Flour Treatments

Enriched Flour

In the 1930s, nutritional surveys conducted by the Department of Agriculture revealed widespread nutritional deficiencies of thiamin, riboflavin and niacin (B vitamins) in the American diet.  These findings prompted the fortification of certain staple foods.  The Food and Nutrition Board recommended a program for fortifying white flour and white bread with thiamin, riboflavin, niacin and iron, with calcium and vitamin D as optional.  

In May 1941, the flour enrichment standards were issued and finally adopted in 1943.  The standards were recently changed, and as of January 1, 1998, enriched flour now also must contain folic acid.  The enrichment of flour has no affect on its baking performance or caloric value.

Maturing Flour

If bleaching describes the whitening of flour, what is maturing?  For hard wheat flour, the term maturing implies the strengthening of dough forming properties, thus improving gas retention of the gluten.  These maturing agents affect the physical properties of the dough and don’t have any direct effect on the yeast.  Three common maturing agents include azodicarbonamide (ADA), potassium bromate and ascorbic acid.  Breads treated with these agents will generally exhibit increased loaf volume, finer grain and improved external characteristics.  Although they produce the effects just stated, they mature at different rates.  ADA’s oxidation is rapid and reacts during the mixing process.  Ascorbic acid is intermediate and reacts toward the end of mixing and into the dough stage.  

Malting Flour

Why are most hard wheat flours treated with malted barley flour?  Malted barley flour (MBF) is added to hard wheat flours to assist yeast fermentation.  During the dough forming stage, the MBF provides specific enzyme activity that converts the starches in the wheat flour into simple sugars.  These sugars then are available as a food source for the yeast to maintain proper fermentation.  

A related effect of MBF is proper crust browning.  Yeast activity will continue in the baked good until it reaches 120º to 130º F in the oven.  Up to this point, the yeast is still consuming simple sugars.  Once the yeast activity ceases, any remaining (residual) sugars in the dough will assist in crust browning.  Bakers who desire increased crust color often will supplement their dough with additional sugar sources.  The most common is regular sugar or non-fat dry milk solids.