Abstract: The effects of high pressure on the extracting of polyphenols from pear residue by alcohol solution were studied. The optimum concentration of alcohol is 70% (V/V). The extracting rate increased with the increasing of pressure and the extracting rate increased acutely before 500 MPa but increased slowly above 600 MPa(besides 400 MPa). The extracting rate increased with extracting time prolonging, and then decreased and the optimum extracting time was 10 min. The extracting rate increased with increasing of temperature, and then decreased and the optimum extracting temperature 50℃. The extracting rate of polyphenols by alcohol solution from the pear residue can be improved notably by high pressure.

Key words: pear residue, polyphenols, extraction, high pressure