DOI: 10.1094/CFW-51-0118 |
A Rapid Method To Determine Quantitatively the In Vitro Adsorption of Taurocholate to Soluble Fiber
B. S. Ghotra, T. Vasanthan, M. Wettasinghe, V. Goel, F. Temelli, and T. Basu. Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada. Cereal Foods World 51(3):118-121.
A new method was developed to study the adsorption of taurocholate to cereal beta-glucan and other commercially available soluble fibers and gums. The method involved mixing soluble fiber with (^14)C-labeled taurocholate, incubation at 37°C for 1 hr, centrifugal microfiltration, and scintillation measurement. Scintillation measurement showed that the filtrate, collected after repeated washing of the mixture through the membrane filter, was free of unbound taurocholate. The level of radioactivity measured in the filtrate of the blank sample was very close to 100% of that added, indicating there was no adsorption of bile salts to the membrane material. The amount of bile salt adsorbed was calculated as the difference between the amount of bile salt added and the amount detected in the filtrate. A coefficient of variation of <5% was achieved, indicating the method is reproducible and sensitive enough to distinguish the taurocholate adsorption capability of cereal beta-glucan and commonly used soluble fibers. Among the soluble fibers and gums evaluated, barley beta-glucan, oat beta-glucan, and guar gum showed higher taurocholate adsorption compared with locust bean gum, carboxymethyl cellulose, high- and low-methoxy pectin, xanthan, gum arabic, microcrystalline cellulose, lambda-carrageenan, and kappa-carrageenan.