Mixed-linked beta-glucan from breads of different cereals is partly degraded in the human ileostomy model.
The purpose of this investigation was to study the degradation of beta-glucan in the small intestine and the molecular weight of beta-glucan in the excreta of nine ileostomy subjects after consumption of different diets based on bread made with oat bran (oat bread), a fiber-rich barley fraction (barley bread), or wheat flour (wheat bread) as the main ingredients. Oat bread with enzymatically degraded beta-glucan was also used (oat + enzyme bread). The beta-glucan intake from the four diets was 12.5, 12.9, 1.1, and 4.0 g/d, respectively. On the basis of dry matter, the night effluents accounted for approximately 15% of the total amount of the excreta, with the highest proportion (22%) being for the wheat-bread diet. A notable loss of beta-glucan (0.7-2.4 g/d, or 13-64%) was found when intake was compared with excretion. In vitro, a higher viscosity development with time for dispersions of oat bread compared with barley bread was noted, which could be related to the higher molecular weight of the beta-glucan in this bread. There seemed to be a depolymerization of the beta-glucan both during bread making and transit through the upper gastrointestinal tract.
Sundberg
B
B
Department of Food Science, Swedish University of Agricultural Sciences, Uppsala, Sweden. Birgitta.Sundberg@lmv.slu.se
Wood
P
P
Lia
A
A
Andersson
H
H
Sandberg
A S
AS
Hallmans
G
G
Aman
P
P
D000328:Adult; D000368:Aged; D002845:Chromatography / Q000379:methods; D004032:Diet; D002523:Edible Grain / Q000737:chemistry*; D005260:Female; D005936:Glucans / Q000032:analysis* / Q000378:metabolism* / Q000652:urine; D001467:Hordeum / Q000737:chemistry; D006801:Humans; D007081:Ileostomy; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010084:Oxidation-Reduction; D014908:Triticum / Q000737:chemistry
D005936:Glucans