FlavScents AInsights Entry: Caffeine (CAS: 58-08-2)

1. Identity & Chemical Information

• Common Name(s): Caffeine
• IUPAC Name: 1,3,7-Trimethylxanthine
• CAS Number: 58-08-2
• FEMA Number: 2224
• Other Identifiers: FL No. 09.001
• Molecular Formula: C8H10N4O2
• Molecular Weight: 194.19 g/mol

Caffeine is a purine alkaloid with a structure characterized by a xanthine core substituted with three methyl groups. Its functional groups include amine and carbonyl groups, contributing to its solubility and reactivity. The structure-odor relevance is minimal as caffeine is primarily tasteless and odorless, but its presence can influence the perception of bitterness in formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Caffeine itself is largely odorless and tasteless, but it is known for its bitter taste at higher concentrations. The bitterness threshold for caffeine is approximately 0.1% in water, which can vary depending on the matrix. In sensory applications, caffeine is often used to enhance the perception of bitterness, providing a balancing effect in sweetened beverages and foods.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Caffeine naturally occurs in over 60 plant species, including coffee beans, tea leaves, kola nuts, and cacao pods. It is biosynthesized in plants through the methylation of xanthosine, a process involving several enzymatic steps. Caffeine's presence in these plants serves as a natural pesticide. In terms of "natural flavor" designation, caffeine extracted from natural sources can be labeled as such, whereas synthetic caffeine does not qualify.

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

4. Use in Flavors

Caffeine is predominantly used in the beverage industry, particularly in soft drinks, energy drinks, and coffee-flavored products. It functions as a flavor enhancer, contributing to the overall taste profile by adding bitterness. Typical use levels in beverages range from 50 to 150 ppm, with higher concentrations in energy drinks. Caffeine is stable under normal beverage processing conditions but can degrade under extreme heat or prolonged exposure to light.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

Caffeine is not commonly used in fragrance formulations due to its lack of a distinct odor. However, it may be included in cosmetic products for its perceived skin benefits, such as reducing puffiness. In such applications, caffeine is used at low concentrations, typically less than 1%. Its volatility is low, and it does not contribute to the fragrance profile in terms of top, middle, or base notes.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Caffeine is generally recognized as safe (GRAS) by the FDA for use in foods and beverages.
• European Union: Caffeine is regulated under Regulation (EC) No 1334/2008, with specific labeling requirements for high-caffeine products.
• United Kingdom: Post-Brexit, UK regulations align closely with EU standards.
• Asia: In Japan, caffeine is regulated under the Food Sanitation Act, with specific limits for certain products. China and ASEAN countries have similar regulations.
• Latin America: Brazil and MERCOSUR countries regulate caffeine in line with international standards, focusing on labeling and maximum allowable concentrations.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Caffeine's safety profile varies with exposure route. Orally, it has an acceptable daily intake (ADI) of up to 400 mg for adults, with a margin of safety considered adequate at typical consumption levels. Dermal exposure is generally safe, with low irritation potential, but high concentrations can cause sensitization. Inhalation exposure is minimal due to low volatility, but occupational exposure in manufacturing settings should be monitored.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Caffeine is valued for its ability to enhance bitterness and provide a stimulating effect. It synergizes well with sweeteners and acidic components, balancing flavor profiles. Common pitfalls include overuse, leading to excessive bitterness, and underuse, resulting in a lack of desired impact. Formulators should consider the target demographic's sensitivity to caffeine when determining use levels.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on caffeine is well-established, with extensive documentation on its sensory properties, regulatory status, and safety profile. Industry practices are well-documented, though some variability exists in regional regulations and consumer preferences. Known data gaps are minimal, primarily related to emerging applications in non-traditional products.

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 2026-02-13 08:39:23 GMT (p2)