Anticaking agents are food additives that prevent lumping and caking in granular or powdered form. By definition, caking is the tendency of dry goods to clump together and causes lumping. Anticaking agents are able to maintain free-flowing characteristics because they readily absorb excess moisture. There are 2 ways anticaking agents do this. By coating the particles to achieve water repellency or by providing an insoluble particulate diluent. These are common in food ingredients such as baking powder and other powdered foods that are hygroscopic (substances that tend to absorb moisture) in nature.
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Because of their ability to absorb moisture, anticaking agents also have uses in cosmetics, fertilizers, cleaning agents, and other similar applications.
COMMON ANTICAKING AGENTS IN FOOD
The most common anticaking agents in food are silicon, phosphate, calcium, aluminum, and sodium salts at low concentrations. In sugar manufacturing, sucrose particles can be as small as 10–15 μm in size. But sugars are naturally hygroscopic, especially brown sugar. Adding an anticaking agent like cornstarch during the manufacturing process prevents the crystals from clumping together. In Europe, table salt often contains sodium ferrocyanide (E535) or sodium ferrocyanide (E536). Another anticaking agent in salt is iron ammonium citrate. In the US, the Food and Drug Administration (FDA) has set the max limit for iron ammonium citrate at 0.0025%.
Calcium silicate (E552), a substance capable of absorbing oil and water, can be applied up to 5% to prevent lumping in baking powder, and up to 2% in table salt. When finely divided, calcium silicate can absorb moisture up to 2.5 times its weight. In addition to water, it also absorbs oils and other non-polar organic compounds. These properties make calcium silicate a good anticaking agent in spices, powdered mixes, and foodstuffs that contain essential oils.
Calcium stearate (E47a) is the calcium salt of stearic acid. It is derived from tallow or animal fat, and plant sources such as cocoa butter, soybean oil, and palm oil. Calcium stearate also works as an emulsifier, binder, lubricant, and thickening agent. As an anticaking agent, calcium stearate promotes free flowing and prevent agglomeration during processing of powdered foods. And since calcium stearate provides a water-repelling coating for the particles, it protects the finished product from caking during storage.
One study found that calcium stearate was found to be most effective at reducing moisture sorption in powders. Other anticaking agents involved in the study were silicon dioxide and, calcium silicate.
There are other anticaking agents use in food.
These include tricalcium phosphate, magnesium carbonate, magnesium silicate, and sodium silicoaluminate. All of these substances are insoluble in water, and they help prevent clumping mainly by absorbing moisture.
ARE ANTICAKING AGENTS SAFE?
Like any other functional ingredients or additives, anticaking agents are carefully studied before being approved for use in food. Inappropriate use of these substances, either natural or synthetic, may be deleterious to the consumer or the product. However, effects may vary, depending on the individual that consumes the product. For this reason, the responsible governing bodies regulate these food additives, including anticaking agents. One way they do is by setting maximum use limits. For example, in Canada, the maximum allowable use of calcium silicate in salt is 1.0%, but 2.0% if used in fine grain salt. You can check out the full list of permitted anticaking agents in Canada here. In India, the Food Safety and Standards Authority of India (FSSAI) has set the allowable quantity for most anticaking agents at 2.0%. These standards are revised, if necessary, as newer research data becomes available.
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Anticaking agents are either metabolized or exhibit no toxic action at levels approved and employed in the food industry. According to World Health Organization’s Codex Alimentarius, there are 36 food additives under the functional class anticaking agents. You can access the full list here.
Other references
M. Gibson (2018). Food Science and the Culinary Arts. Academic Press.
V. Vaclavik and E. Christian (2014). Essentials of Food Science (4th edition). Springer.
S. Damodaran, K. Parkin (2017). Fennema’s Food Chemistry (5th edition). CRC Press.
