Modeling inactivation kinetics of liquid egg white exposed to UV-C irradiation

Abstract

The efficiency of UV-C irradiation as a non-thermal pasteurization process for liquid egg white (LEW) was investigated. LEW inoculated with Escherichia coli K-12 (ATCC 25253), pathogenic strain of Escherichia coli O157:H7 (NCTC12900) and Listeria innocua (NRRL B33314) were treated with UV light using a bench top collimated beam apparatus. Inoculated LEW samples were exposed to UV-C irradiation of known UV intensity of 1.314mW/cm2 and sample depth of 0.153cm for 0, 3 5, 7, 10, 13, 17 and 20min. The populations of E. coli K-12, E. coli O157:H7 and L. innocua were reduced after 20min of exposure by 0.896, 1.403 and 0.960logCFU respectively. Additionally, the inactivation data obtained for each strain suspended in LEW was correlated by using Weibull (2 parameter), Log-Linear (1 parameter), Hom (2 parameter) and modified Chick Watson (2 parameter) models. The inactivation kinetics of E. coli K-12, E. coli O157:H7 and L. innocua were best described by modified Chick Watson model with the smallest root mean squared error (RMSE) (R2≥0.92). © 2010 Elsevier B.V.