Chapter four - Application of high-voltage electrical discharges to the recovery of phenolic compounds from winery wastes

Abstract

Wine industry generates huge amounts of residues that require a suitable management: grape leaves and shoots, stems, pomace, lees, etc. These wastes are rich in valuable compounds, mainly phenolic compounds such as stilbenes, phenolic acids, flavonoids, and tannins. Phenolic compounds present very interesting functional properties, which make them to worth their recovery and application. Most methods employed for the recovery of phenolic compounds from winery wastes require the application of thermal techniques that can result in their deterioration. High-voltage electrical discharge (HVED) is a sustainable and nonthermal alternative with high potential in the valorization of food wastes. The aim of this chapter was to revise the application of HVED in the recovery of phenolic compounds from winery wastes. The optimization of different parameters of HVED (energy input, interelectrode distance, and solid-to-liquid ratio) and the combination of HVED with other extraction techniques are key factors to improve the extractability of phenolic compounds. Moreover, grape variety has also demonstrated to affect the recovery of phenolic compounds.