Colour and Cooking: Betacyanin and Betaxanthin

These two pigments, present in beetroot, fall outside the main groups. Betacyanin is red-violet, betaxanthin yellow. When a beetroot is cooked, its cell walls are made porous and these colours leak out, creating the familiar deep red effect. Betacyanin is an unusually stable red pigment. However, if a highly alkaline cooking medium is used, it may turn yellow. Acid conditions, on the contrary, will make the red colour more purple; and the addition of an acid to beetroots which have turned out yellow will make them red again.