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Glutamic acid and its salts

E620 - E625: food has a stronger smell and sharper taste








Authors: Urmas Kokassaar, Mihkel Zilmer

Article published on 06.09.1998



As the title says, flavor enhancers belong to this group of additives. These additives themselves are not particularly palatable, but they enhance the flavor and taste characteristics of food.


The best-known representatives of this group of additives are glutamic acid (E620) and its salts, or glutamates. In the list of additives, we can find sodium (E621), potassium (E622), calcium (E623), ammonium (E624) and magnesium (E625) salts of glutamic acid. Sodium glutamate is the most well-known additive, which in chemically pure form is a white odorless crystalline powder.


Common in nature


Glutamic acid is an amino acid common in nature. The German chemist Ritthausen was the first to isolate glutamic acid from wheat proteins in 1866. And indeed, this amino acid, which is widespread in nature, is abundant in both plant proteins and muscles. In nature, we can find glutamates in tomatoes, tomato juice, mushrooms, peas, milk, fish, cereals and other foods.

Glutamic acid is part of proteins in organisms or occurs in free form. Humans are no exception here. Glutamic acid can also be synthesized in the human body - our body is able to synthesize tens of grams of it per day.


Glutamic acid is very necessary in nitrogen metabolism in the human body. This is both in the synthesis of other amino acids and in the elimination of dangerous ammonia formed in metabolism. Glutamic acid is also necessary for the functioning of the nervous system.

Glutamic acid is abundant in human muscles, brain and breast milk.


Industrially, glutamic acid is produced either by fermentation of carbohydrate-rich raw materials with special bacterial strains or by hydrolysis of plant proteins.


Chinese restaurant syndrome


From the above, one might think that the addition of glutamic acid and its salts to foods should be beneficial for people. Unfortunately, nothing in the world is completely straightforward, and this truth also applies to glutamic acid and its salts.

Historically, glutamic acid salts, especially monosodium glutamate, have been used the most by Asian (Chinese, Japanese, and Korean) cuisine for flavoring meat dishes. People's hypersensitivity to glutamic acid salts is called the Chinese restaurant syndrome.


Hypersensitivity to glutamic acid salts usually manifests itself as redness of the face, neck and chest, hives, feeling hot, heart rhythm disturbances, dizziness or even a severe headache. Often the person himself does not know that he is hypersensitive to this compound and should avoid monosodium glutamate.

Although in most cases all of the mentioned symptoms disappear within about an hour after they appear, excessive consumption of foods flavored with glutamate salts should be avoided. The strength and duration of the mentioned disturbances depend on the amount of glutamic acid salts eaten. For children, their effect is more powerful and manifests itself mainly as increased activity and restlessness, as well as facial redness or swelling.


Changing the taste


Another objection to the addition of glutamic acid salts is that they hide the true taste and smell of the food.

Because monosodium glutamate enhances the taste of meat broth in foods, so to speak, the consumer's sense of taste can easily fall victim to deception. It tastes like a lot of meat, but in reality there is quite a bit of it. The addition of glutamic acid salts also reduces the use of natural meat.

Some researchers are of the opinion that monosodium glutamate creates a sensation on the taste receptors of the tongue, which is perceived as a kind of spicy taste.


Where are the glutamates?


Glutamates can be found in bouillon cubes, seasoning mixes, ingredients in meat products, packet soups, sauces, potato chips and elsewhere.

You can read a few things from the product packaging. Solid evidencemonosodium glutamatethe presence is either the name of this compound or the additive code E621.

Sometimes the letter combination MSG, i.e. an abbreviation of the English word pair monosodium glutamate, is a synonym for the mentioned compound. Glutamaadirikkust tähistavaid sünonüüme on pakenditel teisigi, näiteks proteiinihüdrolüsaat, pärmi-autolüsaat, Hydrolyzed Vegetable Protein, Natural Flavor etc.


As several grams of glutamic acid can be added per kilo of the product, it is worth evaluating the approximate amount of this compound in the product when buying dry concentrates. Namely, all the components used to make the product must be indicated on the packaging in descending order of weight. If glutamates are among the top five ingredients in the list of bouillon cubes, then this product contains quite a lot of this flavor enhancer. In normally salty food, the optimal amount of monosodium glutamate for the sense of taste is 0.2-0.9%.


Dangerous or safe?


The safety of glutamic acid salts has been much debated. Accusations of allergenicity and even teratogenicity, i.e. fetal damage, have been made against them in press columns.

However, these compounds can rarely cause an acute allergy, but they cause a number of ailments in hypersensitive people. There is no direct scientific evidence of harm to the fetus of glutamic acid salts when consumed normally.


But it must also be taken into account that both glutamic acid and its salts have an important effect on the functioning of our nervous system. For this reason, glutamic acid and calcium glutamate are used in the treatment of several neurological diseases. Considering also that glutamic acid is a precursor of a very important neurotransmitter that works in the nervous system, overconsumption of glutamic acid, and therefore also its salts, should definitely be avoided. Overconsumption must also be avoided by people who have problems with high blood sugar levels.





Image: wikipedia


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