Calcium Carbonate is ubiquitous in various industries, including food product formulations. It is a naturally occurring compound in limestone, marble, shells, and pearls. This diverse compound exhibits multiple properties that are exploited in developing food products. Its wide use is attributed to its unique functional properties, nutritional benefits, and cost-effectiveness.
What is Calcium Carbonate?
The chemical formula of Calcium Carbonate is CaCO3, where it comprises [Ca]2+ & [CO3]2- ions. Carbonate ion has a triangular planar structure. See the molecular form below.
Source: Wikipedia
As a natural food additive, it aids in improved physicochemical, functional & nutritional properties in food products and is used in dietary supplements as a source of calcium.
Calcium Carbonate is an economical choice for food manufacturers due to its widespread availability and relatively low cost. Its firming and anti-caking agent qualities, and calcium sources, make it an appealing option for manufacturers seeking to balance cost with functionality and nutrition.
How is Calcium Carbonate Produced?
Calcium Carbonate is commonly found in the earth’s crust. It is available in different forms, such as limestone, marble, calcite, and aragonite. The bulk production of Calcium Carbonate occurs by mining or quarrying marble stones. Calcium carbonate can naturally be found in shells from shellfish to snails and eggshells. About 95% of dry eggshells, as well as seashells, are made of calcium Carbonate. Eggshells, a natural source, are gaining popularity for nutraceutical/dietary supplement applications. Calcium Carbonate is a carbonic acid salt of calcium and can be produced synthetically.
Use and Applications of Calcium Carbonate in Food and Nutritional Products
One of the most crucial roles of calcium Carbonate in food formulations is as a firming agent. This property is particularly useful in processed foods like canned fruits and vegetables, where it helps maintain their structure and texture.
Calcium Carbonate also acts as an anti-caking agent, preventing the formation of lumps in powdered food products. For example, calcium carbonate in baking powder helps ensure uniform consistency and prevents the powder from clumping together, enhancing its effectiveness.
It is also used as a white pigment and colorant in various food products. Its use contributes to the product’s visual appeal, a critical factor in consumer preferences. Additionally, Calcium Carbonate has a mild basic property, making it a natural pH regulator, critical in foods requiring specific pH levels for safety and taste.
Here’s a breakdown of the different functions calcium carbonate serves in the food industry:
Food Industry
| Function | Applications |
| Color additive | Calcium Carbonate acts as a color additive in food formulations, imparting a white pigment to improve the visual appeal of products. |
| Bulking agent | Calcium Carbonate adds to the bulk in food products without altering the taste or adding to the calorific value. |
| Thickener | Calcium Carbonate is a thickener in food products, improving their texture and consistency, particularly in sauces and soups. |
| Stabilizer | Calcium Carbonate stabilizes food products by strengthening the molecular bonds within the food matrix, thereby maintaining structure and texture. |
| Acidity regulator | As a mild base, Calcium Carbonate plays a crucial role in regulating the pH level of food products, contributing to safety and taste. |
| Anti-caking agent | Calcium Carbonate is used as an anti-caking agent in powdered food products, preventing the formation of clumps to ensure uniform consistency. |
| Dough regulator | In baking, Calcium Carbonate is a dough regulator, maintaining the proper texture and volume of the dough during fermentation. |
| Raising agent | Calcium Carbonate functions as a raising agent in baking.It reacts with acid to release CO2, which helps the dough to rise. |
| Yeast nutrient | Calcium Carbonate is a yeast nutrient in fermentation, promoting yeast growth and activity. |
Nutritional Industry
In the nutrition industry, Calcium Carbonate is an excellent source of dietary calcium, essential for bone health.
