**2.2 The need for bio-colourants**


*Bio-Colours From Spices DOI: http://dx.doi.org/10.5772/intechopen.109830*

Bio-colours can be classified into three main classes [7].


Anthocyanins, a group of water-soluble pigments, impart red to blue colours (250–650 nm). Betalains yield betacyanin (red) and betaxanthin (yellow) pigments. Carotenoid groups are responsible for the yellow and orange pigments (250–650 nm). Chlorophylls are found in two forms: chlorophyll a (blue-green) and b (yellow-green). Caramel is obtained by heating carbohydrates, which imparts a brown colour.
