Flavor element, the chemical component is sodium glutamate. Monosodium glutamate is a food freshener, which was originally extracted from seaweed and is now an industrial synthetic product.
Toxicity: A large number of research data show that regular consumption is harmless to human body.
Symptoms of poisoning: Some westerners have symptoms such as headache, redness, sweating, facial oppression or swelling, numbness in the mouth or around the mouth, burning sensation in the stomach and chest pain within 2 hours after eating food rich in monosodium glutamate. This phenomenon mostly occurs after Chinese meals, so some westerners call it "China restaurant syndrome", but the relationship between this phenomenon and eating monosodium glutamate has not been confirmed so far.
Emergency treatment: No special treatment is required after taking excessive monosodium glutamate by mistake. People with "China restaurant syndrome" can also take vitamin B6 orally, 50mg per day.
Poisoning prevention: you can safely eat monosodium glutamate, but don't use it too much. Generally, the consumption per person should not exceed 20 grams per day.
Monosodium glutamate is a kind of seasoning to enhance flavor, which can be used for cooking, stuffing, cold dishes and soup. Monosodium glutamate has no direct nutritional value to human body, but it can increase the flavor of food, arouse people's appetite and help improve the digestibility of food. In addition, sodium glutamate, the main component of monosodium glutamate, also has the function of treating chronic hepatitis, hepatic coma, neurasthenia, epilepsy, gastric acid deficiency and other diseases.
Although monosodium glutamate can be fresh, it will have the opposite effect if it is used improperly.
I read some posts about monosodium glutamate and summarized them, including the skills of using monosodium glutamate in cooking and how to use it scientifically. I don't know much about the scientific principles, especially glutamic acid, hehe ...
1.For dishes cooked in stock, monosodium glutamate is not necessary. Because the broth itself has the characteristics of freshness, fragrance and clarity, monosodium glutamate has only one flavor, and its flavor cannot be equal to that of the broth. If monosodium glutamate is used, it will cover up the original taste and make the dishes taste neither fish nor fowl.
2. For acidic dishes, such as sweet and sour, vinegar-baked, vinegar-pepper vegetables, etc., monosodium glutamate should not be used. Because monosodium glutamate is not easy to dissolve in acidic substances, the greater the acidity, the lower the solubility and the worse the umami effect.
3. When crystal monosodium glutamate is used to mix cold dishes, it should be melted with a small amount of hot water first, and then poured on cold dishes, which has a good effect (because monosodium glutamate can only play a role at 45℃). If you mix cold dishes directly with crystals, it is not easy to mix them evenly, which will affect the refreshing effect of monosodium glutamate.
4. MSG should be added when cooking. Because at high temperature, monosodium glutamate will be decomposed into sodium pyroglutamate, that is, dehydrated sodium glutamate, which not only has no umami taste, but also produces slight toxins, which is harmful to human body.
5. When using monosodium glutamate, you should master the dosage, not the more the better. Its water dilution is 3000 times, and the taste of monosodium glutamate is 0.033%. When using it, 1500 times is appropriate. If too much is put into the dish, it will produce a strange smell that seems to be wrong and astringent, resulting in the opposite effect. The World Health Organization suggests that monosodium glutamate should not be used in baby food for the time being; Adults should not consume more than 6 grams of monosodium glutamate per person per day.
6. monosodium glutamate is not easy to dissolve at room temperature, and it is the best to dissolve at 70 C～ 90 C, with the best flavor. When it exceeds 100C, monosodium glutamate will be volatilized by water vapor, and when it exceeds 130C, it will deteriorate into sodium pyroglutamate, which will not only have no flavor, but also produce toxicity. For stewed, roasted, boiled, boiled and steamed dishes, it is not advisable to put monosodium glutamate too early, but to put it in when it is out of the pot.
7. It is not advisable to use monosodium glutamate in alkaline raw materials. When monosodium glutamate meets alkali, it will be synthesized into disodium glutamate, which will produce ammonia odor.
About chicken essence
Chicken essence is not extracted from chicken, it is made by adding fresh-keeping nucleotides on the basis of monosodium glutamate. Because nucleotide has the delicate flavor of chicken, it is called chicken essence, but chicken essence is fresher than monosodium glutamate. From the health point of view, chicken essence is harmless to human body, but when cooking, if you add too much chicken essence, it will destroy the original taste of the dish and affect the taste. Chicken essence contains a variety of flavoring agents, and its taste is comprehensive and coordinated.
