Coutaric acid

Fig. 2.79. Chromatograms of a white (I) and red wine sample (II). (LC-DAD signals at three different wavelenghts 256, 324, 365 nm). Peak identification 1 = gallic acid 2 = protocatechuic acid 3 = p-hydroxybenzoic acid 4 = vanillic acid 5 = caffeic acid 6 = (+)-catechin 7 = syringic acid 8 = p-coumaric acid 9 = ( — )-epicatechin 10 = ferulic acid 11 = fraras-resveratrol 12 = rutin 13 = myricetin 14 = cw-resveratrol 15 = quercetin A = caftaric acid B = coutaric acid. Reprinted with permission from M. Castellari et al. [196],...

Figure 11.3.1 HPLC chromatogram of acidic polyphenolics isolated from Niagara grapes and detected at 320 nm. Retention time 8.647 min, frans-caftaric acid 13.789 min, c/s-coutaric acid 14.944, frans-coutaric acid. Reproduced from Lee and Jaworski (1987) with permission from the American Society for Enology and Viticulture.

VL Singleton, J Zaya, EK Trousdale. Caftaric and coutaric acids in fruit of vitis. Phytochem 25 2127-2133, 1986. 

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.

The chemical interpretation of the yellow color in white wines has always been a little-known field. Phenolic compounds are certainly involved, but concentrations are low and their contribution has never really been established. Many studies have investigated the oxidative browning of wines, independently of enzyme mechanisms. Other molecules are involved besides tannins (Sapis and Ribereau-Gayon, 1968), especially compounds that have a high absorption in the visible—and especially ultraviolet—spectrum (Somers and Ziemelis, 1972). Cafeic and coutaric acids are responsible for browning in white wines (Cheynier, 2001). 

Mono (4-hydroxy-E-cinnamoyl) trans-Coutaric acid. tra.ns-p-Coumaroyltarta-ric acid [27174-07-8]... 

Hydroxy-E-cinnamoyl), 3-Ac 2-0-Acety/-trans-coutaric acid. 2-0-... 

The content of coutaric acid was low compared with caftaric acid for all three varieties, which agrees with previous reports (Nagel and Wulf, 1979). In Cabernet Sauvignon, it was not possible to quantify coutaric acid in all the treatments due to poor separation. In... 

Chambourcin, coutaric acid was able to be quantified in all treatments except in 14 day skin fermentation wine. Increasing the skin fermentation time significantly decreased the coutaric acid concentration. In Noble, coutaric acid was present in very low levels in all skin fermentation wines. 

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