E629 - Calcium guanylate

At a glance

• What it is: the calcium salt of 5'-guanylic acid (a guanosine nucleotide), used as a flavor enhancer
• Taste role: strengthens savory, umami notes; often paired with glutamate and inosinate
• Where it shows up: snack seasonings, soups, broths, sauces, bouillon, instant noodles, and ready meals
• Diet notes: sodium-free itself; used in tiny amounts; contributes purines (relevant if you manage gout)
• Regulation: listed in the EU with identity and purity criteria as E629

Why is Calcium guanylate added to food?

Food makers add calcium guanylate to lift savory, umami taste without adding strong flavors of its own. It works especially well with glutamate, including monosodium glutamate, and with inosinate, such as disodium inosinate, creating a bigger flavor impact from small amounts. The EU lists E629 as a flavor enhancer and sets specifications for its identity and purity.¹ The compound is also described in scientific and regulatory databases as a flavoring/flavor-enhancing ingredient.²

What foods contain Calcium guanylate?

You are most likely to find calcium guanylate in:

• Dry seasoning blends and snack coatings
• Instant noodle sachets, ramen broth bases, and bouillon cubes or powders
• Canned or instant soups, gravies, and sauces
• Savory ready-to-eat or frozen meals
• Some cured or processed meats and seafood seasonings

On ingredient lists it may appear as “calcium guanylate,” “E629,” or alongside other nucleotides such as disodium guanylate or dipotassium guanylate.

What can replace Calcium guanylate?

Formulators can reach similar flavor effects with:

• Disodium guanylate (sodium salt) or dipotassium guanylate
• Disodium inosinate or blends like disodium 5'-ribonucleotide
• Monosodium glutamate for the core umami note
• Non-additive options such as yeast extract, mushroom extract, or long-simmered stocks
• For salt reduction strategies, potassium salts like potassium chloride are sometimes used alongside umami enhancers

How is Calcium guanylate made?

E629 is the calcium salt of 5'-guanylic acid. In practice, manufacturers produce 5'-guanylic acid (also called 5'-GMP) from natural RNA-rich materials using food-grade enzymes, then neutralize it with a calcium source to form calcium guanylate. EU specifications define E629 as the calcium salt of 5'-guanylic acid and set purity criteria (for example, assay on a dry basis), ensuring a consistent identity for food use.¹ Chemical identity databases also identify calcium guanylate as the calcium salt of 5'-GMP.²

Is Calcium guanylate safe to eat?

At the levels used in foods, calcium guanylate is considered safe by regulators that set identity and purity criteria and allow its use as a flavor enhancer.¹³ It is commonly used internationally in line with good manufacturing practice. While it is often paired with MSG for stronger umami, calcium guanylate is not the same compound as MSG; the U.S. Food and Drug Administration (FDA) considers MSG itself to be safe when used as intended.⁴

Does Calcium guanylate have any benefits?

The main benefit is sensory: it boosts savory taste and can make seasonings and broths taste fuller. Because it is potent in tiny amounts, it can help developers achieve satisfying flavor without relying only on salt. It does not supply meaningful nutrition and is used at very low levels.

Who should avoid Calcium guanylate?

• People managing gout or high uric acid: calcium guanylate is a purine nucleotide (derived from guanine). Purines break down to uric acid in the body, so some individuals with gout choose to limit added purines; ask your healthcare professional for personalized advice.⁵
• Individuals following specific medical diets (for kidney disease, low-purine, or low-additive diets) should check labels and consult a clinician.
• Those with general sensitivity concerns about flavor enhancers can choose products without added nucleotides.

Myths & facts

• Myth: “Calcium guanylate is the same as MSG.” Fact: They are different compounds. Calcium guanylate is a nucleotide salt; MSG is a glutamate salt. They are often used together to boost umami.⁴
• Myth: “It adds lots of sodium.” Fact: Calcium guanylate is a calcium salt, not a sodium salt; however, it is often used alongside other ingredients that may contain sodium.
• Myth: “It’s a strong-tasting chemical.” Fact: On its own, it has little flavor. Its job is to enhance savory notes already present in food.
• Myth: “It isn’t regulated.” Fact: The EU assigns E629 to calcium guanylate and sets detailed identity and purity criteria for its use in food.¹

Calcium guanylate in branded foods

You can spot “calcium guanylate” or “E629” on labels of potato chips and other snacks, instant noodle seasonings, bouillon and soup powders, canned soups and gravies, savory sauces, and some frozen meals. It often appears next to MSG or other nucleotides such as “inosinate” or “guanylate.” If you prefer to avoid it, look for products labeled without flavor enhancers or choose simpler ingredient lists.

References

Footnotes

1. Commission Regulation (EU) No 231/2012 — Specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩² ↩³ ↩⁴

2. Calcium guanylate — PubChem, National Center for Biotechnology Information (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Calcium-guanylate ↩ ↩²

3. General Standard for Food Additives (CXS 192-1995) — FAO/WHO Codex Alimentarius. https://www.fao.org/gsfaonline/overview.html ↩

4. Questions and Answers on Monosodium Glutamate (MSG) — U.S. Food and Drug Administration. https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg ↩ ↩²

5. Gout — MedlinePlus, U.S. National Library of Medicine (NIH). https://medlineplus.gov/gout.html ↩