| Function | Applications |
| Dietary supplement | Calcium Carbonate is commonly used as a dietary supplement, providing a concentrated source of calcium to meet daily nutritional requirements. |
| Excipient | As an excipient, Calcium Carbonate is used to manufacture tablets and capsules, enhancing their stability and aiding in the controlled release of active ingredients. |
| Fortification Agent | Calcium Carbonate is a fortification agent in food products, such as non-dairy milk and juices, to boost their calcium content and improve their nutritional profile. |
Product Examples
| Type | Examples |
| Bakery | Cake, Bread, Cookies |
| Convenience Foods | Powder and dough mixes, Cereals and breakfast products |
| Beverages | Milk-based beverages, Juices |
| Confectionery | Chewable, Chewing gums, Jellies |
| Dairy | Milk-based beverages, Curd, Ice creams, Cheese, Paneer, Milk powder, Dairy whiteners |
| Nutrition | Calcium supplements, Nutrient premixes, etc. |
Properties of Calcium Carbonate
| Physical Form | Solid |
| Color | White |
| Odor | Odorless |
| Shelf Life | ~60 months (When stored at prescribed conditions) |
| Storage Temperature & Conditions | Store at +5°C to +30°C |
| Appearance | Fine white powder |
| Density | 2.711 g/cm3 |
| Molar Mass | 100.0869 g/mol |
| Refractive index | 1.6583 |
| Melting Point | 825 °C |
| pKa | 9.0 |
| Solubility | 15 mg/L at 25 °C in water |
Typical Formulations
Chewing Gum
Here is an example of a sugar-free center-filled chewing gum formulation table with Calcium Carbonate along with the % weight of ingredients.
| Phase | Ingredient | % Composition |
| Gum | Gum base | 23 |
| Lecithin | 0.6 | |
| Sorbitol | 49.705 | |
| Mannitol | 15 | |
| Glycerin | 9.5 | |
| High-Intensity sweetener | 0.775 | |
| Flavor | 1.42 | |
| Carboxymethyl cellulose | 48.9503 | |
| Center Fill | Flavor | 0.135 |
| High-Intensity Sweetener | 0.025 | |
| Calcium Carbonate | 50 |
Source: Google Patents
Bread
Here is an example of a bread formulation table with Calcium Carbonate along with the % weight of ingredients. The addition of calcium softens crumbs, making them less firm and chewable. It also favors crumb elasticity and particle integration.
| Ingredient | % Composition |
| Wheat Flour | 100 |
| Sodium chloride | 2 |
| Fresh yeast | 3 |
| Calcium carbonate | 1.8 |
| Inulin | 6.5 |
Source: ScienceDirect
Calcium Carbonate Formulation Considerations
Calcium Carbonate is a salt of calcium that, when dissolved in water, increases the alkalinity of the solution. It forms carbonate ions that react with free hydrogen ions to raise the system’s pH. It reacts with acid to neutralize and release CO2. When used in higher concentrations, it imparts white color to the food and can act as bulking aid. The higher water absorption capacity aids in its use as an anti-caking agent, thickener, and stabilizer in multiple applications. It is a versatile ingredient finding application in various food products as follows.
| Physical Forms | Powder or Crystals Calcium Carbonate crystallizes in three anhydrous polymorphs:Calcite: White hexagonal crystalsAragonite: White orthorhombic crystalsVaterite: Colorless hexagonal crystals. |
| Stability | Oxidation: Stable Heat: Decomposes around ~750 °C (Stability Calcite > Aragonite > Vaterite) pH: Highly reactive with strong acids |
| Nutritional Profile | Powder or Crystals Calcium carbonate crystallizes in three anhydrous polymorphs: Calcite: White hexagonal crystals Aragonite: White orthorhombic crystals Vaterite: Colorless hexagonal crystals. |
| Sensory Attributes | Odorless with a slightly chalky taste |
| Dosage | 0.5 – 2% (Varies as per product & formulation) |
| Interaction with Other Components | Incompatible with strong oxidizers and strong acids. May engage in violent explosive reactions with some acids due to higher reactivity |
Safety & Regulatory Considerations
While using Calcium Carbonate in food products is generally considered safe by major food safety organizations like the U.S. Food and Drug Administration and the European Food Safety Authority, it is crucial to be used appropriately to ensure consumer safety. There are specific guidelines regarding the maximum levels of Calcium Carbonate that can be used in food products, which manufacturers must strictly adhere to.
