What is Anisakis?

A photo of Anisakis
Anisakis is usually found on the surface of internal organs, but can also appear on the surface of the fish.

Anisakis is a parasite of fish and shellfish, including mackerel, horse mackerel, sardines, bonito, squid, cod, saury, flatfish, and salmon. Three groups of parasites, Anisakis simplex, Anisakis physeteris, and Pseudoterranova decipiens, are considered to cause Anisakis disease in Japan. Larvae are elongate, 2~3 cm long and 0.5~1 mm wide, and most are translucent white. The species of Anisakis parasitizing fish and shellfish vary depending on the species of fish, the sea area, and the habitat depth.

Anisakis spawns as adults in the stomachs of whales and other marine mammals. When the eggs are excreted with feces, they hatch in seawater, and the larvae are eaten by krill, where they remain as larvae in the krill-eating seafood. Food poisoning occurs when people eat fish and shellfish parasitized by these larvae.

Three to four hours after infection, symptoms such as upper abdominal pain, nausea, and vomiting appear. These symptoms are now known to be an allergic reaction to the stomach wall and the Anisakis, rather than direct pain caused by the Anisakis piercing the stomach wall.

Mackerel is the most common type of Anisakis disease case reported in sashimi and sushi. In Tokyo, more than half of these cases are caused by Shimesaba (vinegared mackerel). When serving ingredients such as sashimi, chefs need to look carefully with their eyes to see if Anisakis is present and to remove the internal organs. Anisakis may not be visible, so care should be taken. The food items should not be served as sashimi if they are visible.

Anisakis larvae are parasites primarily on the surface of internal organs. They do not move from the internal organs if the fish is cold and near iced, but they may move into the flesh as the fish loses freshness or over time. For this reason, when purchasing (catching) and bringing home, it is important to keep the fish cold with ice or refrigerant to prevent loss of freshness. However, it is important to note that some species of fish, such as Chum salmon (Sake), have Anisakis lurking in their entire body. Sushi chefs know this and do not use it in Nigiri sushi. In addition, it has been hoped that soy sauce, wasabi, and vinegar may be effective in preventing Anisakis disease. However, the insect bodies are not killed by the amount and concentration used in cooking and the time of treatment.


How to Prevent Anisakis

In 1968, the Netherlands mandated by law that herring to be eaten raw in vinegar be frozen at -20 ºC or lower for at least 24 hours before cooking, drastically reducing the number of anisakiasis cases. The U.S. FDA recommends that fish for raw consumption be frozen at -35 °C for 15 hours or at -20 °C for 7 days, while EU health management standards require visual inspection of marine fish for parasites. The EU standard requires visual inspection of marine fish for parasites and directs freezing treatment (at -20 °C or below for at least 24 hours) for marine fish intended for raw consumption. In Japan, heat treatment at 70 °C or higher or 60 °C or higher (for about 1 minute) and freezing at -20 °C or lower for 24 hours or longer are supposed to kill the parasites.


New Technology for Killing Anisakis

Japan Seafoods, a seafood processing company, and Kumamoto University’s Institute for Industrial Nanomaterials Research have jointly developed a method and device to kill Anisakis by using an instantaneous electric power like lightning to kill them in fish meat. The establishment of a new method of killing Anisakis without heating has brought the risk of food poisoning from Anisakis on non-frozen raw sashimi closer to zero. However, challenges remain, such as downsizing the equipment and reducing costs.


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Tokyo Food Safety Information Center-Anisakis

Quality Improvement of Frozen Bonito


A photo of bonito sashimi
Frozen bonito begins to mature after thawing.

Large fishing vessels sail the Pacific Ocean year-round in pursuit of bonito (Skipjack tuna). The fishing method is divided into pole-and-line fishing and purse seine fishing. Pole-and-line fishing involves spreading live bait such as Japanese anchovy to attract schools of skipjack tuna, which are then caught in large numbers with the rod in a short period. Because of the need to keep live bait for a long period, this fishing method was limited to the waters around Japan for many years. Still, recent technological advances have also made pole-and-line fishing possible in southern waters.

The bonito caught in the waters around Japan is called Higashi-no-mono. This follows sardines and other fish that serve as bait and come north from the waters around the Philippines. The bonito called Nanpo-mono also approaches the waters around Japan from off Micronesia and other areas. This one is mainly caught by large vessel purse seine fishing. In purse seine fishing, the bonito rub against each other before being hauled on board, easily damaging the flesh. As a result, the fish may be less fresh and damaged than when caught pole-and-line fishing.

Vessels that take skipjack are equipped with sophisticated refrigeration facilities. There is a pool of brine solution, a salt solution with a concentration of about 20%, on board. The flash-frozen skipjack is called B1. After being thawed and filleted, the fish is rigor mortis, which means it is extremely fresh and is distributed as high-quality frozen skipjack for raw consumption. Of course, they are also very expensive. In addition, when caught, the blood is removed and the fish is flash-frozen, called S1, and is distributed as a higher quality product than B1.

Only carefully selected skipjack and those frozen under strict freezing conditions are marketed as B1, while skipjack that is frozen in the same freezer but not according to B1 standards is distinguished from B1 and referred to as B. Incidentally, B1 and B are caught by pole-and-line fishing. There is another type of frozen bonito called PS. This is not caught by pole-and-line fishing but by purse seine fishing. It is not in as good condition as pole-and-line fishing, but it is handled with care and has few scratches.

In summary, Bonito (skipjack) originally deteriorated quickly and was difficult to distribute fresh, but improvements in freezing technology and other factors have ensured that the quality is close to fresh.

What does Hon in front of the fish name mean?

A photo of Bonito (Katsuo)

The tastiest and most highly utilized Katsuo are Ma-gatsuo and Hon-gatsuo.Anyone can tell a fish is a different species if it looks different. However, there are cases where the appearance is so similar that you can’t just inadvertently make a mistake. That is when there are several species and the difference in value is significant. In the past, the fish was used as a fish fraud, and even today it is often used as a substitute.

So, the marketer adds the prefix Hon (本) in the name of a fish or shellfish to avoid confusion with a substitute. One of the meanings of the Japanese word “hon” is “genuine,” so this may have something to do with it.

For example, Hon-zuwaigani refers to Zuwaigani, which has a shorter fishing season and a much higher price than Beni-zuwaigani. To avoid confusion with Beni-zuwaigani, which has a similar name, the Hon is added to emphasize the fact that it is Zuwaigani.


Other fish names begin with the letter Hon.

・Hon-mirugai is Mirugai clam (Mirugai). To avoid confusion with Shiro-mirugai, which was considered a substitute for Mirugai in the past, Hon is added to emphasize the fact that it is Mirugai. Recently, however, the catch of Shiro-mirugai has been decreasing, and the price of Mirugai has skyrocketed.

・There are five main types of tuna distributed in Japan, including Minamimaguro, Mebachi, Kihada, and Binnaga, of which Kuro (kuro means black)-maguro, the largest, is considered the finest. As the name suggests, half of the fish’s body is black from the back to the lateral line, so it is so-called.

