Hydroxycinnamic acid explained

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,^[1] mainly the trans isomer^[2]
• Coutaric acid – grapes and wine, both trans and cis isomers^[2]
• Fertaric acid – grapes and wine, mainly the trans isomer^[2]

Notes and References

1. Straightforward Method To Quantify GSH, GSSG, GRP, and Hydroxycinnamic Acids in Wines by UPLC-MRM-MS. Anna. Vallverdú-Queralt. Arnaud. Verbaere. Emmanuelle. Meudec. Véronique. Cheynier. Nicolas. Sommerer. J. Agric. Food Chem.. 2015. 63. 1. 142–149. 10.1021/jf504383g. 25457918.
2. Vrhovsek . U. . Extraction of Hydroxycinnamoyltartaric Acids from Berries of Different Grape Varieties . J. Agric. Food Chem. . 46 . 4203–8 . 1998 . 10 . 10.1021/jf980461s.