The peeled shrimp then enter the deveining system (shrimp deveining machine,
Laitram, Inc., see Fig. 4.4), which may be a separate machine or part of the peeler.
The vein is the shrimp intestine that runs down the dorsal side near the surface. The
vein is usually filled with food and sand; its removal improves product quality.
Different systems are used, depending on the manufacturer, shrimp size and species.
One system washes the vein out through a cut made along the vein by a knife.
Another system removes the vein by catching it on indentations on the internal
surface of a cylinder. The cylinder revolves in water, and as the shrimp pass through
it, it removes the vein by catching it on the moving indentations on the drum.
Shrimp are further processed into a frozen (raw) or cooked and/or breaded
product before being frozen and stored.