About 2 million tons of tuna are caught annually worldwide, but Kuro-maguro is only about 1% of that amount. Originally, maguro meant Kuro-maguro, but other species (Mebachi, Kihada, etc.) are now distributed, and to distinguish them from Kuro-maguro, what was originally called maguro is now called Hon-maguro.

Aka-kamasu, also called Hon-kamasu, is considered the most delicious of the kamasu family and is sold at high prices in the market. On the other hand, Yamato-kamasu, also called Mizu-kamasu, is a little less tasty, and the name seems to be used to distinguish Yamato-kamasu from Aka-kamasu.

・The official name of the family Pandalidae called Amaebi is Hokkoku-akaebi. It is widely found from the coast of Hokkaido to Toyama Bay and the eastern coast of the Korean Peninsula. It is widely found from the coast of Hokkaido to Toyama Bay and the eastern coast of the Korean Peninsula.

・Akagai is simply called Tama, Hon-dama, Hon-aka, etc. in the Toyosu market. There is also a Bachi-akagai that is very similar to the Akagai, but its real name is Satogai, which is not as red as Akagai and is smaller in size. Satogai is often mixed in with hon-dama and are called Bachi-akagai from Bachigai (it means out of place).


Finally, some seafood uses both Hon and Ma.

For example, there are four species of bonito: Katsuo, Suma-gatsuo, Marusouda-gatsuo, and Hirasouda-gatsuo. The tastiest and most highly utilized Katsuo are Ma-gatsuo (katsuo) and Hon-gatsuo (katsuo).

For your reference.

What does Ma in front of the fish name mean?

A photo of Horse mackerel (Ma-aji)
Ma-aji is the most commonly caught and represented species of Japanese Aji species.

Fish names include scientific names, standard Japanese names, local names, and foreign names.

Scientific names are the scientific names of organisms. They are written in Latin for international uniformity. They are also listed in fish-illustrated books. Standard Japanese names are defined by the Ichthyological Society of Japan. Local names are various names given to one species in different regions. In addition, when looking at English and French names, they do not correspond to species as in the Japanese standard Japanese name, and it is not uncommon for different species to have the same English name, or for multiple species to be called by the same English name. It is rare in the world that each fish species has its standard Japanese name, as is the case in Japan.

In addition to standard Japanese names and regional names, fish names unique to the Japanese language are sometimes used. For example, you have probably heard of the fish named Aji (鯵). Then is Ma-aji (真鯵) a different fish?

Actually, they are the same fish. The “Ma” in the name of a fish or shellfish indicates that it is the most representative, the most superior, or the most valuable among the many related species. The Chinese character “真” means “genuine.

For example, a total of 146 species of horse mackerels have been identified, including Japanese scad (Maru-aji), Bigeye scad (Me-aji), White trevally (Shima-aji), Amberstripe scad (Muro-aji), Red Scad (Aka-aji), Roughear scad (Oakamuro-aji), Great trevally (Gingame-aji), and Torpedo scad (Oni-aji). Ma-aji is the most commonly caught and represented species of Japanese Aji species.

There are other fish names beginning with Ma, which are briefly introduced below.

Ma-iwashi (真鰯) is a representative of sardines (Katakuchi-iwashi, Urume-iwashi, etc.).

・Kaki refers to Ma-gaki (真牡蠣). Ma-gaki is in season during the cold season and is mostly farm-raised, but there is a type of Kaki that is in season during the summer. It is called Iwa-gaki (岩牡蠣) and is characterized by its larger shells and meat compared to Ma-gaki.

・Anago with high market value are Ma-anago (真穴子), Goten-anago (御殿穴子), and Kuro-anago (黒穴子), but it is safe to assume that most Anago used in sushi restaurants are Ma-anago.

Other Ma (真) include Ma-dai (真鯛), Ma-dako (真蛸), Ma-dara (真鱈), and Ma-hata (真羽太).


Which fish tastes better, farm-raised or wild-caught?

A photo of Natural fish

The answer to this question is obvious.

First of all, the most common argument goes something like this.

Some say that farm-raised fish are fatty, but the image of natural fish being superior has simply taken hold. Others say that farm-raised fish are raised in small fish ponds, so they are less active and less chewy, or that feeding them formula feed harms the taste and aroma of their meat. Well, all opinions can be said to be right or wrong.

It could be for the following reasons. It does not touch on the quality as well as the quantity of fat. Not all fish farms are small, and there are far more people who prefer soft flesh to chewy flesh. And we know that feed has a big impact, so formula feed has been greatly improved. It is all about the so-called superficial argument.

And as you probably know, there are fish of the same season, same species, and same freshness that are natural but separately not so tasty. It can be said that the natural one is the one that is more hit or miss.

And, as a wild guess, I would say that most people only know what farm-raised fish tastes like. In Japan, about 60% of Japanese amberjack (Buri), 80% of Red seabream (Tai), and 99% of Japanese eel (Unagi) are farm-raised. In other words, most Japanese likely eat farmed fish for these three species. The situation is similar around the world. Farmed salmon surpassed the catch of wild salmon in 1996, and currently accounts for more than 70% of total production.

This is the prerequisite for the answer so far. We then look impartially at the facts alone to come up with an answer.

A photo of fish farm

It is not difficult for a person with common sense to compare farmed hamachi and wild buri and recognize them. However, for those who have only eaten Hamachi and usually find it tasty, it may take some time to come to feel that Buri is tasty because their brain has a sense that such food is tasty. Modern people who find foods with amino acids and artificial sweeteners tasty command their brains to tell them that they are not tasty without them. When we become accustomed to foods that mask the original taste, we lose sight of the original taste. This is the true nature of convenient food. Therefore, when a fair comparison of natural Buri and cultured Hamachi Sashimi is conducted, more than 80% of people say that cultured Hamachi tastes better.

Fish have different flavors and aromas depending on where they are caught, and once you understand this, you can narrow it down considerably to the place of origin. The factors are the marine environment in which they live and the type of food they have been raised on. Natural fish can choose the food they eat, and those raised on such food have their original flavor. Fish raised in aquaculture are fed a diet that suits their needs because the emphasis is on economics. Because farm-raised fish cannot eat the food they prefer, they can’t develop their original flavors.

Nowadays, farm-raised eels dominate the eel market, and there is not a mere shadow of the natural product to be seen. Whenever we eat wild-caught eel, we always feel that farm-raised eel does not have the smell of earth and mud from the fat condensed in the skin and meat like wild-caught eel. Whether you like this smell or not, it is the original flavor of the eel. As for the quality of fat, farm-raised eel is not so bad when it is hot, but when it cools down, it feels heavy. Compared with farm-raised eel, natural eel is fatty but gives the impression of being light and smooth, which is why it has been called a specialty.

