A calcium salt of lactobionic acid. Not found on the UK FSA or EU authorised food additives lists; its E647 designation has no confirmed regulatory basis.
E647 does not appear on the UK FSA approved additives list or the EU Annex II authorised food additives. Calcium lactobionate is separately listed by some sources as E399, but that number is also unconfirmed in official UK/EU registers. Any food carrying this E-number should be treated as using an unverified additive.
What is it?
Calcium lactobionate is the calcium salt of lactobionic acid, a sugar acid derived from the oxidation of lactose (milk sugar). It consists of two lactobionate anions paired with one calcium cation. As a white crystalline powder it dissolves readily in water. It provides both calcium and a mild sweet-tasting acid component.
What does it do?
Calcium lactobionate acts as a firming agent and stabiliser. The calcium ions cross-link with pectin and other polysaccharides in plant cell walls to maintain texture. It can also function as a sequestrant (binding trace metals that would otherwise accelerate oxidation) and as a mild calcium-delivery vehicle. In pharmaceutical and nutraceutical applications it is a bioavailable calcium source.
Where you will see it
Calcium lactobionate is used in some dairy-analogue and plant-based products to set or firm texture, and in pharmaceutical oral calcium supplements. In food manufacturing it has niche applications in tofu-style gels and specialty desserts where a slow-release, gentle coagulant is needed. On a UK label it would appear as 'calcium lactobionate' or 'E647' in the ingredients list, though no confirmed authorised food uses have been identified in UK or EU legislation.
What the science says
Regulatory status: not found on UK or EU approved lists
The UK Food Standards Agency publishes the definitive list of approved additives and E-numbers. E647 does not appear on that list. The EU's Annex II to Regulation 1333/2008, which governs all permitted food additives across Great Britain (via assimilation) and the EU, also does not contain E647. Some third-party additive databases assign calcium lactobionate the number E399 rather than E647, but neither E399 nor E647 appears as an authorised food additive entry in the primary UK or EU regulatory records checked.
E647 does not appear in the UK FSA approved additives and E-numbers list, the definitive register of food additives permitted for sale in Great Britain.
Annex II to EU Regulation 1333/2008, governing food additives in the EU, does not contain an entry for E647 or for calcium lactobionate under any E-number in the 600-series 'Other' category.
Calcium lactobionate chemistry and biological handling
Lactobionic acid is produced from lactose oxidation and is broken down in the gut to galactose and gluconic acid, both of which are metabolised normally. The calcium component is bioavailable. There are no IARC classifications, no reported endocrine disruption signals, no Southampton Six membership, and no EFSA safety opinion specifically dedicated to calcium lactobionate as a food additive for humans. The absence from authorised lists means no formal ADI has been established for food use.
Lactobionic acid hydrolyses in the gut to galactose and gluconic acid; both are normal metabolic substrates. No specific toxicological concerns have been identified in available literature.
Where it stands with the regulators
Who should be careful
People with a milk allergy should be aware that calcium lactobionate is derived from lactose (milk sugar), so it carries a potential milk-derived allergen risk. Anyone monitoring their calcium intake for medical reasons (such as hypercalcaemia) should note the calcium content. Look for 'calcium lactobionate' or 'E647' on the label.
The honest read
The underlying compound is not exotic or inherently alarming, lactobionic acid and calcium are both ordinary biological materials. The concern here is regulatory: this E-number is not on the UK or EU approved additives lists, meaning there is no confirmed legal basis for its use as a food additive in the UK. Whether this reflects an unassigned number, a database error in the E399 versus E647 designation, or a substance that was never formally evaluated and authorised for food use, the picture is genuinely unclear. No EFSA safety opinion for calcium lactobionate as a human food additive has been identified. The absence of authorisation is not the same as evidence of harm, but it does mean no formal safety ceiling (ADI) has been set for food use under UK or EU law.
Related additives
Common questions
Is E647 banned in the UK?
E647 does not appear on the UK FSA list of approved food additives and E-numbers. It is not listed as explicitly banned by name, but food additives in the UK must be specifically authorised to be used, and E647 has no entry in the authorised list. Its use as a food additive in the UK therefore has no confirmed legal basis.
Is E647 the same as E399?
Some third-party additive databases assign calcium lactobionate to E399 rather than E647. However, neither E399 nor E647 appears in the UK FSA approved additives list or in Annex II to EU Regulation 1333/2008. The exact origin of the E647 designation is unclear and does not correspond to any primary regulatory record found.
What foods contain E647?
No specific food categories are authorised for E647 in the UK or EU. Calcium lactobionate is used in pharmaceutical calcium supplements (under medicines regulation) and in some food applications in other markets such as the United States, where it is used in dairy-free products, specialty desserts and tofu-style gels as a firming agent.
Is E647 vegan?
Calcium lactobionate is derived from lactobionic acid, which is produced by oxidation of lactose, a milk sugar. It is therefore not suitable for vegans or people following a dairy-free diet. It may also be relevant for people with a milk allergy, though the risk depends on processing and residual protein levels.
Sources
- UK Food Standards Agency: Approved additives and E numbers
- EU Regulation (EC) No 1333/2008 on food additives (Annex II)
- PubChem Compound Summary: Calcium Lactobionate (CID 11954336)
- Open Food Facts: E399 Calcium Lactobionate
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