ABSTRACT
Anthocyanins are a major group of natural pigments that confer red, purple, blue, and even black colour on plants. Anthocyanins are also widely exploited by the food industry as natural colourants and putative bioactives. Colour stabilization is provided by molecular interactions of the anthocyanin chromophore with other compounds, referred to as copigments. Interaction of extracted anthocyanins with the solid plant material is another conspicuous phenomenon. Anthocyanin reactions can also occur chemically, especially during heating under acidic conditions or as a result of oxygen exposure during food preparation and storage. Anthocyanin reactions have been particularly explored in wine, as they are responsible for the colour changes from red to purple and then to tawny observed during ageing of red and rose wines. Cooking of red cabbage pigments, especially with alkaline water, results in a shift toward purple hints and to discolouration upon heating.
