E628 - Dipotassium guanylate

At a glance

• What it is: the dipotassium salt of 5′-guanylic acid (a natural nucleotide found in cells)
• What it does: enhances umami, especially when paired with glutamates
• Where it’s used: snacks, soups, seasonings, sauces, instant noodles, and similar savory foods
• Also called: E628, potassium guanylate, dipotassium 5′-guanylate
• Typical partners: monosodium glutamate, disodium inosinate, or blends like disodium 5-ribonucleotide

Why is Dipotassium guanylate added to food?

Food makers add E628 to deepen savory (umami) taste, which helps soups, sauces, and snacks taste fuller and more “brothy.” It is especially effective when used together with glutamates, because the two work in synergy to boost umami perception more than either one alone.¹

What foods contain Dipotassium guanylate?

You’ll most often find E628 in:

• Dry soup mixes and instant noodles
• Snack foods like chips and crackers
• Bouillon cubes, gravies, and seasoning blends
• Ready sauces, canned or pouch meals, and savory spreads

On labels, it may appear alone or next to related enhancers such as monosodium glutamate, disodium guanylate, disodium inosinate, dipotassium inosinate, or the combined blend disodium 5-ribonucleotide. In the European Union, it is an authorized food additive listed as E628 for use as a flavor enhancer under the general food additives regulation.²

What can replace Dipotassium guanylate?

• Other ribonucleotides: disodium guanylate, disodium inosinate, or the blend disodium 5-ribonucleotide
• Glutamates: monosodium glutamate
• Umami-rich ingredients (recipe-level): yeast extract, mushroom extracts, seaweed, long-cooked stocks

Which substitute works best depends on flavor target, sodium goals, and labeling preferences.

How is Dipotassium guanylate made?

Commercial E628 is produced from 5′-guanylic acid (GMP). Manufacturers obtain GMP by breaking down RNA-rich sources (for example, via enzymatic hydrolysis), then purifying the 5′-nucleotide. Neutralizing GMP with potassium hydroxide yields the dipotassium salt (dipotassium guanylate), which is then crystallized and dried.³ Specifications for identity and purity of guanylic acid and its sodium, potassium, and calcium salts are published in international additive monographs.³

Is Dipotassium guanylate safe to eat?

In the EU, E628 is authorized as a flavor enhancer under Regulation (EC) No 1333/2008, which sets the framework for where and how food additives may be used.² Its authorization and conditions of use reflect prior risk assessment by regulators. As with any additive, manufacturers must stay within the legal limits and good manufacturing practice.

Does Dipotassium guanylate have any benefits?

From a food-making point of view, E628 can deliver a strong savory boost at low levels, helping products taste richer and more satisfying. Because it works synergistically with glutamates, developers can often achieve the same flavor impact with smaller amounts of each enhancer.¹

Who should avoid Dipotassium guanylate?

• People managing gout or advised to follow a low‑purine diet: 5′‑guanylic acid is a purine nucleotide, and purines break down to uric acid. While the amounts from additives are typically small, some individuals choose to limit added purines.⁴⁵
• People who must restrict potassium (for example, some with kidney disease): as a potassium salt, E628 adds a small amount of potassium to the diet. Your clinician or dietitian may advise checking labels for potassium sources.⁶

If you have a medical condition, follow your healthcare provider’s advice about specific ingredients.

Myths & facts

• Myth: “E628 is the same as MSG.” Fact: They’re different compounds. E628 is a ribonucleotide; MSG is a glutamate salt. They are often used together because they enhance umami synergistically.¹
• Myth: “All E‑numbers are artificial.” Fact: An E‑number just means an additive is approved in the EU. Some are nature‑identical or made from natural sources, like ascorbic acid and citric acid.
• Myth: “E628 always causes headaches.” Fact: Regulators authorize E628 with use conditions based on safety reviews; adverse reactions are not expected for the general population when used as approved.²

Dipotassium guanylate in branded foods

On ingredient lists, look for “dipotassium guanylate,” “E628,” or simply “guanylate.” It often appears together with monosodium glutamate, disodium inosinate, or blends like disodium 5-ribonucleotide in savory snacks, instant soups, bouillons, and seasoning packets.

References

Footnotes

1. INS 628 — Codex GSFA (function: flavour enhancer). Food and Agriculture Organization of the United Nations. https://www.fao.org/gsfaonline/additives/details.html?id=119 ↩ ↩² ↩³

2. Regulation (EC) No 1333/2008 on food additives — European Union law. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩ ↩² ↩³

3. Guanylic acid and its sodium, potassium and calcium salts — JECFA specifications. FAO JECFA Monographs. https://www.fao.org/3/a-at875e.pdf ↩ ↩²

4. Guanosine 5′-monophosphate (GMP) — PubChem (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/6802 ↩

5. Gout diet basics (purines and uric acid) — MedlinePlus (NIH). https://medlineplus.gov/ency/patientinstructions/000786.htm ↩

6. Potassium in diet — MedlinePlus (NIH). https://medlineplus.gov/ency/article/002413.htm ↩