The Influence of Eggshell Washing on Bacterial Transfer Across the Shell Wall

Cranstoun, Sheila (1992) The Influence of Eggshell Washing on Bacterial Transfer Across the Shell Wall. MSc(R) thesis, University of Glasgow.

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1. All three methods of washing action (brush, rotary and jet) investigated in this study caused damage to the cuticular surface of the egg shell. 2. The physical trauma to the egg caused by the washing procedure resulted in higher levels of protein in the post wash water. Not all of the protein was derived from the cuticular surface, some was also derived from the contents of broken eggs. 3. The pre wash water in both the brush and jet action machines contained bacteria, highlighting the difficulties associated with plant hygiene. The post water from all three washing machines contained a diverse population of bacteria, several of which were potential food pathogens. 4. The persistence of the bacterial population in the three washing systems, particularly the rotary and jet action machines underlined the inadequacies of the sanitiser regime. Eggs improperly rinsed displayed sanitiser residue on the shell surface. Chlorine from the sanitiser penetrated the thickness of the true shell. 5. In general terms, bacteria translocated across the shell wall of washed eggs more readily than the unwashed group. This trend was independent of the type of wash action although it did appear to be strain related. 6. As the bird aged, shell quality declined with a concomitant increase in bacterial transfer. 7. Infectious Bronchitis was verified during the course of this investigation and observed to have a profound effect on shell structure. This structural deterioration correlated with a rapid increase in bacterial penetration (56% in the unwashed eggs and 66% in the washed eggs). During the recovery phase bacterial penetration decreased.

Item Type: Thesis (MSc(R))
Qualification Level: Masters
Keywords: Animal sciences
Date of Award: 1992
Depositing User: Enlighten Team
Unique ID: glathesis:1992-78402
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 28 Feb 2020 12:09
Last Modified: 28 Feb 2020 12:09

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