14 A BACTEKIOLOGICAL STUDY OF EGGS. 



Having been broken, the eggs are usually strained through a colan- 

 der, primarily for the purpose of breaking up the yolks and making 

 a more homogeneous mass. The straining, if a small-meshed colan- 

 der is used, would also remove developing embryos, masses of spots, 

 etc., should they be present. 



After straining, -the eggs may be further blended by mixing in a 

 churn or other specially constructed device used for this purpose. 

 The mixed broken eggs are now ready to be frozen or dried. When a 

 sharp freezer is not located on the premises they may be placed in a 

 chilling room at 33 to 35 F., overnight, or if intended for drying, 

 the liquid material conveyed at once to drying machines. 



METHODS OF DRYING EGGS. 



The normal, whole, hen's egg contains about 73.7 per cent of 

 water. 1 During the drying process this amount is reduced to less 

 than one-tenth of the original amount. It requires about 36 to 40 

 average-sized eggs to make 1 pound of dried material, representing 

 three times the value of one dozen eggs in the shell. 



There are four general methods used by the trade for drying eggs, 

 though each manufacturer may vary the procedure slightly accord- 

 ing to his desire and experience. 



INSTANTANEOUS METHOD. 



In many respects the instantaneous method is highly satisfactory 

 from the sanitary point of view because of the quickness of drying. 

 The high temperature used probably destroys or retards the develop- 

 ment of the less resistant organisms present in the liquid material. 

 The liquid eggs are sprayed into a heated chamber at a temperature 

 of about 160 F., where they are immediately reduced to a fine pow- 

 der which is carried on by currents of air through cotton bags or other 

 filtering devices, on which it is retained and finally falls down into 

 bins. The powdered product usually contains from 3 to 5 per cent 

 of moisture, and is ready to be packed in suitable containers for sale. 



BELT METHOD. 



As suggested by the name, the belt method consists in drying the 

 liquid egg on an endless belt, made of zinc or galvanized iron strips. 

 The belts vary in length according to the size of the rooms and amount 

 of output. The liquid egg may be held in vats and artificially 

 refrigerated with circulating brine, or the feeding device of the dry- 

 ing machine may be equipped with brine pipes to keep the product 

 cold. The liquid egg is applied to the revolving belt through a feeding 

 device which permits a thin film to spread evenly over its surface. 



i Leach, Albert E., Food Inspection and Analysis, 1909, p. 265. 



