INDIGOTINE
Prepared at the 73rdJECFA (2010) and published in FAO Monographs 10 (2010), superseding specifications prepared at the 28th JECFA (1984) and published in the Combined Compendium of Food Additive Specifications, FAO JECFA Monographs 1 (2005). An ADI of 0 - 5 mg/kg bw was established at the 18th JECFA (1974).
SYNONYMS CI Food Blue 1, FD&C Blue No. 2, Indigo Carmine, CI (1975) No. 73015, INS No. 132
DEFINITION Consists essentially of a mixture of disodium 3,3' -dioxo-[delta2,2'-biindoline]-5,5'-disulfonate (principal component) and disodium 3,3'-
dioxo-[delta2,2'-biindoline]-5,7'-disulfonate (isomer) and subsidiary colouring matters together with sodium chloride and/or sodium sulfate as the principal uncoloured components.
May be converted to the corresponding aluminium lake in which case only the General Specifications for Aluminium Lakes of Colouring Matters apply.
Chemical names Disodium 3,3'-dioxo-[delta2,2'-biindoline]-5,5'-disulfonate (principal component)
C.A.S. number 860-22-0 (principal component)
Chemical formula C16H8N2Na2O8S2 (principal component)
Formula weight 466.36 (principal component)
Assay Not less than 85% total colouring matters. Not more than 18% of disodium 3,3'-dioxo-[delta2,2'-biindoline]-5,7'-disulfonate.
DESCRIPTION Blue powder or granules
FUNCTIONAL USES Colour