186 MISC. PUBLICATION 5 4 0, U. S. DEPT. OF AGRICULTURE 



Table 24. — DeTiydrator-tray loadings suggested for specific vegetables and differ- 

 ent systems of air flow 



Vegetable 



Type of piece 



Cross circula- 

 tion of air 

 per square 

 foot 



Through cir- 

 culation of air 

 per square 

 foot 





Whole 



Pounds 



1.5 

 1.5 

 1. 3-1. 8 

 1. 3-1. 5 

 1.5 

 . 75-1. 3 

 1. 3-1. 8 

 1. 0-1. 3 

 1. 2-1. 5 

 1. 0-1. 5 

 . 75-1. 3 

 1. 5-1. 8 



Pound? 



3-4 





Cut : 



(Cubes 



^Slices 



6-12 





6-12 

 2-3 





[Strips 



Shreds 



6-12 



6-8 





(Cubes 



6-12 





\ Slices 



2-3 





[Strips 



6-12 



Celery __ 



Slices 



6-12 





Trimmed loaf 



Whole kernel ... . ... . 



3-6 



Corn, sweet .____.. . - 



3-4 



Kale 







Mustard greens 



...do 







Onions . ____ 



Slices, shreds . . ..... 



1.0-1.3 



6-8 



Parsnips 







Peas, green... 



Same as for lima beans _ 









(Cubes 



1. 3-1. 8 

 1. 0-1. 3 

 1. 2-1. 5 



1.0 



6-12 





1 Slices 



2-3 



Potatoes 



| Strips.. . 



6-12 





I R iced 





Rutabagas. _ . 







Spinach.. .... . 











(Cubes.. ...' 



1.3-1.8 



1.0-1.3 



1.5 



1.0 



1. 3-1. 8 



6-12 





I Slices 



2-3 











6-12 





[Riced .. 



2-3 



Tomatoes.. . .. . 



Slices 



2-3 







When a bin drier is used for finishing the dehydration of vegetables, 

 the most suitable depth of loading will vary from 2 to 6 feet and must 

 be determined by trial. Loading depths of not over 3 feet are sug- 

 gested for cabbage, sweet corn, and tomatoes. The air entering the 

 bin finishing drier should have a dry-bulb temperature of 120°-130° 

 F. and a relative humidity of 10 percent or less. (See p. 107.) 



Variations between varieties and within a single variety due to 

 maturity, cultural conditions, or storage conditions make it necessary 

 to determine safe operating temperatures by trial. The general prin- 

 ciple to be followed is that the finishing temperature shall be carried 

 as high as possible without damage to the product. To serve as a 

 guide the temperature conditions for different systems of dehydration 

 are shown in table 25 for various commonly used types of drying 

 equipment. Types of equipment and their operation are discussed 

 in previous sections of this manual. For some of the vegetables, in- 

 formation is included on storage of the dried product after it has 

 been packaged. Table 26 contains the weights of certain dehydrated 

 vegetables that can be packaged in standard containers. 



