Use of Ultrafiltration Technology to Concentrate Whey Proteins after White Cheese Manufacturing

Dairy industry generates contamination due to whey dumping from the manufacture of coagulated products. Ultrafiltration technology has been extensively studied in acid whey; however, research on sweet whey ─which is obtained from the production of fresh white cheese (Campesino cheese)─ is scarce. The objective of this study was to concentrate sweet whey proteins by ultrafiltration and to evaluate the process conditions. A polyethersulfone membrane with a molecular weight cut-off of 10 kDa was used. The effect of volumetric concentration factor between 5 and 18, transmembrane pressure between 2.5 and 5 bar was evaluated on the permeate flow, protein retention coefficient, and retention yield using a response surface methodology. The process optimization was carried out in that same range. Protein and fat were concentrated and underwent ultrafiltration; however, a less stable system was obtained. A higher concentration of protein can result in more collisions between molecules, thus generating flocculation. Whey protein concentrates had 18.2% of total solids out of which protein represents 45%.