E303

E303 is the European food additive code for ammonium ascorbate, the ammonium salt of ascorbic acid (vitamin C). As with other E numbers, it is used to identify a substance approved for use in foods within the European Union and in other jurisdictions that reference the EU system. Ammonium ascorbate functions primarily as an antioxidant and reducing agent, helping to retard oxidation, preserve color, and maintain flavor in various products. It can also contribute to acidity regulation in some formulations.

Chemical and physical properties: Ammonium ascorbate is water-soluble and derives from ascorbic acid. Its properties as a reducing agent enable it to scavenge reactive oxygen species and slow enzymatic browning in foods. It may degrade with heat, light, or in the presence of metal ions, so it is typically used at low concentrations and stored under appropriate conditions.

Applications: The additive is used in a range of processed foods, including fruit preparations, beverages, and some meat products where antioxidant protection and color stabilization are desired. In cured or processed meats, ascorbate salts help facilitate color development and can reduce nitrosamine formation when used in conjunction with curing agents.

Regulatory status and labeling: E303 is approved for use in foods under EU regulation and must be listed on ingredient statements as E303. Maximum permitted levels vary by product category and are enforced to ensure safety and consistency across products. Storage recommendations typically call for cool, dry conditions away from heat and moisture.

Safety and health considerations: Regulatory authorities generally consider ascorbate salts, including ammonium ascorbate, to be safe at approved usage levels. The EFSA has not assigned a numeric ADI to ascorbic acid and its salts; excess intake from any source can cause gastrointestinal upset in sensitive individuals. As with all additives, it should be used in accordance with good manufacturing practices.