The iodine value is a number that indicates the degree of saturation or unsaturation of fat and oil. The higher this number is, the higher the content of unsaturated fatty acids and the worse the aftertaste tends to be. For example, farm-raised eel has an iodine value of 150, while wild eel has an iodine value of about 80, and contains almost no unsaturated fatty acids. Unsaturated fatty acids are abundant in Pacific saury (Sanma), Japanese sardine (Iwashi), Mackerel (Saba), etc. In short, these fish and farm-raised fish that eat food made from highly unsaturated acids will all have highly unsaturated acidic constitutions and will have a bad aftertaste. Moreover, if the fat is too strong, the fish will not even develop the aroma of the individual fish. This is one aspect of farmed fish.

Red seabream (Tai) is also available in both wild and cultured forms, but the amino acid composition and flavor compounds in both types do not vary much. Why, then, is there such a difference in taste? The only reason is the difference in flavor. The trace amount of aromatic substances in the fat of sea bream determines the original flavor of the fish. As mentioned above, farm-raised Red seabream does not have the same flavor. The question is whether the aroma is good for us or not. Of course, everyone has his or her taste in aroma. But that is where the value of the food is born. The top chefs are very particular about aroma, and they all use natural ones.

Finally, can you imagine what the results would be if you ate farmed Atlantic salmon and wild Atlantic salmon as sashimi? Probably, the farmed salmon would be superior because of its tender meat, appetizing color, and fat content (we could not find such experimental data, so this is speculation). However, what would be the result of making Nigiri sushi? The noble aroma that nature possesses is irreplaceable. In sushi, where the main focus is on enjoying the aroma, the difference is obvious.

The difference between natural and farmed fish is obvious, as the best sushi chefs never use farmed fish. The exception to this is when the fish is raised in an almost natural environment, without artificial food, so that it simply cannot escape.

All in all, the conclusion is that wild fish tastes better.

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What is hybrid artificial fish?

A photo of Kue-tama
The appearance of Kue-tama

What is hybrid fish?

Both Yamame (Landlocked Sakuramasu) and Japanese Iwana (Char) are members of the salmon family. Iwana and Yamame both inhabit the upper reaches of rivers, although Iwana prefers slightly cooler water. In rivers where each species lives alone, both fish occupy the upper reaches of the river, but in rivers where both species live, they do not mix, with Iwana occupying the uppermost reaches and Yamame occupying the lower reaches after a certain point in the upper reaches.

In nature, different species sometimes interbreed and produce hybrid fish. For example, hybrids between Yamame and Iwana are common in nature. The characteristic spots of the Iwana look like those of the Saba (Mackerel), a marine fish, and hence the name Kawasaba. They also rarely become smoltified (silvering) and become the descending sea type, but they do not reach sexual maturity.

Incidentally, the Kawasaba is thought to have been created by the uncontrolled release of Yamame into an area originally inhabited by Iwana, resulting in the mating of two species whose habitats do not originally overlap. The “hybrids” created by thoughtless releases may be a symbol of the destruction of genetic diversity.


What is hybrid artificial fish?

In the aquaculture industry, high growth and survival rates, good flesh quality, and disease resistance are important requirements for a superior species, and artificial crossbreeding has long been used as a method to create such breeds.

In 1964, Kinki University in Japan succeeded in breeding the first hybrid artificial fish, a female Red seabream (Madai) with a male Blackhead seabream (Kurodai). Since then, he has produced many hybrid combinations. The name “Ma-kurodai” is a combination of “Madai” and “Kurodai. In addition, he has created nearly 20 new fish species, including Madai x Hedai (Ma-hedai), Madai x Chidai (Ma-chidai), Ishidai x Ishigakidai (Kin-dai), and Buri x Hiramasa (Buri-hira).


Typical hybrid artificial fish will be mentioned briefly.

What is Buri-hira?

Buri hira is a crossbreed between a female Japanese amberjack (Buri) and a male Goldstriped amberjack (Hiramasa). Buri, which is in season in winter, is characterized by its high fat content and strong flavor, but its meat is tender and its dark red meat (chiai) tends to discolor during the summer. Hiramasa, on the other hand, is firm, has less dark red meat (chiai), and is less prone to discoloration, but has less fat and a lighter flavor, and is only available in summer.

Buri-hira is a very tasty fish that combines the “good points” of these two fish species and combines the “umami” of Buri with the ” chewiness and beauty” of Hiramasa. Because it is completely farm-raised, it can be served all year round, and major conveyor-belt sushi chains have already begun serving Buri-hira. Buri-hira can be caught in the wild very rarely, but they are so few that they are not generally available on the market.


What is Kue-tama?

It is a hybrid species, having as its father a Giant grouper (Tamakai), one of the world’s largest members of the grouper family that can grow to 270 cm in length and 400 kg in weight, and as its mother a Longtooth grouper (Kue), which is a rare and high-end fish with an outstanding taste and popularity.

The hybrid is characterized by the fact that it inherits the growth rate of Tamakai and grows to shipping size in about two years, whereas it normally takes four to five years for farmed Kue to grow to shipping size.

This makes it possible to significantly reduce production costs, and it also has properties that make it resistant to disease and easy to grow. Major conveyor-belt sushi chains have already begun offering Kue-tama.


What is Be-ster?

Be-ster is a hybrid of Beluga and Sterlet, known for producing the finest caviar among sturgeon. Developed by Russia several decades ago for aquaculture, the Be-ster was created amid a worldwide ban on capturing wild sturgeon as an endangered species.


What is Kin-dai?

Kin-dai is a hybrid of a female Barred knifejaw (Ishidai) and a male Spotted knifejaw (Ishigakidai) and was first successfully produced by Kinki University in 1969, and patented and trademarked in 1975.

Ishigakidai, on the other hand, takes more than six years to mature and produces fewer eggs, but grows quickly to commercial size. Kin-dai combines the best features of both, with a good texture and excellent taste. Its name is the same as the abbreviation for Kinki University.

Ishidai is called “Kuchiguro (kuchi means mouth and guro means black)” because its body turns silvery white and the area around its mouth turns black. Ishigakidai, on the other hand, is called “Kuchisiro (shiro means white)” because they have a black body and the area around their mouth turns white. Kin-dai’s entire body turns black, and the tip of its mouth also turns black.


What is Ma-chidai?

Kinki University has also produced a hybrid Ma-chidai, a cross between Red seabream (Madai), which grows well, and Crimson seabream Chidai, which has a less faded red coloration, and has traits that give it a red coloration like natural fish and faster growth than Chidai.

Finally, a second generation has already been produced from the sexes of the hybrid fish. If the hybrid fish are released into natural waters, contamination will occur through genetic infiltration. We should not leave a bad legacy for future generations.

What is Torokinme?

A photo of Fusenkinme.

Fusenkinme (Red bream) is occasionally caught along with Splendid alfonsino (Kinmedai). Until recently, they were considered to be the same species. Kinmedai has elongated slit-like posterior nostrils, while Fusenkinme has oval-shaped posterior nostrils. Kinmedai can grow over 50 cm long, whereas Fusenkinme stops at 40 cm.

