IN-VITRO FERMENTATION AND HYDRATION PROPERTIES OF COMMERCIAL DIETARY FIBER-RICH SUPPLEMENTS

Eight commercial dietary fiber (DF)-rich supplements were analyzed in vitro to assess swelling, water retention capacity (WRC) and fermentat ion. The supplements were fermented with rat cecal as inoculum for 24 h, and short chain fatty acid (SCFA) production, fermentability, dry m atter disappearance (DMD) and gas production were determined. Products containing mainly soluble fiber components (Metamucil, Humamil, Fybog el and Fibraplan) showed the highest capacity of retaining water and f ermentability. Swelling (mL per g dry matter) ranged from 6.2 for Fibr a Leo Apple Prune to 24 for Fibraplan. Total SCFA production was signi ficantly correlated to DMD (r = 0.969, R-2 = 0.9385) and to gas produc tion (r = 0.901, R-2 = 0.8113). Hydration properties and fermentative characteristics were different among the studied supplements, these in vitro techniques could be useful to evaluate their potential physiolo gical effects. (C) 1998 Elsevier Science Inc.