Detection and identification of natural water-soluble colouring matters in foods.

The natural colouring matters of foods can be isolated and identified simultaneously with the synthetic dyes by the benzalkonium method. In the course of isolation anthocyanins, carmine, betanin, caramel and riboflavin are separated from synthetic dyes, as well as from one another, with the exception of first two, which are separated from one another by chromatography or distinguished by oxidation.