M. Kim et al., PECTIN WITH LOW-MOLECULAR-WEIGHT AND HIGH-DEGREE OF ESTERIFICATION INCREASES ABSORPTION OF FE-58 IN GROWING RATS, The Journal of nutrition, 126(7), 1996, pp. 1883-1890
Effects of pectins with different degrees of esterification (DE) and m
olecular weights (MW) on iron bioavailability were investigated in hea
lthy growing rats by following erythrocyte incorporation of a dose of
Fe-58. Rats were fed a control diet for 8 d and then deprived of food
for 16 h. Two hours after the start of feeding iron-deficient diets, w
ith or without pectin (80 g/kg diet), a dose of FeSO4 rich in Fe-58 (6
0.28%) was intubated into the stomach; rats were then allowed to feed
for an additional 4 h before withdrawal of food for 10 h. Rats were th
en fed iron-adequate diets for 9 d. The pectins differed in DE and MW,
respectively, as follows: P-A (73%, 860,000), P-B (75%, 89,000), P-C
(22%, 1,260,000) and P-D (24%, 114,000). Rats fed pectin-free diet wit
h free access to food or restricted to the same quantity consumed by a
respective pectin group served as controls. Iron absorption was 48% i
n the control group and 57% in rats fed PB. Rats fed P-B had higher (P
less than or equal to 0.05) serum iron, transferrin saturation, hemat
ocrit and liver and spleen iron than the control group or the group fe
d P-C. These indices, except for transferrin saturation, were also hig
her in rats fed P-A and P-D compared with those fed P-C and controls,
but to a lesser extent than in rats fed P-B. The data indicate that bi
oavailability of dietary non-heme iron was enhanced when pectin of low
MW and high DE was added to the diet. This improvement was not eviden
t with pectins having high MW and/or low DE.