Annatto is one of the oldest and most widely used natural food colourants, extracted from the outer coating (aril) of Bixa orellana seeds.
The primary pigments are bixin (oil-soluble) and norbixin (water-soluble, obtained by alkaline hydrolysis). Annatto provides yellow-to-orange hues and is extensively used in cheese (Cheddar, Red Leicester), butter, margarine, snacks and bakery products as a clean-label alternative to synthetic colours.