36 CIRCULAR 619, U. S. DEPARTMENT OF AGRICULTURE 



cleaning, and grading by machinery, they are water-blanched, the 

 processing being stopped before it splits the skins. They are then 

 trayed for drying. 



POTATOES 



It is not profitable to use any grades of potatoes lower than No. 

 2, because of the great waste and extra labor in preparation. After 

 being roughly graded for size, the potatoes are peeled and washed 

 in a rotary abrasive peeler. As they darken rapidly in the air after 

 the skins are removed, potatoes are handled rapidly and kept covered 

 with cold running water between the steps of preparation. They 

 must be hand trimmed before being fed through the cutting machine. 

 On leaving the cutters, the pieces are covered with loose starch 

 grains, which, if allowed to remain, will ruin the appearance of the 

 product during drying and storage. The starch is most effectively re- 

 moved immediately after cutting and traying by passing the loaded 

 trays on a conveyor belt through a hood, in which they are copiously 

 sprayed on both upper and lower sides by jets of cold water. This 

 should be immediately followed by steam processing, which should 

 be stopped when the pieces have been heated through to the centers 

 but before they become mealy. 



PUMPKIN AND SQUASH 



Pumpkin and squash receive identical treatment. The firmer- 

 fleshed, deep-colored varieties give a larger yield, with a more attrac- 

 tive color and fuller flavor. The necessity and difficulty of removing 

 the skin makes it impracticable to dehydrate such varieties as the 

 Hubbard. The gourds are stemmed, washed well, to remove ad- 

 hering dirt, and cut into large pieces by hand. The seeds, which 

 contain oils that may become rancid during storage of the dehy- 

 drated product, must then be completely removed. The pith should 

 also be discarded. For general purposes, pumpkins are best cubed, 

 although, if they are ultimately to be ground to flour, they may be 

 sliced or shredded. To make the most attractive cubed product, 

 the skin should first be completely removed. This, of course, is 

 unnecessary if the end product is to be flour. The steam processing- 

 should heat to the center and slightly soften the pieces; but, if contin- 

 ued too long, it will make the product undesirably sticky. Flour is 

 made by grinding the dehydrated product. 



SPINACH 



Very young spinach does not dehydrate as well as that which is 

 fairly well grown, but it should be harvested while still tender and 

 crisp, not fibrous. The roots and coarse stems are cut from the leaves, 

 and the inferior leaves are sorted out. Spinach requires thorough 

 washing to free it entirely from dirt. The steam processing following 

 traying should be stopped before the leaves begin to soften, collapse, 

 and mat on the trays. High-temperature drying (200° F.) will shorten 

 the drying time and retain Vitamin C to a greater degree than where 

 low temperature (140° F.) and longer drying times are used. 



