Latin name: Beta vulgaris
Source material: Dried seeds
Family: Amaranthaceae (Chenopodiaceae)
Common names: Sugar-beet seed, Sugar beet seed
Beta vulgaris produces sugar from its large, white, conical tap roots. Large-scale cultivation in Europe began during the Napoleonic wars when the British blockade stopped imports of sugar cane from the West Indies. The Sugar-beet is native to Europe and the Middle East but is now cultivated worldwide as a commercial sugar crop in temperate climates. About a third of all sugar production in the world is derived from this plant, but this sugar is considered inferior to cane sugar because it does not crystallise as well and is absorbed more quickly by the body.
Sugar beet is an annual or biennial plant growing to 1.5 m. The leaves are oval in shape and dark green or reddish in colour, frequently forming a rosette from the underground stem. The flowers are small and green or red. The Sugar-beet seed is tiny – about half the size of a grain of rice – and rough and bumpy, growing in clusters inside the dry fruit.
Beets and their relatives are grown throughout the world for human and stock food. The seeds, apart from some isolated culinary uses (as in India and Pakistan), serve as an animal feed.
No allergens from the seed of this plant have yet been characterised, but a number of proteins have been isolated from the leaves.
A protein with homology to the chitin-binding (hevein) domain of chitin-binding proteins, e.g., class I and IV chitinases, has been isolated from the leaf of Sugar-beet (1-2). The allergenicity of these chitinases was not assessed, and it may well be present only if the plant is stressed.
Two novel, nearly identical antifungal proteins, IWF1 and IWF2, were isolated from Sugar-beet leaves. The proteins were shown to be related to the family of plant non-specific lipid transfer proteins (3).
An extensive cross-reactivity among the different individual species of the genus could be expected but has not been reported to occur clinically as yet (4).
Sugar-beet seed may uncommonly induce allergy symptoms in sensitised individuals, predominantly in occupational settings such as the animal feed industry and farms.
In a prospective open study over 8 months in a group of 10 atopic children with repeated urticaria, based on oral challenge tests along with history, there were 3 cases of allergy to food colourings. Clinical features were mainly skin symptoms, sometimes associated with GI manifestations which were non specific. Removal of the colorants resulted in the disappearance of the symptoms in a child (Red cochineal) and regression of symptoms in two others (Red cochineal, Red beet) (5). It was not clear whether this is beetroot or sugar beet but both are closely related family members.
The fresh leaf may cause poisoning due to the 1% oxalic acid content. The leaf may also contain dangerous levels of HCN and/or nitrates and nitrites.
Compiled by Dr Harris Steinman, firstname.lastname@example.org
Nielsen KK, Nielsen JE, Madrid SM, Mikkelsen JD. Characterization of a new antifungal chitin-binding peptide from sugar beet leaves.
Plant Physiol 1997;113(1):83-91
Berglund L, Brunstedt J, Nielsen KK, Chen Z, Mikkelsen JD, Marcker KA. A proline-rich chitinase from Beta vulgaris.
Plant Mol Biol 1995;27(1):211-6
Nielsen KK, Nielsen JE, Madrid SM, Mikkelsen JD. New antifungal proteins from sugar beet (Beta vulgaris L.) showing homology to non-specific lipid transfer proteins.
Plant Mol Biol 1996;31(3):539-52
Yman L. Botanical relations and immuno-logical cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
Zenaidi M, Pauliat S, Chaliier P, Fratta A, Girardet JP. Allergy to food colouring. A prospective study in ten children. [French] Tunis Med 2005;83(7):414-8