Betanin, or Beetroot Red, is a red
glycosidic food dye
Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink. They come in many forms consisting of liquids, powders, gels, and pastes. Food coloring is used in both commercial food ...
obtained from
beet
The beetroot is the taproot portion of a beet plant, usually known in North America as beets while the vegetable is referred to as beetroot in British English, and also known as the table beet, garden beet, red beet, dinner beet or golden beet ...
s; its
aglycone An aglycone (aglycon or genin) is the compound remaining after the glycosyl group on a glycoside is replaced by a hydrogen atom. For example, the aglycone of a cardiac glycoside would be a steroid
A steroid is a biologically active organic c ...
, obtained by hydrolyzing away the
glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...
molecule, is betanidin. As a
food additive
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (sal ...
, its
E number
E numbers ("E" stands for "Europe") are codes for substances used as food additives, including those found naturally in many foods such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly ...
is E162.
The color of betanin depends on
pH; between four and five it is bright bluish-red, becoming blue-violet as the pH increases. Once the pH reaches alkaline levels betanin degrades by
hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolysis ...
, resulting in a yellow-brown color.
Betanin is a
betalain pigment, together with
isobetanin,
probetanin, and
neobetanin. Other pigments contained in beet are
indicaxanthin and
vulgaxanthins.
Sources
Betanin is usually obtained from the extract of beet juice; the concentration of betanin in red beet can reach 300–600 mg/kg. Other dietary sources of betanin and other
betalains include the ''
Opuntia
''Opuntia'', commonly called prickly pear or pear cactus, is a genus of flowering plants in the cactus family Cactaceae. Prickly pears are also known as ''tuna'' (fruit), ''sabra'', '' nopal'' (paddle, plural ''nopales'') from the Nahuatl word ...
'' cactus,
Swiss chard, and the leaves of some strains of
amaranth
''Amaranthus'' is a cosmopolitan genus of annual or short-lived perennial plants collectively known as amaranths. Some amaranth species are cultivated as leaf vegetables, pseudocereals, and ornamental plants. Catkin-like cymes of densely ...
.
Uses
The most common uses of betanins are in coloring
ice cream
Ice cream is a sweetened frozen food typically eaten as a snack or dessert. It may be made from milk or cream and is flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit such as ...
and
powdered soft drink beverages; other uses are in some sugar
confectionery, e.g.
fondants,
sugar strand
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double s ...
s, sugar coatings, and fruit or cream fillings. In hot processed candies, it can be used if added at the final part of the processing. Betanin is also used in soups as well as
tomato
The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word , ...
and
bacon
Bacon is a type of salt-cured pork made from various cuts, typically the belly or less fatty parts of the back. It is eaten as a side dish (particularly in breakfasts), used as a central ingredient (e.g., the bacon, lettuce, and tomato sa ...
products. Betanin has "not been implicated as causing clinical food allergy when used as a coloring agent".
[Dean D. Metcalfe, Hugh A. Sampson, Ronald A. Simon: ''Food Allergy: Adverse Reactions to Foods and Food Additives.'' 4th Ed., Blackwell Publishing, 2009, , p. 416.]
Betanin can be also used for coloring
meat and
sausage
A sausage is a type of meat product usually made from ground meat—often pork, beef, or poultry—along with salt, spices and other flavourings. Other ingredients, such as grains or breadcrumbs may be included as fillers or extenders. ...
s.
Betanin has also shown to have antimicrobial activity and can be used as a natural antimicrobial agent in
food preservation
Food preservation includes processes that make food more resistant to microorganism growth and slow the oxidation of fats. This slows down the decomposition and rancidification process. Food preservation may also include processes that inhi ...
.
Degradation and stability
Betanin degrades when subjected to
light
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...
, heat, and
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
; therefore, it is used in frozen products, products with short shelf life, or products sold in dry state. Betanin can survive
pasteurization
Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life.
T ...
when in products with high
sugar content. Its sensitivity to oxygen is highest in products with a high water content and/or containing metal cations (e.g.
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...
and
copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...
);
antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants ...
s like
ascorbic acid
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) a ...
and
sequestrant
A sequestrant is a food additive which improves the quality and stability of foods. A sequestrant forms chelate complexes with polyvalent metal ions, especially copper, iron and nickel, which can prevent the oxidation of the fats in the food. Se ...
s can slow this process down, together with suitable packaging. In dry form betanin is stable in the presence of oxygen.
See also
*
Betalain
References
Further reading
*
{{Plant Pigments
Biological pigments
Food colorings
Glucosides
Betalains
Indoles
E-number additives
Enoic acids