Optimization of the extraction of phenolic compounds from milled berries has been studied and the effective diffusivity and mass transfer coefficient have been measured during solid-liquid extraction in an agitated vessel. Optimization was carried out by a surface response methodology, using ethanol or sulfured water concentration, temperature, and solvent-to-solid ratio as independent variables. Maximum yields of total phenolics and anthocyanins were obtained at 19 l of solvent per kg of milled frozen berries with 1000-1200 ppm SO 2 , or 60% ethanol concentration. The increase of the extraction temperature increased the rate of extraction and reduced the extraction time by increasing the diffusivity. The higher the SO 2 concentration in the solvent mixture, the higher the diffusivity, however ethanol concentration increased diffusivity up to a maximum and decreased it with further increase of ethanol concentration. Diffusivities of 24.3x10 - 1 1 and 12.3x10 - 1 1 m 2 s - 1 and mass transfer coefficients of 3.85x10 - 5 and 2.36x10 - 5 ms - 1 were obtained for extraction of anthocyanins at 40 o C using 700 ppm SO 2 and 67% ethanol, respectively.