caramel a food product used both as a brown colouring and for its bitter-sweet flavour, is produced in the final stage of sugar boiling when sugar is heated above 170 °C (340 °F). The exact temperature at which caramel begins to form depends on the composition of the sugar; the figure given applies to sucrose, common white sugar. The fructose present in honey caramelizes more quickly; but the dextrose (glucose) which is also present in honey is slower. The pentose sugars found in small amounts in various vegetables caramelize particularly well, and toast made from wholemeal bread owes its dark colour to the caramelization of pentoses in the wheat bran.
