The reduction in permeate flux caused by fouling is a drawback in the operation of membrane systems that can be alleviated using mechanical and electrical methods. Alternatively, physicochemical treatments provoking the elimination of fouling agents have been proposed as effective strategies for the enhancement of flux. A procedure (comprising salt addition, pH and temperature modification and centrifugation) that removes calcium and phosphate salts from acid whey without altering the profile of valuable proteins is presented in this research work. It has been demonstrated through the paper that this pretreatment enhances significantly the permeate flux of whey when cross-flow ultrafiltered through a 50 kDa tubular ceramic membrane both in total recycle and continuous diafiltration mode. For modelling purposes, a resistances in series model was applied to explain the effect of transmembrane pressure and a complete-standard blocking model fitted the experimental data of the variation of permeate flux with time.