Calcium acetate or calcium ethanoate, the calcium salt of acetic acid with the chemical formula Ca(C2H3O2)2, which occurs as anhydrous and monohydrate type.
This ingredient can be used as an acidity regulator or buffering agent, nutrient supplement, flavor enhancer, and preservative in food with the European food additive number E263. Meanwhile, it is an oral phosphate binder to treat hyperphosphatemia – high levels of blood phosphate.
It is a synthetic compound commonly produced by reaction acetic acid with calcium hydroxide (limestone) or calcium carbonate (hydrated lime).
The following are two manufacturing methods:
- Neutralization acetic acid with calcium hydroxide. Equation: 2CH3COOH + Ca(OH)2/CaCO3 → (CH3COO)2Ca + 2H2O
- An exothermic reaction between calcium oxide and glacial acetic acid. Equation: 2CH3COOH + CaO → (CH3COO)2Ca + H2O
A white crystalline powder or granular. The anhydrous form is hygroscopic which absorbs water.
Calcium acetate is the strong conjugate base of acetic acid. When dissolved in water, it dissociates CH3COO- ions and Ca+, and forms acetic acid (CH3COOH) and CaOH after these two ions reaction with water respectively, CH3COO- combines with H+, and Ca+ reacts with OH-.
|Other names||Lime acetate, Vinegar salts|
|CAS number||62-54-4 (Anhydrous), 5743-26-0 (Monohydrate)|
|Chemical formula||C4H6O4Ca (Anhydrous), C4H6O4Ca·H2O (Monohydrate)|
|Molecular weight||158.17(Anhydrous), 176.18 (Monohydrate)|
|PH||neutralizes acids and raises pH Alkalinity, 6.0-9.0 (10% aqueous solution)|
|Solubility||freely soluble in water and slightly soluble in ethanol.|
Like sodium acetate, its food grade can be used as a buffering agent to adjust the food acidity, and a preservative to prolong the food shelf life. Plus, it can also be used to fortify foods with calcium nutrition.
We can commonly find this additive in bakery and calcium supplements.
Calcium acetate can inhibit the growth of many bacteria and molds. It is commonly used as a preservative in bakery products (e.g. bread) to extend the shelf life by preventing the formation of rope and the growth of molds. The recommended usage is 0.2 – 0.5% of flour weight.
Calcium acetate is an essential calcium (Ca2+) supplement, which has the advantages of high water solubility and high absorption rate and does not consume gastric acid after taking it.
Hyperphosphatemia (the elevated blood phosphorus) is common in patients with kidney disease, which is mainly caused by renal failure. Hyperphosphatemia may increase the risk of cardiovascular disease and vitamin D metabolism disorder.
The purpose of Calcium acetate
At present, the main effective method of controlling serum phosphorus levels is the use of phosphorus binders, which are used to reduce the absorption of phosphates.
Pharmaceutical grade Calcium acetate (available in the dosage of solution, tablet, and capsule taken by mouth) can be used as a phosphorus binder to treat hyperphosphatemia. The use of oral calcium acetate during dialysis is commonly used for lowering blood phosphorus as dialysis cannot fully remove all phosphorus from the body.
After oral administration, calcium acetate combines with phosphates from food (phosphates present in our diet) and forms insoluble calcium phosphate complexes and is then excreted by the body without biological absorption. This is the mechanism of its action as a phosphorus binder.
Calcium acetate VS calcium carbonate
Another common calcium-based phosphate binder is calcium carbonate, which is not soluble in water and needs to work with acid in our body to release Ca2+ and then works, while calcium acetate is effective at a wider pH range.
Possible Side effects
Calcium-based phosphate binders have the same health problems if with the long-term uses, which may lead to soft tissue and vascular calcification caused by excess calcium deposits. (1)
It can be used as a preservative an a source of calcium in feed and premixes.
Ice and snow on roads is an important safety issue for winter traffic, which not only largely reduces the transportation capacity, but also easily causes traffic accidents.
The commonly used ice and snow melting agents are chloride salts, e.g. sodium chloride and calcium chloride.
However, the long-term employment of chlorine-containing ingredients in roads for deicing and snowing will lead to environmental problems, for example, water pollution, the corrosion of chloride ions on roads and bridges, influence on plant growth, and etc.
Calcium magnesium acetate (CMA) is an environmentally friendly ice and snow removal, which is low corrosiveness and low harm to plants. But with a higher price compared with sodium chloride and calcium chloride.
Yes, when used as a food additive, it is safe and almost has no side effects. The U.S. Food and Drug Administration (FDA) claimed calcium acetate is GRAS, and European Food Safety Authority (EFSA) pointed out acetates are normal components of the diet of humans and are fully metabolized (2), the Joint FAO/WHO Expert Committee on Food Additives (JECFA) also approved its safety earlier.
Calcium acetate is generally recognized as safe (GRAS) that can be used as a firming agent, pH control agent, sequestrant, stabilizer, thickener, and texturizer in food. The following food list may contain it and with the maximum usage (3):
- Baked goods 0.2%
- Cheese 0.02%
- Gelatins, puddings, and fillings 0.2%
- Sweet sauces, toppings, and syrups 0.15%
- Other food categories 0.0001%
Calcium acetate E263 is an authorised food additive in the European Union (EU). Its usages are mainly “not limited” in most of its food categories. The following are some of its approved uses (4):
- Canned or bottled fruit and vegetables
- Prepacked meat
- Processed cereal-based foods and baby foods, only for pH adjustment
Function Class: food additives, acidity regulator, preservative, stabilizer (5)
Acceptable daily intake: ADI “not limited” in 1973. (6)
Now you may have a knowledge of the multifunctional ingredient – Calcium acetate (E263), from the following aspects:
- Manufacturing processes
- Uses in food, Hyperphosphatemia treatment, feed and the derived Calcium magnesium acetate in ice and snow melting.
- Safety as a food additive
What kinds of food labels have you found this ingredient in? Feel free to let me know in the comments.