Other names for the additive (synonyms)
General Information
Calcium sulfates are a multifunctional food additive E516 of mineral origin, used in the food industry as a coagulant, acidity regulator, stabilizer, and carrier.
Calcium sulfate is one of the most common minerals in the Earth's crust. In nature, it occurs as gypsum (CaSO4‧2H2O) or anhydrite (anhydrous form, CaSO4).
Historically, this compound has been known to humans for a long time — gypsum was used in construction and medicine since ancient times. As a food additive, calcium sulfate began to be widely used in the 20th century, when its useful technological properties were discovered, including its ability to stabilize product structures.
The chemical formula of calcium sulfate is CaSO4. E516 is a white or slightly grayish powder without odor, slightly soluble in water, and characterized by high thermal stability.
In the food industry, E516 is obtained mainly by two methods. The first is mechanical and thermal processing of natural minerals such as gypsum (CaSO4‧2H2O) or anhydrite (CaSO4). They are mined, crushed, purified from impurities, and roasted to remove crystallization water. The second method is chemical synthesis, producing calcium sulfate as a by-product in the production of phosphoric and citric acids, or by direct reaction of soluble calcium salts (e.g., calcium chloride, CaCl2) with sulfuric acid (H2SO4).
Regardless of the production method, the final product undergoes multiple stages of filtration and precision purification from heavy metals and foreign impurities to meet strict food and pharmaceutical purity standards.
Effects on the Body
Benefits of Additive E516
Calcium sulfate is a source of calcium — an essential mineral required for the formation of bones, teeth, and normal nervous system function.
Medical studies show that calcium bioavailability from sulfate is comparable to calcium carbonate and dairy calcium, allowing this additive to be used not only as a technological ingredient but also as a nutrient for preventing mineral deficiencies in the diet. This makes E516 one of the main calcium sources for vegans, supporting bone health.
In the framework of the re-evaluation of authorized food additives in the European Union, published in 2019, EFSA experts confirmed that calcium sulfate is safe for consumption in food products according to the principle of quantum satis.
According to JECFA conclusions, no acceptable daily intake (ADI) is established for E516 (ADI "not specified").
Risks of Additive E516
In normal amounts, calcium sulfate is considered safe. It is partially absorbed by the body, and excess is excreted via the intestines and kidneys.
Studies show that excessive calcium intake can lead to mineral imbalance or minor digestive disturbances (e.g., constipation), with possible slowed intestinal motility.
Scientific data confirm that hypercalciuria (excess calcium in urine) is an important risk factor for kidney stone formation, including oxalate and phosphate stones, especially in individuals predisposed to urolithiasis.
In rare cases, usually when high calcium sulfate intake is combined with high doses of vitamin D or certain thyroid conditions, calcium excess can lead to abnormally high blood calcium levels (hypercalcemia).
Moreover, studies show that high calcium concentration from E516 may reduce absorption of other essential minerals, such as iron and zinc, due to competition for intestinal transport systems.
Uses
In the food industry, E516 is used as a multifunctional technological agent, primarily in the baking industry, where it acts as a flour improver, strengthening dough gluten and increasing the volume of finished products.
Due to its ability to gradually release calcium ions, E516 is an indispensable coagulant in traditional tofu production, providing a uniform and firm texture.
Additionally, E516 is widely used as a stabilizer in canned vegetables and fruits to prevent tissue softening, and as a nutrient salt for yeast in brewing and winemaking.
The high bioavailability of this compound allows its use for fortifying food products (breakfast cereals, beverages) with mineral calcium, while also serving as an inert carrier-filler in pharmaceuticals and dietary supplements.
Legal Status
Food additive E516 is approved for use in most countries worldwide.
- European Union: approved under Regulation (EC) No 1333/2008.
- Ukraine: use is regulated by standards harmonized with European regulations.
- USA: calcium sulfate has GRAS status (Generally Recognized as Safe).
- Canada, Japan: approved for use in food products.