In vitro binding of bile acids and triglycerides by selected chitosan preparations and their physico-chemical properties

The selected 11 chitosan samples were evaluated for their fat- and bile acid-binding capacities, physico-chemical properties, and the correlations between each binding capacity and individual physico-chemical properties. The bile acid- and fat-binding capacities were estimated using in vitro assays, whereas the measured physico-chemical properties were deacetylation degree, swelling capacity, and solution viscosity. Chitosan samples might differ in their binding capacities against fat and/or individual bile acids. The bile acid-binding capacities were 0.20-0.61, 0.43-1.63, and 0.61-1.61 mu mol/g chitosan for cholic, deoxycholic, and chenodeoxycholic acids, respectively. Stronger binding capacity of chitosan against a selected bile acid does not warrant greater binding capacity for other bile acid. The fat-binding capacity ranged from 1077-1239 g oil/g for the chitosan samples under the experimental conditions. No correlation was observed between any binding ability and individual physico-chemical properties, although the swelling capacity of chitosan was correlated to the solution viscosity (r = 0.82, P = 0.02) and deacetylation degree (r = -0.62, P = 0.04), indicating that none of the measured physico-chemical properties can be used to predict the fat- or bile acid-binding ability of chitosan. (c) 2005 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.