THE SHRIMP FISHERY 181 



vats and transported by wheelbarrow to the drying platform. The plat- 

 form is raised above the ground on posts to allow free circulation of the 

 air beneath. The platform is built in undulations about three feet high, 

 with about 30 feet between the crests. The shrimp are sun-dried, and at 

 night, or when it rains, the shrimp are raked onto the crests of the undu- 

 lations and covered with a tarpaulin to protect them from moisture. The 

 shrimp are spread over the platform in layers about three inches thick 

 and are turned every two or three hours. Drying usually requires about 

 three or four days in the summer; in the winter five to ten days may be 

 required. 



The shells and heads are removed from the dried shrimp by rotating 

 them in a wire mesh cylinder. The heads and shells drop through the 

 meshes and the meats are retained in the tumbler. 



The peeled shrimp meats are packed in 100-pound bags and sold to 

 concerns which package them in smaller lots. The heads and hulls 

 (shrimp meal or bran) are also placed in 100-pound sacks and sold to 

 firms making poultry feed. 



Freeze-Drying. At least one plant on the Gulf of Mexico was freeze- 

 drying shrimp in 1961 ^ Two considerable advantages are claimed for 

 shrimp processed in this way, these being much reduced weight and good 

 keeping qualities. The weight is said to be reduced by as much as 80 

 per cent, seven pounds of green shrimp being reduced to 133^^ ounces, 

 which fit into a No. ten can. Packed and sealed cans of freeze-dried 

 shrimp require no refrigeration and are said to last indefinitely. 



This product is made from frozen, graded shrimp which are first thawed, 

 cleaned, peeled, deveined, and cooked. They are then frozen in a blast 

 freezer and placed in high-vacuum drying cabinets. The amount of heat 

 applied to the product in the vacuum cabinet is just less than the amount 

 removed by the subliming moisture. Through this exact temperature 

 control, the moisture removed from the shrimp is in the form of vapor 

 and does not pass through the liquid phase. The moisture is collected in 

 condensing traps and the shrimp remain frozen. When the shrimp are to 

 be used they are soaked in water and regain approximately their original 

 form. 



LITERATURE CITED 



1. Andersen, Kenneth A., Canner and Packer, 130, No. 5, 23(1961). 



2. Bullis, Harvey R., Gulf of Mexico Shrimp trawl designs, Fishery Leaflet 394, 



Washington, U.S. Fish & Wildlife Service, 1951. 



3. Camber, C. Isaac, Vance, Mary, H., and Alexander, James, "How to Use Sodium 



Bisulfite to Control 'Black Spot' on shrimp," Florida State Board of Conserva- 

 tion, Special Service Bulletin No. 12, The Marine Lab., Univ. of Miami, 1956. 



