Water-holding and swelling properties of water-insoluble dietary fiber (IDF) from pomelo mesocarp were determined. The effects of adsorption time and temperature, cholesterol concentration, the content and the size of IDF on its adsorption to cholesterol were investigated. IDF from pomelo mesocarp showed good capabilities of holding water and swelling in water, their values being 19.12 g/g and 20.88 ml/g, respectively. IDF also demonstrated a high adsorption to cholesterol. The adsorption capacity achieved maximum during 90~120 min. A suitable cholesterol concentration for the adsorption was 1.2~1.5 mg/ml. The capacity for IDF to adsorb cholesterol gradually decreased with increasing IDF concentration. The size of IDF can markedly influence its absorption to cholesterol. IDF could adsorb more cholesterol at lower temperatures and its capacity of adsorbing cholesterol was 18.44 mg/g at 37 ℃. The adsorption of IDF to cholesterol could fit for Freundlich equation, indicating that IDF adsorb cholesterol physically and chemically.
