Investigation of the effect of grapes processing method on the phenolic complex of table wines

Abstract

The aim of the work is to find the effect of grapes processing method on the phenolic complex of the wine stock. The test material was pink and red dry table wine stock, prepared according to various schemes of grape varieties Petit Verdot, Sangiovese, Syrah, Cabernet Sauvignon (check). The determination of phenolic compounds was performed according to the method with the chromatograph Agilent Technologies, Model 1100. The results of the chromatographic analysis made it possible to determine a significant difference between qualitative composition and quantitative content of anthocyanins, other bioflavonols and non-condensed tannins in wine stock produced from grapes of different varieties. The highest content of phenolic compounds was in wine stocks from the grapes Petit Verdot, the smallest was in Syrah. Wine stocks from Cabernet Sauvignon were characterized by the high level of anthocyanins, although the high content of these compounds was observed in Petit Verdot also. Anthocyanins in all grape varieties were introduced mainly by malvidin-3-O-glycosides and their derivatives. It has been found that the method of processing grapes affects the mixing ratio of the phenolic complex. The content of these compounds was observed in Petit Verdot also. The highest content of anthocyanins was in wine stocks of Syrah and Petit Verdot varieties produced by the way of pulp hypo-fermentation, while in the wine stocks of Cabernet Sauvignon and Sangiovese – of pulp fermentation, that indicates the differences of grape varieties to dyes donation. Cryomaceration provides an opportunity to increase the content of such valuable bioflavonols as catechin and epicatechin in almost every unblended wine stock. Wine processing using the "white" method makes it possible to obtain rose wines that contain mainly kaftaric acid and epicatechin. Anthocyantin complex is epresented mainly by malvidin-3-O-glycosides. The method of infusion on the seeds and skins compared to processing using the "white" method increases the content of epicatechins on an average twice, the anthocyanin content – from 3 to 5 times depending on the variety. The proposed technological wine production schemes make it possible to get the wine stocks that are not inferior to the check sample on the content of flavonols