Monosodium glutamate is a common flavor enhancer that is used particularly in Chinese and Japanese cooking.
Monosodium glutamate, or MSG, is presumably most commonly used in oriental cooking for traditional reasons.
For thousands of years the Japanese have incorporated a type of seaweed known as kombu in their cooking to make food taste better. It was not until 1908, however, that the actual ingredient in kombu responsible for improvement in flavor was identified as glutamate.
From then until 1956, glutamate was produced commercially in Japan by a very slow and expensive means of extraction.
Then large-scale industrial production began and has continued, mainly involving the fermentation of natural substances such as molasses from sugar beet or sugar cane. Today, hundreds of thousands of tons of MSG are produced all over the world.
Monosodium glutamate contains 78.2 percent glutamate, 12.2 percent sodium, and 9.6 percent water.
Glutamate, or free glutamic acid, is an amino acid that can be found naturally in protein-containing foods such as meat, vegetable, poultry, and milk.
Roquefort and Parmesan cheese contain a lot of it.
The glutamate in commercially produced MSG, however, is different from that found in plants and animals. Natural glutamate consists solely of L-glutamic acid, whereas the artificial variety contains L-glutamic acid plus D-glutamic acid, pyroglutamic acid, and other chemicals.
It is widely known that Chinese and Japanese food contains MSG, but people don’t seem to be aware that it is also used in foods in other parts of the world.
In Italy, for example, it is used in pizzas and lasagne; in the U.S. it is used in chowders and stews; and in Britain it can be found in snack foods such as potato crisps and cereals.
It is thought that MSG intensifies the naturally occurring “fifth taste” in some food, the other, better known, four tastes being sweet, sour, bitter, and salt.
This fifth taste is known as umami in Japanese, and is often described as a savory, broth-like, or meaty taste.
Umami was first identified as a taste in 1908 by Kikunae Ikeda of the Tokyo Imperial University, at the same time that glutamate was discovered in kombu. It makes good evolutionary sense that we should have the ability to taste glutamate, because it is the most abundant amino acid found in natural foods.
The Sensory Research Science Center at the University of Chicago, suggests that umami signals the presence of protein in food, just as sweetness indicates energy-giving carbohydrates, bitterness alerts us to toxins, saltiness to a need for minerals, and sourness to spoilage.
A team of scientists has even identified a receptor for umami, which is a modified form of a molecule known as mGluR4.