FlavScents AInsights Entry for (R)-alpha-ionone (CAS: 24190-29-2)

1. Identity & Chemical Information

• Common Name(s): (R)-alpha-ionone
• IUPAC Name: (R)-4-(2,6,6-Trimethylcyclohex-1-en-1-yl)but-3-en-2-one
• CAS Number: 24190-29-2
• FEMA Number: 2593
• Other Identifiers: FL number 07.008
• Molecular Formula: C13H20O
• Molecular Weight: 192.30 g/mol

(R)-alpha-ionone is a monocyclic terpenoid with a ketone functional group. Its structure is significant for its odor profile, contributing to its violet-like scent. The presence of the conjugated double bond system in the cyclohexene ring is crucial for its olfactory properties.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

(R)-alpha-ionone is characterized by its floral, woody, and fruity odor, reminiscent of violets. It is known for its moderate intensity and good diffusion properties. The compound serves as an impact note in fragrance compositions, providing a distinct violet character. Odor thresholds are typically low, enhancing its effectiveness even at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

(R)-alpha-ionone is naturally found in various plant sources, including violets and certain types of berries. It is formed through the oxidative degradation of carotenoids, such as beta-carotene, in plants. This compound is often used to impart a "natural" label in flavor and fragrance formulations due to its occurrence in nature.

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

4. Use in Flavors

(R)-alpha-ionone is utilized in flavor formulations for its ability to impart a floral and fruity note. It is commonly used in berry, floral, and citrus flavor categories. Typical use levels in food and beverages range from 0.1 to 5 ppm, depending on the desired intensity and application. It is relatively stable under normal processing conditions but may degrade under extreme heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In perfumery, (R)-alpha-ionone is a versatile ingredient used across various fragrance families, including floral, woody, and chypre. It acts as a modifier and impact note, often contributing to the middle notes of a fragrance composition. Typical concentrations range from 0.1% to 1% in finished products, depending on the formulation. Its volatility allows it to contribute to both top and middle notes.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Recognized as GRAS by FEMA for flavor use.
• European Union: Approved under Regulation (EC) No 1334/2008 with FL number 07.008.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific restrictions in some ASEAN countries.
• Latin America: Generally accepted, with specific regulations in Brazil and MERCOSUR countries.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, (R)-alpha-ionone is considered safe at typical use levels, with an established ADI by relevant authorities. Dermal exposure in fragrances is generally safe, but it may cause mild irritation in sensitive individuals. IFRA guidelines provide usage limits to mitigate sensitization risks. Inhalation exposure is minimal due to its low volatility, but occupational exposure should be monitored.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

(R)-alpha-ionone is valued for its ability to enhance floral and fruity notes in both flavors and fragrances. It synergizes well with other floral compounds like beta-ionone and methyl ionone. Formulators should be cautious of its potential to overpower delicate compositions and should consider its stability under varying pH and temperature conditions.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on (R)-alpha-ionone is well-established, with comprehensive sensory and regulatory information available. While industry practices are well-documented, some regional regulatory nuances may require further clarification. Known data gaps are minimal, primarily concerning long-term exposure studies.

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 2026-04-24 01:34:47 GMT (p2)