SG is a sodium salt of the amino acid glutamic acid that enhances the flavor of certain foods. Originally isolated from seaweed, MSG is now made by fermenting corn, potatoes and rice. It does not enhance the four basic tastes (bitter, salty, sour, sweet) but it does enhance the complex flavors of meat, poultry, seafood, and vegetables. MSG is an important ingredient in the cuisines of China and Japan and is used commercially worldwide in many types of foods. It is naturally present at high levels in tomatoes and Parmesan cheese. In China, MSG is known as wei jing, which means flavor essence.