75
self-collapse of one or more limbs of animals. Generally, it is a self-defence mechanism applied to get rid of the hunter (Sherwin 2001; Gardner 2004). In a study, crabs
were placed in boilers with cold water and heated slowly to 40 °C. As a result of the
study, it was observed that the animals died silently without pain and nauseous
symptoms (Gunter 1961).
Picking
The removal of crab meat is called picking. Crab meat can be removed manually or
mechanically. It requires a serious experience in manual removal. Otherwise, the
losses will be higher, and the efficiency will decrease. The yield of crabs removed
by hand varies from Jumbo lump to small bits leg meat. First, the hinges are
removed, and then back, gills and aprons are removed. This allows easy access to
the carapace that can be taken with picks. To remove the claw’s flesh, the shell is
first broken with a wooden mallet. Roller is used to remove the remaining meat from
the leg. An experienced person should be able to extract a crab every 30 s. In a good
meat removal process, meat yield of Dungeness or blue crab can reach up to 25%.
However, generally 10–20% yield can be obtained. This means about 80–85%
waste (Galetti 2010).
Meats that cannot be completely removed by hand and remain as waste, particularly leg meats, may be removed with the help of compressed air jets. First, the body
is pulled, and the brown meat is scraped off with a spoon. The claws are broken into
segments and each segment is broken by a heavy rod. The white meat is collected
with a short knife or a specially designed tool (Edwards and Early 1978).
Crabs are usually sold live. But it is also available in fresh, cooked, pasteurized,
and frozen forms. Crabs are also canned.
Crabs should be kept alive at the beginning of the processing and must be killed
before boiling. Crabs are killed either by drowning in fresh water or by inserting a
sharp object into the centre of the brain. Crabs are kept in fresh water at 10 °C for
3–4 h. Small crabs are usually killed by this method. Crabs should be cooked immediately after killing. It should be boiled for 20–30 min in the water added with 2–3%
salt. Boiling time may vary depending on the size of the crab. The cooking process
will kill the existing bacteria and destroy the organisms that cause the disease
(Edwards and Early 1978).
Prior to some operations, crabs are pre-cooked. In commercial crab cooking, two
different cooking processes are applied, namely pressure steam and boiling water.
In the pressurized steam cooking process, the cooking temperature is 121 °C and the
duration is 3–20 min, while the temperature in cooking in boiling water is 100 °C
and the time is 15–20 min (Thomas and Thomas 1983). Whilst the boiling process
is preferred by the producers because of the higher crab yield, it is preferred by the
consumers because the crab cooked with steam is tastier (Moody 1974).
2.2 Crabs
self-collapse of one or more limbs of animals. Generally, it is a self-defence mechanism applied to get rid of the hunter (Sherwin 2001; Gardner 2004). In a study, crabs
were placed in boilers with cold water and heated slowly to 40 °C. As a result of the
study, it was observed that the animals died silently without pain and nauseous
symptoms (Gunter 1961).
Picking
The removal of crab meat is called picking. Crab meat can be removed manually or
mechanically. It requires a serious experience in manual removal. Otherwise, the
losses will be higher, and the efficiency will decrease. The yield of crabs removed
by hand varies from Jumbo lump to small bits leg meat. First, the hinges are
removed, and then back, gills and aprons are removed. This allows easy access to
the carapace that can be taken with picks. To remove the claw’s flesh, the shell is
first broken with a wooden mallet. Roller is used to remove the remaining meat from
the leg. An experienced person should be able to extract a crab every 30 s. In a good
meat removal process, meat yield of Dungeness or blue crab can reach up to 25%.
However, generally 10–20% yield can be obtained. This means about 80–85%
waste (Galetti 2010).
Meats that cannot be completely removed by hand and remain as waste, particularly leg meats, may be removed with the help of compressed air jets. First, the body
is pulled, and the brown meat is scraped off with a spoon. The claws are broken into
segments and each segment is broken by a heavy rod. The white meat is collected
with a short knife or a specially designed tool (Edwards and Early 1978).
Crabs are usually sold live. But it is also available in fresh, cooked, pasteurized,
and frozen forms. Crabs are also canned.
Crabs should be kept alive at the beginning of the processing and must be killed
before boiling. Crabs are killed either by drowning in fresh water or by inserting a
sharp object into the centre of the brain. Crabs are kept in fresh water at 10 °C for
3–4 h. Small crabs are usually killed by this method. Crabs should be cooked immediately after killing. It should be boiled for 20–30 min in the water added with 2–3%
salt. Boiling time may vary depending on the size of the crab. The cooking process
will kill the existing bacteria and destroy the organisms that cause the disease
(Edwards and Early 1978).
Prior to some operations, crabs are pre-cooked. In commercial crab cooking, two
different cooking processes are applied, namely pressure steam and boiling water.
In the pressurized steam cooking process, the cooking temperature is 121 °C and the
duration is 3–20 min, while the temperature in cooking in boiling water is 100 °C
and the time is 15–20 min (Thomas and Thomas 1983). Whilst the boiling process
is preferred by the producers because of the higher crab yield, it is preferred by the
consumers because the crab cooked with steam is tastier (Moody 1974).
2.2 Crabs