What is E629?
Complete guide to understanding E629 (Calcium Guanylate) in your food
The Quick Answer
E629 is calcium guanylate, a flavor enhancer made from guanylic acid (GMP) bonded with calcium.
It’s used in food to enhance savory and umami flavors, particularly in low-sodium and reduced-salt products where sodium reduction would otherwise leave food tasting bland.
Like other guanylate flavor enhancers, E629 works synergistically with glutamate-based flavor enhancers like MSG to create powerful umami taste amplification.
📌 Quick Facts
- Category: Flavor enhancer, umami intensifier
- Chemical form: Calcium salt of guanylic acid (GMP)
- Also known as: Calcium 5′-guanylate, guanosine-5′-monophosphate calcium salt
- Found in: Low-sodium products, convenience foods, instant products, soups, sauces, processed meats, snacks
- Safety: Approved in EU and most countries; limited approval in some regions
- Acceptable Daily Intake (ADI): “Not specified” (group ADI with guanylic acid and other guanylate salts)
- Source: Commercially prepared from yeast extract or sardines
- Water solubility: Sparingly soluble in water (pH 7.0-8.0)
- Physical form: Odorless white or off-white crystals or powder
- Important note: Contains purines; metabolizes to uric acid in the body
What Exactly Is It?
E629 is the calcium salt of guanylic acid (GMP—guanosine monophosphate).
Guanylic acid is a naturally occurring ribonucleotide found in all living cells as part of RNA. When you eat foods rich in purines—such as meat, fish, mushrooms, or yeast—you consume guanylate compounds.
E629 is the concentrated, purified form of guanylic acid, bonded with calcium to create a white crystalline powder suitable for food manufacturing.
Chemical formula: Ca(C₁₀H₁₂O₈N₅P) – containing one calcium ion per guanylate molecule.
How it enhances flavor:
E629 doesn’t independently create umami taste. Rather, it amplifies existing umami from glutamate (MSG, cheese, tomatoes, mushrooms):
• Guanylate (E629) + Glutamate = vastly enhanced savory perception
• The synergistic effect is far more potent than either compound alone
• Often used in combination with disodium inosinate (E631) as the “I+G” mixture for maximum flavor amplification
• Food manufacturers can reduce sodium while maintaining intense savory flavor intensity
Key distinction: Unlike disodium guanylate (E627) and dipotassium guanylate (E628) which use sodium and potassium salts respectively, E629 uses calcium—offering a different mineral profile suited to specific food applications.
Where You’ll Find It
E629 appears in various processed foods emphasizing low-sodium or intense savory flavor:
• Low-sodium and reduced-salt soups and broths
• Instant noodles and cup noodles
• Powder soups and instant soups
• Chips and savory snacks
• Sauces and gravies
• Processed meat and charcuterie products
• Pizza and prepared meals
• Fish and seafood products
• Seasoning blends and spice mixes
• Rice-based products
• Pre-cooked meals and convenience foods
• Olives and preserved vegetables
• Vegetable-based products with umami enhancement
E629 is less commonly used than disodium guanylate (E627), but appears frequently in products specifically formulated for low-sodium diets or where calcium fortification is desired.
Why Do Food Companies Use It?
E629’s primary function is enhancing savory flavor while allowing sodium reduction.
Food manufacturers use calcium guanylate for specific advantages:
• Flavor synergy with glutamate: Creates dramatically enhanced savory perception when combined with MSG or other glutamates
• Salt reduction enabler: Allows reduction of sodium while maintaining perceived flavor intensity
• Calcium fortification: Provides calcium content alongside flavor enhancement (useful for health-marketed products)
• Low-sodium product solution: Essential in products where sodium has been removed but intense savory flavor is desired
• Water solubility: Suitable for aqueous food systems and beverages
• Umami amplification: Creates meaty, savory taste in plant-based and lower-cost meat products
• Combination synergy: Works particularly well when combined with inosinate (E631) as “I+G” mixture
• Appetite stimulation: Umami enhances perceived palatability and encourages consumption
• Cost efficiency: Small concentrations achieve significant flavor effects
• Stability: Stable at various temperatures and pH levels used in food processing
E629’s combination of flavor enhancement with calcium content makes it particularly valuable in products marketed for cardiovascular health or bone health, where reducing sodium while adding beneficial minerals is strategically important.
Is It Safe?
E629 is approved in the EU and most countries and is considered safe at approved use levels.
