The effect of different sterilization methods on the physical and chemical properties of egg white liquid

Egg white was chosen as a substrate, inoculated with E.coli, Salmonella and Staphylococcus aureus, and then compared the bactericidal effects and the changes of physicochemical properties of egg white after treated respectively by dense phase CO2 ( DPCD) , pulsed electrical fields ( PEF) , and thermal treatment.After the determination of relevant indicators, the conclusions could be drawn as follows: DPCD had achieved the best bactericidal effect for E.coli and Salmonella.Thermal treatment could reduce 2 to 3 logarithm of bacteria, and the bactericidal effect was better than PEF treatment.The shelf-life of untreated egg white lasted only 2 days, while the shelf-life of egg white treated by DPCD, PEF, and thermal treatment combined with cold storage were extended to20 days, 12 days and 14 days.DPCD, PEF and heat treatment also made the physical and chemical properties of egg white change on a certain extent.The pH value and gel strength of egg white was significantly reduced by DPCD treatment, while this kind of treatment greatly increased its electrical conductivity.PEF treatment increased the viscosity of egg white, but reduced its gel strength. Compared with the fresh egg white, the effect of heat treatment on the change of physical and chemical properties was the largest, and this kind of treatment reduced the viscosity but significantly increased gel strength of egg white.