2 BULLETIN 729, U. S. DEPARTMENT OF AGRICULTURE. 



GENERAL CONSIDERATIONS. 



The function of the storage warehouse is to preserve the product, 

 so as to extend its season of distribution to the consumer. This is 

 accomplished by providing certain conditions of temperature, moisture 

 and ventilation which arrest the deteriorating processes and retard 

 the development of decay-producing organisms. The warehouseman 

 is responsible for the quick cooling of the product after it is placed 

 in storage as well as for the maintenance of proper temperature and 

 humidity conditions. Too much emphasis cannot be given to the 

 matter of holding even temperatures in storage rooms. Fluctuations 

 in the temperature shorten the storage life of fruits and vegetables, 

 and cause deterioration of such products as fish and poultry. As a 

 guide in maintaining uniform temperatures an accurate thermograph 

 record should be kept. The thermograph, or recording thermometer, 

 should be corrected when necessary with an accurate mercury ther- 

 mometer. 



The relative humidity of the air in storage rooms has an important 

 relation to the keeping quality of the product. When the humidity 

 or moisture content of the air is too low there is deterioration through 

 the increased loss of moisture" by the product, causing shrinkage or 

 wilting; when it is too high moisture may be deposited on the product, 

 making conditions favorable for the growth of molds and bacteria. 

 Most of the common fruits and vegetables require a high humidity 

 and low temperature in storage, although a drier atmosphere is desir- 

 able for certain products, as in the case of sweet potatoes and onions. 

 Tn common storage houses, special methods for producing and main- 

 taining a high relative humidity are necessary. 



The period during which perishable products will keep in good con- 

 dition usually depends as much on the treatment they receive before 

 being placed in storage as on the conditions under which they are held 

 in storage. In many cases the responsibility rests as much with the 

 producer or handling organization as with the storage warehouseman. 

 Varieties, stage of maturity and soundness are among the considera- 

 tions which are discussed more fully elsewhere. Containers used in 

 storing food products should be clean and strongly made. In storing 

 they should be so arranged as to permit of free and unobstructed air 

 circulation through and around all containers. 



It is often difficult to determine the probable storage life or possible 

 storage period of a perishable food product. The best methods for 

 handling and the most suitable storage conditions vary with the dif- 

 ferent products. The storage life of the product is governed primarily 

 by the extent to which carefully established methods of handling 

 and storage have been followed. Frequent and thorough inspection 