Fusenkinme is fattier than Kinmedai and is called Aburakinme or Torokinme by fishermen, in areas that distinguish between Fusenkinme and Kinmedai, there is a difference in market price, but it is rarely distributed and is consumed locally.

Torokinme does not refer to the belly part of Kinmedai but to Fusenkinme, a rare species of Kinmedai. Incidentally, three Kinmedai, Nanyokinme, and Fusenkinme species are distributed in Japan.

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What is the thought behind Toro?

What is Torokarei?

A photo of Torokarei fillet
The appearance of Torokarei fillet

Consumers are inevitably confused by the word Toro. It isn’t easy to separate the word from a mere marketing term. Therefore, the market contains fish names with Toro as a prefix.

Torokarei (karei means flounder) is a trade name for a fish named after the toro of tuna, which has a rich, tender texture, and is an arrowtooth halibut (Aburakarei).

Aburakarei is distributed north of Choshi, the northern Sea of Japan, the Sea of Okhotsk, and the western Bering Sea. Aburakarei is a typical eating fish among flounder species, and unfortunately, it is considered the most tasteless and has low commercial value. Black halibut (Karasugare), a relatively tasty and inexpensive fish, has become expensive, so perhaps it is Aburakarei’s turn.

So a name that would sell was needed, so it became Torokarei.

In recent years, Aburakarei has been imported from the U.S. and other countries in large quantities of fillets processed for frying. It is inexpensive and its distribution is stable. Aburakarei is characterized by its meat containing so much fat that it melts when heated. Even when heated, the flesh remains tender, and it is often used overseas for frying as fish and chips. The most common type of engawa at conveyor-belt sushi restaurants is either Aburagarei or Karasugarei.

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What is Kewpie mayonnaise?

An image of Kewpie mayonnaise
Since its launch in 1925, this mayonnaise has been the most popular mayonnaise in Japan!

Find out why Mayonnaise has become a citizen on the dinner table

Japan is not a large country. Even so, fresh produce from the sea and mountains is abundant. Even without a large-scale distribution system in place, we Japanese have been able to obtain fresh ingredients in fresh conditions easily.

This is thought to have given rise to a raw food culture in which vegetables, eggs, fish, and even internal organs such as horse meat, beef, and liver are eaten raw. Since fresh ingredients are readily available, it is only natural that there is no need to make unnecessary modifications to them. For this reason, Japanese cuisine has become dominated by methods that do not require much modification of the ingredients. In Italy, the ingredients are fresh, and in China and France, cooking techniques have developed to compensate for the lack of freshness of ingredients. This is just my personal opinion.

And speaking of Japan’s unique food culture, we must not forget its rice culture. Japanese rice is japonica rice, which is light and delicate in flavor. Inevitably, the rice is not eaten by itself but is accompanied by a strong-flavored side dish.

This is likely what led to the development of flavorful seasonings in Japan. The traditional Japanese soy sauce and miso, not to mention ketchup and Worcestershire sauce, which are two of the most popular sauces in Western cuisine, along with mayonnaise, are seasonings with a very distinct flavor. Likewise, mayonnaise is a strong-flavored seasoning, so it is assumed that side dishes made with it went well with rice.

In general, the Japanese palate is said to be well suited to amino acids and the peptide umami before it becomes an amino acid, and this amino acid is found mainly in fermented foods. Japan’s mild and humid climate is ideal for the production of fermented seasonings, and it is no wonder that miso (fermented soybean paste), soy sauce, and salted fish, which are fermented foods, have developed.

Interestingly, mayonnaise also begins to mature about a week after it is made, and the protein contained in the egg yolk in mayonnaise is broken down into amino acids and peptides, resulting in the umami that the Japanese like. Mayonnaise is usually not pasteurized because it separates when heated. This phenomenon occurs because the mayonnaise is still alive after being packed in the container.

Compared to the Western type of mayonnaise, which uses whole eggs, the yolk type of mayonnaise is more common in Japan. The yolk has a higher umami of amino acids and peptides than the egg white, and this may be the reason why Japanese mayonnaise has adapted well to Japanese tastes. The combination of this taste backbone and the umami of Japanese-style mayonnaise has helped mayonnaise to firmly establish itself in Japanese food culture.


What kind of food is mayonnaise?

I said mayonnaise is a food, but many people may think of it as a condiment. Mayonnaise, as you know, is made from vinegar, oil, and eggs. In Europe, where it originated, it was made from lemon juice, wine vinegar, olive oil, and eggs. However, in modern Europe, mayonnaise seems to be made at home, unlike in the United States or Japan.

Mayonnaise has some notable characteristics. First, the oil in mayonnaise has the effect of masking the bitterness of the food. Furthermore, the oiliness of mayonnaise is reduced by emulsification, making it very easy to eat. The bitterness of vegetables is sometimes unacceptable, but mayonnaise envelops it. Meat marinated in mayonnaise becomes tender. It has the effect of softening the hardened tissues of meat. Mayonnaise quickly removes the odor of raw fish. The sour vinegar flavor overcomes the unpleasant smell of raw fish, and when it is eliminated, it has so many positive aspects that there is no end to it.

Japanese mayonnaise is restricted by JAS standards for consumer safety. Incidentally, JAS is based on the standards of the U.S. FDA. According to the standard, mayonnaise contains 65% or more edible vegetable oil, vinegar and citrus juice, egg yolk and egg white, salt, sugar, spices, chemical seasonings, acidifiers, and citric acid. In Japan, mayonnaise may not contain any preservatives, emulsion stabilizers, food coloring, or soy protein. Yellow mayonnaise is just made with lots of eggs. This is why the JAS standard does not allow the use of food coloring that misleads people into thinking that there are lots of eggs in the product.


Why doesn’t commercial mayonnaise go bad?

Japanese standards for mayonnaise prohibit the use of any preservatives or food coloring. It is natural to ask the question, then, why mayonnaise does not spoil when it is made from egg yolks.

Simply put, think of pickles pickled in vinegar. Depending on the method of production, they can be stored for a year or more. The reason for this is that the acetic acid in vinegar has powerful bactericidal properties.

According to mayonnaise standards, at least 65% of the edible vegetable oil does not go rancid. The sterilizing power depends on how much acetic acid and salt are present in the remaining 35% of the ingredients.

Homemade mayonnaise made at home or in a restaurant is used up quickly, so there is no need to think about shelf life, just make it to your own taste. However, this is not the case with store-bought mayonnaise. And since mayonnaise is not heat sterilized, its composition is very important to prevent it from spoiling in its raw state. Of course, it is also important to manufacture it hygienically in a factory. The combination is determined by considering factors such as the fact that it must not separate during transportation and that it must have a taste preferred by the consumer.

According to actual bacterial test data, Escherichia coli is killed in 6 hours in mayonnaise. Staphylococcus and salmonella, which cause food poisoning, are killed in 24 hours. Even the yeast Hansenula anomala, which is relatively acid-resistant, dies in about 8 days.

