150 BACTERIA, YEASTS, AND MOLDS 



food, particularly fruits, are ruined by freezing. In these 

 cases the temperature may approach freezing but must 

 never quite reach it. Such food will be preserved for a 

 while, perhaps for months if the temperature is low, but 

 not indefinitely. 



The cold-storage plant cannot be utilized by the house- 

 wife, and need not therefore be further considered here. 

 She should always remember, however, that during the 

 winter and spring a considerable part of the perishable 

 food products purchased in markets has come from cold- 

 storage plants, where they have been retained for a long 

 period at a temperature in the vicinity of freezing, or even 

 below it. If she buys fish, fowl, or fruit during the win- 

 ter, in a city market, she may regard it as probable that 

 they have come from cold storage. This is a matter of 

 considerable importance because of the practical question 

 of the keeping property of such material. 



The question has frequently been raised whether foods 

 from cold storage is not subject to exceptionally rapid 

 decay after being brought again to a warm temperature. 

 It is a general belief that meats and other materials that 

 have been frozen decay very rapidly after they are thawed 

 out, and hence that food taken from cold storage must 

 be used quickly, since it will putrefy more rapidly than 

 when fresh. This belief seems to be well founded, but 

 the reason for it is not clear. Possibly the food is slightly 

 changed in its physical nature by the freezing so that 

 bacteria can more readily act upon it when it is thawed. 

 In many cases, however, especially with fruits, which are 

 not actually frozen, the rapid decay which follows re- 

 moval from cold storage is due to the large amount of 



