(+/-)-trans- And Cis-2-hexenal Propylene Glycol Acetal

(+/-)-trans- And Cis-2-hexenal Propylene Glycol Acetal (CAS Number: 648434-55-3) is a synthetic organic compound classified as a flavoring agent. It exists as a mixture of geometric isomers (trans and cis forms) and represents a chemical derivative formed by the reaction of 2-hexenal with propylene glycol. This compound belongs to the broader category of acetals, which are organic compounds formed through condensation reactions. The molecular structure contains the characteristic features of both a hexenal moiety and a propylene glycol acetal functionality, which contribute to its sensory properties.

This flavoring agent is utilized in the food industry primarily to add fruity, green, and herbaceous flavor notes to consumer products. It may be found in beverages, confectionery, dairy products, and other processed foods where complex fruity flavor profiles are desired. The compound's ability to provide fresh, natural-like sensory characteristics makes it valuable in formulations attempting to replicate fruit and plant-derived flavors. Typical usage levels in food applications are very low, measured in parts per million (ppm), as is standard for most synthetic flavoring compounds.

According to FDA records, there have been zero reported adverse events associated with this additive and zero product recalls linked to its use. The compound has not generated safety signals in post-market surveillance data. As a synthetic flavoring agent used in minimal quantities, the exposure levels from food consumption are typically very low. The chemical structure—combining a natural-derived hexenal component with propylene glycol, a commonly used food ingredient—suggests a reasonable safety profile for the intended use levels.

The absence of extensive published toxicological studies on this specific compound is not uncommon for flavoring agents, many of which operate under the FDA's GRAS (Generally Recognized as Safe) framework or similar approval mechanisms in other jurisdictions. However, it should be noted that this particular additive does not carry FDA GRAS status, indicating it has not undergone the specific GRAS determination process or has not been formally affirmed through that pathway.

This additive is not listed as FDA GRAS (Generally Recognized as Safe). This means it does not have formal FDA affirmation through the GRAS notification process. However, the absence of GRAS status does not necessarily indicate a safety concern—rather, it reflects the regulatory pathway or classification under which the compound operates. Different jurisdictions have varying approval frameworks for flavoring agents. In the European Union, similar compounds may be evaluated under different regulatory schemes, such as the Flavoring Regulation (EC) No 1334/2008.

The compound's regulatory standing should be verified for specific intended uses and markets, as flavoring agents are subject to varying approvals depending on food category and geographic region. Manufacturers using this flavoring must ensure compliance with applicable regulations in their target markets.

Published scientific literature specifically examining this exact chemical compound appears limited in publicly available databases. This is not atypical for proprietary synthetic flavoring compounds, which may have confidential toxicological assessments submitted to regulatory bodies but limited peer-reviewed publication. Safety evaluation of flavoring agents typically relies on structural analogy to related compounds, acute and subchronic toxicity studies, and consideration of intended use levels. The chemical similarity to propylene glycol—a widely used and well-established food ingredient—and hexenal derivatives provides some framework for safety assessment through read-across approaches.