Cochineal extract and carmine are natural anthraquinone red dyes
originally used to colour fabrics. Today, the colouring is utilized by food, cosmetic and pharmaceutical industries. Colour manufacturers extract carminic acid from the female cochineal insect (Dactylopins coccus Costa
), a cactus-dwelling insect native to Mexico and South America.
Cochineal is a natural colouring that provides a characteristic pink, red or purple hue while demonstrating excellent heat and light stability.
Hues vary depending on the extraction method, water or alcohol. Carminic acid is orange in low pH and violet in high pH.
The colour shift results from pH affecting the phenolic groups on the carminic acid molecule.
Extracting carminic acid in the presence of aluminum or calcium ions results in carmine. “Carmine” is the common term for insoluble cochineal-based pigments. These hues follow the same shifts as carminic acid but will precipitate at low pH before becoming orange. Acid-proofing results from a hydroxyl group being replaced by an amino group and results in red to violet hues in low pH applications where carminic acid would otherwise be orange.