Approval status:
• Approved: European Union (E629), Japan, South Korea, and most countries worldwide
• Limited availability: Not permitted in some regulatory jurisdictions
• FDA status: Not approved for use in the United States (not listed as GRAS)
Safety profile:
• JECFA (Joint FAO/WHO Expert Committee on Food Additives) established ADI as “not specified” in 1985, with group ADI applying to guanylic acid and all its salts
• EFSA has evaluated guanylic acid and guanylates and found no safety concerns at reported use levels
• No evidence of carcinogenicity, mutagenicity, or reproductive toxicity in scientific studies
• The body metabolizes guanylates the same way it handles guanylate compounds from natural foods (meat, fish, mushrooms)
• Decades of use without documented widespread safety incidents
• Generally considered safe among flavor enhancers
Critical consideration—purine metabolism:
Like all guanylate and inosinate flavor enhancers, E629 contains purines that the body metabolizes to uric acid. This creates specific concerns for certain populations:
⚠️ Important Health Consideration:
E629 is metabolized to purines, which convert to uric acid. This creates potential problems for:
• Gout sufferers: Higher purine intake increases serum uric acid levels, worsening symptoms and increasing attack frequency
• Hyperuricemia: People with elevated uric acid levels should limit purine consumption
• Chronic kidney disease: Impaired kidney function makes purine metabolism problematic
• History of kidney stones: Uric acid contributes to certain types of kidney stone formation
• People on uric acid-lowering medication: Should limit purine intake to maintain medication effectiveness
For these groups, while E629 is “approved as safe” for the general population, it may not be appropriate for them personally. Health authorities classify E629 as “may trigger gout.” Consult your healthcare provider if you have any of these conditions.
Natural vs Synthetic Version
E629 can be derived from natural sources or synthetically produced:
Production sources:
• Natural extraction (most common commercial method): Extracted from yeast extract or sardines; then calcium is chemically bonded
• Bacterial fermentation: Can be produced via fermentation using Bacillus subtilis or similar microorganisms
• Chemical synthesis: Laboratory synthesis of the nucleotide from chemical precursors
Vegetarian/vegan status: Depends on production method. If extracted from sardines or other fish, it’s not suitable for vegetarians/vegans. If extracted from yeast or synthetically produced, it can be vegetarian/vegan. Always verify source with manufacturers, as labels don’t always specify.
Chemically identical: Regardless of production method, E629 is the same compound. Your body metabolizes it identically.
Natural Alternatives
Want to avoid E629 or manage purine intake?
Some alternatives include:
• Disodium guanylate (E627) or Dipotassium guanylate (E628) – Similar guanylate-based enhancers with different mineral salts
• Disodium inosinate (E631) or other inosinates – Similar inosinate-based enhancers; also purine-based
• Monosodium glutamate (MSG, E621) – Umami flavor but lacks the guanylate synergy
• Disodium 5′-ribonucleotides (E635) – Mixture of guanylate and inosinate; similar combined effect
• Natural yeast extracts – Contain natural guanylates; more expensive
• Fish sauce and fermented fish products – Traditional umami enhancers; contain natural guanylates
• Mushroom extracts – Natural umami from glutamates, with lower purines
• Aged cheeses – Natural umami from glutamates
• Tomato extracts – Natural glutamates without nucleotide-based compounds
For people with gout or hyperuricemia, alternatives must also be evaluated for purine content—many umami-rich natural foods contain some purines.
The Bottom Line
E629 (calcium guanylate) is a flavor enhancer used to amplify umami (savory) taste through synergistic interaction with glutamate.
It’s found in low-sodium products, instant foods, soups, sauces, and processed meats—particularly valuable in products where sodium has been reduced but intense savory flavor is desired.
E629 is approved in the EU and most countries worldwide, though notably absent from USA approval.
The key health consideration is that E629 contains purines that metabolize to uric acid. Health authorities explicitly classify E629 as “may trigger gout.” While approved as safe for the general population, it may be inappropriate for people with gout, hyperuricemia, chronic kidney disease, or those managing uric acid levels.
E629’s advantage over disodium guanylate (E627) is that it provides calcium content alongside flavor enhancement—potentially beneficial for products marketed for bone health or cardiovascular management. However, the sodium form (E627) remains more widely available.
For healthy individuals without purine metabolism concerns, E629 at approved levels is considered safe by regulatory bodies. If you have metabolic concerns related to uric acid, consult your healthcare provider before regularly consuming products containing E629.