Urea used in chewing gum to neutralise mouth acids after eating, and occasionally as a flour treatment agent in baking.
What is it?
Carbamide is the chemical name for urea, a nitrogen-containing compound the human body naturally produces and excretes. As a food additive it is manufactured synthetically. It is a white, odourless crystalline solid that dissolves readily in water.
What does it do?
In chewing gum, carbamide acts as a buffering agent. Bacteria in dental plaque produce an enzyme called urease that breaks urea down into ammonia and carbon dioxide. The ammonia raises the pH of saliva around the teeth, counteracting the acid produced when bacteria digest sugars, which reduces the risk of enamel demineralisation. In breadmaking and baked goods it can act as a nitrogen source for yeast, promoting fermentation, and as a dough conditioner.
Where you will see it
Most commonly found in sugar-free chewing gum, where it works alongside other plaque-neutralising ingredients. Occasionally present in certain baked products as a dough improver. On a UK label it appears as 'carbamide' or 'E927b'.
What the science says
Plaque acid neutralisation in chewing gum
Carbamide in sugar-free gum has been studied for its effect on plaque pH. When chewed, oral bacteria convert the urea to ammonia, which buffers the acid environment around teeth. EFSA reviewed this mechanism and confirmed the evidence supports a cause-and-effect relationship between chewing carbamide-containing sugar-free gum and neutralisation of plaque acids.
Sugar-free chewing gum containing carbamide consistently increased plaque pH compared to gums without carbamide, with the buffering effect correlating positively with the urea content of the gum.
Endogenous substance and dietary exposure
Urea is a natural metabolic end-product of protein breakdown in all mammals, produced continuously by the liver and excreted by the kidneys. The amount added via food additives is small relative to what the body makes and handles daily. No regulatory body has identified dietary urea from additive use as a hazard at the levels used in food.
Urea is a normal human metabolite present at substantial concentrations in blood and urine. The quantities introduced through food additive use represent a negligible addition to endogenous production.
Where it stands with the regulators
Who should be careful
No specific population group is required to avoid carbamide at additive levels found in food. People with urea cycle disorders (a rare group of inherited metabolic conditions) are managed by specialists on overall protein and nitrogen intake, not food additive labels; they should seek individual dietary advice. Look for 'carbamide' or 'E927b' on the ingredients list.
The honest read
Carbamide is urea, something the human body makes and processes in large quantities every day. Its use as a food additive is narrow, its mechanism in chewing gum is well understood, and it has been reviewed by EFSA without any identified hazard signal at the amounts used. No credible concern has been raised by any major food safety authority. The science here is not a live debate.
Related additives
Common questions
Is E927b banned in the UK?
No. E927b carbamide is on the UK FSA approved-additives list and is permitted for use in chewing gum and certain baked goods under assimilated EU Regulation 1333/2008.
Is E927b the same as urea in urine?
Chemically yes: carbamide and urea are the same molecule. The body produces urea continuously as a by-product of protein metabolism and excretes it in urine. The additive is a synthetically manufactured version of the same compound, used in tiny quantities. The dietary amount added through food is negligible compared with what the body produces and handles naturally.
What foods contain E927b?
Carbamide is most commonly found in sugar-free chewing gum, where it helps neutralise mouth acids. It can also appear in some baked goods as a dough improver or yeast nutrient. It is not a widely used additive and most everyday foods will not contain it.
Is E927b vegan?
Yes. Food-grade carbamide is produced synthetically (typically from ammonia and carbon dioxide) and does not involve animal products or by-products.
Sources
- UK FSA Approved Additives and E Numbers
- EFSA Scientific Opinion on health claims related to sugar-free chewing gum with carbamide and plaque acid neutralisation (ID 1153), EFSA Journal 2011;9(6):2071
- Regulation (EC) No 1333/2008 of the European Parliament and of the Council on food additives
- European Commission Food Additives Database
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