Coffee constituents of chlorogenic acid

The chlorogenic acids are ubiquitous in the plant kingdom. Although chlorogenic acids are common in vegetables foodstuffs, the relatively large quantity present in coffee make it an important dietary sources.

Chlorogenic acid and its isomers represent major coffee constituents of phenolic acid. They are family esters of quinic acid with several hydroxycinnamic acids, particularly caffeic, ferulic, p-coumaric acids.

In coffee they are essentially mono- and diesters and by far the prevailing acids. Other esters may occur but generally only in small amounts.

The quality of coffee depends in part on the relative proportion of mono and dichlorogenic acids, The ratio between these two acids is slightly less in robusta than in arabica. An excess of dichlorogenic acids might result in a metallic after-taste in the beverage.

Oral ingestion by man of 200 mg of chlorogenic acid was found to stimulate stomach secretion with enhancement of hydrochloric acid production. Caffeic acid had the same effect, and quinic acid, XII was inactive.
Coffee constituents of chlorogenic acid