1997 Volume 50 Issue 3 Pages 209-216
Digestibilities of high-amylose corn starch (HAS) and normal corn starch (CS) were determined and compared in ileorectostomized and normal rats fed diets containing graded levels of HAS (10, 20, 40 and 65.5%, respectively). Dietary supplementation of HAS was done at the expense of sucrose. In the ileorectostomized rats, the digestibility of CS was more than 99%, irrespective of its dietary level, whereas that of HAS was reduced in accordance with the increase in the dietary level (67-74%). In normal rats, the digestibility of HAS was also reduced in accordance with the increase in the dietary level (83-99%). Regression analysis revealed significant negative correlations between dietary HAS intake and HAS digestibility in both ileorectostomized rats (r=-0.761, p<0.0001) and normal rats (r=-0.853, p<0.0001). The difference in the digestibilities of HAS between ileorectostomized and normal rats suggested that 16-25% of the ingested HAS was degraded in the cecum and colon through bacterial fermentation. When HAS was the sole dietary carbohydrate source (65.5% of the total diet), 66.5% of the HAS ingested was digested in the small intestine, 16.4% was degraded in the cecum and colon, and 17.1% was excreted into the feces.
