Indicators of the composition of grape vine extracts

The significant areas allocated for vineyards in the Russian Federation and the ongoing care activities allow us to consider the grapevine as a valuable source of secondary raw materials. The aim of this work is to study the effect of the extraction process on the component composition of extracts from fresh grapevine samples of common grape varieties such as Cabernet Sauvignon, Merlot, Moldova, and Isabella. The analytical work was conducted using capillary electrophoresis and gas-liquid chromatography. Distilled water (when implementing the microwave process), acetone, and 10% ethyl alcohol were used for the extraction process. Using capillary electrophoresis, the concentrations of potassium, sodium, magnesium, calcium, tartaric, malic, succinic, and citric acids, as well as some phenolic substances, including resveratrol, were determined in the studied extracts. The highest concentrations of biologically valuable components, in grams per liter, were found in microwave extracts, while the lower content of organic acids, at 0.1 g/L, and cations, at 0.05-0.1 g/L, and the higher content of phenolic substances, were characteristic of the extract using acetone. This suggests that the acetone extract can be used to extract the most valuable phenolic components, and the solvent can be easily removed afterward. At the same time, microwave extraction can be recommended for extracting the entire range of sub-stances characteristic of the grapevine. The gas chromatography analysis showed a significant difference in the extraction of volatile components present in the extracts. The resulting extracts can then be subjected to concentration processes or the removal of the undesirable extracting component, such as acetone or ethyl alcohol residues.