Description
Carmine is a bright red pigment and food colorant obtained from carminic acid, which is extracted from dried female cochineal insects and then converted into an aluminium or calcium salt.
Source and chemistry
Carmine is produced from cochineal insects (Dactylopius coccus) that live on prickly pear cacti; the dried insects contain about 17–24% carminic acid by weight.
Carminic acid is a complex anthraquinone derivative (C₂₂H₂₀O₁₃); when precipitated with aluminium or calcium salts it forms the insoluble red lake pigment known as carmine.
Production process
To prepare carmine, dried, powdered insects are boiled in an ammonia or sodium carbonate solution, the insoluble material is filtered off, and alum is added to precipitate the red aluminium salt of carminic acid.
Additives such as stannous chloride, citric acid, borax, gelatin, or lime may be used to adjust shade and precipitate properties, yielding tones from bright red to purplish red.
Uses
Carmine (E120, Natural Red 4) is widely used as a stable, heat- and light‑resistant red colorant in foods such as confectionery, pastries, yogurts, beverages, as well as in cosmetics and pharmaceuticals.
It is also used historically and artistically as a fine art pigment for watercolours, textiles, and other coatings where a natural red dye is desired.
Safety and labeling notes
Carmine is generally regarded as safe as a food additive, but in rare cases it can trigger allergic reactions, including asthma or anaphylaxis, likely due to residual insect proteins.
Because it is insect‑derived, many regulations and consumer guides require it to be explicitly declared (e.g., “carmine,” “cochineal extract,” or E120), and it is not considered suitable for vegan or some religious dietary restrictions.