AInsights Entry for Dextro-Limonene (CAS: 5989-27-5)

1. Identity & Chemical Information

• Common Name(s): Dextro-limonene, (R)-limonene
• IUPAC Name: (R)-1-methyl-4-(1-methylethenyl)cyclohexene
• CAS Number: 5989-27-5
• FEMA Number: 2633
• Other Identifiers: FL No. 02.015
• Molecular Formula: C10H16
• Molecular Weight: 136.24 g/mol
• Functional Groups and Structure–Odor Relevance: Dextro-limonene is a monocyclic monoterpene with a characteristic citrus odor. The presence of the isopropenyl group contributes to its fresh, lemon-like scent, which is widely used in flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: Dextro-limonene is characterized by a strong, fresh, and sweet citrus odor reminiscent of oranges and lemons. It is often described as having a bright, zesty, and uplifting scent.
• Taste and/or Odor Thresholds: The odor threshold for dextro-limonene is typically low, allowing it to be perceived at concentrations as low as 0.01 ppm in air.
• Typical Sensory Role: It serves as an impact note in citrus flavors and fragrances, providing a realistic and vibrant citrus character. It is also used as a modifier to enhance the freshness of other flavor and fragrance components.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: Dextro-limonene is naturally found in the rinds of citrus fruits such as oranges, lemons, and limes. It is a major component of citrus essential oils.
• Formation Pathways: It is biosynthesized in plants via the mevalonate pathway, where it is derived from geranyl pyrophosphate.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Due to its natural occurrence in citrus fruits, dextro-limonene is often labeled as a natural flavor or fragrance ingredient.

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

4. Use in Flavors

• Flavor Categories and Applications: Dextro-limonene is extensively used in citrus-flavored beverages, candies, and baked goods. It is also employed in savory applications to impart a fresh citrus note.
• Functional Role in Flavor Systems: It acts as a primary flavoring agent and a modifier to enhance the overall citrus profile.
• Typical Use Levels: Documented use levels range from 10 to 100 ppm in finished products, with industry-typical levels around 20–50 ppm.
• Stability Considerations: Dextro-limonene is relatively stable under acidic conditions but can oxidize when exposed to air, leading to off-flavors. It is sensitive to heat and should be protected from light and oxygen during storage.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: Dextro-limonene is used in citrus, floral, and fresh fragrance families. It is commonly found in perfumes, household cleaners, and personal care products.
• Functional Role: It serves as a top note, providing an initial burst of freshness and realism.
• Typical Concentration Ranges: Concentrations in fragrances typically range from 0.1% to 5%, depending on the desired intensity.
• Volatility and Top/Middle/Base Contribution: As a highly volatile compound, dextro-limonene contributes primarily to the top note of a fragrance composition.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Dextro-limonene is generally recognized as safe (GRAS) for use in food and beverages.
• European Union (Reg. (EC) No 1334/2008; FL Number Status): Approved for use as a flavoring substance under FL No. 02.015.
• United Kingdom (Post-Brexit Alignment or Divergence): Regulatory status aligns with EU regulations.
• Asia (Japan, China, ASEAN): Approved for use in food and cosmetics, with specific concentration limits varying by country.
• Latin America (e.g., Brazil, MERCOSUR): Recognized as safe for use in food and fragrance applications.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Dextro-limonene has a high margin of safety with an acceptable daily intake (ADI) not specified due to its low toxicity.
• Dermal Exposure: It may cause skin irritation or sensitization in sensitive individuals. IFRA provides guidelines for safe use in fragrances.
• Inhalation Exposure: Generally considered safe for inhalation at typical fragrance concentrations, but high concentrations may cause respiratory irritation.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: Dextro-limonene is prized for its authentic citrus aroma and versatility in both flavor and fragrance formulations.
• Typical Synergies: It blends well with other citrus oils, floral notes, and green accords to enhance freshness.
• Common Formulation Pitfalls: Overuse can lead to overpowering citrus notes, while underuse may result in a lack of freshness.
• Situations Where It is Frequently Over- or Under-Used: Often overused in attempts to mask off-notes; underused in complex formulations where subtlety is required.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Extensive research supports its safety and efficacy in flavor and fragrance applications.
• Industry-Typical but Undocumented Practices: Use levels and synergies are often based on industry experience rather than formal studies.
• Known Data Gaps or Regulatory Ambiguities: Limited data on long-term inhalation exposure effects.

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 2026-08-12 12:05:51 GMT (p2)