FlavScents AInsights Entry for Isobutyraldehyde (CAS: 78-84-2)

1. Identity & Chemical Information

• Common Name(s): Isobutyraldehyde
• IUPAC Name: 2-Methylpropanal
• CAS Number: 78-84-2
• FEMA Number: 2173
• Other Identifiers: FL No. 02.015
• Molecular Formula: C4H8O
• Molecular Weight: 72.11 g/mol

Isobutyraldehyde is an aliphatic aldehyde characterized by a branched structure, which contributes to its distinct odor profile. The presence of the aldehyde functional group is crucial for its reactivity and sensory characteristics, often imparting a pungent, fruity aroma that is leveraged in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Isobutyraldehyde is known for its sharp, pungent odor with fruity and nutty undertones. It is often described as having a green, apple-like scent, which can be quite intense and diffusive. The compound serves as an impact note in formulations, providing a fresh and vibrant character. While specific taste and odor thresholds are not widely documented, its potent aroma suggests a low threshold, making it effective even at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Isobutyraldehyde occurs naturally in various fruits and fermented products. It can be formed through the oxidative degradation of isobutanol or via the Maillard reaction, a common pathway in food processing that contributes to flavor development. Its presence in natural sources supports its designation as a "natural flavor" in certain regulatory contexts, although this may vary by region.

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

4. Use in Flavors

Isobutyraldehyde is utilized in a variety of flavor categories, including fruit, nut, and dairy flavors. It acts as a functional component in flavor systems, often used to enhance freshness and complexity. Typical use levels in finished food or beverages range from 0.1 to 5 ppm, with higher concentrations potentially leading to overpowering notes. It is relatively 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, isobutyraldehyde is incorporated into citrus, green, and fruity fragrance families. It serves as a top note, providing an initial burst of freshness and realism. Typical concentrations range from trace amounts to 0.5% in formulations, depending on the desired intensity and product type. Its volatility makes it suitable for top note contributions, enhancing the initial impact of a fragrance.

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 an assigned FL number.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Approved for use in Japan and China, with specific limits varying by country.
• Latin America: Generally accepted under MERCOSUR regulations, though specific country guidelines should be consulted.

Explicit approvals and harmonized assumptions are common, but formulators should verify compliance with local regulations due to potential variability.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, isobutyraldehyde is considered safe at typical flavor use levels, with a high margin of safety. Dermal exposure in fragrance applications may pose irritation risks, necessitating adherence to IFRA guidelines. Inhalation exposure, particularly in occupational settings, should be managed to minimize irritation due to its volatility. Overall, the risk profiles for food and fragrance applications are similar, with appropriate safety measures in place.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Isobutyraldehyde is valued for its ability to impart freshness and complexity in both flavors and fragrances. It synergizes well with other aldehydes and esters, enhancing fruity and green notes. Common pitfalls include overuse, leading to harshness, and instability under certain conditions. It is often under-utilized in formulations seeking a natural, fresh character.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on isobutyraldehyde is well-established, with comprehensive sensory and regulatory information available. Industry practices are documented, though some regional regulatory nuances may require further clarification. Known data gaps are minimal, primarily related to specific sensory thresholds.

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 2026-09-02 15:38:42 GMT (p2)