A friend sent me the following. This guy seems to be saying that
bromated flour is okay. I disagree. Any comments?
Bob the Tarheel Baker
> From "Oil Slick" (washingtonpost.com)
> By Robert L. Wolke
> Wednesday, May 30, 2001; Page F01
QUESTION: How does bleached flour differ from unbleached flour?
Unbleached wheat flour looks pretty white to me, so why do flour
manufacturers bother with the bleaching step? Does the bleaching process
leave any unsavory residues or leach out any nutrients?
ANSWER: Wheat flour is naturally yellowish, but people apparently don't
like yellow flour, except for the semolina used in pasta-making, which
isn't usually bleached. Yellow bread and snow-white pasta wouldn't sell
very well. If given half a chance, though, flour bleaches itself. That is,
as it ages in air, the yellow color is oxidized away. But that takes time
and time is money, so manufacturers speed up the process by using an
oxidizing or bleaching agent such as potassium bromate (in which case the
flour is said to be brominated), chlorine dioxide or benzoyl peroxide.
These bleaching agents aren't mere cosmetics. Flour that has been "aged,"
either naturally or by being treated with oxidizers, makes doughs that
handle better and produce better bread. Unbleached flour generally costs
more than bleached flour because it has been whitened by natural aging,
which entails the costs of storage. Some people are concerned with the
intimidating natures of these chemicals. But they are all unstable and,
after doing their jobs, do not remain in the flour. The bromate, after
reacting with the yellow compounds in the flour, is converted into harmless
bromide. Chlorine dioxide is a gas that dissipates, so there is none of
that left in the flour either. Any excess of benzoyl peroxide would
decompose as soon as the flour is heated. The claim that bleaching flour
destroys its Vitamin E is true but empty, because wheat flour contains
negligible amounts of Vitamin E to begin with.
Robert L. Wolke: http://www.professorscience.com is professor emeritus of
chemistry at the University of Pittsburgh