Caftaric acid is a non-flavonoid phenolic compound.
It is found in the juice of grapes
(''Vitis vinifera'') and impacts the color of
white wine.
It is an esterified phenolic acid, composed of
caffeic acid, a
hydroxycinnamate produced by plants, and
tartaric acid, the principal organic acid found in grape berries. As such, caftaric acid is found in all grape juices and wines.
During
alcoholic and
malolactic fermentation, the ester can be enzymatically hydrolysed, releasing the two constituents. Caffeic acid is susceptible to chemical oxidation, and subsequent redox reactions involving caffeic acid can contribute to wine
browning over time, and the straw-gold color that can develop in some white wines after bottling.
Aside from wine, it is abundantly present in
raisins. It also occurs in ''Cichorium intybus'' (common
chicory) and is one of the bioactive components of ''
Echinacea purpurea
''Echinacea purpurea'', the eastern purple coneflower, purple coneflower, hedgehog coneflower, or echinacea, is a North American species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as w ...
'' (Eastern purple coneflower).
Caftaric acid has a good bioavailability when fed in rats. Intact trans-caftaric acid was detected in rat plasma along with its O-methylated derivative trans-
fertaric acid
Fertaric acid is a hydroxycinnamic acid found in wine and grapes. It is an ester formed from ferulic acid bound to tartaric acid.
It is a metabolite of caftaric acid
Caftaric acid is a non-flavonoid phenolic compound.
It is found in the juice ...
.
[
]
In wine
Winemakers measure caftaric acid levels as their primary method to estimate the oxidation levels that a wine has undergone. For example, press wines, which undergo a high degree of oxidation, will have little to no caftaric acid.
Grape reaction product (2-S glutathionyl caftaric acid) is an oxidation compound produced from caftaric acid and found in wine. Malvidin 3-glucoside
Oenin is an anthocyanin. It is the 3-glucoside of malvidin. It is one of the red pigments found in the skin of purple grapes and in wine.
Color stabilization of malvidin 3-glucoside at a higher pH can be explained by self-aggregation of the flavy ...
alone is not oxidized in the presence of grape polyphenol oxidase (PPO), whereas it is degraded in the presence of a crude grape PPO extract and of caftaric acid, forming anthocyanidin-caftaric acid adducts.
See also
* Chicoric acid
Chicoric acid (also known as cichoric acid) is a hydroxycinnamic acid, an organic compound of the phenylpropanoid class and occurs in a variety of plant species. It is a derivative of both caffeic acid and tartaric acid.
As a suitable marker for ...
(dicaffeoyltartaric acid)
References
{{Hydroxycinnamic acid
Hydroxycinnamic acid esters
Catechols
Vinylogous carboxylic acids