Abstract:To explore differences in adsorption capacity among dietary fiber from different sources, insoluble dietary fiber (IDF) from three different sources (pomelo, carrot, and rice bran) were selected for comparative analysis of their microstructural characteristics, physiochemical properties (including water and oil holding capacities, swelling capacity, and viscosity) and adsorption properties (including cholate adsorption capacity, diffusion kinetics of cholate release, cholesterol, glucose and nitrite absorption capacities). Carrot IDF was composed of smooth spherical particles and exhibited the strongest swelling capacity (7.92 mL/g), and cholate (57.80 mg/g) and cholesterol (11.72 mg/g) adsorption capacities in a simulated intestinal environment (pH valu 7) among the three IDFs. Rice bran IDF had a rough, porous and irregular structure and exhibited the strongest oil holding capacity (3.00 g/g), glucose adsorption capacity (20.67 mmol/g), nitrite absorption capacity (1 482.22 μg/g at pH 7 and 2 836.23 μg/g at pH valu 2), cholic acid blocking capacity (4.47 mg/g) and cholesterol adsorption capacity (8.56 mg/g) in a simulated gastric environment (pH valu 2). Pomelo IDF had a layered scale-like structure and exhibited the strongest water holding capacity (15.48 g/g), high viscosity, and excellent cholic acid blocking capacity (3.55 mg/g). The three dietary fibers from different sources had their own microstructural and physicochemical characteristics, which resulted in different adsorption properties. This study provided data support for the processing and utilization of different types of dietary fiber in health foods.
