Anti-caking agents are anhydrous compounds that are added in small amounts to dry foods to prevent the particles from caking together and to ensure the product remains dry and free-flowing.
Anti-caking agents function by absorption of excess moisture or by coating particles to make them more water repellant.
Without anti-caking agents, dry soup, cake, and biscuit mixes would be clumped and chunky, cappuccino and hot chocolate vending machines would not function properly, and premixes for manufacturing would be more difficult to use.
Anti-caking agents are often found in milk and cream powders, flour-based mixes, baking powder, table salt, cocoa, and mixed coffee beverages, to name a few. In manufacturing, the addition of anti-caking agents helps prevent bridging during the packaging process, which can reduce production rates. The bridging of powders occurs when particles interlock or bond together to build a bridge or arch above the outlet of a container like a silo, hopper, or mixer vessel.
Silica — also known as silicon dioxide — is an oxide of silicon and is one of the most effective anti-caking agents. Silica, derived from naturally occurring quartz, is the most abundant mineral in the earth’s crust. It’s also found naturally within plants and water. In powdered foods, silica clings to food particles and prevents them from clumping. Silica also has uses as a stabilizer in beer production, and is absorbed for dl-α-tocopheryl acetate and pantothenyl alcohol in tableted foods, a carrier, and a defoaming agent.
Tricalcium phosphate — commonly abbreviated as (TCP) — is another common anti-caking agent that’s mainly used to prevent powered food from caking, lumping, and improve the fluidity. It’s commonly found in powdered drink mixes, powdered milk, non-dairy creamer, instant powders, table salt, and spices. As the calcium salt of phosphoric acid, tricalcium phosphate is also used to increase the calcium content of foods, mainly dairy alternatives.
Here are more common anti-caking agents, along with their functions in foods:
AGENT | E-NUMBER | FUNCTION |
Mannitol | E421 | A sugar alcohol that can be added to limit sticking. |
Powdered cellulose | E460ii | Used in shredded cheeses to reduce clumping. |
Magnesium stearate | E470b | Aids in tableting due to its lubricating properties. |
Sodium bicarbonate | E500 | Also a leavening agent. |
Sodium ferrocyanide | E535 | May be used in salt. |
Potassium ferrocyanide | E536 | May be used in salt. |
Calcium ferrocyanide | E538 | May be used in salt. |
Bone phosphate | E542 | May be added to dry product mixes or sugar. |
Calcium silicate | E552 | Prevents caking in baking powder, salt, and dry mixes. Absorbs oil and water and can be used to contain free oils in spices. |
Magnesium silicate | E553a | Often used with powdered mixes, grated cheeses, and seasonings. |
Talc | E553b | Used in rice, tablet coatings, salts, and powdered foods. |
Aluminium silicate/Kaolin | E559 | Often used in sugars, salts, and supplements |
Stearic acid | E570 | Found in both animals and plants. A crystalline solid fat at room temperature, used for coating particles. |
Polydimethylsiloxane | E570 | Useful in coating particles. |
Iron Ammonium Citrate | Used in salt for human consumption. | |
Yellow prussiate of soda | Used in salt and as an adjuvant in the production of dendritic salt crystals. |
This is not a comprehensive list, but it shows the variety available within the anti-caking additive category.
When used in powdered systems, anti-caking agents like calcium phosphate, calcium silicate, and silicon dioxide may increase the chemical degradation of chemically labile deliquescent ingredients like vitamin C. As such, anti-caking agent usage and storage conditions should be monitored in blending powder systems to ensure final products meet label claims.1
In the EU, most anti-caking agents have E-numbers in the 500 range, but some have multiple functions and fall into further categories.
Some of the multi-functional compounds include:
- Mannitol (E421) – also functions as a humectant, sweetener, and texturizer.
- Microcrystalline (E460a) and alpha (E460b) Cellulose (E460a) – also functions as a binder, stabilizer, and bulking agent.
Alternatives to anti-caking agent additives seen in some markets include rice hull powder and corn starch.
For example, one study showed adding powdered rice to salt as an anti-caking agent during manufacturing at a concentration of 1% could replace other common anti-caking food additives used in table salt production.2
In addition to food, anti-caking agents aid other industries, mainly the cosmetic and detergent industries.
Indeed, the high versatility of anti-agents like silicon and tricalcium phosphate is anticipated to further strengthen the rising demand from various industries.
References:
- Lipasek RA, Taylor LS, Mauer LJ. Effects of anticaking agents and relative humidity on the physical and chemical stability of powdered vitamin C. J Food Sci. September 2011;76(7):C1062-74.
- Akay C, Ogur R, Korkmaz A, Gocgeldi E, Yaren H, Gulec M. Could rice be used as an anticaking agent in table salt? Int J Food Sci Nutr. March 2009;60(2):95-99.
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To suggest anticaking agent to be added in potassium chlorate (KCL03) to get free flowing material and avoid caking as material is packed in hot condition immedia tely after pulverising.