VEGETABLE AND FRUIT DEHYDRATION 203 



and Katahdin is the third most important variety. The Green Moun- 

 tain group is important in Maine and the neighboring States. Pro- 

 duction of the Russet Burbank group of varieties is concentrated en- 

 tirely in the Northwest. In California, the White Rose is the leading 

 variety. Rural Russet and Rural Xew Yorker No. 2 are grown ex- 

 tensively in certain States in the region of the Great Lakes. The con- 

 ditions under which these varieties are grown affect their suitability 

 for dehydration. 



A variety of potato, to be suitable, for dehydrating, must be grown 

 in a district and under conditions to which it is suited, and where it 

 will give optimum yields. Russet Burbank when grown in Idaho, for 

 example, is excellent, but the same variety grown in Maryland, where 

 it is not adapted, makes an inferior product. Likewise, potatoes satis- 

 factor} T for dehydrating can be grown in a certain district only if 

 varieties adapted to that district are used. 



Limited tests have shown the following varieties to be among the 

 best when grown in the States indicated : 



Michigan : Rural Russet, best ; Irish Cobbler, Green Mountain, Chippewa, 

 Katahdin, and Sebago, very good. 



New York : Green Mountain and Pioneer Rural best ; Katahdin and Chippewa, 

 very good. 



Washington: Russet Burbank and Sebago, best. 



Idaho : Russet Burbank. best ; Sebago, Triumph, and Katahdin, very good. 



Colorado : Triumph and Katahdin, best. 



Maine : All the varieties named above produce excellent or very good stock 

 for dehydrating. 



Immaturity or other factors that result in high water content defi- 

 nitely impair quality for dehydration. Immature "new" potatoes are 

 not suitable for this purpose. 



Only mature tubers, free from disease and bruises, should be stored. 

 A storage temperature of 40° F. is low enough to keep mature potatoes 

 dormant 3 to 5 months. At this temperature, however, they may 

 become mildly sweet. If stored at 40° or lower, the potatoes may show 

 marked }^ellowing and browning at the center of the piece after being 

 dehydrated. For short-time storage, a temperature of 50° to 60° 

 results in good texture, color, and flavor in the cooked product. 

 Potatoes stored at the lower temperatures should be held at 60° to 65° 

 for 3 to 4 weeks just prior to dehydration. Lender these conditions 

 the sweet taste will be lost and a satisfactory dried product obtained. 

 The relative humidity recommended for potato storage is 85 to 90 

 percent. 



Potatoes are commonly stored in pits or large bins of 150 to 1,000 

 bushels in the Northern States, but in milder climates they should be 

 stored in small units. Heat insulation and ample ventilation are 

 needed to provide the best conditions for storage. Potatoes should 

 alwa} T s be stored in the dark because in the light they become green 

 and unfit for food as a result of the development of solanine, a bitter 

 poisonous substance. In most districts potatoes are handled and stored 

 in bags. After delivery to the plant, measures must be taken to make 

 sure that the crop will remain in good condition until used. An even, 

 moderately cool temperature should be provided, in insulated rooms 

 if necessary. The bags should be stacked so as to provide enough 

 aeration to prevent heating. When the weather becomes cold, heat 

 should be provided to prevent freezing. Since potato handling is 



