ADSORPTION of BILE ACIDS ON CEREAL TYPE FOOD FIBERS

Abstract

A study involving measurement and analysis of adsorption of common bile acids, namely cholic, deoxycholic, and lithocholic acids, on cereal type dietary fibers was conducted. the selected food fibers were oat fiber, rice fiber, barley fiber, corn bran, and wheat bran, which are all extensively used in processed foods. the adsorption data were measured at 37C and 25C, which correspond to approximate human body and room temperatures. Influence of particle size reduction, due to grinding, on a fiber's bile acid binding capacity was examined by using macro size (35–60 mesh) and micro size (100–300 mesh) fibers as adsorbents. the investigation also included the effects of medium pH and the chemical composition. the experimental data were correlated with the Langmuir and the Freundlich isotherms in order to utilize the data in future predictions and simulations. It was found that the particle size reduction, accompanied by surface area increase, has a significant influence on the adsorption capacity of the fiber. Macro size fibers adsorbed the same bile acid with the following trend: oat > barley > rice > wheat > corn; while micro size fibers followed a somewhat different trend: rice > barley > oat > wheat > corn. This was due to the surface area change after grinding, and a positive correlation between the surface area and the adsorption capacity was observed in each case. the adsorption was favored by acid pH surroundings, and it was positively correlated with the hydrophobicity of the bile acid. were adsorbed on the same fiber with the following trend: lithocholic acid > deoxycholic acid > cholic acid. Fibers adsorbed more bile acid at 25C than they did at 37C. However, the increase in the uptake capacities were not very signipcant.

Effect of Particle Size on the Water Sorption Properties of Cereal Fibers1

“…This increase was attributed to increased surface area available for adsorption due to micropore openings. The trends noted by Huang and Dural (1995) for bile acids were opposite to our results for WAI.…”

“…Both corn and wheat brans showed an increase in adsorption of bile acids when particle size was reduced (Huang and Dural 1995) but oat bran showed only a minimal increase. This increase was attributed to increased surface area available for adsorption due to micropore openings.…”

Easy Preparation of Dietary Fiber with the High Water-Holding Capacity from Food Sources

“…Kern et al reported that fiber exhibits greater binding for dihydroxy bile acids (chenodeoxycholic acid) than trihydroxy bile acids (cholic acid) [33]. Thus, adsorption of bile acids by dietary fiber will be dependent on both the hydrophobicity [34].…”

Chemical Composition and Bioactive Potential of Dehydrated Peels ofBenincasa hispida, Luffa acutangula, andSechium edule

“…Three methods as mentioned above were used for analysis of antioxidant activities and final values represent average of triplicate determinations. Alpha-amylase inhibition and bile acids binding ability of samples were determined as described earlier (6,10). For both alpha-amylase inhibition and bile acid binding ability, the samples were run in triplicate and averaged.…”