20 MISC. PUBLICATION) 524, U. S. DEPT. OF AGRICULTURE 



food. Cooking also results in vitamin losses; and even storage of 

 fresh products, especially over long periods or under unsuitable con- 

 ditions, may reduce vitamin C content in particular. Vitamin C, 

 or ascorbic acid, is the hardest to retain. It is easily lost on con- 

 tact with the air, and it dissolves in water. It is more readily retained 

 in an acid than in an alkaline medium ; dried tomato flakes and 

 spray-dried citus juices retain satisfactory amounts. 



On the basis of experience so far, it may be said that it is of pri- 

 mary importance that containers for dehydrated foods should be 

 airtight and keep the foods dry. Use of an inert gas in the con- 

 tainer is important in controlling loss of carotene and vitamin C. 

 Low-temperature storage slows down changes that result in vitamin 

 losses. An adequate blanch is necessary to reduce subsequent losses 

 of carotene and vitamin C in stored dehydrated products. 



RECONSTITUTION AND COOKING 



Replacing water in a dehydrated vegetable or fruit is known as 

 reconstituting, rehydrating, or, sometimes, refreshing it. A properly 

 dried product, when placed in water, soaks it up and returns to 

 approximately its original form and texture. 



The success of the rehydration process depends on many factors, 

 including the quality of the material, the amount of liquid added, 

 the composition of the liquid, and the length of time the food is 

 soaked or boiled in it. 



The Bureau of Human Nutrition and Home Economics has car- 

 ried on experiments in cooking dehydrated foods and has also con- 

 ducted research on methods of drying foods in home driers. 4 Reconsti- 

 tuting and cooking methods for dehydrated vegetables have also been 

 thoroughly tested at the Western Regional Research Laboratory. 



General principles to keep in mind in cooking dehydrated vegetables 

 are: (1) Soak them only until they are plump, or cook them without 

 soaking; (2) cook them in the same water in which they are soaked; 

 (3) simmer rather than boil; (4) cook only until tender; and (5) 

 use any left-over cooking water. Cooked dehydrated vegetables are 

 seasoned and served exactly like cooked fresh vegetables. Salt may 

 be added during soaking, while cooking, or just before serving. 



Some dehydrated vegetables are improved by being soaked before 

 being cooked. Length of soaking time depends largely on the kind of 

 vegetable and the size of the pieces. Whole snap beans may need to 

 be soaked for 6 hours, while the same beans cut or sliced need soak 

 only 2 hours. Some young, thin-podded beans which have been 

 thoroughly cooked before drying need not be soaked at all. 



Other dehydrated vegetables require no soaking before being 

 cooked. Leafy vegetables, such as spinach, kale, beet greens, and 

 turnip greens, may be dropped directly into a pan of boiling salted 

 water and cooked with the cover on until tender. Almost any 

 shredded, finely cut, or powdered vegetable can be cooked without 

 preliminary soaking. 



The soaking Avater may be hot or cold and should cover the dried 

 material. Any floating pieces should be pushed down into the water. 



1 For instructions on home drying see Farmers' Bulletin 1918, Drying Foods for Victory 

 Meals. 



