Cabernet Sauvignon grape skin extract

Figure 2.14 HPLC anthocyanins profile of Cabernet sauvignon grape skins extract. 1. delphinidin-3-glucoside (glu), 2. cyanidin-3-glu, 3. petunidin-3-glu, 4. penidin-3-glu, 5. malvidin-3-glu, 6. delphinidin-3-glu-acetate (ac.), 7. cyanidin-3-glu-ac., 8. petunidin-3-glu-ac., 9. peonidin-3-glu-ac., 10. malvidin-3-glu-ac., 11. delphinidin-3-glu-p-coumarate (p-coum.), 12. malvidin-3-glu-caffeate, 13. cyanidin-3-p-coum., 14. petunidin-3-p-coum., 15. peonidin-3-p-coum., 16. malvidin-3-p-coum...

Figure 2.15 HPLC profile of HCTA of a Cabernet Sauvignon grape skins extract recorded at wavelength 320nm. (1) ds-CTA, (2) trans-CTA, (3) t/s-p-CuTA, (4) traws-p-CuTA, (5) as-FT A, (6) trans- TK...

Figure 1. HPLC chromatograms of Cabernet Sauvignon grape skin extract (A) young wine Cabernet Sauvignon wine make in R D (B) 1997 Cabernet Sauvignon wine from Napa valley (C).

Extraction of anthocyanins in Cabernet Sauvignon grape skins. 

Cabernet Sauvignon grape skins (50g) were extracted twice with 100 mL of methanol. Extract was combined and evaporated under reduced pressure to remove methanol. Residue was reconstituted to 20 mL with water. Five milliliters of water solution was passed through a preconditioned C-18 Sep-Pak cartridge (Waters Corporation). The adsorbed pigments were washed with 5 mL of water and eluted with 2 mL of 0.01% HCl methanol. The eluant was stored at -20 °C prior to HPLC analysis. Cabernet Sauvignon grape skins were also extracted with 75% acetone with 0.2% acetic acid to compare anthocyanin profiles in different extraction procedures. 

Table 1. Molecular ions and product ions of anthocyanins in Cabernet Sauvignon wine and grape skin extract...

Climatic conditions evidently have an infiuence on all grape constituents—in particular, secondary metabolites such as phenohc compounds and aromatic substances. Studies on these substances are incomplete and have often been carried out with very different techniques—especially extraction. Table 10.9 gives an example of the phenohc composition of Cabernet Sauvignon grapes at the time of harvest for the 1983, 1984 and 1985 vintages. The skin anthocyanin content is higher in quality vintages. This relationship is not valid for tannins. 

HPLC analysis of the development of dimeric and trimeric procyanidins, as well as simple flavanols, extracted from the skins and seeds of red and white grapes, shows that concentrations decrease to a greater or lesser extent, but never increase (de Freitas, 1995). It has been observed that procyanidin B2 is the most common dimer in ripe Merlot and Cabernet Sauvignon (Table 6.11), followed by trimeric Ci. All the dimers are present in the seed extract, whereas procyanidins B4,... 

The results of the present studies showed that wines made from immediate press juices of the three varieties had the lowest total phenolics among all the treatments (Table 1). Heat treatment of the crushed grapes extracted phenols from the skins, but to a lesser extent than any of the hull treatments. In all varieties, hot press wines and juices were much higher in flavonoids and total phenolic content than immediate press wines and juices. The total phenolic concentrations of hot press wines and juices from Cabernet Sauvignon and Noble were shown to be lower than all the skin contact wines. However, for Chambourcin, hot press wine had the highest total phenol concentration among all treatments, and hot press juice had a similar phenol concentration to skin contact wines. 

Chira K, Schmauch G, Saucier C, Fabre S, Teissedre P-L (2009) Grape variety effect on proanthocyanidin composition and sensory perception of skin and seed tannin extracts from Bordeaux wine grapes (cabernet Sauvignon and merlot) for two consecutive vintages (2006 and 2007). J Agric Food Chem 57 545-553... 

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