Title: Application of Membrane Separation Technology for Removal of Microorganisms from Unpasteurized Liquid Egg White Authors
|Van Hekken, Diane|
Submitted to: UJNR Food & Agricultural Panel Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 1, 2008
Publication Date: August 24, 2008
Citation: Mukhopadhyay, S., Tomasula, P.M., Van Hekken, D.L., Luchansky, J.B., Kwoczak, R., Call, J.E., Porto Fett, A.C. 2008. Application of Membrane Separation Technology for Removal of Microorganisms from Unpasteurized Liquid Egg White. UJNR Food & Agricultural Panel Proceedings. pg. 68-69. Technical Abstract: Liquid egg products provide a unique, well-balanced source of nutrients to the diet. Pasteurization (56.6 degree C; 3.5 min) is used industry wide to reduce the microbial load and ensure elimination of salmonella contaminants. However, pasteurization may be inadequate for eliminating salmonella in certain liquid egg products and does not reduce the microbial load sufficiently, hence, limiting shelf life. Heat pasteurization also impairs some of the delicate functional properties of the egg products. The present work was conducted to determine if crossflow microfiltration (MF) can be used to eliminate the microflora of a viscous liquid food such as liquid egg white (LEW) while keeping the functional properties intact. Commercial unpasteurized LEW was pretreated initially to alter the fluid rheology and to stabilize the protein matrix of LEW. It was then microfiltered using a 1.4 micron ceramic membrane at a cross flow velocity of 6 m/s. Retentate and permeate samples were analyzed to enumerate egg-borne natural microorganisms (Aerobic, anaerobic, yeasts, molds, coliforms) and inoculated pathogens (Salmonella enteritidis). Microbial removal efficiency was found to be greater than 6 log10 CFU/mL, with a limit of detection less than 10 cfu/mL. pH adjustment from 9 to 6 at 40 degree C resulted in about a 150% increase in permeate flux improving the efficiency of the process. Total protein and SDS-PAGE analysis indicated that MF did not alter the protein composition of the feed LEW. Functional property analyses indicated retention of all functional qualities in the post-processed samples.