Hydroxycinnamic acid

Hydroxycinnamic acids (hydroxycinnamates) are a class of aromatic acids or phenylpropanoids having a C6–C3 skeleton. These compounds are hydroxy derivatives of cinnamic acid.

In the category of phytochemicals that can be found in food, there are :
 * α-Cyano-4-hydroxycinnamic acid
 * Caffeic acid – burdock, hawthorn, artichoke, pear, basil, thyme, oregano, apple
 * Cichoric acid
 * Cinnamic acid – aloe
 * Chlorogenic acid – echinacea, strawberries, pineapple, coffee, sunflower, blueberries
 * Diferulic acids
 * Coumaric acid
 * Ferulic acid (3-methoxy-4-hydroxycinnamic acid) – oats, rice, artichoke, orange, pineapple, apple, peanut
 * Sinapinic acid (3,5-dimethoxy-4-hydroxycinnamic acid or sinapic acid)

Hydroxycinnamoyltartaric acids

 * Caftaric acid – grapes and wine, mainly the trans isomer
 * Coutaric acid – grapes and wine, both trans and cis isomers
 * Fertaric acid – grapes and wine, mainly the trans isomer