Vitamin B2 (Riboflavin)
Riboflavin is a yellow to orange-yellow, crystalline powder of faint odour and intensely bitter taste. Its solubility in water is very slight and depends on the crystalline structure. The saturated aqueous solution of riboflavin shows neutral reactions to litmus (pH about 6.0). Solubility is markedly increased in the presence of various substances, especially sodium chloride, urea and nicotinamide. Riboflavin is also soluble in alkali hydroxide solutions, but will decompose. In the common organic solvents riboflavin is practically insoluble.