Two main goals in milling wheat flour are:
Separating as much endosperm as possible from bran and germ in wheat berries.Turning separating endosperm into fine flour .Unfortunately, this process also inadvertently removes many natural and valuable vitamins, minerals, dietary fibers.Lacking these essential nutrients in daily diets makes people very susceptible to diseases such as beriberi and pellagra. Many birth defects are also linked to nutrient deficiency.In response to this problem, the Food and Drug Administration began, in 1941, to encourage millers to enrich freshly milled or "green" flour with iron, thiamin, riboflavin, niacin, and folic acid. The last four vitamins are also known as vitamin B. The recommended amount added to white flour should be equal to or exceed the amount in wheat flour.Adding back some of the lost nutrients is only one form of flour enrichment. Natural aging is another.
The purpose of aging freshly milled or "green" flour is to improve dough handling and ultimately quality of baked goods.To many millers, this process is economically unfavorable and time consuming with inconsistent result. It depends on oxygen in air to perform two functions:
Whitening flour by changing chemical structure of a flour pigment known as carotenoid.Strengthening gluten forming proteins, glutenin and gliadin. This ultimately results in better volume and finer crumb in breads .Because natural aging does have its disadvantages, many millers instead like to add chemical or maturing additives such as potassium bromate or ascorbic acid to "green" flour.Types of baked goods also determine, to some extent, a preferred additive for flour. Since bread baking requires strong flour, potassium bromate is added to flour used for this purpose.On the other hand, cake flour does not need strong gluten formation, but its starch must be able to absorb moisture quickly. Therefore, chlorine is added to whiten flour and weaken gluten proteins.
.Trinh Lieu.Additional reading on gluten proteins and gluten formation is available on http://www.cookies-in-motion.com/Gourmet-Cookies.html.Copyright 2006 Trinh Lieu.
By: Trinh Lieu
