“Almost everyone today has heard of a substance like monosodium glutamate. And most people think it’s harmful. What is it really is and is it so dangerous? Let’s understand in the material.
What we will tell
What is monosodium glutamate?
It is the sodium salt of glutamic acid. It consists of glutamate and sodium. The former is a naturally occurring amino acid that is found in large quantities in the human body and in many foods. These include seaweed, tomatoes, potatoes, mushrooms, soy sauce and parmesan. Most animal protein consists of 11-22% glutamate, while plant protein can contain more than 40%. The second is an important mineral.
If you look at the amino acid profile of a protein, you won’t see glutamate itself. Instead, you may see “glutamic acid”. There’s not much difference. Glutamate is simply glutamic acid with an added mineral ion. It is the most abundant free amino acid in the brain. Our body also produces it. In addition, it can act as a neurotransmitter.
The substance was first discovered by Ikeda Kikunae, a professor at the University of Tokyo, in 1908. The chemist wondered what gives seaweed broth such a piquant flavor? The scientist himself was able to isolate 30 g of glutamic acid from 40 kg of the product. He didn’t stop there. Kikunae started commercial production of the flavor enhancer. Back then, however, it was called “Ajinomoto”.
Today, it’s used as a flavor enhancer. It looks like a white crystalline powder. It dissolves well in water and has a faint protein odor.
On product labels, monosodium glutamate is designated as E621.
In Russia, the substance is included in the list of food additives that are authorized for use in the manufacture of products. The exception is baby food. The American Food and Drug Administration (FDA) also considers it safe.
It is now added to sauces, fish, meat products, instant noodles, condiments, chips and snacks. That is, in all products that have a meaty taste or smell. It is also actively used in Thai, Korean, Vietnamese, Chinese and Japanese cuisines.
How is monosodium glutamate obtained?
There is a myth that it is a harmful chemical product that is addictive. However, this additive is of natural origin. It is obtained from the bacterium Corynebacterium glutamicum, which is formed from sugar cane, beets, tapioca. The process releases amino acids from which monosodium glutamate appears. That is, it is a method of fermentation of natural products.
Scientists have also tried to obtain glutamate using hydrolysis of plant proteins and direct synthesis. Most often from kombu algae. However, such methods are not as effective as fermentation. Therefore, they are not used.
Effect of monosodium glutamate on flavor
Monosodium glutamate makes spicy dishes more pleasant, and other products with its addition have a “meaty” flavor.
This food additive is one of the strongest stimulators of salivation. However, it is a harmless effect. The way it enhances flavor is by acting on specific glutamate taste receptors on the tongue.
Although monosodium glutamate is found in large quantities in many protein foods, it only enhances flavor when it is free. That is, it is not bound to other amino acids. By stimulating the taste buds, the savory flavor is enhanced.
Humans are capable of distinguishing four tastes: sweet, salty, sour, and bitter. In this case, we have receptors that recognize glutamic acid and its salts. The fifth taste is called umami in Japanese. It is a kind of protein food marker that tells the body that the food has a large amount of the right protein.
Is monosodium glutamate harmful?
Concerns about the harm of monosodium glutamate began after Dr. Kwok of the United States wrote a letter to the New England Journal of Medicine in 1968. In his appeal, the doctor described “Chinese restaurant syndrome.” This is “numbness of the back of the neck, gradually irradiating to both arms and back, as well as weakness and palpitations.”
The expert suggested that these symptoms could have been caused by the wine, high sodium or monosodium glutamate flavoring. However, it was the flavor enhancer that was found to be the likely culprit.
There are also concerns about adverse effects due to reports of disturbing effects that have been observed in animal studies.
In the analysis, it was found that the additive may be a neurotoxin. This is because brain damage was found in newborn mice that were fed this substance. It is worth noting that the rodents were given extremely high doses that do not correspond to the norm of human consumption. Therefore, it is incorrect to apply these results to humans.
The potential effect on weight is another concern. Many people refer to the rat model with obesity that was observed after glutamate consumption. But the animals were injected with it in the brain. This damaged the tissues of this organ, which caused this effect.
Studies show that high doses of the flavor enhancer, taken orally or as an injection, can damage brain tissue. However, recent evidence suggests that monosodium glutamate added to people’s diets has no adverse effect on body weight. Also, normal consumption of the enhancer with food does not affect energy absorption or fat metabolism.
But there is a group of people for whom it is not recommended. These are people with kidney disease, cardiovascular disease, pregnant women and children under the age of three. If you have an individual intolerance, then you should exclude from the diet products containing the sodium salt of glutamic acid.
Benefits of monosodium glutamate
The surprising fact is that monosodium glutamate has benefits.
Reduction in salt intake
The flavor enhancer contains 61% less sodium than table salt. Partially replacing it with monosodium glutamate reduces the sodium content of dishes by 32%. The flavor is not adversely affected.
Improved taste
As we age, our sense of taste and smell tend to deteriorate. This can lead to a decrease in appetite. This problem is exacerbated by an age-related decrease in saliva production, which makes chewing and swallowing difficult.
Monosodium glutamate improves both taste and salivation. Therefore, it may influence calorie intake in older adults. But there is an important point here – to which foods it is added. If it is added to spicy foods, it leads to a greater increase in calorie intake than adding it to bitter, sweet, salty or sour foods.
Positive effects on body processes
Sodium salt takes part in the production of gastrointestinal juice. Products with this mineral normalize water-salt metabolism and maintain acid-base balance. Also, the flavor enhancer helps to preserve blood volume, maintain normal blood pressure.
There is no need to be wary of this flavor enhancer. In modern studies reporting its side effects, large doses (≥3 g) were administered without food for a short period of time. Even so, clinical manifestations were mild and transient. Similar doses would be difficult to achieve by consuming foods with added monosodium glutamate under real-world conditions. There is also no data indicating harmful effects of monosodium glutamate on the general population.
What foods have a lot of monosodium glutamate?
It is important to note that a large number of the foods we consume daily contain glutamate in free or bound form. Among them (in 100 g):
- nori – 1400 mg;
- kombu – 3000 mg;
- Roquefort, 1280 mg;
- Parmesan – 1200 mg;
- soy sauce – 800 mg;
- walnuts – 660 mg;
- tomatoes – 260 mg;
- grape juice – 260 mg;
- peas – 200 mg;
- mushrooms – 180 mg;
- broccoli – 170 mg;
- oysters – 140 mg.
By the way, there are a number of products that do not contain this flavor enhancer. It is never added to candy, chocolate, yogurt or carbonated drinks.