Protein Concentrate from Cheese Whey by Ultrafiltration

A concentrate containing up to 65% protein in the solids was recovered from cheese whey by the use of tubular cellulose acetate ultrafiltration membranes designed to reject solutes larger than 20,000 molecular weight. Removal of 90% of the water as permeate resulted in a concentrate containing 20% solids with 35 to 37% protein and 50 to 52% lactose in the solids. By diluting and recycling, a concentrate containing 60 to 65% protein and 30 to 35% lactose in the solids was obtained. for 90% reduction in volume, fractionation averaged 12 gallons per square foot of membrane surface per day