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
• 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. This structure is crucial for its reactivity and sensory characteristics. The carbonyl group contributes to its pungent, fruity odor, which is significant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Acetaldehyde is characterized by a sharp, pungent odor with fruity and green nuances. It is often described as having a fresh, apple-like aroma. The intensity of its odor is high, and it is known for its rapid diffusion. In flavor applications, acetaldehyde serves as an impact note, providing a fresh, fruity top 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, which occurs during the cooking of foods, 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" in certain regulatory contexts.

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

4. Use in Flavors

Acetaldehyde is widely used in flavor formulations, particularly in fruit flavors such as apple, citrus, and berry. It acts as a key impact note, providing freshness and authenticity. Typical use levels in finished food products range from 1 to 50 ppm, with higher concentrations used in more robust flavor profiles. Acetaldehyde is volatile and can be sensitive to heat and oxidation, which formulators must consider to maintain flavor integrity.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, acetaldehyde is used in various fragrance families, including fruity and green compositions. It serves as a top note, providing a fresh, crisp opening to the fragrance. Typical concentrations in fragrance formulations are low, often less than 1%, due to its high volatility and strong odor. Its role is primarily as a modifier, enhancing the freshness and realism of the fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Acetaldehyde is FEMA GRAS approved for flavor use. It is also listed by the FDA as a food additive.
• European Union: Approved under Regulation (EC) No 1334/2008 with FL No. 02.001.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific restrictions on concentration levels.
• Latin America: Recognized in Brazil and MERCOSUR countries, with harmonized regulations similar to the EU.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Acetaldehyde's safety profile varies by exposure route. Orally, it is considered safe at low concentrations, with an ADI established by JECFA. Dermal exposure in fragrances is limited due to potential irritation and sensitization, with IFRA providing guidelines on safe use levels. Inhalation exposure is a concern in occupational settings due to its volatility, necessitating adequate ventilation and protective measures.

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 green notes but can be overpowering if used excessively. Formulators should be cautious of its volatility and potential for oxidation, which can alter the intended sensory profile. It is often under-used in complex formulations where its impact could enhance overall perception.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on acetaldehyde is well-established, with comprehensive regulatory and sensory information available. Industry practices are well-documented, though some variability exists in natural occurrence data due to differences in source materials and processing methods.

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 2026-01-16 19:21:14 GMT (p2)