14 BULLETIN 235, U. S. DEPARTMENT OF AGRICULTURE. 
A machine of this nature would be available and practical not 
only for wrapping and sealing cracker and cereal cartons, but also 
for raisins, currants, figs, prunes, and all small packages of other 
dried fruits. 
PREPARATION OF A STERILE PACKAGE OF DRIED FRUIT. 
A description has been furnished of a method of preparing packages 
of cereals so that they will not become infested. This process is 
being successfully carried out by several large mills, the only real 
difficulty arismg from the cost of sealing the carton. This objection 
is being gradually overcome. 
The process consists in running the cereal through a sterilizer and 
then through a clean chute directly into an insect-free packing room, 
where it is packed in sterilized cartons and sealed. The writer be- 
heves that such a process can be applied to dried fruit, and the follow- 
ing suggestions are made to that effect: 
In order to sterilize the fruit so far as insects are concerned it is 
necessary to heat it to 180° F. With the fruits which are regularly 
dipped in hot solutions this heating is readily accomplished, but in 
the case of those which are dipped in cold solutions before being 
packed the use of the belt heater described on pages 7-8 is suggested. 
After sterilization by one of the foregoing processes the fruit must 
be protected from reinfestation, and the use of the screened packing 
room, a plan for which is shown on page 8, figure 3, and described 
below, will serve this purpose nicely. 
The fruit should be run directly from the sterilizer or dipping vat 
into the packing room, where it is packed and sealed. It may then 
be removed to a warehouse, and if properly sealed it will not become 
infested by insects. 
THE SCREENED PACKING ROOM. 
A simple packing room (fig. 3) can be cheaply constructed by 
covering a light framework with lath, cloth, and paper. The windows, 
the floor, and ali corners and joints should be made tight, and venti- 
lation accomplished by blowing air through an opening covered with 
cheesecloth or No. 20 screen wire. Such a packing room can be 
constructed to admit plenty of light and air and still be free from 
insects. Whenever necessary the openings may be closed and the 
room thoroughly fumigated. 
Note.—The writer has observed as many as 10 eggs of insects on the inside of a carton in a cereal mill. 
It is advisable, therefore, to sterilize all cartons before filling them. This may be readily done by placing 
a truck load in a heating chamber over night or during the day. 
