﻿8 BULLETIN 15, U. S. DEPARTMENT OF AGRICULTURE. 



SUMMARY. 



The foregoing observations and experiments have brought out 

 several points: 



(1) Cereals may become infested before they are packed, after the 

 packages are placed in warehouses, and in the grocery stores. 



(2) Insects find their way in at the small holes which are usually 

 present at the corners of unsealed packages or at holes accidentally 

 punched in the sides. 



(3) Thorough sterilization 1 at 180° F. kills all insect life; and if 

 the cereal is run from the sterilizer either through a sterile cooler or 

 directly into sterile packages and immediately sealed, it will not 

 become infested unless the package is broken. 



(4) Sterilization of the knocked-down cartons before packing and 

 cleanliness with regard to the exclusion of insects from the packing 

 room will greatly facilitate the preparation of sterile packages and 

 is strongly recommended. 



(5) It is absolutely necessary that all machinery connecting the 

 sterilizer and the packages be free from insects. If the cereal is 

 passed through chutes or conveyors which can not be sterilized or 

 are not kept sterile, it will, through these sources, become infested 

 even though the cereal was previously sterile and was packed in 

 sterile packages. 



i The writer has not extensively investigated sterilizers, but the following description, furnished through 

 the kindness of Mr. Bert D. Ingles, of a sterilizer used by a large flour mill in California may be of interest 

 here. "In this sterilizer the screw conveyor is 6 inches in diameter and handles approximately 500 pounds 

 of cereal per hour. The steam is held at 160 pounds pressure, which is equal to 370.5° F. A machine 8 feet 

 long will heat the cereal under these conditions to 180° F. in two minutes without any difficulty. Such a 

 sterilization does not injure the cereal." 



ADDITIONAL COPIES of this publication 

 -£i- may be procured from the Superintend- 

 ent of Documents, Government Printing 

 Office, Washington, D. C , at 5 cents per copy 



