FlavScents AInsights Entry for Thymoquinone (CAS: 490-91-5)

1. Identity & Chemical Information

• Common Name(s): Thymoquinone
• IUPAC Name: 2-Isopropyl-5-methylbenzo-1,4-quinone
• CAS Number: 490-91-5
• FEMA Number: Not applicable
• Other Identifiers: FL number not available; CoE number not available; IFRA reference not applicable
• Molecular Formula: C10H12O2
• Molecular Weight: 164.20 g/mol

Thymoquinone is a monoterpene quinone, characterized by its quinone functional group, which is crucial for its biological activity and contributes to its distinctive odor profile. The structure-odor relationship is influenced by the presence of the isopropyl and methyl groups, which enhance its aromatic properties.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Thymoquinone is known for its distinctive odor, often described as herbal, medicinal, and slightly spicy. It has a moderate intensity and a characteristic diffusion that makes it a notable impact note in formulations. The taste and odor thresholds for thymoquinone are not well-documented, but it is typically used in small concentrations due to its potent sensory attributes. In flavor systems, it serves as a background realism enhancer, adding depth and complexity to herbal and spice profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Thymoquinone is primarily found in the seeds of Nigella sativa, commonly known as black cumin or black seed. It is also present in other plants of the Ranunculaceae family. The compound is biosynthesized through the oxidative degradation of thymol, a process that involves enzymatic reactions. Thymoquinone's presence in natural sources qualifies it for use in "natural flavor" and "natural fragrance" designations, provided it is extracted and processed according to regulatory standards.

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

4. Use in Flavors

Thymoquinone is utilized in various flavor categories, including herbal, spice, and medicinal profiles. It acts as a functional component that enhances the authenticity and depth of flavor systems. Typical use levels in finished food or beverages are not explicitly documented, but industry practices suggest low ppm ranges due to its potent nature. Stability considerations include moderate resistance to heat and pH variations, although it may be susceptible to oxidation, necessitating careful formulation and storage.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, thymoquinone is incorporated into herbal and spicy fragrance families. It functions as a trace realism enhancer and a modifier, contributing to the complexity of the scent profile. While specific concentration ranges are not well-documented, it is typically used in trace amounts due to its strong odor. Thymoquinone's volatility places it in the middle note category, where it provides a sustained aromatic presence.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Thymoquinone is not explicitly listed as FEMA GRAS, indicating limited direct use in flavors.
• European Union: Under Regulation (EC) No 1334/2008, thymoquinone's use is subject to general safety assessments for flavoring substances.
• United Kingdom: Post-Brexit, the UK aligns with EU regulations, maintaining similar safety and usage standards.
• Asia: In Japan and China, thymoquinone's use in flavors and fragrances is subject to national safety evaluations, with no specific approvals noted.
• Latin America: Regulatory information is limited, but general safety assessments apply.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Thymoquinone's safety profile is primarily assessed through oral exposure, where it exhibits a moderate margin of safety. No specific ADI or MSDI values are available, but it is generally considered safe at low concentrations typical in flavor applications. Dermal exposure in fragrance use may pose irritation or sensitization risks, necessitating adherence to IFRA guidelines. Inhalation exposure is less documented but should be managed to minimize occupational risks due to its volatility.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Thymoquinone is valued for its ability to impart a distinctive herbal and medicinal character to formulations. It synergizes well with other herbal and spice notes, enhancing overall complexity. Formulators should be cautious of its potent nature, as overuse can lead to overpowering effects. It is often under-utilized in formulations seeking authentic herbal profiles, where its unique attributes can be leveraged effectively.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on thymoquinone is well-established in terms of its chemical identity and sensory profile. However, industry-typical practices regarding use levels and regulatory status are less documented, leading to some uncertainties. Known data gaps include specific ppm ranges for flavor use and detailed toxicological assessments for inhalation exposure.

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 2026-02-05 19:36:24 GMT (p2)