Wednesday, February 24, 2021

Caffeoylquinic acids in coffee beans

Caffeic, ferulic, and p-coumaric acids are the main phenolic compounds in coffee which derive from trans-cinnamic acid.

Naturally, they may present as mono- or diesters with quinic acid, forming chlorogenic acids, which are known to be the most active antioxidant compounds. Caffeoylquinic acids and particularly 5-CQA (5-O-caffeoylquinic acid) are found to be the most abundant compounds in coffee beans, where they can form vacuolar complexes with caffeine.

Caffeoylquinic acids are cinnamate conjugates derived from the phenylpropanoid pathway. They are generally involved in plant responses to biotic and abiotic stress.

Since caffeoylquinic acids contribute to acidity, astringency, and bitterness of the brewed coffee, they are relevant to sensorial properties of the beverage.

Caffeoylquinic acid compounds are widespread in plants. They protect plants against predation and infection and may have several beneficial functions in the human diet.

Esters formed between hydroxycinnamates and quinic acid represent a major family of plant phenolics. Chlorogenic acid (5-CQA) is the most widespread of all monoesters formed between caffeic and quinic acids.

Due to their antioxidant and antibiotic properties, hydroxycinnamoylquinic acids are involved in numerous biological plant functions such as pest and disease resistance. The caffeoylquinic acids are among numerous phenolic compounds found in plants that are thought to function in defense against predation and parasitism.

In coffee trees, hydroxycinnamoylquinic acids accumulate in beans. This is particularly marked in Coffea canephora where their content can exceed 10 % of dry bean weight.

On a molecular basis, oxidative activity increases in proportion to the number of caffeoyl residues in the molecule. Other potential beneficial effects of caffeoylquinic acid compounds on humans that have been demonstrated in laboratory studies include anti-inflammatory activity; reduced skin aging by inhibiting the enzyme, collagenase; anti-spasmodic activity; antihyperglycemic activity; suppression of melanogenesis.
Caffeoylquinic acids in coffee beans

The Most Popular Posts

History of Beverages