Brief Introduction
Synonyms--- Un-roasted Coffee Bean
Chlorogenic Acid
Chemical Name: (1S,3R,4R,5R)-3-{[(2Z)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}
-1,4,5-trihydroxycyclohexanecarboxylic acid
Molecular Formula: C16H18O9
Mol. Wt.: 354.31
Molecular Structure:
Chlorogenic acid is a family of naturally occurring organic compounds. These are
esters of cinnamic acids and (-)-quinic acid. It is an important
biosynthetic intermediate. It also is one of the phenols found in
Green Coffee, in Eucommia ulmoides leaf, Honey Suckle Flower, in
the bamboo Phyllostachys edulis as well as many other plants. This
compound, long known as an antioxidant, also slows the release of
glucose into the bloodstream after a meal. Structurally,
chlorogenic acid (CGA) is the ester formed between caffeic acid and
(L)-quinic acid (1L-1(OH),3,4/5-tetrahydroxycyclohexanecarboxylic
acid). Isomerization of chlorogenic acid have been reported with 3
isomerizations of the quinic acid in position 3 (3-CQA), 4 (4-CGA)
and 5 (5-CQA). Isomerisation at position 1 has not yet been
reported. This acid is an important intermediate in lignin
biosynthesis. Chlorogenic acid is marketed under the tradename
Svetol in Norway and the United Kingdom as a food active ingredient
used in coffee, chewing gum, and mints to promote weight reduction.
Coffee (coffea) is a large genus (containing more than 90 species) of flowering
plants in the family Rubiaceae. They are shrubs or small trees,
native to subtropical Africa and southern Asia. Seeds of several
species are the source of the popular beverage coffee. After their
outer hull is removed, the seeds are commonly called "beans". There
are several species of Coffee that may be grown for the beans, but
Coffea arabica is considered by many to have the best overall
flavor and quality. The other species (especially Coffea canephora
(var. robusta)) are usually grown on land unsuitable for Coffea
arabica.
The term green coffee bean” refers to un-roasted mature or immature
coffee beans (for extraction use, immature ones are the best).
Chlorogenic acids belong to a group consisting of compounds which
are known as polyphenols, which are antioxidants. The content of
chlorogeneic acid in dried green coffee beans of robusta is 65 mg/
g and of arabica 140 mg / g, depending on the timing of harvesting.
At roasting temperature, more than 70% of chlorogenic acids are
destroyed, leaving a residue of less than 30 mg/g in the roasted
coffee bean. These chlorogenic acids could be a valuable
inexpensive source of antioxidants. Chlorogenic acids are
homologous compounds comprising caffeic acid, ferulic acid and 3,4
dimethoxycinnamic acid which are connected by an ester-bond to the
hydrolysis groups of quinic acid (1alpha, 3R, 4 alpha,
5R-tetrahydroxy-cyclohexane carboxylic acid). The anti-oxydation
capacity of Chlorogenic acid is more potent than of ascorbic acid
(vitamine-C) or mannitol, which is a selective hydroxy-radical
scavenger. Chlorgenic acids have a bitter taste in low
concentrations such as 50mg / L water. At higher concentrations of
1 g/ 1 L water they have a sour taste. Chlorogenic acid increases
the solubility of caffeine and are important modulaters of taste.
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