EFFECT OF THE BENCH SCALE EXTRACTION CONDITIONS ON Pinus radiata BARK EXTRACT YIELD, ANTIOXIDANT PROPERTIES AND COMPOSITION

Many pine bark extracts have antioxidant properties. This work examined bench scale extraction on the yield, the composition and antioxidant properties of Pinus radiata. Acetone solvent (98.7% w/w at 120 °C) yielded maximum phenols concentration, tannins concentration, anti-radical activity (DPPH) and reducing activity (FRAP), although its extraction yield was the lowest. When the organic solvent in the mixture decreased, the chelating activity increased (ICA) and antiradical and reducing activities decreased. The extract largest yield was obtained with water at 120ºC, but the antioxidant properties were relatively poor. Taxifolin (dihydroquercetin) and catechin were the main extract components detected by RP-HPLC. The best extraction conditions for high extractive yield and antioxidant properties was achieved with ethanol/water at 120 °C.