VJhile common carriers of the "exempt" type may account for 

 most of the truck shipments, some of the larger processors in the in- 

 dustry own and operate their own refrigerated trucks which are used for 

 transporting shrimp from primary markets to consuming centers. In re- 

 distribution in consuming areas trucks, many of them privately owned, 

 are also predominantly used. 



In the movement of canned shrimp in over-the-road service the 

 railroads are a more important factor. The rate schedules for shipments 

 of canned shrimp to consuming centers have tended to favor rail transport. 



Transportation costs constitute a smaller percentage of the re- 

 tail price of canned than of frozen shrimp. Refrigeration equipment and 

 care in handling are factors which make the transportation of frozen shrimp 

 more costly. Greater risks are involved in moving the frozen product. 

 Spoilage losses and loss and damage claims against the carriers have a 

 bearing on rate schedules. Since canned shrimp usually are more valuable 

 pound per pound than frozen shrimp, transportation costs represent a 

 smaller share of retail price. 



QUALITY PRESERVATION AND CONrROL 



The technical problems of quality preservation and control are 

 directly related to processing and marketing functions. Because of the 

 perishable nature of shrimp, quality preservation is of utmost importance 

 from the time the shrinrp are caught to the moment they are consumed. 



Causes of Quality Deterioration 



The principal causes of shrimp spoilage are bacterial action 

 and autolysis. Autolysis or self -digestion is caused hy enzymatic action 

 after death. . VJhen an animal is alive enzymes are prevented from attacking 

 living cells but when death occurs the protective system is broken down 

 and the enzymes start their action on the flesh. 



Bacterial action appears to be much more important than autolysis 

 in the spoilage of fishery products. The heaviest concentrations of 

 bacteria are in the slime and the entrails of the shrimp. Spoilage micro- 

 organisms are chiefly bacteria, yeasts, and molds. The micro-organisms 

 found on shrimp are those commonly found in the waters and mud in which the 

 shrimp live. 



Methods of Debectiag Spoilage 



Deterioration of quality is detected by a study of the physical 

 characteristics of the shrimp which are altered by decomposition. To 

 determine spoilage two methods of examination are available. The shrimp 

 may be examined subjectively by taste, smell, sight or touch and objectively 

 by chemical analysis, 



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