2-phenylpropionaldehyde is also known as 2-phenylpropanal. It belongs to the family of phenylacetaldehydes. These are compounds containing a phenylacetaldehyde moiety, which consists of a phenyl group substituted at the second position by an acetalydehyde. 2- phenylpropionaldehyde is a naturally occurring compound in various foods including roasted nuts, cooked potatoes, cheese, wine, fruit, vegetables, coffee, tea, and cocoa. 2-phenylpropionaldehyde is used as a flavoring agent. Once absorbed, 2-phenylpropionaldehyde can be converted to phenyl-substituted carboxylic acids, which can be conjugated with glucuronic acid and excreted in the urine. 2-phenylpropionaldehyde can also undergo β- oxidation to benzoic acid or phenylacetic acid derivatives, which are conjugated with glycine or glutamine before being excreted in the urine.