9420.pdf

4.4.3 Thawing and Roe Popping
Herring may be thawed in water or in air. Air thawing is substantially more Iabour intensive
than water thawing and requires placing the frozen herring on racks for thawing. Air
thawing also generates wastewater, as the thawed herring are generally stored in water
until roe popping takes place.
When the thawing process is complete, the fish are separated from the tote water using
tote dumpers. Conveyors then transport the fish to popping stations for roe removal. At
manual popping stations the fish are broken open, and the roe removed and collected.
The fish carcasses are collected separately.
Automatic roe popping machines which only require the fish to be manually placed on an
infeed belt are also available. These machines also separate the roe from the milt of the
male herring, although this separation is not without errors, and further manual separation
of milt from roe and vice versa is required. The milt is collected with the carcasses and
generally is directly transported to offal hoppers.
The roe from manual and/or automatic popping is rinsed with water, and washed and
cured in diluted brine, followed by the curing of the roe in concentrated brine for four to
seven days.
After curing, the roe is manually graded, packed in pails to which concentrated brine and
salt is added, and shipped.
Carcasses, milt and other offal may be used for pet food production, or production of fish
meal and oil.
4.5 Shellfish Processing
4.5.1 Shrimp Processing
The simplest of the shrimp processing operations is that of the packing plant which
receives the shrimp either whole or deheaded, deheads them if necessary, weighs the
catch and packs it in ice for shipment to another processor for breading, freezing or
canning.
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