FlavScents AInsights Entry: Acetaldehyde (CAS: 75-07-0)

1. Identity & Chemical Information

• Common Name(s): Acetaldehyde
• IUPAC Name: Ethanal
• CAS Number: 75-07-0
• FEMA Number: 2003
• Other Identifiers: FL No. 02.001, CoE No. 01
• Molecular Formula: C₂H₄O
• Molecular Weight: 44.05 g/mol

Acetaldehyde is a simple aldehyde with a carbonyl group (C=O) adjacent to a methyl group. Its structure contributes to its characteristic pungent, fruity odor, which is significant in both flavor and fragrance applications. The carbonyl group is primarily responsible for its reactivity and sensory properties.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Acetaldehyde is known for its sharp, pungent, and fruity odor, often described as green apple-like. It has a high diffusion rate and is considered an impact note in formulations. The odor threshold is relatively low, making it detectable at minimal concentrations. In flavor applications, it provides a fresh, fruity note that enhances the realism of fruit flavors.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Acetaldehyde occurs naturally in various fruits, such as apples and grapes, and is a byproduct of fermentation processes. It is also formed during the Maillard reaction, contributing to the flavor profile of baked goods and roasted foods. Its presence in natural sources allows it to be designated as a "natural flavor" under certain regulatory frameworks.

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

4. Use in Flavors

Acetaldehyde is widely used in fruit flavor formulations, particularly for apple, citrus, and berry profiles. It acts as an impact note, providing freshness and authenticity. Typical use levels in finished products range from 1 to 50 ppm, with higher concentrations potentially leading to overpowering notes. It is relatively stable under acidic conditions but can degrade under high heat or oxidative environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrances, acetaldehyde is used in citrus and green floral compositions, contributing to the top notes with its high volatility. It serves as a modifier, enhancing the freshness and realism of the fragrance. Typical concentrations are low, often less than 0.1%, due to its potent odor and volatility.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Acetaldehyde is FEMA GRAS approved for flavor use.
• European Union: Listed under Regulation (EC) No 1334/2008 with an assigned FL number.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally recognized as safe, with country-specific regulations in Brazil and MERCOSUR.

Explicit approvals exist for flavor use, while fragrance use is subject to IFRA guidelines. Variability in regulations may occur, particularly in Asia and Latin America.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Acetaldehyde has an established ADI, with a wide margin of safety for typical flavor use.
• Dermal Exposure: Potential for irritation and sensitization exists; IFRA guidelines recommend restrictions in fragrance applications.
• Inhalation Exposure: High volatility necessitates caution in occupational settings to prevent respiratory irritation.

Risk profiles differ between food and fragrance applications, with stricter controls in place for dermal and inhalation exposures.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Acetaldehyde is valued for its ability to impart freshness and authenticity to both flavors and fragrances. It synergizes well with other fruity and citrus notes but can be overpowering if overused. Formulators should be cautious of its volatility and potential for rapid degradation in certain conditions.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on acetaldehyde is well-established, with comprehensive regulatory and sensory information available. Industry practices are well-documented, though some variability exists in regional regulatory interpretations.

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
• No section 5a required as acetaldehyde is a single compound

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 2026-02-26 13:51:50 GMT (p2)