what is ferulic acid ?

Ferulic acid is a hydroxycinnamic acid, a type of organic compound. It is an abundant phenolic phytochemical found in plant cell wall components such as arabinoxylans as covalent side chains. It is related to trans-cinnamic acid. As a component of lignin, ferulic acid is a precursor in the manufacture of other aromatic compounds.

Ferulic acid is found in the seeds of coffee, apple, artichoke, peanut, and orange, as well as in both seeds and cell walls of commelinid plants (such as rice, wheat, oats, the Chinese water chestnut (Eleocharis dulcis) and pineapple).
In cereals, ferulic acid is localized in the bran the hard outer layer of grain. In wheat, phenolic compounds are mainly found in the form of insoluble bound ferulic acid and be relevant to resistance to wheat fungal diseases. The highest known concentration of ferulic acid glucoside has been found in flax seed (4.1 +/- 0.2 g). It is also found in barley grain.
Asterid Eudicot plants can also produce ferulic acid   The tea brewed from the leaves of yacón (Smallanthus sonchifolius), a traditionally grown in the Northern and Central Andes, contains quantities of ferulic acid, as well as the tea brewed from the European centaury (Centaurium erythraea), a plant used as a medical herb in many parts of Europe. In legumes, the white bean variety navy bean is the richest source of ferulic acid among the common bean (Phaseolus vulgaris) varieties