Glutamic acid is just one of many amino acids that are the building blocks of proteins. It occurs naturally in many foods such as tomatoes, milk, and mushrooms. It is also found in the cells of our bodies, including mothers milk, and involves a wide variety of brain functions since it acts as a neurotransmitter. This natural glutamate in plants and animals is known as L-glutamic acid. Our normal digestive process slowly breaks down this natural or bound glutamic acid and it is eventually delivered to glutamate receptors in our body and brain. Broken down this natural way, it is harmless. However, for the person extremely reactive to excess glutamate, eating too many foods naturally high in glutamate is not recommended. Even bound glutamate will eventually reach the blood stream. In a factory, however, the bound glutamic acid in certain foods (corn, molasses, wheat, yeast) is broken down or made free by various processes (hydrolyzed, autolyzed, modified or fermented with strong chemicals, bacteria, or enzymes). The major process today involves a fermentation process in which bacteria excrete free glutamate from the corn substance they are mixed with. Sodium is added to make a salt-like substance which is more soluble. This substance is known as monosodium glutamate or MSG. It is 78.2% free glutamic acid, 12.2% sodium, and 9.6% water. It is odorless and has no distinct flavor, although some describe a salty/sweet flavor. This factory created substance is comprised of L-glutamic acid, D-glutamic acid, pyroglutamic acid, carcinogens, and other contaminants. This factory made version causes sensitive individuals more serious reactions than any other form of glutamic acid. Keep in mind, D-glutamic acid is rarely found in nature, and never in the natural foods we eat.
We are getting so much MSG from the growing number of processed food items that we have come to rely on. When glutamate is in its pure concentrated form, it must be labeled as MSG on food products containing it. Since free glutamate can be a component part of certain food additives, such as autolyzed yeast or hydrolyzed protein, the FDA allows it to go into food not labeled as MSG. A label may say yeast extract, calcium caseinate, or beef flavoring, but the product still contains varying amounts of free glutamic acid. This makes it very difficult for consumers who are trying to avoid it. It is also very dangerous for those who suffer severe reactions to it. But food manufacturers only value MSGs ability to enhance product flavors and big profits.
Glutamate from dried seaweed (Kombu) has been used for thousands of years in East Asian countries. Today, free glutamate or MSG is made from many different raw materials (mostly corn, molasses, and wheat) using various chemical processes previously mentioned. Strong acids, alkalis, enzymes, bacteria, and heat are used to hydrolyze animal, vegetable, or milk products, also producing food additives rich in free glutamate. Calcium caseinate and sodium caseinate are products of hydrolyzed milk protein. Maltodextrin and citric acid come from processed corn and although corn syrup and cornstarch are not as highly processed as maltodextrin is, they may not be totally free of glutamate as a result of their production. Yeast extract or autolyzed yeast is made by chemically processing natural yeast to create or isolate more free glutamic acid, and is now being widely substituted for pure MSG in many processed foods. Many such food labels state proudly, “No MSG”, but the yeast extract contains a substantial amount of free glutamate. Whey protein concentrate or protein isolate will contain free glutamate since hydrolyzed milk proteins are present or added. Soy protein isolate and soy protein concentrate are high in processed free glutamate and are often a component of textured protein, baby formula, cereal, energy bars, and drinks. Most smoke flavor or smoke flavorings use hydrolyzed protein to intensify flavor. Gelatin, which is a highly processed by-product of animal protein, and soy sauce, made from a fermentation process of soy beans are also rich in free glutamate. Pure MSG powder is sometimes added to cheaper brands of soy sauce which increases the free glutamate content, intensifying the flavor. Carrageenan is made from a type of seaweed known as Irish moss. It may contain free glutamate depending on how its processed. Hydrolyzed milk protein may be added to it. The book, Battling the MSG Myth goes on to cover many other hidden sources and the foods in which they are hidden.