Iron absorption from wheat bread. Influence of various amounts of bran.

Abstract

Bran is known to reduce iron absorption. There is, however, no information on the relationship between the amount of bran added and the decrease in iron absorption. In the present study a comparison was made of the iron absorption from a white wheat bread and a bread baked with different amounts of bran added (from 10 to 0.3%). There was a decrease in iron absorption from rolls baked with added bran in amounts equal to and greater than 3.3 %. A significant linear relationship was found between the ratio of absorption with/without added bran and the log amount of bran added. From the relationship observed it is concluded that addition of approximately 7% of bran to wheat bread decreases ironabsorption by a factor of two. It is considered reasonable to ascribe the marked reductionin iron absorption to the content of phytate in bran.