Monosodium glutamate is a modern condiment made from grain. Monosodium glutamate is a kind of seasoning, which is the crystal of sodium glutamate purified by fermentation with grain as raw material. The main component is sodium glutamate, which belongs to one of the most abundant non-essential amino acids in nature. Its main function is to increase the umami taste of food. It is most used in Chinese food and can also be used in soup and sauce.

Monosodium glutamate was discovered by Japanese Ajisen Company on 1909 and applied for a patent. The appearance of pure monosodium glutamate is a white crystalline powder. When monosodium glutamate is dissolved in water, it will rapidly ionize into free sodium ions and glutamate ions. Monosodium glutamate gives people a sense of taste by stimulating specific taste receptors on the taste buds of the tongue. This kind of taste is defined as umami by the Japanese, but this Japanese umami is obviously different from the umami among the five familiar flavors in China.