Factors affecting the mechanism of flux decline during ultrafiltration of Cottage cheese whey.

The mechanism of fouling of ultrafiltration membranes during the processing of cheese whey was studied. Attempts were made to develop a mathematical model of the flux decline and to determine the contribution of individual proteins and the aqueous environment to fouling. In general, proteins dissolved in a salt-free system resulted in higher flux than in whey dialysate systems, implicating the salts as a major contributor to flux decline. Statistical analysis and evaluation of the parameters of the model indicated that fouling could be considered in two time periods. In the initial period of operation, α-lactalbumin appeared to cause greater flux decline and bovine serum albumin the least. After 10 min of operation, β-lactoglobulin was the major contributor to fouling. The native whey gave the most rapid rate of flux decline. These differences could be due to variations in protein structure or differences in the nature of the deposit on the membrane.