As a general guideline, raw food is considered hygienic if it contains less than 100,000 live bacteria per gram. Frozen food that is heated and eaten meets the criteria of the Food Sanitation Law with a count of 3 million live bacteria or less per gram. Normally, it is considered that even if there are 100,000 bacteria per gram of food, the food will not spoil, but if the bacteria count exceeds that level, the food will gradually start to spoil or go rancid. In other words, most bacteria die in mayonnaise. Therefore, it is safe to assume that commercial mayonnaise is first of all free of bacteria.


Why is vinegar good for your health?

The answer is simple. It is because vinegar lubricates the citric acid cycle. In 1953, Dr. Hans Krebs of England won the Nobel Prize in Physiology or Medicine for his research on the pathway of tissue respiration in the human body. This is called the citric acid cycle, which is the only mechanism that produces the energy necessary for life, and without this cycle, organisms cannot live!

The problem here is that during strenuous exercise or illness, large amounts of glucose are burned, creating an abnormally high amount of pyruvate, which is further converted into lactic acid. That lactic acid makes body fluids and blood acidic, causing so-called Acidosis. In addition, lactic acid combines with proteins in body tissues to form lactic acid protein, which causes stiff shoulders and muscle pain, as well as increased deposition of cholesterol, leading to arteriosclerosis and hypertension.

At this time, it is explained that when vinegar is eaten with salads, the organic acids contained in vinegar, such as acetic acid, malic acid, and citric acid, can smoothly advance the citric acid cycle and bring lactic acid back into the cycle. In other words, vinegar has been elucidated to act as a lubricant for the Citric acid cycle.

The vinegar in mayonnaise does more than just accentuate the delicious taste; it also helps to clear away fatigue. The Citric acid cycle explains why the blood and body fluids of healthy people are slightly alkaline and become acidic when tired or ill. It also depends on the diet. Eating only acidic foods, i.e., meat and seafood, will cause the blood and body fluids to become more acidic, and cholesterol will be deposited in the blood vessels more easily. The diet must be well-balanced. This is where vinegar comes into play. Vinegar is burned efficiently in the body and is incorporated into the metabolic mechanism to act as an alkaline food. Other effects include increasing appetite and aiding digestion, and it is also very effective in cleaning the body and activating the body’s internal energy.

Where does mayonnaise’s good taste come from?

Mayonnaise is an oil-rich food. Oil stimulates the brain to release hormones that make us want to eat again. However, oil does not remain in its original state, but is scattered throughout the food, creating a richness. Humans respond to this richness with a sense of deliciousness. In other words, mayonnaise is a synergy between the richness created by the oil mixed and dispersed in the egg and the richness of the egg yolk itself.

What makes mayonnaise different from other seasonings is that it contains the egg itself, rather than food extracts or essences. We believe that mayonnaise itself may be regarded as an independent food or dish, beyond the framework of a mere sauce.

Isn’t too much mayonnaise bad for you?

One of the main components of mayonnaise is egg, a food high in cholesterol. However, since mayonnaise is a food high in cholesterol, it is too early to assume that it is bad for you.

The main functions of cholesterol include “making cell membranes,” “making bile acids,” and “being a raw material for sex hormones and adrenal corticosteroids. The production of cell membranes is the basic building block of the human body, without which the human body would not exist. Bile acids are necessary for digestion, and without normal amounts of bile acids in the body, digestion would be out of balance. The same is true for hormones. Without a certain amount of cholesterol in the body, the human body cannot function normally.

The term “cholesterol” refers to both HDL cholesterol and HDL cholesterol. HDL cholesterol is necessary for the body, and most of the cholesterol contained in egg yolks is HDL cholesterol. On the other hand, LDL cholesterol, which is said to cause arteriosclerosis, is not in itself bad. It is believed that oxidized LDL cholesterol, which is created when LDL cholesterol is oxidized by active oxygen, damages the vascular wall, causing inflammation and arteriosclerosis.

Cholesterol is not only ingested through diet. About 70% of the cholesterol needed by the body is synthesized in the body, and the remaining 30% is taken in by the diet. Incidentally, the amount of cholesterol synthesized by the body is 600~700mg per day. On the other hand, a 50 g egg contains about 235 mg of cholesterol. The proportion of egg in Mayonnaise is lower than it appears, and the amount of cholesterol contained in a tablespoon (15g) is only 24mg. This is not an amount to be concerned about.

The human body is well designed to maintain balance by reducing the amount of cholesterol synthesized in the body when the amount of cholesterol in the diet is too high. In addition, cholesterol is transported from the liver to each tissue, and conversely, cholesterol is collected from each tissue to the liver, thereby keeping the amount of cholesterol in the blood at a constant level. The problem is not the intake of cholesterol itself, but the imbalance of cholesterol in the blood.

And an experiment has been conducted with surprising results. Healthy subjects and hyperlipidemic subjects were given 15 g of Kewpie mayonnaise per day for 12 weeks in addition to their conventional diet, and the lipid levels in their blood were measured. The total cholesterol concentration in the blood of the healthy subjects was slightly decreased. The hyperlipidemic subjects also showed a decreasing trend. It would seem that a constant intake of mayonnaise would increase the amount of cholesterol, but in the experiment, there was no trend toward an increase. In addition, there was no change in body weight after 12 weeks of mayonnaise consumption, a result that defies the conventional wisdom about mayonnaise. Similar experiments have been conducted elsewhere with the same results.

New Possibilities for Eggs

The amount of choline needed per day is said to be around 450 mg. 1 egg weighing 60~70 g contains 1000 mg of choline. 1 tablespoon of 15 g of mayonnaise contains about 110 mg of choline, which is 1/4 of the daily requirement. One-quarter of the daily requirement of choline can be obtained from a 15 g spoonful of mayonnaise. Incidentally, 200 cc of milk contains 28 mg, and a tablespoon of butter contains 20.4 mg, so eggs are by far the most efficient way to eat.

Mayonnaise contains a lot of salt

Mayonnaise is a sour and salty food, and while one may worry about too much salt if one eats too much, it is much less salty than one would generally imagine. The saltiness is due to the seasonings and spices. It contains less salt than other seasonings. Mayonnaise has 0.3 g of salt per tablespoon, the lowest amount of salt among the major seasonings, compared to 0.6 g of ketchup, 3 mg of soy sauce, and 2 mg of miso. Despite its low salt content, the full-bodied mayonnaise can add a lot of flavors to ingredients even in small amounts, and may be considered a good choice for dieting.

Does eating mayonnaise make me fat?

Usually, a tablespoon of mayonnaise has 100 kcal. One hot dog has about 289 kcal, so three tablespoons would be the same calories. It is certainly a high-calorie food. It is a very oily food, but the vinegar makes it surprisingly refreshing, which is one of the reasons why we tend to eat a lot of it. We should not eat too much of this food just because it tastes good but try to eat about 1 tablespoon per meal. It is not harmful to your body even if you continue to eat it every day, but only if you know how much to eat. It is not recommended to eat so much that you can’t see the salad. Instead of worrying about gaining weight, one should try to eat a well-balanced diet by eating green and yellow vegetables together.

