IKE-Jimi-Japanese traditional technique of killing fish. In General, it is the most common in the world, although in Australia and New Zealand began to use anesthesia, which is even more advanced. There are two reasons why we should care about how fish died: the right technique ensures good quality of meat and, moreover, it is the most humane. Three years ago I published a series of articles on this topic. Since that time, I had the opportunity to compare different techniques, tastes and, equally important, to visit the market in Tokyo to see professionals at work.

The less stress the fish will experience before and during the murder, the better the quality of the meat. For a visual representation-see the Attached photo showing tissue destruction during stress.

Stolen without permission D. Bahuaud, T. Mørkøre, T.-K. Østbye, E. Veiseth-Kent, M. S. Thomassen, R. Ofstad. Muscle structure responses and lysosomal cathepsins B and L in farmed Atlantic salmon (Salmo salar L.) pre - and post-rigor fillets themselves exposed to short and long-term crowding stress, Food Chemistry, Volume 118, Issue 3, 1 February 2010 (see references)

In comparison with red meat and poultry, the fish is more tender. And it is important to preserve its structure. So unlike meat, where protein breakdown is good for us, making it softer, anything that destroys the structure of the fish is not good for her. Stress is one of the reasons.

Stress before or during slaughter, from tightness in the nets or from open air, as well as long-term stress from the content in the wrong aquatic system entails actual wear of tissues. As a result of the collapse of glucose in the muscles formed lactic acid(and decreases the level of acidity). This in turn leads to an increase in the number of muscle enzymes that destroy proteins. One study even claims that stress increases the amount of these enzymes, making them more effective. Also, stress leads to the appearance in the blood of a greater number of "stress compounds", which also lead to the destruction of muscle structure.

In addition, in the tissues of the tired fish contains smaller amounts of ATP (adenosinetriphosphate). It is a universal source of energy for all biochemical processes. At the time of death of the animal, its muscles remain flexible up until the get ATP(synthesized with glucose). After the supply of ATP is exhausted, the muscles tense up and do not weaken - the process of rigor Mortis. In fish, this process can reduce the muscles so much that it will cause a rupture of connective tissues. Mortis tired of fish with low levels of ATP occurs more rapidly. In the end, rigor passes when the links between muscle fibers are broken.

Even if you decapitate the fish, the muscles will still perform their functions under the influence of the autonomic nervous system, which continues to work, even if the brain is absent. The spinal cord continues to send signals to the muscles, which in turn consume ATP and in this case rigor occurs faster than if we destroyed the spinal cord. This can be done by inserting a thin wire along the top of the spine.

This is particularly important for tuna-these fish can regulate their body temperature, unlike most cold-blooded fish. Many professional fishermen say that the autonomic nervous system still regulates the temperature of the case even after death. So if you do not destroy the spinal cord, it will heat up and lose ATP - which is twice unpleasant.

The correct murder of fish begins before the immediate action.

Relaxed fish is better than not relaxed. One study shows that fish caught in the ocean, which was then placed in a tank and only then killed, was of better quality than those left in nets and died of suffocation. There is a technique even better — rested to take the fish and put her under with anesthesia. The most common is isoeugenol, part clove oil. The consumer version of this product is called Aqui-s.

For a long time, its properties have been studied around the world and used in New Zealand and Australia. At home, you can use a mixture of clove oil and liquor to lull the fish. Almost every study of the effect of anesthesia on fish showed improvement in quality and, in addition, this technique is more humane.

Once the fish is pulled out of the water, it must be killed. The traditional technique of a sharp blow to the head is not so good. First, such strikes are not always accurate, and secondly, they do not kill, but stun. Japanese technique of IKA - Jim involving the severing of the spinal cord and blood vessels between the head and the body - good for preserving lean tissue. Not so humane. This method I used for several years, but now I do not recommend. First, you can drop the fish on the floor. Second, when you cut the spine, the head is still alive. I have heard from many people that gills movement is just convulsions and nervous cramps, but I have not seen any data in support of this opinion. Instead, I tend to believe that the head continues to function even after it is cut off.

In my opinion, the best technique is to drive the needle into the brain in a soft spot above the eye. This is a fast, easily mastered technique.

Bleeding

The release of blood is important for the appearance and taste of the fish. Some studies show that compounds in the blood soften muscles (which is not good). In the Japanese technique, cutting the spinal cord and two main arteries entails bleeding. The arteries in the tail are also cut. Then the fish is placed in salted water. In large fish, such as tuna, there is no practice of tearing the spinal cord, incisions are made near the pectoral fins.

The more I think about the usual Japanese technique, the more I doubt that it is the best. They cut all the arteries and veins in front and behind, completely removing the heart from the circulatory system. Isn't just Gill bleeding enough to keep the blood from returning to the heart?

Interesting question.

The destruction of the spinal cord occurs when a needle is inserted through the spine. You do everything right if the fish starts to twitch. No? You were wrong. Insert the needle only once-do not pull it along the spinal canal to preserve ATP. When handling small fish you have two ways-front or back. In the case of decapitation (or partial decapitation), it is easier to do it from the front. For fish you can't decapitate, insert the needle from the tail side. Try not to cut off the tail or head completely (depending on the type)- they can be used as a stop.

For the killing of large fish, such as tuna, it is customary to insert a needle through the head into the spinal cord(Taniguchi Method). You make a small hole between the eyes and insert the wire into the spine. If the fisherman kills the fish using this method, he leaves the wire to show that the tuna is killed correctly. Theoretically, the brain cavity forms a funnel, which itself directs the needle in the spine. I tried this method on the head of bluefin tuna, but it was not successful. The needle went out through the muscles.

Evisceration, butchering and cooking - before and after rigor Mortis.

All research points to the importance of immediate evisceration. There's nothing good about leaving the guts out for as long as possible.

Removing fillets is a different story. If you cut the fish before rigor Mortis, the muscles will not be so damaged (due to lack of skeleton), but the fillet will be smaller and denser.

I prefer to eat fish after rigor Mortis has subsided. Before rigor Mortis, they're almost crunchy if cooked like sashimi. If you like it-the IKE-Jimi and the introduction of the needle-the optimal technique, because it increases the time during which the fish can be cooked and served until the onset of rigor Mortis.

As for me and everyone who prefers fish after rigor Mortis, this technique is not suitable, because it delays the onset of rigor Mortis. However, when it does come, meat is better than fish killed by Western technology.

Certain types of fish are good through the day, some through two and even more. For sashimi advantages of the infrared Jimmy is obvious. The more you cook the fish, the less noticeable the benefits

What does all of the above mean to you?

Just a little. Of course, unless you are a supplier or a professional fisherman. But we all need to know about good practice.