Abstract: In order to improve the permeability and ultrafiltration efficiency of whey protein, the flocculation of whey protein with CaCl2 was optimized by one-factor-at-a-time and orthogonal array design methods based on protein content, fat content and transmittance. The optimal flocculation conditions were determined as pH 7.5, 1 mol/L CaCl2 addition at a ratio of 12 mL/L, and gentle stirring on 60 ℃ water bath for 15 min. After these pretreatments, the loss rate of whey protein was only 13.6%, the defatting rate was over 86%. Meanwhile, the transmittance was significantly improved.

Key words: cheese whey, flocculation, centrifugation