Optimization of Procedures for In-Line Extraction of Lipids and Polyphenols from Grape Seeds

Grape seeds (Vitis vinifera L.), a type of raw material containing around 20 % (w/w) of lipids and 20 % (w/w) of phenolic compounds in dry weight, are the main by-products in wine industry. In this work, water and hydroalcoholic mixtures have been first investigated to obtain the optimal solvent for further extractions. Polyphenols and lipids were then extracted by three combined extraction procedures to compare their effectiveness so that the optimal procedure was determined. The results showed that the best yield was achieved by the in-line combination of maceration before grinding and followed by Soxhlet extraction using aqueous ethanol (ethanol/water, 80:20 v/v) at 80 °C.