Monosodium glutamate

The taste is not so much “salty” or “sweet”, but mainly umami: a deep, savory flavor that makes dishes taste fuller and richer. MSG itself has little odor or strong taste, but enhances existing flavors in a dish.

It is used in soups, sauces, snacks, instant noodles and processed foods. It is popular in the food industry because it increases the flavor intensity without adding many extra ingredients.