Effect of superfine grinding on the physicochemical properties and antioxidant activity of red grape pomace powders

Abstract The objectives of this study were to determine the physicochemical properties and antioxidant activity of red grape pomace powders (GPPs) from winemaking residue with particle sizes of > 300, 250–125, 125–70, 70–38, and 3 ), tapped density (from 0.51 to 0.31 kg/m 3 ), and fluidity (repose angle from 33.87 to 56.34° and slid angle from 36.76 to 71.97°, respectively) of GPPs, but improve the solubility (from 9.38 to 48.86%). The extract of GPP with a particle size of