Structural characterization and in-vitro adsorption capacity of olive pomace insoluble dietary fiber

Olive pomace insoluble dietary fiber( IDF) was prepared by alkaline method with defatted olive pomace.In addition to its chemical composition and structure characterized by IR and X- ray diffraction,the effect of olive pomace IDF on the in vitro adsorption capacity of NO_2~-,Pb~(2+),Cu~(2+),Cd~(2+) was studied. These results showed that the IDF content in olive pomace IDF reached 90.09%,which was mainly comprised by cellulose,hemicellulose and lignin.The result of IR showed that olive pomace IDF appeared characteristics absorption peaks of sugars and lignin. The result of X-ray diffraction indicated that IDF had celluloseⅠcrystal structure,and its crystallinity achieved 47.94%.The quantities of equilibrated adsorption to NO_2~- using IDF under the simulated gastric condition( pH2) was attained 826 μg / g at 240 min.The adsorption capacity of IDF for Pb~(2+),Cu~2+),Cd~(2+) under the simulated intestine condition( pH7) was far stronger than that in the gastric. The equilibrated adsorption quantities for Pb~(2+),Cu~(2+),Cd~(2+) in simulated intestine condition could reach 418.7,686.6,849.5 μg / g,respectively.Besides,the pseudo- second- order kinetics equations were exactly fit for those adsorption processes of IDF for Pb~(2+)、Cu~(2+)、Cd~(2+).