Flour Helps Cut Fat, Keeps Bread Fresh
By Jan Suszkiw
March 5, 2002
Agricultural Research Service scientists
and cooperators have bred a new kind of durum wheat, called "waxy
wheat," whose flour may give rise to reduced-fat bread.
In commercial baking, vegetable oil or other types of fat often are added to
dough to produce loaves of bread with improved crumb softness, volume and
texture. Shortening also keeps the bread from becoming stale too quickly during
storage. But vegetable shortening is high in trans fatty acids and can be a
costly ingredient to add when millions of loaves are being produced, according
to chemist Doug Doehlert at the ARS
Red River Valley Agricultural Research Center in Fargo, N.D.
There, he and North Dakota State University (NDSU) associates show that flour from the
new waxy durum wheat (WDW) can replace vegetable shortening without losing the
desired properties the shortening confers to bread. A single bread loaf might
have two tablespoons of shortening, so replacing that with WDW flour would save
about 26 grams of fat, or 234 calories. Doehlert credits the flour's
fat-replacing capacity to a unique type of starch that differs from that in
most bread wheat cultivars.
Starch is a polymer, or chain, of glucose molecules containing both amylose
and amylopectin. Amylose is the straight-chain form of this polymer, while
amylopectin is the branched form. Most wheat cultivars have about 24 percent
amylose and 76 percent amylopectin. But WDW starch is nearly 100 percent
WDW flour works best as a shortening substitute when it comprises 20 percent
of a dough formulation, according to Doehlert, at the centers
Cereal Crops Research
Unit. In trials, quarter-pound loaves of the experimental bread had the
same softness, texture and volume as those containing 100 percent bread wheat
flour and 3.25 grams of shortening. And in tests for freshness, the WDW bread
stayed much softer than the nonwaxy wheat bread after five days of storage.
Doehlert, along with ARS chemist Linda Grant and NDSU associates Monisha
Bhattacharya, Sofia Erazo-Castrejon and Michael McMullen, have been developing,
evaluating and testing applications for the new WDW flour for about five years.
ARS is the U.S. Department of
Agricultures chief scientific research agency.