COMMERCIAL DEHYDRATION 27 



for 5 to 10 minutes before being peeled. After they have been peeled 



and cut into .slices, cubes, or strips, the pieces are held in water or a 

 1- to 2-percent citric acid solution, which removes starch from the cut 

 surfaces. Length of blanching time is 6 to 10 minutes. Sweetpotatoes 



are dried to 7 percent moisture content or less. 



To reconstitute these types of sweetpotato, boil 1 cup of the dried 

 sliced product in 3 cups of water for 30 minutes or until tender. 



TOMATOES 



Firm-fleshed varieties of tomatoes such as Globe, Marglobe, Early 

 Detroit, Greater Baltimore, Stone, and Santa Clara are recommended, 

 for dehydration. 



Tomatoes are washed, dipped in boiling water, peeled, and any 

 defects cut out. Slices one-fourth inch thick are blanched in live 

 steam for 2 to 3 minutes. The finishing temperature should not exceed 

 150° F. 



To reconstitute, add 1 cup of dried tomato slices to three-fourths 

 of a cup of water, and boil gently -for 5 minutes. 



Tomatoes are more often pureed and dried on a drum drier, or the 

 juice is spray-dried. 



. Fruits 

 apples 



Dried, or evaporated, apples have long been a staple commercial 

 product. Locally grown varieties which it is not profitable to sell 

 in the fresh market or culls of market varieties are chiefly used for 

 drying. The principal requirements are good appearance, a minimum 

 diameter of 2 1 j inches, and other factors not connected with nutritive 

 value, flavor, or palatability. Commercial grades are at present based 

 on color, the whitest apples being rated highest. A better l>a>is for 

 grading would be inherent good quality or the quality of sauce, pie, 

 or other products made from the dried fruit. Either of these standards 

 would place such varieties as Winesap, Northern Spy. Stayman 'Wine- 

 sap, and Esopus Spitzenberg in a preferred grade for drying. 



The varieties chiefly used for drying in New York and Pennsyl- 

 vania are Baldwin and Northern Spy: in Virginia and Wesl Virginia, 

 York Imperial, Winesap, and Stayman Winesap; in the Ozark region, 

 Ben Davis and Winesap: in California, Yellow Newtown, (Jraven- 

 stein, Yellow Bellflower, and Rhode Island Greening; and in Wash- 

 ington and Oregon, Jonathan, Delicious, Newtown. Rome Beauty. 

 Winesap. Esopus Spitzenberg, and Grimes. 



Apples of different varieties should not be run through the dehy- 

 dration plant together, since they may differ in size and shape and 

 in the amount of sulfuring necessary to prevent discoloration. Fruit 

 should be stored carefully and not be held too long before it is dried. 



Apples are prepared for drying by being washed, graded, pared, 

 cored, cut, and sulfured. The finishing temperature should not ex- 

 ceed 160° F. 



To reconstitute, follow tlw? general directions given for fruits on 

 page 21. 