| FDA Information | Calcium Carbonate is generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA). Per § 184.1(b)(1), the ingredient can be used in food without limitations other than current good manufacturing practice. |
| EU Information | Approved to be used as a food additive as E170 with a specific maximum level being quantum satis. |
Health Benefits of Calcium Carbonate
Calcium is found naturally in some food. The body needs calcium minerals for healthy bones, muscles, the nervous system, and the heart. The increased consumption of refined foods has prompted the addition of calcium through fortification or dietary supplements. Also, it is worth noticing that for you to absorb calcium, your body also needs vitamin D. The RDA of calcium is between 1,000-1,200 mg daily, depending on age. Calcium Carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach.
Identification Numbers
| Chemical Name | Calcium Carbonate |
| CAS Number | 471-34-1 |
| EC Number | 207-439-9 |
| INS No. (Food Additive) | 170 |
Acceptable Limits or Maximum Usage
The maximum usage level of Calcium Carbonate in the food industry as per the CODEX is as follows.
| Number | Food Category | Max Level |
| 01.2.1.2 | Fermented milks (plain), heat-treated after fermentation | GMP |
| 01.2.2 | Renneted milk (plain) | GMP |
| 01.4.1 | Pasteurized cream (plain) | GMP |
| 01.4.2 | Sterilized and UHT creams, whipping and whipped creams, and reduced fat creams (plain) | GMP |
| 01.8.2 | Dried whey and whey products, excluding whey cheeses | 10,000 mg/kg |
| 04.2.2.7 | Fresh pasta and noodles and like products | GMP |
| 06.4.1 | Dried pasta and noodles and like products | GMP |
| 06.4.2 | Dried pastas and noodles and like products | GMP |
| 08.1.1 | Fresh meat, poultry, and game, whole pieces or cuts | GMP |
| 08.1.2 | Fresh meat, poultry, and game, comminuted | GMP |
| 09.2.1 | Frozen fish, fish fillets, and fish products, including mollusks, crustaceans, and echinoderms | GMP |
| 09.2.2 | Frozen battered fish, fish fillets, and fish products, including mollusks, crustaceans, and echinoderms | GMP |
| 09.2.3 | Frozen minced and creamed fish products, including mollusks, crustaceans, and echinoderms | GMP |
| 09.2.5 | Smoked, dried, fermented, and/or salted fish and fish products, including mollusks, crustaceans, and echinoderms | GMP |
| 12.1.1 | Salt | GMP |
| 12.1.2 | Salt Substitutes | GMP |
| 13.2 | Complementary foods for infants and young children | GMP |
| 14.1.5 | Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa | GMP |
| 09.2.4 | Cooked and/or fried fish and fish products, including mollusks, crustaceans, and echinoderms | GMP |
| 12.2.1 | Herbs and spices | GMP |
Source: FAO
Fun Facts About Calcium Carbonate
- The white cliffs of Dover, a famous UK landmark, are made almost entirely of Calcium Carbonate in chalk deposited over millions of years.
- Calcium Carbonate plays a role in winemaking. Adding it to the soil where the grapes are grown can reduce the acidity of the grapes, which is crucial for the taste of the wine. It’s also used in the traditional Champagne method to assist in removing sediment.
- When Calcium Carbonate dissolves in water containing carbon dioxide, it forms a solution that can create stalactites and stalagmites in caves.
- Calcium Carbonate is a common ingredient in antacids as it neutralizes stomach acid. If you’ve ever taken Tums for heartburn or indigestion, you’ve used Calcium Carbonate!
- Calcium Carbonate, specifically chalk or limestone, has been used for centuries in artwork, from prehistoric cave paintings to modern chalk art festivals.
- Many fossils are composed of Calcium Carbonate. The substance preserves the intricate details of ancient organisms, providing key insights into prehistoric life on Earth.
