Other names for the additive (synonyms)
General information
The food additive E132 is known as indigocarmine or indigotine. It belongs to the category of colourings and is used in the food industry to impart an intense blue or blue-violet shade to products.
By origin, additive E132 is a synthetic substance. Although historically the blue dye indigo was obtained from plants of the genus Indigofera, modern indigocarmine for food use is produced industrially, which ensures consistent quality and purity.
Indigocarmine is a dark blue powder or granules that dissolve well in water. Its history is linked to ancient natural dyes used for textiles. However, with the development of chemistry in the 19th–20th centuries, it became possible to create a purified blue dye suitable not only for textiles but also for food products.
The chemical formula of indigocarmine is C16H8N2Na2O8S2. In terms of its properties, it is a stable compound that retains its colour during heating and in acidic environments. At the same time, it is sensitive to light, which is taken into account when storing products.
For the food industry, colouring E132 is obtained by chemical synthesis based on indigo compounds followed by purification. Thus, it is a process of producing a stable blue dye with strictly controlled properties, without impurities from natural raw materials.
Effects on the body
Benefits of Additive E132
Indigocarmine is not a substance inherent to the human body and does not participate in physiological processes. It has no nutritional value and provides no health benefits. The role of additive E132 is exclusively technological — to create a stable colour in food products.
The European Food Safety Authority (EFSA) confirms that, when established intake limits are observed, additive E132 does not pose a risk to health.
Risks of Additive E132
After entering the body, indigocarmine is only partially absorbed. Most of the substance passes through the digestive system and is excreted unchanged, mainly in the urine.
Potential risks of additive E132 are associated with excessive consumption of products containing high amounts of indigocarmine. If the acceptable daily intake (ADI) is exceeded, undesirable reactions may occur, including irritation of the gastrointestinal tract or allergic manifestations in sensitive individuals.
At the time of the EFSA re-evaluation in 2014, the colour indigocarmine raised no concerns regarding developmental toxicity, genotoxicity, or cytotoxicity. The JECFA Committee holds a similar position regarding the safety of indigocarmine. The U.S. Food and Drug Administration (FDA) permits the use of indigocarmine as a food colouring in specified product categories.
At the same time, an analysis of recent studies showed that indigocarmine may penetrate human fibroblast cells and exhibit cytotoxicity; in particular, a reduction in cell proliferation by 60–80% was observed. Another in vitro study using human tumour cells HL-60 showed some inhibition of growth, while an in vivo experiment from the same report on fruit flies (Drosophila) revealed a reduction in healthy lifespan after 6 days of exposure to indigocarmine. Similarly, a report on the effects of indigocarmine on Tenebrio molitor larvae recorded a decrease in body weight.
However, the concentration of indigocarmine used in these studies was very high — 1 g/kg administered over a period of 3 weeks.
These data are difficult to extrapolate to humans, and the risk is likely to be very low when indigocarmine is used as a food colouring; nevertheless, its potential toxicity requires further investigation.
All organisations have established an acceptable daily intake for additive E132 at a level of 5 mg/kg body weight.
Uses
In the food industry, additive E132 is used as a blue colouring. Indigocarmine is applied to create or enhance colour, as well as to obtain green and violet shades in combination with other colourings.
Most commonly, colouring E132 can be found in confectionery products, jellies, desserts, ice cream, decorative sprinkles, beverages, and some dairy products. A characteristic feature of the additive is its high colour intensity; therefore, minimal doses are used in the food industry.
Legal Status
Indigocarmine (additive E132) is authorised for use in the European Union in accordance with Regulation (EC) No 1333/2008 with a clearly defined ADI. In Ukraine, the additive is permitted in accordance with harmonised European requirements.
In the United States, additive E132 is permitted as a food colouring provided that established limits are observed. Canada and Japan also allow the use of indigocarmine in certain product categories.
A complete ban on additive E132 does not exist in most developed countries; however, strict control of dosage is mandatory.