SCIENCE AND INDUSTRY. 
Progress in the Dehydration Industry. 
By C. E. MANGELS, Washington, D.C.* 
The preservation of fruits and vegetables by dehydration has been 
given much prominence during the past three years. Dried fruits have 
been staple articles of food for a number of years, but the dehydration 
of vegetables presented many problems not met in the drying of fruits. 
Fresh vegetables wilt or spoil much more quickly as a rule than fruits. 
The slow processes used for fruits have not, therefore, been applicable 
to vegetables. 
Dehydration of fruits and vegetables has been, and still is, a very 
fertile field for investigation. Dehydration became still more important 
to us when the United States entered the war, and ‘the necessity for 
vegetable food in the concentrated form became apparent. The United 
States Department of Agriculture, particularly the Bureau of Chemis- 
try, has conducted extensive investigations on the preservation of fruits 
and vegetables by dehydration. These investigations have had a very 
wide range, and the problem has-been attacked from many different 
angles. ; 
When the United States entered the war in 1917, a vegetable dehydra- 
tion industry already existed in Canada. The plants in Canada de- 
hydrated vegetables for the allied armies, the principal products being 
dried sliced potatoes, and the Julienne soup mixture. A few plants 
engaged in the dehydration of vegetables existed in this country before 
the war, and the declaration of war by the United States gave impetus 
to the enlargement of existing plants and the formation of new organiza- 
tions. Unfortunately, there was also created a very fertile field for 
stock-selling schemes and exploitation of worthless patents. 
When the armistice was signed in November, 1918, a number of 
plants were engaged in the dehydration of vegetables. Practically all 
of these plants were engaged solely in the filling of Army contracts, and 
had not even attempted to develop any other outlet for their products. 
Consequently, when all outstanding contracts were cancelled by the 
Army in February, 1919, the whole industry was placed in a very pre- 
carious condition. The outlook for dehydration was unquestionably 
discouraging, but many of the manufacturers immediately made plans 
for the development of other outlets for their products, and planned 
primarily to develop a domestic market. The success of their efforts 
has been encouraging. Not only have many of the existing plants 
continued to operate, but new organizations have been formed, and new 
plants erected during the past year. Dehydration has not been merely 
a war visitor, it has come to stay. ; 
The products produced for Army use were not unwholesome, but 
their quality was not such as would tend to create a strong domestic 
* Investigator, Division of Dehydration, United States Department of Agriculture. Paper 
presented at annual meeting of the American Society of Heating and Ventilating Engineers, New 
York, N.Y. January, 1920. . 
369. 
