Bleached flour

Unbleached flour

Composition

Flour

Flour is a powder which is made by grinding cereal grains, other seeds or roots (like Cassava). It is the main ingredient of bread, which is a staple food for many cultures. Wheat flour is one of the most important foods in European, North American, Middle Eastern and North African cultures, and is the defining ingredient in most of their styles of breads and pastries. Maize flour has been important in Mesoamerican cuisine since ancient times, and remains a staple in much of Latin American cuisine. Rye flour is an important constituent of bread in much of central/northern Europe

The word "flour" is originally a variant of the word "flower". Both derive from the Old French fleur or flour, which had the literal meaning "blossom," and a figurative meaning "the finest." The phrase "fleur de farine" meant "the finest part of the meal," since flour resulted from the elimination of coarse and unwanted matter from the grain during milling.

It was discovered around 9000 BC that wheat seeds could be crushed between simple millstones to make flour. The Romans were the first to grind seeds on cone mills. In 1879, at the beginning of the Industrial Era, the first steam mill was built in London. In the 1930s, some flour began to be enriched with iron, niacin, thiamine and riboflavin. In the 1940s, mills started to enrich flour and folic acid was added to the list in the 1990s.

Flour contains a high proportion of starches, which are a subset of complex carbohydrates also known as polysaccharides. In the USA the kinds of flour used in cooking include all-purpose flour, self-raising flour, and cake flour including bleached flour. The higher the protein content the harder and stronger the flour and will produce crusty or chewy breads. The lower the protein the softer the flour for better cakes, cookies, and pie crusts.

Unbleached flour is simply flour that has not undergone bleaching and therefore does not have the color of "white" flour. An example of this would be the Graham flour. Sylvester Graham was against using bleaching agents, which he considered unhealthy.

"Refined flour" has had the germ and bran removed and is typically referred to as "white flour". "Bleached flour" is any refined flour with a whitening agent added.

Bleached flour is artificially aged using a bleaching agent, a maturing agent, or both. A bleaching agent would affect only the carotenoids in the flour; a maturing agent affects gluten development. A maturing agent may either strengthen or weaken gluten development.

The four most common additives used as bleaching/maturing agents in the USA at this time are:

Potassium bromate (will be listed as an ingredient/additive) - a maturing agent that strengthens gluten development. Does not bleach.

Benzoyl peroxide - bleaches. Does not act as a maturing agent - no effect on gluten.

Ascorbic acid - Maturing agent that strengthens gluten development. Does not bleach.

Chlorine gas - both a bleaching agent and a maturing agent, but one that weakens gluten development. Chlorination also oxidizes starches in the flour, making it easier for the flour to absorb water and swell - this makes stiffer doughs. For bread, this is bad (because gluten is weakened and bread is heavily dependent on gluten formation), but for cakes, cookies, and biscuits, it's a good thing, because gluten development in these types of baked goods makes them tough. The modification of starches in the flour allows the use of wetter doughs (making for a moister end product) without destroying the structure necessary for light fluffy cakes and biscuits. Chlorinated flour allows cakes and other baked goods to rise better, the fat to be distributed more evenly.

Cake flours in particular are nearly always chlorinated. There is at least one flour labeled "unbleached cake flour blend" (marketed by King Arthur) that is not bleached, but the protein content is much higher than typical cake flour at about 9.4% protein (cake flour is usually around 6% to 8%). According to King Arthur, this flour is a blend of a more finely milled unbleached wheat flour and cornstarch, which makes a better end result than unbleached wheat flour alone (cornstarch is a common additive for part of the flour used in cake where actual cake flour is called for but you only have all purpose on hand).

All bleaching and maturing agents (with the possible exception of ascorbic acid) have been banned in the EU. The home baker in the EU must struggle with the unbleached flours that typically do not lend themselves to the making of light fluffy cakes. At least one home baker has developed a method for heat treating flour at home to break down the starches and make it more acceptable for use in the making of cakes; this process is currently referred to as "Kate Flour" in Internet baking communities, after the woman who continues to develop the process.

Bromation of flour in the USA has fallen out of favor and while it is not yet actually banned anywhere, few retail flours available to the home baker are bromated anymore.

Some other chemicals used as Flour treatment agents to modify color and baking properties include:

• chlorine dioxide
• Calcium peroxide

• Atmospheric oxygen causes natural bleaching.

Дата добавления: 2014-01-11