VEGETABLE AND FRUIT DEHYDRATION 



125 



method commonly results in analyses below 2 percent of oxygen, the 

 time is not accurately measured and the cans have been found to con- 

 tain as much as 8 percent of oxygen. 



Tests have shown that the introduction of an iron-case dry-gas 

 meter, of stock design, between the cylinder and purge tube improves 

 the method. The stock meter used in testing had one dial that meas- 

 ured 1 cubic foot per revolution. In the displacement of air by this 



Figuee 61. — Filling 5-gallon cans with diced dehydrated carrots. 



method, the lid of the can is placed over the opening; the can is 

 gassed and, after removal of the tube, the lid is attached to the can 

 by seaming to form an hermetic seal. Soldering is an effective method 

 of closing cans but is a slower method than seaming. The following 

 results have been obtained in tests of the cylinder- and-meter method 

 of gassing : 



Time Oxygen content of 

 Cubic feet of ^as : (seconds) can (percent) 



2 -—1 60 0.8-1.0 



1 30 1.2-1.6 



1 10 1.8-2.4 



These results were obtained with dehydrated cabbage and carrots at 

 typical loads per can, 



