Anthoxanthins in food

Anthoxanthin pigment is a flavonoid and is similar to anthocyanin, but it exists in less oxidized state as the oxygen on the central group is uncharged.

It is actually a composite of compounds known as flavones, flavonols, and flavonones. The anthoxanthins are glycosides when on boiling with dilute acid yield one or two molecules of monosaccharides and a flavone or flavone derivatives.

Anthoxanthins are white or pale yellowish, water-soluble pigments found in a plant’s cell sap. They contribute the cream or white color of cauliflower, onions, white potatoes and turnips.

turnips

Short cooking is desired. With prolonged heat, the pigment turns into a brownish gray color. For example, white, anthocyanin potatoes with their low organic acid content may become dark colored after prolonged cooking due to formation of an iron-chlorogenic acid complex.

Vegetable containing anthoxanthins, such as turnips and cauliflower can also change color if they are cooked in a covered pan for long periods of time.

The sulfur containing compounds in the vegetables will be released in the form of hydrogen sulfide which will convert the colorless anthoxanthin to anthocyanins as will be noted in the pink pigment in overcooked turnips and cauliflower.
Anthoxanthins in food