The use of glutamate to enhance the taste of food is internationally widespread because it enhances the taste of food and increases the desire to eat
The letter E precedes in Spain the food additives authorized as flavor enhancers. E621 is monosodium glutamate, which is widely used, especially in Chinese food. It is, in fact, associated with Chinese restaurant syndrome, a series of symptoms that can include migraine headaches, flushing, or sweating. In addition, it is proven that its taste causes more desire to eat. More information about glutamate and its interesting uses is given in the following lines.
In our country, the letter E precedes the additives authorized as flavor enhancers. "E620, for example, is glutamic acid, while E621 is monosodium glutamate, which was patented by Japanese professor Kikunae Ikeda," explains researcher Víctor Tagua, from the Higher Council for Scientific Research (CSIC). “But there are other glutamates that also confer umami flavor, like E622 or monopotassium glutamate; E623 or calcium diglutamate; E624 or monoammonium glutamate and E625 or magnesium diglutamate ”, comments this expert.
E621, which is the most widely used, could be associated with the so-called “Chinese restaurant syndrome”, a term coined in the 1960s in the United States, where the first cases were linked to the ingestion of very rich Chinese food in glutamate. Recent scientific research does not endorse that the origin of the symptoms of this syndrome (migraine, flushing and sweating) is really that component. What is proven is that its taste causes more desire to eat, which can lead to ingesting a greater amount than necessary.
But ... what does umami taste like?
Glutamate in its acid form (glutamic acid or E620) has a mild umami flavor, while the salts of glutamic acid, the glutamates, are easily ionized (i.e., their atoms become electrically charged) to provide the characteristic taste of umami.
This flavor is persistently spread through the tongue, promotes salivation, activates receptors in the stomach and is non-satiating. What triggers that sensory cascade? “It is due, above all, to a molecule well known to chemists and biologists: glutamic acid, one of the amino acids that are part of proteins, and which, in addition, is a neurotransmitter. But ribonucleotides such as guanosine monophosphate (GMP) and inosine monophosphate (IMP) also give this flavor ”, points out Víctor Tagua.
Umami is reminiscent of a pleasant meat or broth flavor that leaves a lingering sensation, covering the entire tongue and inducing salivation.
An additive difficult to avoid, but not impossible
A group of researchers from the University of Ontario (Canada) studied the effects of the product in 61 people and 36% of them had symptoms. But there is no conclusive evidence that they were a direct consequence of umami consumption.
In 2000 another investigation was done, this one with 130 people who considered themselves reactive to MSG, although perfectly healthy in other aspects of health. All were given a dose dissolved in water, or a placebo, and those with any of the conditions described as "MSG symptom complex" were subjected to a new test.
They were given a higher dose to see if the ailments increased and the process was repeated. At the end of several rounds, only two of the patients showed consistent reactions to MSG and not to placebo. And when they were given another test with the glutamate included in the food, they did not have the same reaction and did not show symptoms.
While in the United States it is considered safe for people, in Europe it is classified as a food additive and is allowed in certain products and in limited doses. There are many detractors of this product, who consider it as harmful to health as many other foods, especially processed, that contain chemical compounds.