The treatment of flour with chemical agents is a widespread commercial practice. In general these chemical agents are applied either for "bleaching" or for "improving" the flour. Common usage has made the term bleaching synonymous for both of these effects. The main reasons for using chemical improvers are that they enable bakers to produce loaves of bread which appeal to the palate, allow millers to use any supply of sound wheat for the production of bread flour with uniform properties and circumvent the waste and spoilage which occur when flour is aged naturally during storage.
Although flour bleaching was first used widely at the turn of the century, during the past twenty-five years approximately 90 per cent of all white wheat flour milled in North America and in England (among other countries) has been treated with nitrogen trichloride (NC13).1 Flour treated in this way produces a loaf of
SILVER ML, JOHNSON RE, KARK RM, KLEIN JR, MONAHAN EP, ZEVIN SS. WHITE BREAD AND EPILEPSY IN ANIMALS. JAMA. 1947;135(12):757–760. doi:10.1001/jama.1947.02890120011005