FlavScents AInsights Entry: Yuzu Leaf Oil (CAS: 233683-84-6)
1. Identity & Chemical Information
Yuzu leaf oil is a natural complex material derived from the leaves of the yuzu plant (Citrus junos). It is not a single chemical compound but a mixture of various constituents. The CAS number for yuzu leaf oil is 233683-84-6. While it does not have a specific FEMA number, it is recognized in the flavor and fragrance industry for its unique profile. As a complex natural material, it does not have a single molecular formula or molecular weight. The composition of yuzu leaf oil can vary significantly depending on factors such as the geographical origin of the plant, the time of harvest, and the extraction method used.
Citation hooks: FlavScents; PubChem; FEMA
2. Sensory Profile
Yuzu leaf oil is characterized by its fresh, green, and citrusy aroma with subtle floral undertones. It is often described as having a bright and uplifting scent, reminiscent of a blend between grapefruit and mandarin. The intensity of the odor is moderate, making it suitable for both impact notes and background realism in formulations. The oil is primarily used for its aromatic properties rather than taste, as it is not typically consumed directly. The sensory role of yuzu leaf oil in formulations is often as a modifier or enhancer, providing a fresh and natural citrus note.
Citation hooks: FlavScents; peer-reviewed sensory literature
3. Natural Occurrence & Formation
Yuzu leaf oil is naturally sourced from the leaves of the yuzu plant, which is native to East Asia, particularly Japan, Korea, and China. The oil is obtained through steam distillation of the leaves. Yuzu is a hybrid citrus fruit, believed to be a cross between the mandarin orange and the ichang papeda. The oil's natural occurrence and extraction from plant leaves qualify it for use in products labeled as "natural flavor" or "natural fragrance," depending on the regulatory definitions in different regions.
Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs
4. Use in Flavors
Yuzu leaf oil is used in flavor applications primarily for its citrusy and fresh notes. It is commonly found in flavor categories such as citrus blends, beverages, and confectionery. The oil acts as a functional component in flavor systems, providing a natural and refreshing citrus note. Typical use levels in finished food or beverage products range from 1 to 10 ppm, with variations depending on the desired intensity and product type. The oil is relatively stable under normal conditions but may degrade under high heat or acidic conditions, which should be considered during formulation.
Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature
5. Use in Fragrances
In the fragrance industry, yuzu leaf oil is valued for its fresh and uplifting scent, fitting well within citrus and green fragrance families. It is used in a variety of product types, including perfumes, colognes, and personal care products. The oil serves as a top note, providing an initial burst of freshness and brightness. Typical concentration ranges in fragrance formulations are from 0.1% to 1%, depending on the desired effect and product type. Its volatility makes it an excellent choice for top note applications, contributing to the initial impression of a fragrance.
Citation hooks: FlavScents; IFRA; fragrance chemistry texts
5a. Key Constituents (Typical)
Yuzu leaf oil contains several key constituents that contribute to its characteristic aroma. These include limonene, linalool, and citronellal, among others. The exact composition can vary based on factors such as the plant's growing conditions and the extraction process. It is important for formulators to consider these variations when using yuzu leaf oil in their products.
Citation hooks: FlavScents; peer-reviewed literature; authoritative industry references
6. Regulatory Status (Regional Overview)
In the United States, yuzu leaf oil is generally recognized as safe (GRAS) for use in flavors, although specific regulatory approvals may vary. In the European Union, it is subject to the regulations outlined in Reg. (EC) No 1334/2008, with its status as a natural flavoring substance. The United Kingdom follows similar regulations post-Brexit. In Asia, particularly Japan and China, yuzu leaf oil is traditionally used and accepted in both flavor and fragrance applications. In Latin America, regulatory acceptance may vary, and it is advisable to consult local regulations for specific guidance.
Citation hooks: FEMA; EFSA; national authority publications
7. Toxicology, Safety & Exposure Considerations
Yuzu leaf oil is considered safe for use in both flavor and fragrance applications when used within recommended levels. For oral exposure, the oil is used at low concentrations, minimizing potential toxicity. Dermal exposure in fragrance applications is generally safe, but formulators should be aware of potential sensitization or irritation, particularly in sensitive individuals. Inhalation exposure is typically not a concern at the levels used in consumer products, but occupational exposure should be managed with appropriate ventilation and safety measures.
Citation hooks: EFSA; FEMA; PubChem; toxicology literature
8. Practical Insights for Formulators
Yuzu leaf oil is valued for its ability to impart a fresh and natural citrus note to both flavors and fragrances. It synergizes well with other citrus oils and can enhance the overall brightness of a formulation. Common pitfalls include overuse, which can lead to an overpowering scent, and underuse, which may result in a lack of desired freshness. Formulators should carefully balance yuzu leaf oil with other components to achieve the optimal sensory profile.
Citation hooks: FlavScents; industry practice
9. Confidence & Data Quality Notes
The data on yuzu leaf oil is well-established, with consistent sensory and compositional information available from multiple sources. While industry practices are generally well-documented, some variability in composition due to natural factors remains. Regulatory information is comprehensive, though formulators should verify specific regional requirements.
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
- Includes section 5a for complex natural material
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 2026-09-22 11:39:11 GMT (p2)
