E627: Disodium Guanylate (GMP Umami Synergist)

Direct Answer

E627 (Disodium 5'-Guanylate / GMP) is the sodium salt of guanylic acid, a purine nucleotide naturally concentrated in dried shiitake mushrooms. INS 627, ADI is Not Specified, exhibiting massive 8x–30x synergistic umami amplification when paired with MSG.

Source: JECFA / EFSA · Last reviewed Aug 28, 2026

Specs

E-Number Code	E627
INS / Codex Number	INS 627
Functional Class	Flavor Enhancer (Purine Nucleotide Umami Synergist)
Acceptable Daily Intake (ADI)	Not Specified (Quantum Satis)
Chemical Formula	C10H12N5Na2O8P · xH2O
Primary Mechanism	Binds allosteric site on T1R1/T1R3 umami receptor, locking glutamate into the orthosteric binding pocket
Common Target Foods	Savory snack seasonings (Doritos, chips), instant ramen noodle seasoning packets, bouillon cubes
Dietary Compliance	Vegan (Microbial fermentation of tapioca/sugar), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 172.530)

The 1+1=8 Umami Synergy Multiplier

While E627 provides minimal savory taste on its own, adding just 2% E627 to 98% MSG increases perceived savory umami intensity by over 800%, allowing dramatic sodium reductions in commercial seasonings.