Cis-6-nonenal

Cis-6-nonenal (CAS Number 2277-19-2) is a nine-carbon aldehyde with a cis double bond configuration. It is a volatile organic compound that occurs naturally in various plants and foods, where it contributes to characteristic fresh, grassy, and green aromas. The compound belongs to the class of aliphatic aldehydes commonly found in nature, particularly in vegetables, fruits, and plant materials. Its chemical structure makes it highly volatile, meaning it readily evaporates and disperses into the air—a property that makes it useful for flavor applications.

Cis-6-nonenal is utilized as a flavoring agent in the food industry to create or enhance fresh, green, and herbaceous flavor profiles. It is particularly valued in products seeking to replicate natural vegetable or fresh plant notes, including beverages, dairy products, baked goods, and savory processed foods. The compound's ability to provide subtle, fresh aromatic characteristics has made it appealing to manufacturers formulating products with clean-label aspirations. However, its use remains limited compared to GRAS-approved flavoring agents due to its regulatory status.

Cis-6-nonenal has not been formally evaluated and approved by the FDA as a GRAS (Generally Recognized as Safe) substance. This designation does not necessarily indicate the compound is unsafe; rather, it reflects that comprehensive safety data sufficient for GRAS affirmation has not been submitted to or reviewed by the FDA. The absence of reported adverse events or recalls associated with this additive in FDA databases suggests no documented safety incidents in commercial food applications to date. As a naturally occurring volatile compound present in food plants, cis-6-nonenal has an inherent history of human consumption in trace quantities through unprocessed foods.

The European Union's approach to flavoring substances provides additional context. The EFSA (European Food Safety Authority) maintains lists of approved flavor compounds, and cis-6-nonenal's presence or absence on these lists reflects the regulatory framework's assessment based on available toxicological data. Like many naturally occurring flavor compounds, adequate toxicological studies would be necessary to support regulatory approvals in major jurisdictions.

Cis-6-nonenal does not have GRAS status in the United States, meaning it cannot be marketed as a food ingredient in conventional food products without specific FDA authorization or approval. This restriction applies to direct food use in the U.S. market. In other jurisdictions, including the European Union and other regions, the regulatory status may differ, and the compound may be permitted under specific conditions or as part of harmonized flavor chemical lists. Manufacturers seeking to use this compound would need to either obtain regulatory approval or demonstrate that it falls under existing regulatory exemptions in their target markets.

Scientific literature on cis-6-nonenal is limited, as comprehensive regulatory review studies have not been publicly disclosed. Research on similar C9 aldehydes and natural volatile compounds has provided general toxicological frameworks for assessing aldehyde safety. Volatility and rapid metabolism are general characteristics of aldehyde flavorings that inform safety assessments. Any manufacturer pursuing regulatory approval would typically need to commission studies evaluating acute toxicity, genetic toxicity, and subchronic exposure effects—standard requirements for flavor substance approvals. The absence of such published studies in peer-reviewed literature reflects the limited regulatory history of this particular compound in approved food applications.