Pairing mayonnaise with other foods

The range of uses for mayonnaise is unlimited. Please listen to this article without preconceived notions that mayonnaise would not be suitable for such foods. First of all, in the case of Japanese food, it is difficult to find foods that mayonnaise does not go well with, such as broiled eel, tempura, yakitori, oden, chilled tofu, soba noodles, and so on. Other than that, it goes well with all kinds of food such as gyoza, ramen, shumai, spring rolls, bibimbap, kimchi, tom yang kung, beef stew, omelets, curry rice, minestrone, edamame, banana, apple, orange, apple pie, pudding, chocolate, donuts, and many others. It can soften the aroma of stinky foods, freshen oily foods with its acidity, and deepen the flavor of overly light foods with the richness of eggs.

The emergence of polyethylene multi-layered containers

When Mayonnaise was launched in Japan, it was in glass bottles. In the 1960s, plastic was developed, polyethylene containers appeared, and bottling containers were quickly converted to polyethylene containers. Glass bottles were used because oxygen permeation would oxidize the mayonnaise oil and form peroxides, which would gradually ruin the flavor. However, the ability to squeeze out without using a spoon seems to have been significant, and it seems to have been replaced.

The difference in preservation effect on mayonnaise between polyethylene containers and glass bottles was that polyethylene alone had the disadvantage of poor preservation compared to bottling due to its oxygen permeability.

In the 1970s, technological advances made it possible to improve the oxygen permeability of polyethylene. A three-layer technology was developed, with polyethylene on both sides and an oxygen-impermeable plastic-like eval resin in between.

The three-layer polyethylene-eval resin-polyethylene container is used today for most food containers. This has greatly improved the shelf life of mayonnaise and has made bottled and polyethylene multi-layer containers nearly identical in terms of quality.

Bottled mayonnaise is more prone to oxidation after opening because of the large area exposed to air when the lid is opened. Polyethylene multi-layer containers have become the mainstream in Japan because of their advantages such as easy squeezability, no risk of breakage, lightweight, and low container cost.


Here is a summary of the characteristics of Kewpie mayonnaise.

The main ingredients of Kewpie mayonnaise are also oil, eggs, and vinegar. Of course, each of these ingredients should be carefully selected and good ones used, but the strange thing about mayonnaise is that it does not taste perfectly delicious on its own.

What became clear in Kewpie’s laboratory is that what is important is the compatibility of vinegar and oil, and vinegar is a major key, especially in terms of umami. Surprisingly, vinegar and oil go together better when they are both strong. If one of the habits is weak, the other will win out and instantly become unbalanced.

Let’s look at the history of the oil used in Kewpie mayonnaise. In the postwar period when mayonnaise became popular, cottonseed oil from cotton seeds was mainly used. Since this oil has a strong habit, it was combined with malt vinegar, apple cider vinegar, and other vinegar with strong characteristics. However, with the development of synthetic fibers in the 1960s, cotton cultivation decreased and cottonseed became scarce. This made it difficult to secure cottonseed oil, and other oils with weaker characteristics were used instead. Kewpie has changed the vinegar to match the oil.

These days, Kewpie uses a blend of vinegar made from sake lees and grains. The ingredients of oil that are good for the body are generally considered to be oleic acid, linoleic acid, and α-linolenic acid in the ratio of 60:32:8. Rapeseed oil, for example, is close to this ratio, and Kewpie uses salad oil that is also close to this ratio.

Although oil accounts for the largest proportion of ingredients, vinegar can be said to be the key to flavor. Taste preferences are said to change over time; for example, Kewpie mayonnaise was sourer in the past. The percentage of vinegar is said to be less now than in the past. In the past, there were few homes with air conditioning, and people sweated a lot. Therefore, mayonnaise with a lot of vinegar and a strong flavor was preferred. On the other hand, today, air conditioning is available everywhere, and people do not sweat as much, so the amount of vinegar is less than in the past.

Compared to mayonnaise made overseas, Japanese mayonnaise generally contains almost double the amount of vinegar. This is because mayonnaise is a unique egg yolk type of mayonnaise in Japan, and cannot be heat sterilized like other foods because it decomposes when heated. In addition, mayonnaise with high yolk content is prone to spoilage, and to prevent this, a lot of vinegar, a natural preservative, was used. This ultimately made Kewpie mayonnaise tastier.

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Revision date: March 15, 2024

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What is sushi or sashimi grade fish?

sushi or sashimi grade fish photo
Do you know when this fish was caught?

Fish is not only cooked and eaten as grilled or boiled fish but also eaten raw as sushi or sashimi. Naturally, the way to eat fish depends on individual tastes. But in fact, the way we eat fish depends on the time frame after we catch it.

Fish that is still alive or freshly dead is ideal for sashimi. In this case, you should enjoy the elasticity of the flesh, or texture, rather than the umami of the fish. Only the freshest fish is suitable for sashimi. The fish will go rigor mortis within a few hours at the earliest, and within a few days at the latest. The period leading up to rigor mortis is the time when the umami component increases, making it ideal for sushi.

On the other hand, the flesh becomes softer, so it is the sushi chef’s job to find the right balance between the umami and the chewiness of the fish. Of course, for those who prefer fish with more umami, it can also be served as sashimi. The rigor mortis of the fish is eventually dissipated and it gradually begins to decompose, so it is consumed as sashimi or sushi until a certain point in time.

The chef’s job is to determine when the fish cannot be used as sashimi or sushi. After that, the fish will be consumed as grilled or boiled fish. Eventually, the color, taste, and aroma of the fish will change dramatically, and it will reach the so-called putrefied state, making it inedible. The chef’s job is to determine when the fish cannot be used as sashimi or sushi. After that, the fish will be consumed as grilled or boiled fish. Then the color, taste, and aroma change dramatically, and the fish reaches the so-called putrefied state and becomes inedible.

A variety of conditions exist before rigor mortis sets in. Ideally, the fish should be properly processed and cooled as soon as possible after it is caught. Without this, rigor mortis will set in immediately, shortening the time until the rigor mortis is dissipated and speeding up the decomposition process. In other words, it will affect the length of time the fish can be enjoyed.

It is difficult to judge whether fish can only be used for grilled or boiled fish. It is not a simple matter of how many hours after the fish has died. Even if the fish is in sushi or sashimi grade, you can imagine that some are in good condition, and others can only be used almost exclusively for grilling or boiling.

Look around the world and you will see fish being sold around fishing ports as soon as they return from fishing. The fish is truly freshly caught and could not be fresher. Usually, the fish is cooked by dinner at the latest, so the loss of freshness is not a concern at all. People call fish in this state very fresh. To be more precise, it takes a few hours from the time the fisherman catches the fish to the time it is on the market, or at most 12 hours before it is served for dinner. This is what we call sushi or sashimi grade. However, because the fish is not caught in large quantities, it is not distributed to supermarkets in urban areas. This is limited to fishing with small boats.

