Bleached Wheat Flour

Bleached flour is a white flour treated with <a href="http://en.wikipedia.org/wiki/Flour_bleaching_agent" title="Flour bleaching agent" >flour bleaching agents</a> to whiten it (freshly milled flour is yellowish) and to give it more <a href="http://en.wikipedia.org/wiki/Gluten" title="Gluten" >gluten</a>-producing potential. Oxidizing agents are usually employed, most commonly <a href="http://en.wikipedia.org/wiki/Organic_peroxide" title="Organic peroxide" >organic peroxides</a> like <a href="http://en.wikipedia.org/wiki/Acetone_peroxide" title="Acetone peroxide" >acetone peroxide</a> or <a href="http://en.wikipedia.org/wiki/Benzoyl_peroxide" title="Benzoyl peroxide" >benzoyl peroxide</a>, <a href="http://en.wikipedia.org/wiki/Nitrogen_dioxide" title="Nitrogen dioxide" >nitrogen dioxide</a>, or <a href="http://en.wikipedia.org/wiki/Chlorine" title="Chlorine" >chlorine</a>. A similar effect can be achieved by letting the flour oxidize with oxygen in the air ("natural aging") for approximately 10 days; however, this process is more expensive due to the time required. Flour bleached with <a href="http://en.wikipedia.org/wiki/Benzoyl_peroxide" title="Benzoyl peroxide" >benzoyl peroxide</a>has been prohibited in the UK since 1997.<a href="http://en.wikipedia.org/wiki/Wheat_flour#cite_note-fab-bleach-1" >[2]</a>

According to the <a rel="nofollow" class="external text" href="http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=21&PART=137&SECTION=165&YEAR=2001&TYPE=TEXT" >FDA</a>, a pound of enriched flour must have the following quantities of nutrients to qualify: 2.9 milligrams of <a href="http://en.wikipedia.org/wiki/Thiamin" title="Thiamin" class="mw-redirect" >thiamin</a>, 1.8 milligrams of<a href="http://en.wikipedia.org/wiki/Riboflavin" title="Riboflavin" >riboflavin</a>, 24 milligrams of <a href="http://en.wikipedia.org/wiki/Niacin" title="Niacin" >niacin</a>, 0.7 milligrams of <a href="http://en.wikipedia.org/wiki/Folic_acid" title="Folic acid" >folic acid</a>, and 20 milligrams of <a href="http://en.wikipedia.org/wiki/Iron" title="Iron" >iron</a>. The first four nutrients are <a href="http://en.wikipedia.org/wiki/B_vitamin" title="B vitamin" class="mw-redirect" >B vitamins</a>. <a href="http://en.wikipedia.org/wiki/Calcium" title="Calcium" >Calcium</a> also may be added at a minimum of 960 milligrams per pound.

Enriching is necessary because the <a href="http://en.wikipedia.org/wiki/Refined_grains" title="Refined grains" >processing</a> used to make <a href="http://en.wikipedia.org/wiki/White_flour" title="White flour" class="mw-redirect" >white flour</a> destroys some of these nutrients that originally were present in the <a href="http://en.wikipedia.org/wiki/Whole_grain" title="Whole grain" >whole grain</a>.