Radish red color belongs to the anthocyanin class and is a glucoside derivative of geranium pigment. It is processed from fresh roots of red heart radish (rouge red radish) through processes such as cleaning, cutting, soaking, enrichment, and drying. As a natural pigment, radish red pigment has the characteristics of high safety factor, high nutritional value, and low production cost, and is widely used in fields such as food, cosmetics, and medicine. The main coloring substance of radish red color is the anthocyanins of geranium, with a molecular formula of C15H11O5.

Radish red color is dark red amorphous powder, easily hygroscopic, clumps after hygroscopicity, but generally does not affect use and is prone to oxidation. Sunlight exposure can promote its degradation and fading, easily soluble in water and ethanol aqueous solutions, insoluble in non-polar solvents. The maximum absorption peak of the aqueous solution of this product shifts backwards with increasing pH of the medium, and the absorbance decreases significantly. The color tone of the solution presents in sequence with the pH of the medium ranging from 2.0 to 8.0: orange red pink bright red violet. Its aqueous solution is thermally unstable, and as the temperature increases, degradation accelerates, resulting in color fading. Cu2+can accelerate its degradation and turn it blue; Fe3+can turn its solution into a rusty yellow color; Mg2+and Ca2+have little effect on this product; A13+, Sn2+, and ascorbic acid have protective effects on it.