Large vessels use large nets and other equipment to catch large numbers of fish. When the nets are raised on deck, many of the fish are live. They are quickly sorted, cooled with ice or other means, and placed in refrigerated or frozen storage. Some of the larger fish are stored after Ikejime, etc. Once fishermen go out to fish, they are not allowed to return for at least three days and as long as several months.

Although refrigeration and freezing technology have advanced considerably, freshness is not the same when the fish is caught as it is when it returns to the fishing port. And by the time the fish reaches the supermarket, which is a long way from the fishing port, it is arguably even less fresh. It has already been almost 24 hours since the fishermen caught the fish. It will then spend several days in the supermarket enduring temperature changes and drying out. One wonders if this can be called sushi or sashimi-grade fish.

So far, we think you can understand that this is a typical situation in countries other than Japan.

The situation in Japan is a bit different.

Regardless of the size of the boat, the fish are not allowed to get out of control, Ikejime and other processing is done. And cooling is always done. That is what even the average fisherman does as a matter of course. In other words, it is recognized that keeping fish fresh means delaying the time until rigor mortis.

On top of that, a distribution system has been established to deliver the caught fish to markets and restaurants while keeping them alive. Not only are the fish kept alive, but the know-how to reduce stress during fishing and transportation is shared among fishermen. For example, fish are transported by truck to the consumption area in a state of suspended animation to prevent them from getting out of control. In other cases, fish are not shipped immediately from the fishing port, but are allowed to calm down in a fish tank. By trying to keep the fish as close as possible to the state in which they were swimming in the sea, the fish can recover their original amount of adenosine triphosphate. This is because adenosine triphosphate is the source of umami, which eventually converts to inosinic acid.

In other words, a system is in place to distribute fresher and tastier fish. As a matter of course, it is safe to say that the fish is delivered from the fishing port to the place of consumption and then displayed in supermarkets within 12 hours.

The minimum requirement is that the fish must be usable for sashimi. The words sushi or sashimi grade do not exist in the market. Who caught the fish? What time and minute it was caught? How was it processed? Whether the fish was caught by fishing or by netting, and other details are required. These things change the price of the fish in the market.

In summary, there is no legal definition of sushi or sashimi-grade fish. When seafood is labeled as sashimi grade, it means that the seller, such as a supermarket, has determined that the fish is suitable for sushi or sashimi, based on its evaluation of criteria such as bacteria levels, temperature, parasites, appearance, odor, taste, display method, and time since catch. It is very vague and does not state that they are responsible for any problems that may occur, such as food poisoning. In the extreme, it is merely a marketing term for sales promotion purposes. Above all, they say nothing about actual quality or taste.

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Revision date: March 1, 2024

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What is traditional Ikejime?

a photo of Ikejime Madai
In order to fully drain the blood from the red seabream, the spinal cord at the base of the tail is also cut off.

Articles related to Sushi are now filled with jargon such as Shinkeijime, Chinuki, Noujime, Ikekoshi, and Korijime. That much confirms the fact that opportunities to eat fish are increasing all over the world. And it has also become a common occurrence to find articles written by people who have heard Ikejime in bits and pieces. According to what we have heard, Ikejime processing is one of the reasons why red seabream from Akashi, which is said to be the best in Japan, is so tasty, and the technology has been around since the Edo period (1603-1868).

The Ikejime procedure consists of four parts or some of them, and the point of Ikejime is to kill the fish in a relaxed state.

The first step is a brain-dead the fish by stabbing it in the head with a sharp object. This process is called Noujime (Nou means brain and jime means kill).

After the fish is out of the water and before it gets out of control, it is stabbed in the head with a hook called a Tegaki (手鉤). If the brain is not destroyed by one blow, the fish will struggle. When this happens, a large amount of ATP, which is the source of umami, is consumed. As a point of caution, the right side of the head is stabbed so that the puncture wound is not on the upper side, as the fish will be handled later in the distribution process with the belly facing forward and the head facing to the left.

Next, use a knife to quickly kill the live fish.

Place the fish with its head facing left, open the gill cover, and cut a spinal cord below the lateral line that is visible on the fish’s body. Since bones have hard parts, move the cutting edge slightly to the left and right if it is difficult to cut. If you don’t cut it completely, you have not killed the fish, and the blood will not drain well. To drain the blood sufficiently, the spinal cord at the base of the tail is also cut off. Place the fish’s head to the right and cut the front part of the tail so that the spinal cord is visible. At this point, the knife should be placed at a right angle to the spinal cord so that the cut surface is not at an angle.

The next step is to remove the nerves and delay rigor mortis. This process is called Shinkeijime (Shinkei means nerve).

Shinkeijime is a technique to delay rigor mortis in fish. A wire is inserted into a small hole in the upper part of the spinal cord. When the wire hits the nerve, the fish will act violently, so hold it down. The nerve hole tapers from the head side to the tail, so when stabbing in from the tail side, make sure to insert the wire securely first, so that the wire does not pierce through the nerve hole and pierce the body. Once you have securely inserted the wire, repeatedly pull out and insert the wire to completely destroy the nerve in the hole. When the nerve is destroyed, the body color quickly changes to white. The destroyed nerve appears as a white, sludgy fluid.

Any wire can be used for this purpose as long as it is straight, but a piano wire that does not bend easily can be used many times. The diameter of the nerve hole differs depending on the fish. Use a thick wire for Tai and Suzuki, which have large nerve holes, and a thin wire for Aji and Anago, which have small nerve holes. Several types between 0.8mm and 1.5mm should be enough. As you get used to it, you will be able to stick the wire in without visually seeing the nerve hole. If you remove a few scales from the upper part in front of the tail, insert the wire along the spinal cord, probe the nerve hole, pierce it, and destroy it, you can remove the nerve without making any cuts on the fish’s body. The same applies to the head side. The nerve hole is probed and pierced from the head side, but the key is to keep the head and body straight so that the nerve hole is not misaligned by the spinal cord severed behind the gills. In any case, it takes experience and familiarity to pierce the nerve hole without seeing it.

The final step is to perfectly remove the blood from the fish’s body. In Japanese, it is called Chinuki (Chi means blood and nuki means remove).

The blood is removed by cutting the spinal cord and immersing the fish’s body in seawater. At this time, running water is more reliable to remove blood. In the case of stored water, leave it for a while and then replace it with other stored water. If the water does not turn red with blood, the fish has already been drained. Blood has a tendency to clot, so it is important to wash off any blood that has clotted on the gills or other parts of the body. The body temperature of the fish is raised by the Ikejime process and by human hands. Since the fish were originally in the sea, which has a lower temperature range than that of the ground, the higher temperature increases the speed of deterioration, so the fish is soaked in ice water to lower the temperature of the fish’s body. If the fish is soaked too long, its body surface will turn white, so remove it from the water when it cools down.

