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

Abstract

The main chemoprotective polyphenolic compounds in the <i>Vitis vinifera</i> 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), <i>trans</i>-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), <i>trans</i>-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 <i>trans</i>-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.