|Main ingredients||Wheat flour|
|Other information||glycaemic load 37 (100g)|
White bread typically refers to breads made from wheat flour from which the bran and the germ layers have been removed (and set aside) from the whole wheatberry as part of the flour grinding or milling process, producing a light-colored flour. This milling process can give white flour a longer shelf life by removing the natural oils from the whole grain. Removing the oil allows products made with the flour, like white bread, to be stored for longer periods of time avoiding potential rancidity.
The flour used in white breads are bleached further--by the use of chemicals such as potassium bromate, azodicarbonamide, or chlorine dioxide gas to remove any slight, natural yellow shade and make its baking properties more predictable. This is banned in the EU. Some flour bleaching agents are also banned from use in other countries.
While a bran and wheat germ discarding milling process can help improve white flour's shelf life, it does remove nutrients like some dietary fiber, iron, B vitamins, micronutrients and essential fatty acids. Since 1941, however, fortification of white flour-based foods with some of the nutrients lost in milling, like thiamin, riboflavin, niacin, and iron was mandated by the US government in response to the vast nutrient deficiencies seen in US military recruits at the start of World War II. This fortification led to nearly universal eradication of deficiency diseases in the US, such as pellagra and beriberi (deficiencies of niacin and thiamine, respectively) and white bread continues to contain these added vitamins to this day.
Folic acid is another nutrient that some governments have mandated is added to enriched grains like white bread. In the US and Canada, these grains have been fortified with mandatory levels of folic acid since 1998 because of its important role in preventing birth defects. Since fortification began, the rate of neural tube defects has decreased by approximately one-third in the US.