Aquatic products-- chilled processing technology for fishing tuna

Tuna is a highly swimming marine fish with delicious meat and high nutritional value, so it is deeply loved by consumers, so it has become one of the key fishing targets in various fishing countries.

I. handling on deck

1. Avoid blood stasis of the fish: after the fish is on deck, do not let it jump, so as not to cause blood stasis in the body. After congestion, it can cause muscle damage of 5 times the area, especially in the abdomen. The way to deal with it is to put it on the carpet, hold the fisheye with both hands, or hit the fish on the head with a hammer, but be careful not to break it, and then bleed.

2. Tail cutting: usually cut between the penultimate section 3 and 6 with a sharp knife. For larger fish, the tail should be cut between the penultimate 4 and 5 in order to prevent the tail from being too thin.

3. Cut off blood vessels: there are usually two arteries and veins at the back of the pectoral fin of tuna, which are cut off separately. The cut edge is 5 cm deep and 4 cm long, and the cutting degree should be appropriate. If the knife edge is cut too deep, the blood will invade the internal flesh and cause waste. The above overshoot must be carried out even if the fish has died in the water.

4. Cut off the cephalic artery in front of the heart: cut off the cephalic artery in front of the heart, rinse the fish with sea water to prevent the temperature of the fish from rising, and then drain blood. Cut a hole in the intima of the Gill to drain blood, and pour sea water into it with a water pipe until there is almost no blood. Whether the blood is drained is based on the tail.

5. The pin insertion at the back of the head: the pin insertion is carried out after the end of the snow drainage treatment. The purpose of this operation is to destroy the cartilage of the fish's brain and put the fish in a dead state. The pin is inserted at the inside point or depression of the head or at the top of the head above the fisheye.

6. Remove the viscera and gills: cut open the abdomen from the anus to the chest with a sharp knife, take the excellent internal organs and rinse them with sea water. Pay attention to the removal of a layer of film affixed to the inner wall of the abdominal cavity and rinse the abdominal cavity with sea water. To cut the Gill is to cut the periosteum of the fish Gill along the edge of the fish Gill and remove part of the Gill. When removing the gills, the piece cut in the posterior part of the Gill should be as large as possible, and it is best to push the knife along the inside of the Gill until it touches the bone, and then cut off the Gill directly from the upper part of the Gill to make the product feel good. After removing the gills, use a spoon to chop off the miscellaneous meat attached to the bones inside the gills, but can not break the meat inside the gills.

7. Washing: when brushing the fish body, you must scrub the fish from the tail to the head, then take a sea water bath, and then make ice clothes from the preparation room to the freezing room to keep cold, so that the commercial fish can meet the requirements of high quality and high price.

2. Chilled process

1. Bilge and bulkhead handling: bilge and bulkheads should be covered with 30cm ice, fish should be released 30cm away from the bulkhead, and ice should be used to fill the gap.

2. Stuff the ice from the fish's mouth into the abdomen and fill it with ice.

3. Placement: the fish should be placed flat, 30 cm apart and filled with ice in the middle. Each layer of fish should also keep 30 centimeters of ice, the fish between the layers should be staggered to form a triangle, and head and tail upside down, after the placement, sealed with ice, covered with ice quilt, so that the ice fish process ends.

4. Knock the ice and cover it twice: generally, before the ice fish on the next day, the ice cover of the ice fish the day before should be broken again, covered with a layer of ice, and then ice the fish.

5. The temperature of the chilled fish tank should be controlled between 0 ℃ and 2 ℃, the highest being no more than 5 ℃.

6. The shelf life of chilled food is 12 days, 14 days is the right of permission, and it will deteriorate gradually after 14 days.