Purification and crystallization of riboflavin

Abstract

Purified and crystallized riboflavin is prepared by a process that includes dissolving needle-shaped riboflavin of the stable modification A form in an aqueous mineral acid solution at a temperature not exceeding about 30.degree. C. with intensive intermixing. Active charcoal is then added to the resulting solution. After adsorption of the dissolved impurities from the solution onto the active charcoal, the solution containing the active charcoal is subjected to counter-current filtration over a ceramic membrane having a pore size of about 20 to about 200 nm. The resulting filtrate is treated with a five- to ten-fold amount of water (vol./vol.) at a temperature not exceeding about 30.degree. C. The resulting precipitated, spherical crystals of riboflavin are then separated by centrifugation or filtration. If desired, the spherical crystals of riboflavin may be washed with water and subsequently dried. The purified and crystallized riboflavin formed by this process is suitable for pharmaceutical and foodstuff applications.