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Revision date: August 18, 2023

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What is the difference between fermentation, putrefaction, and maturing?

a photo of soysauce

In academic terms, “fermentation” is a reaction that uses no oxygen to break down carbohydrates to obtain energy. On the other hand, the reaction that uses oxygen to break down organic matter to obtain energy is called “respiration”.

In more familiar terms, microorganisms such as lactic acid bacteria, koji-mold, and yeast break down organic compounds such as carbohydrates and proteins to produce a variety of by-products to obtain energy in their own life activities. Among these, “fermentation” is a phenomenon in which beneficial substances are produced for humans, while “putrefaction” is a phenomenon in which harmful substances are produced for humans. Food spoilage can be detected by the five senses, such as smell, appearance, and taste.

What is the difference between fermentation and maturing?

While “fermentation” and “putrefaction” are caused by microorganisms, “maturing” is a process in which the food itself is transformed by enzymes and other substances to produce something beneficial to humans. Or, “maturing” is the process of improving the flavor and quality of food by allowing it to rest under controlled temperature and humidity after fermentation is complete. Maturing is said to be beneficial to humans because it changes the texture and taste of the fish, making it tastier.

In case you are wondering, “enzyme” is mainly composed of protein, which promotes chemical reactions such as digestion, absorption, and metabolism that are necessary for all living things, including humans, animals, and plants, to survive. It is said that there are approximately 5,000 enzymes in our body, but each enzyme is a specialist that performs only one function and is largely divided into “Digestive enzymes” and “Metabolic enzymes.

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Revision date: May 25, 2023

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What is Blue rainbow trout (Cobalt masu)?

a photo of Blue rainbow trout
Blue rainbow trout are an angler’s dream.

The Japanese name for the blue rainbow trout is Cobalt masu, derived from its blue body color. Blue rainbow trout is a mutation in the hatchery production of rainbow trout. This fish lacks the middle lobe of the pituitary gland. This resulted in blue body color. This rare genetic glitch has occurred only in rainbow and brown trout. It is said that one blue rainbow trout is born for every ten of thousand rainbow trout. This trait is inherited recessively. It does not reproduce and is susceptible to disease. Therefore, although it has a beautiful body color, it is difficult to produce in large numbers.

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Revision date: April 8, 2023

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What is Albino rainbow trout?

a photo of Albino rainbow trout
Other Albino fish have a white body color, but the Rainbow trout has a yellow body color.

There is a Rainbow trout with yellow body color.

This is the Albino rainbow trout.

The Albino has no pigmentation. Other Albino fish have a white body color, but the Rainbow trout has a yellow body color. Since its first discovery in 1956 at the Fisheries Experiment Station in Nagano Prefecture, Japan, experiments conducted by crossbreeding Albino with other Albino or Albino with ordinary Rainbow trout have shown that it is genetically dominant. Pure descendants of the Albino are now being produced in aquaculture farms throughout Japan.

Albino is rarely found in the normal production of Rainbow trout in aquaculture farms. Albino is a mutation of the Rainbow trout that lacks tyrosinase (An enzyme that breaks down tyrosine, a type of amino acid, to produce melanin). This prevents the production of melanin, a black pigment, and causes the trout to turn yellow. The yellowish coloration is thought to be due to the other pigments that remain after the melanin-black pigment is gone.

Normal Albino is genetically recessive, so if both parents are not Albino, their offspring will not be Albino. However, Albino rainbow trout is dominant, so if either male or female parent is an Albino, their offspring will be born as an Albino.

Neither the albino rainbow trout nor the blue rainbow trout is a protective color, so if it were to occur in nature, it would have little chance of surviving due to bird damage.

Albino rainbow trout has little edible value but is released for recreational fishing because of its scarcity. In fish farms, it is sometimes used as a visible indicator of growth. There may be some differences in taste, smell, and texture, but these are within the range of individual differences. And Sushi chefs do not use Albino rainbow trout for sushi.

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Revision date: April 7, 2023

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What is real Omakase at a sushi restaurant?

Omakase sushi experience
She is very interested in eating sushi toppings for the first time.

We’ll start by breaking down the meaning of this word in Japanese.

The “O” of “Omakase” is a prefix generally used as an honorific expression. The meaning of “makase” refers to a judgment of things and means to entrust a task you were meant to do to someone else, allowing them to perform the task at their own discretion. In terms of sushi, while a customer normally chooses which toppings they want to eat on their own, a customer with limited sushi topping knowledge may ask the chef to prepare his own recommendations.

There are various other ways to order sushi toppings as well. First, sushi restaurants generally have a set menu called “Okimari.” For example, let’s consider an Okimari set that contains 8 pieces of nigiri sushi. This set of 8 pieces will contain the same toppings and maintain the same price throughout the year. In contrast, a customer may choose the number of toppings they like in whatever order they prefer, such as ordering two pieces each of four types of toppings, which is called “Okonomi.” They can even order eight of the same topping. The price for “Okonomi” depends on what is ordered, the more expensive the toppings are, the higher the price will be. For “Omakase,” the chef would select 8 toppings and serve them in his recommended order. However, the customer conveys their budget to the chef in advance so the sushi course can be provided within that budget. The customer can also specify toppings they prefer to avoid. In other words, you need to let the chef know in advance about your budget according to the market, and any requests (For example, I would like to eat the Splendid alfonsino (Kinmedai) in season) that you can’t budge on. You don’t need to leave those two things up to the chef’s discretion.

Now, in actuality, there are many sushi restaurants that stray from the original definition of “Omakase.”

For instance, he/she may include Tsumami as part of the course, rather than only sushi. This would be Sushi Kappo (sitting at the counter to enjoy Japanese food and served directly by the chef). A sushi restaurant was once a place where only Nigiri sushi was served. To explain in more detail, if only Nigiri sushi is served, then even if you were to eat 20 pieces of Nigiri sushi, your time in the restaurant would only be around 30 minutes (this is true the case of the establishment of the famous Jiro). Nowadays sushi restaurants are used for entertaining business clients or going on dates, so the customer may stay for around two hours. In situations like this conversation is the priority, so the actual ordering of the sushi takes the backseat. Incidentally, the practice of drinking Japanese sake at sushi restaurants is said to have begun around 1910.

Next, we’ll let you in on a common misconception that you probably don’t want to hear.

Apparently, people believe that ordering Omakase means that you will be served rare pieces that are not disclosed on the menu. Some are even convinced that they can get more expensive toppings than they would if they ordered with the Okonomi method. However, the restaurant just sets the price for the Omakase course and just adjusts the menu items accordingly (to suit the budget) based on current stock. The benefit to the restaurant is that it only stocks the amount of seafood necessary and will waste less. Unfortunately, rare finds are reserved for customers who know what they like. Go ahead and toss any such expectations out of your mind right now. Instead, acquiring sushi knowledge will allow you to avoid being recommended toppings that are approaching expiration.

Finally, if you just get an expensive Omakase course without understanding where the toppings came from or when they are in season, then it won’t contribute to your deeper understanding of the magnificence of Nigiri sushi.

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Revision date: April 18, 2023

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