Mineral absorption of diets containing natural carob fiber compared to cellulose, pectin and various combinations of these fibers

The influence of the consumption of natural carob fiber (NCF), an insoluble hypocholesterolemic fiber, as the unique dietary fiber or combined with ce llulose (CEL) or pectin (PEC), on mineral bioavailability was studied. Six groups of rats were fed for 10 days diets containing 10% GEL, NCF, PEC or C EL+NCF, CEL+PEC and NCF+PEC mixtures at 50%. Food intake was lower with PEC than NCF and CEL+NCF, but final body weight was unaffected. Fecal weight s howed significant differences in the following order: GEL, NCF, CEL+NCF > C EL+PEC, NCF+PEC > PEC. Percentage of calcium absorption was higher with CEL +PEC and NCF+PEC compared with the rest of fibers. Magnesium absorption was also significantly enhanced in these two groups compared to NCF (p < 0.000 4). Iron absorption did not show variations. Zinc apparent absorption was r educed by PEC, but the NCF+PEC mixture counterbalanced this effect. Liver i ron was significantly lower with NCF+PEC than GEL, and liver iron concentra tion was significantly lower with NCF+PEC compared to CEL+PEC. Liver zinc w as significantly higher with CEL+NCF than PEC while liver zinc concentratio ns were slightly higher with the former (p = 0.05 compared to NCF). The res ults indicate that NCF, compared to CEL and PEC, did not decrease the effic iency of calcium, magnesium and iron absorption in rats, while compared to PEC it increased zinc apparent absorption. Moreover, by combining NCF with PEC calcium and magnesium, absorptions enhanced in comparison with NCF alon e, which was probably a result of the combination of soluble and insoluble fibers.