Monosodium glutamate is a titanium salt of glutamic acid with strong meat flavor. It contains one part in crystal water, and its molecular formula is C5H8O4Na·H2O. . The salt we eat every day can't feel salty when diluted 400 times with water, nor can ordinary sucrose feel sweet when diluted 200 times with water, but monosodium glutamate can still feel delicious when diluted 300 times with water. Therefore, people call it "monosodium glutamate".
MSG has become an indispensable condiment in our life, but do you know? Monosodium glutamate can not only add flavor to dishes, but also has rich nutrition. After being eaten by us, sodium glutamate can be dissociated into glutamic acid through the action of gastric acid, which can be quickly digested and absorbed and become an essential protein in human tissues. Glutamate is a kind of advanced nutritional supplement, which has the functions of protecting liver, detoxifying, improving nervous system in medical treatment, and promoting the development of nervous system for children. Therefore, in daily life, regular and moderate consumption of monosodium glutamate can promote development and enhance physical fitness.
Glutamic acid was first obtained in 1866 when German Liehausen cooked gluten with sulfuric acid. However, the official production of monosodium glutamate in the world was 1908. The production of monosodium glutamate in China was first produced by Shanghai Tianchu monosodium glutamate factory by hydrolysis in 1923.
Hydrolysis method is to hydrolyze gluten with 34% hydrochloric acid under pressure to obtain hydrolysate, which is decolorized and concentrated to obtain glutamic acid, then dissolved in water and neutralized with sodium hydroxide, and concentrated until the salt of glutamic acid is crystallized out. Gluten used in the production of monosodium glutamate is uneconomical, and it needs a lot of wheat to be ground into flour. According to calculation, the production of 1 ton monosodium glutamate needs more than1ton of water gluten, which is equivalent to 40 tons of wheat, and it must be hydrolyzed by hydrochloric acid under high temperature and high pressure. This method consumes a lot of grain and acid, which seriously corrodes the equipment and is not conducive to the health of workers.
Later, microbiologists found that in the fermentation world, there are still some "skilled craftsmen" who can turn starch into glutamic acid, which is the bacterial Corynebacterium glutamicum. Since then, the production of monosodium glutamate has changed from chemical method to fermentation method.
Since the 1960s, the production of monosodium glutamate in China has gradually changed to bacterial fermentation. Using bacterial fermentation method, only 3 tons of starch and a small amount of ammonium sulfate, urea and ammonia water are used to produce 1 ton of monosodium glutamate.
After the 1960s, extra fresh monosodium glutamate, also known as strong monosodium glutamate, appeared internationally. The so-called extra fresh monosodium glutamate is that 5 ~10% of 5 ′-inosinic acid and 5 ′-uridylic acid are mixed into monosodium glutamate, which can improve the freshness of monosodium glutamate by dozens of times.
Inosine and uridine are organic compounds belonging to nucleosides. Nucleotide is the essence of life forms, which plays an important role in the genetic variation, growth and development of organisms and the synthesis of protein. Nucleotides also play a great role in medicine. Inosine can treat acute and chronic hepatitis, toxic hepatitis, liver cirrhosis, thrombocytopenia, coronary and arterial infarction, rheumatic heart disease and so on. Uridine can be used to treat radiation sickness, improve the hematopoietic system of bone marrow, make white blood cells rise, and also treat central retinitis, optic atrophy and other diseases. Therefore, extra-fresh monosodium glutamate is not only a fresh aid and an ideal condiment, but also an efficient nutritional adjuvant and chemotherapy agent.
Inosine and Uridine used to be imported, and their prices were as high as one kilogram of 200 yuan. Since 1970s, China has successfully used bacteria (such as Corynebacterium glutamicum 265 and Brevibacterium ammoniagenes 926) to produce inosinic acid and uridylic acid by fermentation, and the cost is only 2 ~ 3 yuan per kilogram.
At present, the third-generation monosodium glutamate sold in the market-chicken essence, its freshness is 1.58 times higher than that of 99% crystalline monosodium glutamate, which is not only delicious, but also full of strong chicken flavor and is welcomed by people.