FlavScents AInsights Entry: Toffee Furanone (CAS: 19322-27-1)

1. Identity & Chemical Information

Toffee furanone, also known as 4-Hydroxy-5-methyl-3(2H)-furanone, is a single chemical compound with the CAS number 19322-27-1. It is recognized by its IUPAC name and is sometimes referred to by its FEMA number, which is 3161. The molecular formula for toffee furanone is C5H6O3, and it has a molecular weight of 114.10 g/mol. This compound features a furanone ring, which is crucial for its characteristic caramel-like aroma. The presence of hydroxyl and methyl groups contributes to its sweet, toffee-like scent, making it a valuable ingredient in flavor and fragrance formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Toffee furanone is renowned for its rich, caramel-like aroma, often described as reminiscent of toffee, caramel, and maple syrup. It possesses a sweet, creamy character with moderate intensity and good diffusion. The compound is primarily used as an impact note in flavor formulations, providing a warm, sweet base that enhances the overall sensory experience. While specific taste and odor thresholds are not widely documented, its potent aroma suggests that it is effective at low concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Toffee furanone occurs naturally in a variety of foods, including strawberries, coffee, and roasted meats. It is primarily formed through the Maillard reaction, a complex chemical process that occurs during the cooking of foods, particularly those rich in sugars and amino acids. This reaction is responsible for the development of many flavor compounds, including toffee furanone, which contributes to the "browned" flavor profile. Its presence in natural foods allows it to be designated as a "natural flavor" in certain regulatory contexts.

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

4. Use in Flavors

Toffee furanone is extensively used in flavor formulations, particularly in categories such as bakery, confectionery, and dairy products. It serves as a key component in creating caramel, toffee, and butterscotch flavors. Typical use levels in finished food products range from 0.1 to 5 ppm, depending on the desired intensity and the complexity of the flavor system. It is generally stable under typical processing conditions, although it may degrade at very high temperatures or in highly acidic environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, toffee furanone is used to impart a sweet, gourmand note to various fragrance families, including oriental and gourmand. It acts as a modifier, enhancing the sweetness and warmth of the fragrance composition. Typical concentration ranges in fragrance formulations are from trace amounts up to 0.5%, depending on the desired effect. Due to its moderate volatility, it contributes primarily to the middle notes of a fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, toffee furanone is recognized as GRAS (Generally Recognized As Safe) by FEMA for use in flavors. In the European Union, it is approved under Regulation (EC) No 1334/2008 and assigned an FL number. The United Kingdom follows similar regulations post-Brexit. In Asia, including Japan and China, it is generally accepted for use in food flavors, although specific regulations may vary. In Latin America, countries like Brazil and those in MERCOSUR also permit its use, aligning with international standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Toffee furanone is considered safe for use in food and fragrance applications at typical exposure levels. For oral exposure, it has a high margin of safety, with no adverse effects reported at typical use levels. Dermal exposure in fragrance applications is generally safe, with no significant irritation or sensitization reported. Inhalation exposure is minimal due to its moderate volatility, and occupational exposure limits are not typically exceeded in standard use scenarios. Overall, the risk profiles for food and fragrance applications are similar, with no significant safety concerns.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Toffee furanone is valued for its ability to impart a rich, caramel-like sweetness to both flavors and fragrances. It synergizes well with other sweet and creamy notes, such as vanilla and chocolate. Formulators should be cautious of overuse, as its potent aroma can dominate a composition. It is often under-utilized in savory applications, where it can add depth and complexity. Balancing its intensity with other ingredients is key to achieving the desired sensory profile.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on toffee furanone is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, although specific sensory thresholds are less frequently reported. There are no significant data gaps or regulatory ambiguities, and the compound is widely accepted in both flavor and fragrance industries.

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 2026-06-11 08:14:11 GMT (p2)