Heptanal, also known as n-heptanal or heptaldehyde, is a straight-chain aliphatic aldehyde with the formula C7H14O. It occurs naturally in essential oils of citrus fruits, herbs, and some vegetables, contributing green, fatty, and citrus-like aroma notes. In food science and spice chemistry, it serves as a key flavor compound in formulations for its characteristic odor profile. Produced industrially via hydroformylation of hexene or oxidation of heptanol, it is volatile and used in perfumery and flavorings. It exhibits moderate solubility in water but high solubility in organic solvents and lipids, making it suitable for fat-based food matrices. Research confirms its presence in natural products like olive oil and its role in Maillard reaction byproducts.