TO 



STORE 



CLEANED 



EGGS 



JAMES E. FULLER AND WALTER C. FLANDERS * 



SINCE Mr. and Mrs. Consumer 

 are insisting more and more on 

 neat, attractive food displays, 

 eggs are not acceptable for market 

 until they have been cleaned. The 

 use of germicides for cleaning eggs is 

 prohibited by law in many states; 

 therefore most of the cleaning is 

 done by washing, with or without 

 soap, or by sanding. The wash 

 water cannot be very warm because 

 too much heat might partially cook 

 the egg. For sanding, a type of sand- 

 blasting is used. 



Egg shells contain pores filled with 

 a mucilaginous substance that al- 

 lows air to pass into the egg but re- 

 sists the passage of microorganisms. 

 Washing or sanding will remove 

 this protective substance. 



To find out the extent to which 

 microorganisms will penetrate 

 through cleaned shells, eggs from the 

 University poultry flocks were ex- 

 amined after their removal from 

 nests. Only an occasional egg was 

 found to contain bacteria. Both 

 uncleaned eggs and eggs cleaned by 

 the methods mentioned were stored 

 dry for several weeks under normal 

 cold-storage conditions. No bac- 

 teria were found inside the eggs. 

 Other eggs were immersed in nu- 



■*■ Dr. Fuller, Research Professor, Bacteriology, 

 assisted by W. C. Flanders, graduate student. 



trient broth and held at room temp- 

 erature to allow bacteria on their 

 shells to grow and to penetrate the 

 egg if possible 



Bacteria penetrated cleaned egg 

 shells to a greater extent than the 

 uncleaned shells; however, bacteria 

 invaded all eggs in substantial num- 

 bers. From the results of the in- 

 vestigation, then, it would seem 

 that eggs in dry storage would be in 

 little danger of contamination from 

 bacteria on the shells, whether the 

 eggs were uncleaned or were cleaned 

 by washing or sanding. 



Eggs are washed by placing them loosely 

 in wire baskets which are then immersed 

 in warm water and soap. 



