Monosodium glutamate (MSG) is the sodium salt of glutamic acid, one of the most abundant amino acids in our diet. It has been used for more than a hundred years to enhance and balance the savory taste of food.

Glutamate (from the amino acid glutamine) is found naturally in protein-containing foods such as meat, vegetables, poultry and milk. The human body also produces glutamate as part of normal metabolism. The muscles, brain and other organs store about four pounds of glutamate, and mother's milk is rich in glutamate.

Glutamate is found in two forms: "bound" glutamate (linked to other amino acids in protein) and "free" glutamate. Foods which are high in free glutamate, like ripe tomatoes and cheeses, are considered tasty. The umami receptors on the tongue are uniquely receptive to glutamate, which explains why free glutamate is effective in enhancing the tastiness of food.

The glutamate from MSG seasoning and the glutamate occurring naturally in food is exactly the same, and the body treats glutamate in the same way no matter what its source.

Glutamate-rich seasonings have been used in recipes all around the world for centuries: garum, a fermented fish sauce, was a valuable condiment in ancient Rome, for example.

However, it was not until 1908 that Professor Kikunae Ikeda of the University of Tokyo isolated glutamate from kelp seaweed, an ingredient used in Japanese dashi stock, and unlocked the secret of its flavor-enhancing properties which he called umami. Since that time, MSG has been, and continues to be, widely used as an effective means of making good food taste better.

Monosodium glutamate (MSG) is produced by fermentation, a process similar to that used in making beer, vinegar and yogurt. Carbohydrates from crops such as corn, sugar beets/cane or cassava are fermented to produce glutamate which is purified and crystallised before drying. The finished product is a pure, white crystal which dissolves easily and blends well in many recipes.

Because free glutamate has a unique affinity with the umami taste receptors on the tongue, glutamate is the purest source of umami taste. Umami is our fifth taste, with sweet, sour, salty and bitter and gives food a rich savory character.

Increasing the level of free glutamate in a recipe, during cooking or processing, is a simple and effective way to increase the umami taste and balance.

As foods ripen, the levels of free glutamate increase resulting in a richer, more flavorful taste. This is why foods naturally high in glutamate when ripe or mature, such as tomatoes, cheese and mushrooms, are used to enhance the taste and balance of savory recipes. Glutamate-rich stocks or condiments, including MSG, can also be used increase umami.

The glutamate added to foods in the form of MSG seasoning represents only a small fraction of the total amount of glutamate consumed in the average daily diet. The average person consumes around 10 grams of bound glutamate and up to one gram of free glutamate daily.

Most of the glutamate consumed as food is used by the digestive system for energy - and therefore does not reach the bloodstream. The human body produces about 50 grams of free glutamate each day as part of normal metabolism.

Yes. Since its discovery in 1908, MSG has been used safely as a food ingredient and seasoning. A great deal of scientific research has been undertaken into MSG's role in the diet and its safety. This research, which has been reviewed by scientists and regulators around the world, demonstrates that monosodium glutamate (MSG) is safe for everyone.

In the United States, MSG has been included in the U.S. Food and Drug Administration's (FDA's) list of substances that are Generally Recognized as Safe (GRAS). Foods designated GRAS include ingredients like sugar, baking powder and vinegar, whose safety has been established through common use in food and/or through extensive testing.

The glutamate in MSG seasoning and the glutamate in many foods we enjoy as part of our normal diets, like vegetables, cheese, fish and meat, is exactly the same and is treated by the body in exactly the same way no matter what the source. For this reason is it unlikely that people are sensitive to MSG.

Decades of research have shown no scientific evidence of sensitivity to MSG. Studies have also found that most people who believe that they respond adversely to MSG, with symptoms that range from mild and transitory to more severe, do not have these reactions when evaluated in carefully controlled tests.

If you believe that you react to a particular food or ingredient, you should seek proper medical diagnosis, rather than attributing to MSG symptoms which may have another more serious cause.

Yes. MSG is safe for everyone, including pregnant women and babies. Breast milk is naturally high in glutamate; the average newborn baby consumes 150 to 200 milligrams of free glutamate each day from mother's milk.

Despite the popular misconception, baby food manufacturers in the USA were never prohibited from using MSG - rather, the use of food additives in general in baby food was ended voluntarily many years ago.

The FDA requires packaged foods to list every ingredient used so, by looking on the ingredient panel, you will be able to identify those products that use MSG seasoning.

In addition to MSG, there are other seasonings and ingredients that contain free glutamate which are also used widely. Soy sauce, hydrolyzed vegetable protein (HVP) and yeast extracts are all glutamate-rich seasonings. When used in small amounts, all of these ingredients significantly enhance the overall taste balance of the foods to which they are added. To determine whether packaged food contains these glutamate-rich ingredients, all you need to do is look on the ingredient panel.