Indigotine

Identifiers

Indigo Carmine
INS No. 132
FD&C Blue No. 2
E 132
CI Food Blue 1

Physical Description

Indigotine occurs as a blue-brown to red-brown powder or as granule. It is an indigoid dye, consisting of a mixture of disodium 3,3′-dioxo-[delta2,2′-biindoline]-5,5′-disulfonate (the principal component), disodium 3,3′-dioxo-[delta2,2′-biindoline]-5,7′-disulfonate (an isomer) and subsidiary coloring matters and may be converted to the corresponding aluminum lake.

Common Uses

Indigotine is distinguished by its rich royal blue color, and can be used for coloring foods and drugs, including dietary supplements, blueberry bagels, breakfast cereals, cakes and cupcakes, candies including chocolate, chewing gum, dairy products, decorations for baking, frozen treats, and sauces and seasonings.

Specifications

Regulatory Approvals

JECFA: ADI of 0-5 mg/kg bw (86TH Report, 2019). There are more than 50 food categories for which maximum permitted levels (MPLs) for indigotine (INS No. 132) have been adopted in the General Standard for Food Additives.

USA: FD&C Blue No. 2, along with its aluminum lake (21 CFR 82.102), are a subject to certification and may be safely used for coloring foods (including dietary supplements) generally (21 CFR 74.102) and for coloring ingested drugs (21 CFR 74.1102) in amounts consistent with GMP. FD&C Blue No. 2 was first permanently listed as a color subject to certification for use in food and ingested drugs in 1983.

EU: ADI of 0-5 mg/kg body weight (EFSA, 2014); EFSA has also established MPLs for use of Indigo carmine in foods and beverages in Europe

Safety Reviews

Safety Evaluation of certain food additives (Eighty-sixth report of the Joint FAO/WHO Expert Committee on Food Additives) WHO Food Additives series no. 77, 2020. Available online

EFSA ANS Panel (2014) Scientific opinion on the re-evaluation of Indigo Carmine (E 132) as a food additive. EFSA Journal, 12(7), 3768 [51 pp]. Available online

FDA Final Rule. 48 FR 5252; Feb 4, 1983. Available online

FDA Final Rule. 52 FR 28553; Jul 31, 1987. Available online