Concentration of Egg White by Ultrafiltration ¹

Unpasteurized egg white was concentrated by ultrafiltration to about one half of its original volume. Twenty four batches, each started with 5,000 pounds of fresh egg white, were carried out in a 12-month period with a SANOVO Unit in an egg products plant. The optimum operating pressure was found to be about 415 psi. Higher pressure did not benefit the overall efficiency; on the contrary, it increased the chances of fouling and possibly compaction of the membrane and shortened the membrane life. As no refrigeration was provided in the system, egg white temperature rose linearly in all trials. The aerobic plate count of microorganisms was found to be doubled within 1-3 h when the ending temperature was above 20 C and over 10 h when the ending temperature was less than 16 C. The logarithm of permeation rate (R, lb./min) was linearly proportional to operating time (t, min) and the percent solids content of egg white (S). The solids content at a given time can be predicted by the equation: The estimated cost of concentrating egg white from 11.5 to 23% solid and at a volume of 10,000 lb. per day or 2,500,000 lb. per year, was $0.0295 per pound of concentrate. The accountable net savings for liquid egg white which would be shipped in tankers from the west coast to the midwest, and subsequently spray dried, was about $0.0117 per pound of concentrate and $0.0095 for frozen products. The return on capital investment would be approximately 35-40%.