CONSERVATION AND PREPARATION OF FEEDING STUFFS 17 



winter storage season amounts to 10 per cent of the dry matter (prin- 

 cipally digestible carbohydrates). 



Germination or sprouting entail considerably greater losses. Accord- 

 ing to Kramer the loss in sprouting potatoes with sprouts 1 to 2 cm long 

 amounts to 3 per cent of the starch; 2 to 3 cm., 5 per cent; 3 to 4 cm., 

 10 per cent. 



Prevention of loss. — To avoid deterioration and consequent deprecia- 

 tion in value, root crops and tubers should be stored in a cool place. In 

 this respect the external temperature is of minor importance, because root 

 crops are usually harvested in the cooler season of the year (this applies 

 more particularly to the climate of Northern Europe than to that of the 

 Northern and Middle United States). It is much more important to con- 

 sider the heat generated by the processes of respiration and of decomposi- 

 tion and decay. Since moisture favors the latter, as well as freezing, root 

 crops should be buried, or stored in cellars, in as dry condition and sound 

 as possible. 



On the other hand, these living feeding stuffs must be protected from 

 the action of frost. Freezing temperatures destroy the life of these plants, 

 cause them to rot after thawing, and by contact with healthy plants the 

 infection is spread. 



Potatoes freeze at a temperature of approximately 26° F., beets at about 

 30° F. 



Before all vitality is destroyed in potatoes by freezing, they "turn 

 sweet," which is caused by the conversion of starch into sugar. The sweet 

 taste can be detected when the amount of sugar reaches 0.8 per cent. 

 When the amount of sugar reaches 2 per cent the potatoes are no longer 

 considered fit for food. Sugar formation begins at a temperature of about 

 43° F., doubles in rapidity at 37° F., and at 32° F. is six times as inten- 

 sive as at 43° F. (Appel). 



At 32° F., 0.8 per cent of sugar is formed in 3 weeks, 2 per cent in 4 

 weeks and 3 per cent in 8 weeks (Mueller-Thurgau). 



The "sweetening of potatoes" is due to the conversion of the starch 

 into sugar by the continued action of the ferments (enzymes) and pre- 

 vention of the further decomposition or splitting up of the sugar by the 

 reduced or inhibited respiration due to low temperature. As the tempera- 

 ture rises (50° F.) respiration is resumed or increased and the excess of 

 sugar disappears (in the course of 8 to 11 days at 68° F.). 



Food potatoes and potatoes intended for the manufacture of starch 

 should never be exposed (except very temporarily) to temperatures be- 

 low 40° F. 



A portion of all root crops is spoiled by disease (Phytophthora) during 

 storage, and by decomposition, which also affects their food value and 

 wholesomeness. Losses due to these causes under reasonably favorable 

 conditions amount to 8 per cent in the course of four or five months. 

 When storing potatoes in the ground (pits) care should be observed in 



