Flour bleaching agent is the agent added to fresh milled grains to whiten the flour by removing the yellow colour pigment called
xanthophyll
Xanthophylls (originally phylloxanthins) are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes. The name is from Greek: (), meaning "yellow", an ...
. It whitens the flour, which is used in the baking industry.
Overview
Usual flour
bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from (i.e. to whiten) fabric or fiber (in a process called bleaching) or to disinfect after cleaning. It often refers specifically t ...
ing agents are:
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Organic peroxide
In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group (). If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily b ...
s (
benzoyl peroxide
Benzoyl peroxide is a chemical compound (specifically, an organic peroxide) with structural formula , often abbreviated as (BzO)2. In terms of its structure, the molecule can be described as two benzoyl (, Bz) groups connected by a peroxide ...
)
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Calcium peroxide
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Chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...
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Chlorine dioxide
Chlorine dioxide is a chemical compound with the formula ClO2 that exists as yellowish-green gas above 11 °C, a reddish-brown liquid between 11 °C and −59 °C, and as bright orange crystals below −59 °C. It is usually ...
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Azodicarbonamide
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Nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic, bent molecule with C2v point group symmetry. Industrially, is an intermediate in the s ...
*Atmospheric
oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...
, used during natural aging of flour
Use of chlorine,
bromates, and
peroxide
In chemistry, peroxides are a group of Chemical compound, compounds with the structure , where the R's represent a radical (a portion of a complete molecule; not necessarily a free radical) and O's are single oxygen atoms. Oxygen atoms are joined ...
s is not allowed in the
European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
.
Bleached
flour
Flour is a powder made by Mill (grinding), grinding raw grains, List of root vegetables, roots, beans, Nut (fruit), nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredie ...
improves the structure-forming capacity, allowing the use of dough formulas with lower proportions of flour and higher proportions of
sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose
Glucose is a sugar with the Chemical formula#Molecular formula, molecul ...
. In
biscuit
A biscuit is a flour-based baked food item. Biscuits are typically hard, flat, and unleavened. They are usually sweet and may be made with sugar, chocolate, icing, jam, ginger, or cinnamon. They can also be savoury, similar to crackers.
...
making, use of chlorinated flour reduces the spread of the dough, and provides a "tighter" surface. The changes of functional properties of the flour
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
s are likely to be caused by their
oxidation
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...
.
In countries where bleached flour is prohibited,
microwaving plain flour produces similar chemical changes to the bleaching process. This improves the final texture of baked goods made to recipes intended for bleached flours.
See also
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Chorleywood bread process
The Chorleywood bread process (CBP) is a method of efficient dough production to make yeasted bread quickly, producing a soft, fluffy loaf. Compared to traditional bread-making processes, CBP uses more yeast, various food additives, and high-spee ...
– another bread making process that increases volume
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Flour treatment agent
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Graham flour
Graham flour is a type of coarse-ground flour of whole wheat named after Sylvester Graham. It is similar to conventional whole-wheat flour in that both are made from the whole grain, but graham flour is ground more coarsely. It is not sifted ...
– an early unbleached whole-grain flour
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Maida flour
Maida, ''maida flour'', or ''maida mavu'' is a type of wheat flour originated from the Indian subcontinent. It is a super-refined wheat flour used in Indian cuisine to make pastries and other bakery items like breads and biscuits. Some maida may ...
– a commonly bleached flour in India
References
Food additives
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