Influence of parameters of subcritical water extraction over yield of target components from grape pomace

Abstract

The influence of parameters of extraction process of grape pomace (GP) by subcritical water (SCW) has been researched, the antioxidant activity of these extracts has been analyzed, the parameters of the process, ensuring the maximum yield of the desired component - dry and reducing substances, titratable acids, polyphenols have been determined. Extraction was performed in the temperature range T 100°C ÷ 1600С, pressure P = 12 MPa, exposure dose t from 30 to 90 min., hydro ratio 1: 5 and 1:10. It has been found out that under the extraction of SCW dry extract yield is more than two times higher than by washing sweet pomace with hot water. Yield of polyphenolic compounds exceeds the amount of polyphenols obtained in the extraction with organic solvents and water at temperatures up to 600С. The extracts obtained in the medium of SCW are characterized by high antioxidant activity. Yield of acids under extraction at temperatures (100-120 0С) of SCW is comparable with the number of acids in the original grape pomace.