Monosodium glutamate. Computer model of a molecule of the food flavouring monosodium glutamate (C5.H8 N.O4.Na). The atoms (tubes) of the molecule are colour-coded: carbon (light blue), nitrogen (dark blue), oxygen (red), hydrogen (white) and sodium (Na, yellow sphere). This chemical is a salt made from the negative glutamic acid anion (tubes) and the positive sodium cation. It is viewed as either enhancing the four standard tastes (sweet, salty, sour and bitter), or as a fifth taste that is called umami.