E-2-Decenal, also known as (E)-2-Decenal, is an unsaturated aldehyde commonly found in citrus oils, particularly in oranges and coriander, contributing to their fresh, citrusy, and fatty odors. It is a volatile organic compound used extensively in the food industry as a flavoring agent to impart orange-like or waxy notes in beverages, candies, and perfumes. Chemically, it features a 10-carbon chain with a double bond at the second position in the E (trans) configuration, making it an alpha-beta unsaturated aldehyde. This structure enhances its reactivity and sensory properties, allowing it to participate in reactions like aldol condensation. In food science, E-2-Decenal is valued for its low threshold of detection, meaning even small amounts can significantly impact flavor profiles. It is derived from natural sources or synthesized via oxidation of decanol. Research from peer-reviewed sources, such as the Journal of Agricultural and Food Chemistry, highlights its role in aroma compounds and its stability under various pH conditions. Safety-wise, it is generally recognized as safe (GRAS) by the FDA for food use at low concentrations, though it requires handling to prevent irritation. Its physical properties include a colorless to pale yellow liquid form, and it is sensitive to light and air, which can lead to oxidation. Overall, E-2-Decenal exemplifies how chemical structure influences sensory and functional roles in food and fragrance applications, with studies emphasizing its non-polar nature due to the hydrocarbon chain.