PRECOOLING 



31 



packed, shipped and refrigerated governs the distance the 

 product may be safely transported as well as the length of 

 time it may be held in market awaiting disposal and con- 

 sumption. This principle is referred to here because it has 

 a most important bearing upon the utilization of improved 

 refrigeration facilities. 



In the study of refrigeration facilities it was found that, 

 under ordinary shipping conditions in present-day refrigera- 

 tor cars, a considerable length of time elapses between the 

 picking and packing of a fruit product and the reduction of 

 the initial temperature to the point when deterioration and 

 decay will be arrested. This time varies from one to five or 

 six days, depending upon the fruit product and the outdoor 

 temperatures during transit. 



When it is considered that the development of ripening and 

 the progress of the physiological processes of deterioration 

 of fruits or vegetables are hastened as soon as the product 

 is harvested, the important influence of the character of 

 handling, packing, temperature or any other agency which 

 tends either to retard or increase the rapidity with which 

 these develop, readily becomes apparent. 



Temperature and Keeping. 



The temperature of the product after harvesting has been 

 found to be one of the most important factors affecting the 

 life activities of fruits, and the length of time the product 

 remains at a comparatively high temperature governs the 

 length of time the product may be held in consumable con- 

 dition. Consequently, the promptness and rapidity with 

 which the initial temperature can be lowered to the point 

 where the life activities will proceed at a minimum rate are 

 most important. In some of the Bureau work a difference 

 of a few days in the reduction of the initial temperature has 

 been found to make a difference of from two to four weeks 

 in the length of time the fruit may be held in good condition. 

 The injurious effect of delay in cooling is most serious for 

 the soft fruits, such as the berries, peaches and grapes. The 

 ideal condition, therefore, is to reduce the temperature as 

 soon as possible after the product has been harvested. So 



