Calcium acetate
The calcium salt of acetic acid, used to control acidity and inhibit mould in baked goods and other foods.
What is it?
Calcium acetate is the calcium salt of acetic acid (the acid in vinegar). It is a white, odourless powder that dissolves readily in water. In food it can supply both a mild acidity-regulating function and a small amount of calcium.
What does it do?
As an acidity regulator it buffers the pH of food, keeping it stable during processing and storage. At higher concentrations it can inhibit the growth of mould and certain bacteria by lowering water activity and acidifying the local environment around microbial cells. It also acts as a firming agent in some applications by cross-linking pectin molecules in plant cell walls.
Where you will see it
Found mainly in bread, rolls and other bakery products, where it extends shelf life and controls crumb texture. Also used in some cheeses, processed vegetable products, and certain confectionery. On a UK ingredient label it appears as 'calcium acetate' or 'E263'.
What the science says
Calcium contribution at food use levels
Calcium acetate contributes a small amount of dietary calcium. At the quantities used in food this is nutritionally insignificant for most people. In clinical medicine, much higher doses of calcium acetate are used as a phosphate binder for patients with chronic kidney disease, which is a distinct medical context from food use.
Calcium acetate is used therapeutically as a phosphate binder in renal patients at gram-level doses, far above amounts encountered from food additives.
Acidity-regulating and antimicrobial mechanism
Acetic acid salts including calcium acetate inhibit spoilage organisms by acidifying the food environment and reducing available water. This is the same chemistry behind vinegar preservation, applied in a buffered, calcium-bound form. No adverse biological effects have been identified at food-grade concentrations.
EFSA concluded that calcium acetate raises no safety concern at the levels used or proposed for use as a food additive.
Where it stands with the regulators
Who should be careful
People with chronic kidney disease who are already prescribed calcium acetate as a medical phosphate binder should be aware that additional dietary sources of calcium exist, but this is a clinical management question for their renal team rather than a reason to avoid ordinary foods. Look for 'calcium acetate' or 'E263' on the label if your clinician has asked you to track calcium intake precisely.
The honest read
Calcium acetate is one of the more chemically straightforward food additives: a combination of calcium and the acid in vinegar, used in quantities small enough that regulators have not found a basis to set any upper limit. The science on it at food use levels is not contested.
Related additives
Common questions
Is E263 banned in the UK?
No. Calcium acetate is permitted in the UK under the UK FSA approved-additives list, carried forward from EU Regulation 1333/2008 after Brexit.
Is E263 just vinegar calcium?
Effectively yes. Calcium acetate is the calcium salt of acetic acid, which is the acid that gives vinegar its taste and preserving properties. The calcium is bonded to acetate ions, making it a stable powder used in food manufacturing.
What foods contain E263?
Most commonly found in bread and rolls, where it helps control mould and pH. It also appears in some processed cheeses, vegetable products, and confectionery. Check the ingredients list for 'calcium acetate' or 'E263'.
Is E263 vegan?
Yes. Calcium acetate is produced synthetically from acetic acid and a calcium source, with no animal-derived ingredients.
Sources
- UK FSA Approved Additives and E Numbers
- EFSA ANS Panel re-evaluation of acidity regulators including acetic acid, acetates and diacetates (E260-E263)
- EU Regulation 1333/2008 on food additives, Annex II
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