E551 - Silicon Dioxide

Silicon dioxide, or silica, is a chemical compound with the formula SiO2. It is a colorless solid present in abundance in the natural environment and in various living beings.


E551 - Silicon Dioxide:

Silicon dioxide, identified by the code E551 in the International Numbering System for Food Additives, is a common food additive that serves various purposes in the food industry.


  • Anti-Caking Agent: Silicon dioxide is primarily used as an anti-caking agent. It helps prevent the formation of lumps or clumps in powdered or granulated food products, ensuring a free-flowing and uniform texture.
  • Carrier: It is used as a carrier for certain flavors, colors, and active ingredients, helping to disperse them evenly throughout the food product.
  • Thickener: In some instances, silicon dioxide can act as a thickening agent, contributing to the texture of certain food items.


Silicon dioxide can be derived from natural sources such as sand or quartz. It can also be produced synthetically for use in the food industry.


Commonly found in a variety of food products, including powdered spices, seasoning blends, grated cheese, and powdered drink mixes.


Silicon dioxide is generally recognized as safe (GRAS) by regulatory authorities when used within established limits. It is considered inert and does not undergo significant absorption or metabolism in the digestive system.


Food products containing silicon dioxide are required to list it on the ingredients label, often identified as "Silicon Dioxide" or simply as "E551."

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