189
to mention freshness in case bivalves. If the bivalve is alive, it means a good price
for the farmer. However, scallops are susceptible to stress if they live outside their
habitat. Aerobic conditions and temperature changes have a significant effect on
this. This leads to loss of quality. The scallops are more vulnerable to dry as they do
not close the valves when they are out of the water. In addition, the growth of microorganisms and the accumulation of waste products cause deterioration of physical
conditions and thus the death of the scallop. Therefore, the time and temperature for
transport and storage must be well regulated (Lopes Da Costa 2018).
There are three methods of transporting scallops: dry, water and packaging.
Temperature, moisture, oxygen, and pressure are effective factors for dry transport
of scallops. Maintaining the scallops at low temperature generates low metabolism.
When scallops are held at lower metabolic states, they require less oxygen. Adding
moisture prevents the scallops from dehydrating and keeps the gills moist so that
gas exchange can continue to take place. A high oxygen level in the transport box
creates a higher oxygen gradient in the air surrounding the gills and facilitates the
transport of oxygen into the scallops. Careful placement of scallops in the shipping
container places a moderate amount of pressure on the shells, which keeps them
closed to help avoid excessive dehydration. Oxygen, water temperature, carbon
dioxide, ammonia, water flow and induction of spawning are effective factors in
transporting scallops in water (Overaa 2001).
Juvenile and adult scallops are suitable for extended live shipment in insulated
containers without the addition of seawater. Survival and quality are maintained if
metabolic rates and other processes are depressed by cool, humid conditions. High
humidity from seawater-moistened packing materials and the application of gentle
mechanical pressure on the scallops will prevent desiccation of delicate mantle and
gill tissues and lessen incidence of valve flapping that can cause damage to mantle
tissue. Effective transport methods for scallops will take advantage of these factors
(Heath 2001).
The packing methods are primarily based on the harvester’s experiences. The
most common method is packing the scallops in layers in styrofoam boxes with
moist paper or wood fibres under and on top of the product. Some exporters use
freshwater ice on top of the product to keep the temperature low. Use of freshwater
ice is not proper for scallop. Because, the melting water leaks into the scallop, thus
causes osmotic abnormalities and death (Overaa 2001). Styrene or styrofoam boxes
with cardboard sleeves or outer boxes, with frozen gel packs for cooling are also
common. However, other well-insulated containers will serve well, but are generally more expensive. The frozen gel packs are placed at the bottom of the container
and insulated from the scallops with a layer of packing dampened with seawater.
The scallops are positioned over the covered gel packs and are covered with another
layer of damp packing material. The lid is placed on the container and taped securely
shut. It is important to put some mechanical pressure on the scallops to prevent gaping and dehydration. If Styrofoam is used, the box is then placed in its cardboard
housing (Heath 2001).
In general, chilling or refrigeration is effective for keep freshness and avoid the
mortality of live scallop. It is reported that scallops react to stress factors differently
3.1 Bivalves
to mention freshness in case bivalves. If the bivalve is alive, it means a good price
for the farmer. However, scallops are susceptible to stress if they live outside their
habitat. Aerobic conditions and temperature changes have a significant effect on
this. This leads to loss of quality. The scallops are more vulnerable to dry as they do
not close the valves when they are out of the water. In addition, the growth of microorganisms and the accumulation of waste products cause deterioration of physical
conditions and thus the death of the scallop. Therefore, the time and temperature for
transport and storage must be well regulated (Lopes Da Costa 2018).
There are three methods of transporting scallops: dry, water and packaging.
Temperature, moisture, oxygen, and pressure are effective factors for dry transport
of scallops. Maintaining the scallops at low temperature generates low metabolism.
When scallops are held at lower metabolic states, they require less oxygen. Adding
moisture prevents the scallops from dehydrating and keeps the gills moist so that
gas exchange can continue to take place. A high oxygen level in the transport box
creates a higher oxygen gradient in the air surrounding the gills and facilitates the
transport of oxygen into the scallops. Careful placement of scallops in the shipping
container places a moderate amount of pressure on the shells, which keeps them
closed to help avoid excessive dehydration. Oxygen, water temperature, carbon
dioxide, ammonia, water flow and induction of spawning are effective factors in
transporting scallops in water (Overaa 2001).
Juvenile and adult scallops are suitable for extended live shipment in insulated
containers without the addition of seawater. Survival and quality are maintained if
metabolic rates and other processes are depressed by cool, humid conditions. High
humidity from seawater-moistened packing materials and the application of gentle
mechanical pressure on the scallops will prevent desiccation of delicate mantle and
gill tissues and lessen incidence of valve flapping that can cause damage to mantle
tissue. Effective transport methods for scallops will take advantage of these factors
(Heath 2001).
The packing methods are primarily based on the harvester’s experiences. The
most common method is packing the scallops in layers in styrofoam boxes with
moist paper or wood fibres under and on top of the product. Some exporters use
freshwater ice on top of the product to keep the temperature low. Use of freshwater
ice is not proper for scallop. Because, the melting water leaks into the scallop, thus
causes osmotic abnormalities and death (Overaa 2001). Styrene or styrofoam boxes
with cardboard sleeves or outer boxes, with frozen gel packs for cooling are also
common. However, other well-insulated containers will serve well, but are generally more expensive. The frozen gel packs are placed at the bottom of the container
and insulated from the scallops with a layer of packing dampened with seawater.
The scallops are positioned over the covered gel packs and are covered with another
layer of damp packing material. The lid is placed on the container and taped securely
shut. It is important to put some mechanical pressure on the scallops to prevent gaping and dehydration. If Styrofoam is used, the box is then placed in its cardboard
housing (Heath 2001).
In general, chilling or refrigeration is effective for keep freshness and avoid the
mortality of live scallop. It is reported that scallops react to stress factors differently
3.1 Bivalves