Relationship Between Carbon Dioxide Permeability and Bacterial Penetration in Chicken Egg Shell Models

EGG shell porosity and its relation to bacterial penetration has been the concern of several investigators (Kraft et al., 1958 a, b; Haines and Moran, 1940; Walden et al., 1956; Fromm and Monroe, 1960). Marshall and Cruichshank (1938) defined porosity as that property of the shell which permits the exchange of water vapor and gases between the contents of the egg and the outer atmosphere. Egg shell porosity has been evaluated by several methods. Almquist and Holst (1931) dipped egg shells into alcoholic methylene blue and counted the pores. Bryant and Sharp (1934) immersed eggs in water, created a vacuum and counted the sources of bubbles arising from the egg. Romanoff (1940) measured the flow of various gases through a half section of dried shell while Mueller (1958) measured carbon dioxide loss from intact eggs by absorbing it in potassium hydroxide. Fromm (1959) evaluated porosity by measuring the amount of …