Verma R S, Motzok I, Chen S S, Rasper J, Ross H U
J Assoc Off Anal Chem. 1977 Jul;60(4):759-65.
Elemental iron powders produced by different processes were separated by nitrogen elutriation into fractions based on particle size. The fractions containing fine particles (7-10 micrometer) of electrolytic iron, hydrogen (H2)- and carbon monoxide (CO)-reduced iron, and the whole sample of carbonyl iron (92% less than 11 micrometer) were blended into freshly milled wheat flour and stored at about 21 degrees C. Storing the enriched flour up to 9 months had no effect on the relative biological value (RBV) of iron for rats from each type of iron supplement. Baking bread with flour containing electrolytic, H2-reduced, and carbonyl iron after storage for 10 months also had no effect on the RBV of the iron powders. There was no change in the RBV of iron for rats from flour enriched with electrolytic iron (200 mg/kg) and ascorbic acid (200 and 1665 mg/kg flour) after storage for 1 week and 3 months. The decreases in RBV due to increase in size of particles (7-10 vs. 20-26 micrometer) were significant for H2-reduced iron and CO-reduced iron but not for electrolytic iron and carbonyl iron. The RBVs of elemental iron powders for rats were similar to the values obtained with humans, based on iron absorption after an overnight fast.
通过不同工艺生产的元素铁粉，利用氮气淘析法按粒径分离成不同级分。将含有细颗粒（7 - 10微米）的电解铁、氢气（H₂）和一氧化碳（CO）还原铁的级分，以及羰基铁的全样品（92%小于11微米）与新磨制的小麦粉混合，并在约21摄氏度下储存。将强化面粉储存长达9个月，对每种铁补充剂的大鼠铁相对生物利用率（RBV）没有影响。储存10个月后，用含有电解铁、H₂还原铁和羰基铁的面粉烘烤面包，对铁粉的RBV也没有影响。富含电解铁（200毫克/千克）和抗坏血酸（200和1665毫克/千克面粉）的面粉储存1周和3个月后，大鼠铁的RBV没有变化。对于H₂还原铁和CO还原铁，由于颗粒尺寸增大（7 - 10微米对20 - 26微米）导致的RBV降低是显著的，但对于电解铁和羰基铁则不显著。基于过夜禁食后的铁吸收情况，元素铁粉对大鼠的RBV与人类获得的值相似。
