FREEZING INJURY OF FRUITS AND VEGETABLES 3 



falls below their freezing points; sometimes they are loaded into 

 cars or truck without adequate protection from low outside tem- 

 peratures during the loading process ; in still other instances they 

 are transported in cars where heater service is not furnished at the 

 proper time or in the necessary amount; or they are hauled to 

 market in trucks with little or no protection except that furnished 

 by the containers. In all such instances the use of foresight and 

 care will do much to prevent damage from freezing. In cold 

 weather the transportation of fruits and vegetables by truck can 

 be made safer by placing straw, hay, or paper around the inside of 

 the truck body and tarpaulins over the top of the load. Under ex- 

 treme conditions it may be advisable not to attempt long-distance 

 transportation of these commodities by truck. 



If a carload of produce showing signs of freezing arrives on the 

 market there are several possible ways in which it may be handled, 

 although the receiver may not always be free to choose the one he 

 will use. In many instances he can do nothing but unload the car 

 and put the produce into trade channels. On the other hand, he 

 may be able to leave it in the car to thaw out either because of mod- 

 erate outside temperatures in the local area or by the use of heaters 

 placed in the car. As a third choice, he may unload the produce 

 and take it to a pier, warehouse, or store and leave it to thaw 

 slowly. 



A temperature of about 40° F. has been found most satisfactory 

 for the thawing of apples, onions, and potatoes, and probably it 

 would be desirable for other fruits and vegetables. Too high tem- 

 perature — 60° to 70°, for example — will favor decay and may 

 bring about yellowing or withering of vegetables and too rapid 

 ripening of fruits if the produce is left at such temperatures for 

 several days. If packages have to be handled in order to put them 

 in a place where the produce will thaw, they should be stacked in 

 such a way as to permit free circulation of air around them. In 

 the experimental work discussed on pages 5 to 25 and partially 

 summarized in table 1, thawing temperatures of 45° and 60° 

 were frequently used in order to determine within a relatively 

 short time how much and what kind of deterioration occurs in 

 products that have frozen. There is no intent to imply that the 

 thawing temperatures shown in column 9 of table 1 are the 

 optimum for the different commodities. 



Whatever method is used in caring for a shipment, it should 

 always be remembered that produce should not be handled while 

 frozen if such handling can possibly be avoided ; the reason for this 

 is that when fruits or vegetables are in a frozen condition the ef- 

 fect of even slight bruising extends deep into the flesh and much 

 more damage results than from similar bruising of unfrozen prod- 

 ucts. Leafy vegetables when frozen are easily broken and mashed 

 by being handled. 



If fruits or vegetables have to be hauled to a pier, warehouse, or 

 store in freezing weather, they should be protected by means of 

 paper, hay, or straw around the inside of the truck body and tar- 

 paulins over the top. Individual packages in small lots, if hauled 

 to stores in unheated trucks in freezing weather, can be protected 

 by wrapping them in heavy paper. 



