Iron, calcium, zinc, and phytic acid content of yeast-raised breads containing distillers' grains and other fiber ingredients

Abstract

A comparison was made between the total and soluble iron, calcium, zinc, and phytic acid content of yeast raised breads, each containing approximately 13% total dietary fiber (TDF, as is basis) as either white wheat bran, white wheat distillers' grains, barley fiber (brewer's spent grains), soy fiber, or oat fiber. Substitution level of the fiber ingredients into the breads varied from 12 to 23% flour replacement (w/w) depending upon the TDF content of the fiber ingredient. The phytic acid content was highest in the wheat bran and oat fiber breads (24 mg/100g and 27 mg/100g, respectively). When formulated on an equal TDF basis, the level of soluble mineral in the fiber ingredient was not predictive of the level of soluble mineral in the bread. The highest amount of soluble calcium was found in the control and white wheat distillers' grain breads, 167 and 146 μg/g, respectively. The highest amount of soluble iron was found in the soy fiber bread (31.6 μg/g) and the greatest amount of soluble zinc (5.3 μg/g) was found in the wheat bran bread.