1 + 1= 8: Gustatory synergy

What is very unusual about umami is that the intensity of the taste it imparts is not solely dependent on how much glutamate is present. To a much greater extent, it is affected by synergistic interactions with other substances that increase its gustatory intensity. Most often this involves a 5’-ribonucleotide, especially inosinate and guanylate. Somewhat imprecisely and proverbially, it has been said that the taste imparted by equal amounts of glutamate and a nucleotide is eight times stronger than that produced by glutamate alone. As we will see, however, the synergistic effect can be much stronger.