FlavScents AInsights Entry for Beta-Thujene (CAS: 28634-89-1)

1. Identity & Chemical Information

• Common Name(s): Beta-Thujene
• IUPAC Name: (1S,5S)-1-isopropyl-4-methylbicyclo[3.1.0]hex-3-ene
• CAS Number: 28634-89-1
• FEMA Number: Not available
• Other Identifiers: Not available
• Molecular Formula: C10H16
• Molecular Weight: 136.24 g/mol

Beta-thujene is a bicyclic monoterpene hydrocarbon. Its structure consists of a bicyclo[3.1.0]hexane ring with an isopropyl group and a methyl group, contributing to its distinct odor profile. The functional groups present in beta-thujene are crucial for its interaction with olfactory receptors, influencing its sensory characteristics.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Beta-thujene is characterized by a fresh, herbal, and slightly woody aroma. It is often described as having a moderate intensity with a sharp, green note that can be perceived as both refreshing and slightly pungent. The compound is typically used as a modifier in fragrance compositions to add complexity and enhance the freshness of the blend. Specific odor thresholds are not well-documented, but its impact is notable even at low concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Beta-thujene is naturally found in various essential oils, including those of juniper, sage, and some coniferous plants. It is biosynthesized in plants through the mevalonate pathway, a common route for the formation of monoterpenes. Its presence in essential oils contributes to the "natural fragrance" designation, making it a valuable component in both flavor and fragrance industries.

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

4. Use in Flavors

Beta-thujene is used in flavor formulations to impart a fresh, herbal note. It is commonly found in flavor categories such as herbal, spice, and citrus. Its functional role is often as a background realism enhancer or a modifier to add depth to the flavor profile. Typical use levels in finished food or beverages are not extensively documented, but industry practices suggest low ppm levels, typically ranging from 0.1 to 5 ppm, depending on the application. Beta-thujene is relatively stable under normal conditions but may degrade under high heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, beta-thujene is used across various fragrance families, including fougère, woody, and herbal compositions. It serves as a modifier or impact note, providing a fresh, green character that enhances the overall complexity of the fragrance. Concentration ranges in formulations are typically low, often less than 1%, due to its potent aroma. Beta-thujene contributes primarily to the top and middle notes due to its moderate volatility.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Beta-thujene is not explicitly listed under FEMA GRAS but is used in compliance with general safety guidelines.
• European Union: Not specifically listed under Regulation (EC) No 1334/2008; usage is subject to general safety assessments.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Limited specific data; usage generally follows international safety standards.
• Latin America: Usage is typically aligned with international guidelines, though specific national regulations may vary.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Beta-thujene's safety profile is primarily assessed through its use in flavors and fragrances. Oral exposure through flavor use is considered safe at low concentrations, with no specific ADI or MSDI established. Dermal exposure in fragrances is generally regarded as safe, with no significant irritation or sensitization reported, aligning with IFRA guidelines. Inhalation exposure is minimal due to its moderate volatility, but occupational exposure should be managed with standard safety practices. Risk profiles do not significantly differ between food and fragrance applications.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Beta-thujene is valued for its ability to impart a fresh, herbal character to both flavors and fragrances. It synergizes well with other monoterpenes and can enhance the complexity of a formulation. Common pitfalls include overuse, which can lead to an overpowering or harsh aroma. It is often under-used in formulations seeking a subtle green note. Formulators should consider its stability under various conditions to maintain the desired sensory profile.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on beta-thujene is well-established in terms of its chemical identity and sensory profile. However, specific quantitative data on use levels and regulatory approvals are less documented, relying on industry-typical practices. Known data gaps include detailed toxicological studies and comprehensive regulatory listings across all regions.

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 2026-03-05 19:45:31 GMT (p2)