PHYSICOCHEMICAL CHARACTERIZATION OF BARLEY CARBOHYDRATES RESISTANT TODIGESTION IN A HUMAN ILEOSTOMATE

Physicochemical techniques, monosaccharide, and linkage analysis, have been used to investigate the digestibility of different forms of cook ed barley starch in an ileostomist model. An ileostomate volunteer con sumed a flapjack-type biscuit containing either barley flake, flour, o r starch. Both starch and mucin were identified in the effluent and we re found to make a significant contribution to the potentially ferment able substrate available to the large intestine. Chemical analysis of the effluents showed that the content of resistant starch in the efflu ent varied with presence and form of nonstarch polysaccharide and afte r consumption of barley flake and flour was 10.1 and 5.9% of the starc h ingested, respectively. Wide-angle X-ray diffraction showed the excr eted starch to be A-type only, indicating that the starch consumed in all three flapjack types was ungelatinized. These data demonstrate the potential of physico-chemical techniques in the analysis of physiolog ical samples.