R-phycoerythrin

The brilliant red light-harvesting pigment of certain red algae, a phycobiliprotein built from two protein chains each gripping an open-chain tetrapyrrole chromophore. Its intense pink-red color and water solubility recommend it as a natural food colorant for confectionery, dairy, and drinks, where formulators seek alternatives to synthetic reds. Like all protein pigments it is sensitive to heat, light, and pH extremes, so applications favor mildly processed, chilled products. Extraction and stabilization technology continues to widen its practical use. Encapsulation technologies are improving its stability in commercial applications.