CHARACTERIZATION OF RESIDUAL FIBERS FROM FERMENTATION OF PEA AND APPLE FIBERS BY HUMAN FECAL BACTERIA

Two dietary fibres with distinct structural features (pea hull and app le fibre) were fermented in vitro with human faecal bacteria. The comp osition and physicochemical properties (cation exchange, hydration pro perties) of the residues were examined. Gas and short-chain fatty acid (SFCA) productions attested of the highest fermentability of apple fi bre. After 24 h, 75% of the pea fibre and 42% of the apple fibre could be recovered. Production of the major SCFA, acetate, propionate and b utyrate occured in the molar ratio 68:17:9 for both fibres. Uronic aci d and arabinose were the most extensively fermented sugars while xylos e and glucose were the least fermented. Cation exchange capacity of th e two fibres did not decrease much during fermentation, which implies that the amount of bound mineral is proportional to the amount of resi dual fibres. The values of the hydration properties of the residual fi bres were at least equal to or higher than those of initial fibres. In spite of the degradation of the fibres during fermentation, a physica l structure able to retain water remained.