CITRONELLAL

CAS: 106-23-0 FLAVORING AGENT OR ADJUVANT

Citronellal is a synthetic flavoring agent or adjuvant used to impart citrus-like aroma in foods and beverages and evaluated internationally for safety at typical use levels.

What It Is

Citronellal is a flavoring agent or adjuvant identified by the Chemical Abstracts Service (CAS) number 106-23-0 and recognized under regulatory code 172.515 in certain jurisdictions. It is an aldehyde that occurs naturally in several essential oils like lemon eucalyptus and citronella, and also can be produced synthetically. The molecule is part of the class of compounds known as monoterpenoids, which are commonly used to provide characteristic citrus, lemon, or leaf-like aromas in flavor applications. Other synonyms for citronellal include Citronellal 3,7-Dimethyl-6-Octenal, Rhodinal 6-Octenal, 3,7-Dimethyl- Citronellal, and Beta- 2,3-Dihydrocitral, reflecting its structural variations identified in flavor chemistry contexts. Its role as a flavoring agent or adjuvant means it can be incorporated in formulations to enhance or modify sensory perceptions of food products.

How It Is Made

The production of citronellal can involve extraction from natural sources or chemical synthesis. In nature, it is found in the essential oils derived from certain aromatic plants, such as lemon eucalyptus (Corymbia citriodora) and citronella grasses (Cymbopogon spp.). When obtained naturally, essential oil feedstocks undergo processes like steam distillation to isolate the volatile components, including citronellal, which is then purified for use in flavor and fragrance applications. Synthetic citronellal may be produced by catalytic oxidation of precursors like citronellol or by precise chemical synthesis pathways designed for industrial scalability. Regardless of its origin, quality control measures ensure that any technical grade citronellal conforms to appropriate purity specifications for its intended use in foods, with attention to minimizing impurities that could affect safety or flavor quality.

Why It Is Used In Food

Citronellal is used in the food industry primarily for its aromatic qualities, contributing a fresh, citrus-like note to a variety of products. Flavor formulators value it for its ability to enhance or complement fruit, citrus, and herbal flavor profiles, often blending it with other compounds to achieve a desired sensory balance. While it does not contribute nutritional value, its inclusion at low levels can make products more appealing by intensifying pleasant smell and taste characteristics that consumers associate with freshness or natural citrus notes. In complex flavor systems, it acts in concert with other volatile compounds to round out the overall perception of the flavor, which is why it is categorized as both a flavoring agent and adjuvant in regulatory inventories.

Adi Example Calculation

An illustrative example of how ADI concepts might be applied (for additives with a numeric ADI) would involve using a body weight and a hypothetical ADI figure to calculate daily intake allowances; however, for citronellal, international evaluations have not assigned a specific numeric ADI value because it was concluded that safety concerns are not expected at typical intake levels. Therefore, rather than providing a numeric calculation, this section emphasizes the principle: if a numerical ADI existed, one would multiply the mg per kg body weight guideline by the body weight of an individual to estimate a tolerable daily intake. Citronellal’s safety evaluation does not provide such a numeric benchmark, and the focus remains on adherence to authorized use conditions and good manufacturing practices that keep actual dietary exposure low.

Safety And Health Research

Safety assessments of citronellal focus on its toxicological profile at levels relevant to food use. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has evaluated citronellal as a flavoring agent and determined that there is no safety concern at current intake levels typical of its use in foods, based on international evaluations. These assessments consider standard toxicological endpoints such as general systemic toxicity, metabolic fate, and potential for irritation or sensitization at exposure levels far above those encountered from food use. While some hazard data exist from chemical safety sheets and fragrance industry evaluations indicating irritation potential at high concentrations external to food, regulators evaluate such data in context of dietary exposure, which is substantially lower. However, detailed human exposure or chronic health effect studies directly related to dietary intake may be limited, and as such, professional regulatory bodies emphasize compliance with good manufacturing practice and adherence to authorized use conditions.

