Title: Removal of Salmonella enteritidis from unpasteurized liquid egg white using a cross flow microfiltration Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 10, 2009
Publication Date: June 1, 2009
Citation: Mukhopadhyay, S., Tomasula, P.M., Call, J.E., Porto Fett, A.C., Luchansky, J.B. 2009. Removal of Salmonella enteritidis from unpasteurized liquid egg white using a cross flow microfiltration [abstract]. Institute of Food Technologies Annual Meeting. 123(54):156-157. Technical Abstract: Liquid egg white (LEW) is typically pasteurized to prevent common foodborne illnesses such as salmonellosis; however, heat pasteurization does not eliminate all pathogenic or spoilage microbes. In this study, a novel intervention technology based on cross-flow microfiltration (MF) was evaluated for its ability to remove Salmonella Enteritidis from LEW. In each of 16 trials, unpasteurized LEW (ca. 110 L) from a local egg breaking plant containing approximately 6.0 log10 CFU/ml of total aerobic bacteria was wedge-screened, homogenized, and diluted with deionized water (1:2 w/w) containing 0.5% sodium chloride to lower the viscosity of the LEW and subsequently facilitate MF. Next, LEW was adjusted to pH 6.0, 7.0, 8.0 or 9.0 with 6N HCl or NaOH and then inoculated with ca. 7.0 log10 CFU/ml of a five-strain cocktail of Salmonella Enteritidis prior to microfiltration (Membralox Pilot Skid System, Pall Inc.) at 25 degrees or 40 degrees C using a ceramic membrane with a nominal pore size of 1.4 mm at a crossflow velocity of 6 m/s. Permeate flux was maximum at the lowest pH studied, pH 6, but temperature had little influence on the flux at any value of pH studied. Under all MF conditions investigated, Salmonella levels were reduced to below the detection limit of less than 0.5 log10 CFU/ml (total reduction of greater than 6.8 log10 CFU/mL) by direct plating. In addition, there was no subsequent outgrowth of any remaining cells of the pathogen for up to 21 days at 4 degrees C, and only about 0.7 log10 CFU/ml increase during storage at 10 degrees C. This study establishes that MF as an intervention to heat pasteurization has the potential to ensure the safety of LEW.