In Vitro and In Vivo Digestibility of Recrystallized Amylose and Its Application for Low Glycemic Foods

To predict physiologic functions of recrystallized amylose (RCA), the true resistant starch (RS) content of RCA in the small intestine was directly measured using ileorectostomized rats where the distal ileum was anastomosed to the rectum (the cecum and colon were surgically resected together). The estimated in vivo resistant starch content of RCA was the same as the value obtained from the in vitro enzymatic RS determination (∼50%). RCA resistance to amylolytic enzymes in the small intestine was retained even after RCA incorporation into processed foods, and a bread containing 20% RCA showed a significantly lower glycemic response in rats compared with that of a control bread. Also, RCA ingestion significantly and dose-dependently decreased the body fat accretion and lowered serum concentrations of cholesterol and triglycerides in rats compared with cornstarch. These lipid-lowering effects of RCA were comparable to those obtained with high-amylose cornstarch. The restricted energy value as well as suppressed insulin response with RCA ingestion might be related to preferable changes in lipid metabolism. These nutritional properties of RCA may suggest a possible benefit as an alternative source of resistant starch for preventing diabetes, hyperlipidemia and obesity, and so on.