation.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-Methyl butyric acid is valued for its ability to impart authenticity and complexity to both flavors and fragrances. It synergizes well with other dairy and fruity notes, enhancing the overall profile. Formulators should be cautious of its potent odor, as overuse can lead to an undesirable, overpowering effect. It is often under-used due to its strong aroma, but when balanced correctly, it can significantly enhance product realism.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-methyl butyric acid is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though specific use levels may vary based on formulation goals. Some data gaps exist in precise toxicological thresholds, but general safety is supported by GRAS status and 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 2026-03-31 12:31:34 GMT (p2)