Fertaric acid

For different Vitis vinifera varieties, differences of phenols in the juice are mainly quantitative, and caffeyl tartaric acid (denominated caftaric acid, CTA) always prevails on p-coumaryl tartaric (coutaric acid, p-CuTA) and ferulyl tartaric (fertaric acid, FTA) acids. In the skins, the principal cinnamic acid is CTA, or alternatively p-CuTA, while FTA... 

Table 2.2 Polyphenols extracted from Pinot noir grape skins using three extractive solvents CTA, caftaric acid p-CuTA, coutaric acid FTA, fertaric acid, n.d., not detected.

Fertaric acid R,=tartaric acid R3=OCH3 Protocatechuic acid R,=H R2=0H R3=0H... 

Hydroxycinnamic acids are found mainly in skin and, to a lesser extent, in leaves [101,102] and stems [97]. The most abundant acids (viz., caffeic, p-coumaric, and feralic) are present as tartaric esters (caftaric, cutaric, and fertaric acids Figure 4.7) or in acylated anthocyanins (basically, p-coumaric and caffeic acids). 

The phenolics in red wines are the hydroxydimamates, coutaric, caftaric and fertaric acids, and malvidin-3-O-glucoside and other anthocyanins with lower levels of gallic acid, stilbenes and flavonols. From the data presented in Table 7.8, which are based on a study by Burns et al. (2000), it is evident that the levels of the flavan-3-ol monomers (-l-)-catechin and (-) -epicatechin are not high, and that there is a large discrepancy between the levels of phenolics measured by HPLC and the total phenolics determined by the Folin-Ciocalteau... 

R HC—OH 1 COOH rrans-f>coiinaroyltartaric acid (cUaric acid) Trans-fenJoyllaftanc acid (fertaric ackt) H OCHj... 

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