Effect of modified and unmodified tapioca starches on 59Fe retention in rats

The effects of a chemically-modified tapioca starch hydroxypropyl distarch phosphate (HDP), and unmodified tapioca starch (UMS) on 59Fe retention by rats were compared. Three experimental variables were evaluated: 1) the type of starch in the diet, 2) cooking of either the starch alone or the entire diet, and 3) the iron status of the rats. There were no significant differences in 59Re retention between iron-adequate rats fed either UMS or HDP. 59Fe retention by iron-deficient rats was not affected by the type of starch in the diet when uncooked starch was used. However, if the starch was cooked, substitution of HDP for UMS resulted in a significant depression in iron retention by iron-deficient rats. Cooking the entire diet produced a similar but less marked effect. The results of these experiments suggest that the inclusion of one particular type of modified tapioca starch in the diet may affect iron utilization.