Beetroot is a rich source of some valuable, active compounds, such as carotenoids, glycine betaine, saponins, betacyanines, folates, betanin, polyphenols and flavonoids.
It is composed of different pigments all belonging to the class betalaine, main colouring principle, which is broadly divided into:
- Betacyanins (red-violet color) ; of which betanine accounts for 75–95%
- Betaxanthine (yellow color) and degradation products of betalaines (light brown color), which may be present in minor concentration
Betanine is responsible for the red coloration of beetroot and used as a dye in the food industry as ‘beetroot red’. Two other compounds, named vulgaxanthin and indicaxanthin are also found in beetroots that contribute towards its coloration as well.
Betalain are alkaloid pigments, named after the Red beet (Beta vulgaris). They replace anthocyanins in plants of the order Caryophyllales and are also found in some fungi species (e.g. fly agaric).
Advantages of Betalain as Food Dye
- Colouring from red beets is water-soluble, and its flavor can easily be masked
- Though betalains are less heat-stable compared to other natural colorants, they are known to have excellent light stability (betalain colors won’t fade away in light, easily) and pH stability (betalains are relatively resistant to changes in the pH of food and beverages, unlike anthocyanins)
- It is economical as well as has no known allergic: side-effects