Changes in microbial, physiochemical, and functional properties of pasteurized liquid whole egg during refrigerated storage

J Sci Food Agric. 2020 May;100(7):2873-2879. doi: 10.1002/jsfa.10311. Epub 2020 Mar 3.

Abstract

Background: Liquid eggs have the advantages of high hygiene security, easy use, and convenient transportation, but their shelf life is only limited to 2~3 weeks. The microbial, physiochemical, and functional properties of pasteurized LWE were investigated in this study to evaluate the quality of pasteurized liquid whole egg (LWE) during refrigerated storage.

Results: The tested shelf life of the pasteurized LWE was 16 days when stored at 4 °C. During refrigerated storage, Pseudomonas gradually became the dominant bacterium in LWE following lactic acid bacteria, although the initial number of Pseudomonas after pasteurization was relatively limited (< 10 CFU mL-1 ). A total of 23 strains, including six Pseudomonas strains, were obtained. The pH of pasteurized LWE decreased with the growth of microorganisms, while the content of total volatile basic nitrogen (TVB-N) increased curvilinearly. The average particle size increased almost continuously until the sample reached its shelf life. The functional properties of pasteurized LWE were also reduced after a week of refrigerated storage at 4 °C when the microorganisms in pasteurized LWE entered an exponential growth period and the TVB-N content of pasteurized LWE reached its first peak.

Conclusion: During refrigerated storage, Pseudomonas was the dominant bacterium in LWE next to lactic acid bacteria. After a week of refrigerated storage at 4 °C, the particle size of LWE increased, while the functional properties of LWE reduced. This study provides a basis for extending the shelf life of liquid egg products in future research. © 2020 Society of Chemical Industry.

Keywords: functional properties; pasteurized liquid whole egg; physiochemical properties; psychrophile; refrigerated storage; shelf-life.

MeSH terms

  • Bacteria / classification
  • Bacteria / growth & development
  • Eggs / analysis
  • Eggs / microbiology*
  • Food Handling
  • Food Microbiology*
  • Food Storage*
  • Hydrogen-Ion Concentration
  • Particle Size
  • Pasteurization*
  • Pseudomonas / growth & development
  • Refrigeration