176 DESCRIPTION OF IMPORTANT FISHERIES A ND THEIR PRODUCTS 



Shrimp are received at the freezer plants in bulk or in boxes, in either 

 case mixed with crushed ice. They are dumped into a wash vat where 

 they are separated from the ice and rinsed. They are then removed from 

 the wash vat by scoop or by conveyer belt. Usually they are graded for 

 size at this point, mechanical graders separating them typically into four 

 size categories. They may be inspected while on the conveyer belt en 

 route to the grader, the inspector removing extraneous material and 

 broken or spoiled shrimp that can be detected visually. 



Graded shrimp are packed into waxed cardboard cartons, slightly more 

 than five pounds of shrimp tails to the carton. The excess weight is to 

 allow for adhering water and for shrinkage. The carton is weighed and 

 the weight adjusted if necessary. The size grade is then stamped on the 

 carton which is placed on a pallet or other device for transport to the 

 freezer. 



The usual method of freezing is by blast freezer or plate freezer. The 

 temperature is usually maintained at 10 to — 40°F, and unless the 

 freezer is overloaded or some other abnormal circumstance prevails, the 

 shrimp are frozen in about 15 hours. 



After removal from the freezer, the top of the package is raised and 

 about eight ounces of water are added to the package with a spray. The 

 lid is then closed and the package inverted. In this way a nearly solid 

 block of ice and shrimp is formed, protecting the shrimp from desiccation. 

 Ten five-pound packages are packed in a master carton and placed in 

 cold storage to await shipment. 



Frozen Peeled and Deveined Shrimp. Frozen peeled and de veined shrimp 

 were first produced in the United States in about 1947, but the quantity 

 was so small for several years that the production was not listed as a 

 separate item. The convenience of the item to the housewife created an 

 increasing market so that its production has risen at a rapid rate (Table 

 12.5). In 1960 there were 45 plants producing raw or cooked frozen, 

 peeled, and deveined shrimp. Many of these plants were those set up 

 primarily to produce frozen breaded shrimp, with the peeled and deveined 

 shrimp being a secondary item. 



About half the raw peeled and deveined shrimp is packed in seven- 

 ounce cartons and is sold to housewives. The remainder is packed in 

 packages containing two pounds or more and is purchased by restaurants 

 for shrimp cocktails or for breading. 



The raw material for the peeled and deveined shrimp is mostly fresh, 

 iced shrimp, delivered directly to processing plants on the water front. 

 Some plants, either because of the geographical location or because of 

 unavailability of fresh shrimp, use frozen headless shrimp, domestic or 

 imported. 



