On the occurrence of derivatives of hydroxycinnamic acids, hydroxybenzoic acids, and hydroxycoumarins in citrus fruits (author's transl)

Oranges, grapefruits and lemons contained p-coumaric acid, caffeic acid, ferulic acid, and sinapic acid in bound form in concentrations of 10-100 mg/kg, whereby p-coumaric acid is localized chiefly in the peel. Hydroxybenzoic acids, chiefly salicylic acid and gentisic acid, and hydroxycoumarins were only found in traces.