Regulatory Status Worldwide

Citronellal is recognized under the U.S. Code of Federal Regulations section 21 CFR 172.515, which lists synthetic flavoring substances and adjuvants that may be safely used in food when applied in accordance with good manufacturing practice and in the minimum amount necessary to achieve the intended effect. This regulatory listing indicates that citronellal’s use as a flavoring agent is permitted under specified conditions in the United States based on historical evaluations. Internationally, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) evaluated citronellal and concluded that it poses no safety concern at the levels of intake typical for flavoring agents, based on comprehensive review in 2003. Such evaluations provide a scientific basis for regulatory acceptance in multiple regions, although specific national rules may vary and require adherence to local labeling and usage guidelines. These evaluations reflect review of safety data and justify its continued use as a flavoring component under controlled conditions.

Taste And Functional Properties

Citronellal is characterized by a distinct citrus-like aroma with fresh lemon and mild herbal nuances, which makes it a useful sensory ingredient to evoke citrus or leafy impressions in flavor systems. It is generally volatile at room temperature, with a liquid physical state under standard conditions, and exhibits solubility properties typical of many aromatic aldehydes—being more soluble in ethanol and oils than in water. In formulation, citronellal must be used in quantities that align with the principles of good manufacturing practice, ensuring that its sensory impact is effective but not overpowering. Although it contributes sensory properties primarily through aroma, its function as a flavor adjuvant means it can interact with other flavoring compounds, sometimes modifying their perception by subtly changing volatility or synergizing aromatic effects.

Acceptable Daily Intake Explained

The concept of acceptable daily intake (ADI) helps contextualize how much of a given food additive can be consumed daily over a lifetime without appreciable health risk. For flavoring agents like citronellal, specific numeric ADI values are not always established, especially when international evaluations conclude that there is no safety concern at typical intake levels. In such cases, regulatory bodies signify that normal levels of use do not warrant setting a formal numerical ADI, indicating that typical dietary exposure is well below any threshold of toxicological concern identified in available studies. The absence of a numeric ADI in regulatory documentation should not be interpreted as a recommendation to consume large amounts, but rather as an indication that, under authorized and typical use conditions, dietary exposure remains within safe bounds as assessed by expert review.

Comparison With Similar Additives

Citronellal is part of a broader class of flavoring aldehydes and terpenoid-derived compounds used in food formulation. Comparable compounds include citral, which also imparts citrus notes and is used in lemon flavor systems, and limonene, a terpene with a strong orange-citrus aroma frequently used in beverages and confectionery. While citral is often more intensely lemon in character, and limonene provides more orange-like notes, all share the functional property of contributing volatile citrus aromas at low concentrations. Another related compound is neral, an isomer of citral, which offers a slightly softer lemon profile. In use, these compounds are selected by flavorists based on the specific sensory target, and their safety profiles are evaluated individually or through group evaluations by expert bodies, ensuring that their use in food remains consistent with regulatory frameworks and intake assessments.

Common Food Applications Narrative

Citronellal’s citrus-like aroma lends itself to a broad range of food applications where a fresh, lemony or herbal note is desirable. In beverage formulations, it may be included in citrus-flavored soft drinks, iced teas, and flavored waters to augment natural fruit essences and provide a consistent aromatic character. In confectionery, it can be part of citrus-flavored candies or chewing gums, supporting the overall fruity profile by contributing subtle top notes that enhance consumer perception. Bakery products with lemon or citrus themes may incorporate citronellal in fillings, glazes, or frostings to deliver a nuanced aroma that complements sweet and tart elements. Additionally, it may find niche use in savory applications, such as salad dressings or sauces, where a hint of citrus can refresh and brighten the flavor impression. Across these applications, its use is guided by flavorists who balance its impact with other components to achieve the desired sensory experience.

Safety & Regulations

FDA

  • Approved: True
  • Regulation: 21 CFR 172.515

EFSA

  • Notes: EFSA specific evaluation not identified in the available sources

JECFA

  • Year: 2003
  • Adi Display: No safety concern at typical intake levels

Sources

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