Solid residues from winemaking processes have been subjected to extraction with superheated water–ethanol mixtures. Identification and characterization of the extracted compounds were achieved by spectrophotometry, gas chromatography with either flame-ionization or mass detectors, and-high performance liquid chromatography with UV detection. Extraction was performed statically with single or repeated cycles. All variables affecting the extraction process have been studied and optimised. The extraction time and temperature were 65 min and 210 °C, respectively. Extracts comprised two phases—an aqueous phase, rich in phenolic compounds, and an oily phase, comprising mainly fatty acids. The method allows manipulation of extract composition by changing the applied pressure, temperature, water-to-ethanol ratio, and pH. The method is faster than traditional extraction procedures for obtaining valuable compounds from these residues.
Solid-liquid extraction Liquid chromatography Gas chromatography Mass spectrometry Superheated liquids Winemaking residues