Blackwell Publishing Journal Backfiles 1879-2005
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Process Engineering, Biotechnology, Nutrition Technology
Previous research has suggested that dietary fiber can reduce the bioavailability of certain micronutrients by ionic binding or physical entrapment. In this study, the ability of eight purified polysaccharides, lignin, and wheat bran to bind B-6 vitamers was examined in vitro using equilibrium dialysis under physiological conditions. The polysaccharides used were cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, methyl cellulose, citrus pectin, xanthan gum, sodium alginate, and gum arabic. No significant binding was detected when pectin was dialyzed to equilibrium at, 0.5, 0.75, and 1% levels in the presence of 0.1 or 0.1 mM pyridoxine, pyridoxamine, or pyridoxal. When 1% wheat bran, lignin, and the test polysaccharides were incubated overnight with 0.1 mM pyridoxine prior to dialysis, to allow for any slow binding process to occur, no in vitro binding of pyridoxine by any of the test materials could be observed on equilibrium dialysis. These results are consistent with findings of in vivo experiments which showed that cellulose, pectin, and bran did not significantly decrease the bioavailability of vitamin B-6 when fed to the rat and/or the chick.
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