Acetylated oxidised starch

Acetylated oxidised starch is a modified starch produced by two sequential chemical treatments: first, oxidation of the native starch with sodium hypochlorite or hydrogen peroxide (which cleaves and shortens starch chains, reducing viscosity and improving clarity), followed by acetylation with acetic anhydride (which introduces acetyl groups that reduce retrogradation and improve film-forming properties). This combination produces a low-viscosity starch with excellent paste clarity, good film-forming capability, and stable texture under refrigeration — properties particularly valued in surface-coating and encapsulation applications.

JECFA evaluated acetylated oxidised starch in 1981 and assigned a "not specified" ADI. Both the oxidation and acetylation modifications produce starch products that are metabolised normally in the digestive system. The oxidation by-products from hypochlorite treatment are washed away during processing, and the acetyl groups are hydrolysed in the gut to acetic acid and the starch chain. No novel toxic metabolites are generated.

Acetylated oxidised starch is approved in the EU as E1451 and in other food markets for use primarily as a coating, encapsulation, and binding agent rather than as a thickener — its low viscosity compared with cross-linked modified starches makes it suited for applications where a thin, stable film rather than a thick paste is needed. It is used in confectionery panning (sugar-coating), flavour encapsulation for dry mixes, and as a surface treatment for certain food products. Consumers are most likely to encounter it in hard-coated confectionery and nutritional supplement capsules. Gluten-free status depends on the starch source.