Distribution of major polyphenolic compounds in vine grapes of different cultivars growing in South Moravian vineyards

Abstract

Mikeš O., Vrchotová N., Tříska J., Kyseláková M., Šmidrkal J. The main chemoprotective polyphenolic compounds in the Vitis vinifera berries, rachis, and pedicels of 10 cultivars classified for the production of wine and growing in Southern Moravian vineyards, the Czech Republic, were studied. The following compounds were determined in the frozen fresh berries: gallic acid (1.8-13.3 mg/kg), catechin (70.3-659.1 mg/kg), epicatechin (67.1-237.2 mg/kg), trans-resveratrol (0.1-1.5 mg/kg), and pterostilbene (in traces); in the freeze-dried rachis and pedicels: rutin (10.5-68.6 mg/kg), isoquercitrine (29.8-218.3 mg/kg), catechin (283.7-2227 mg/kg), epicatechin (47.2-215.2 mg/kg), trans-resveratrol (2.6-37.1 mg/kg), and pterostilbene (0.01-0.13 mg/kg), respectively. The contents of polyphenolic compounds were different in various cultivars. The highest levels of catechin and epicatechin were found in the grapes of cv. Blauer Burgunder (3195 mg/kg), in which the second highest content of trans-resveratrol (33.2 mg/kg) was also found. The content of pterostilbene in the whole berries or stems was estimated for the first time. The rachis and pedicels could serve as a prospective source of polyphenolic compounds.

The changes of selected phenolic substances in wine technology

“…The essential information on limits of detection and repeatability of the used analytical methods was described in a paper of Mikeš et al (2008).…”

“…The composition of polyphenols is dependent on the variety, growing conditions, ripeness of grapes, and their infestation by fungal diseases, and wine making (Pezet & Cuenat 1996;Jeandet et al 2006;Mikeš et al 2008). Phenolic composition of white wines can be affected by pressing and grape maceration .…”

Antioxidant activity of wines and related matters studied by EPR spectroscopy

“…The decreasing intensity of nitroxide radical's spectrum is value of antioxidant capacity of the studied sample. The samples were prepared from natural materials by extraction with methanol and filtration according Mikeš et al (2008).…”

“…In grapes, trans-resveratrol is considered to be the main stilbene derivative. It is present above all in skins of berries and also in leaves and grape stalks (Mikeš et al 2008) and during the process of maceration it passes into wine. It is known that after the infestation with fungal diseases (Botryotinia fuckeliana Whetzel anamorph Botrytis cinerea Pers.)…”

Content of trans-resveratrol in leaves and berries of interspecific grapevine (Vitis sp.) varieties

“…In grapes, trans-resveratrol is considered to be the main stilbene derivative. It is present above all in skins of berries and also in leaves and grape stalks (Mikeš et al 2008) and during the process of maceration it passes into wine. The occurrence of trans-resveratrol in leaves was described in papers (Adrian et al 2000;Okuda & Yokotsuka 1996) dealing with the synthesis of resveratrol under the effects of UV radiation, aluminium chloride and/ or mechanical damage.…”