Tomoko Sasaki 1), Kaoru Kohyama 1), Yasuhiro Suzuki 2), Timothy R. Noel 3), and Steve G. Ring 3)
1) National Food Research Institute, Tsukuba, Japan
2) National Institute of Crop Science, Tsukuba, Japan
3) Institute of Food Research, Norwich, United Kingdom

Abstract

Resistant starch (RS) is known to be a portion of starch not digested and absorbed in the small intestine. RS has physiological functionalities such as improving colonic health, controlling energy release, and lowering blood-glucose response. The rate and extent of starch digestibility and absorption in the small intestine are important nutritionally. High amylose corn starch and retrograded amylose are well known to be resistant to digestion. However, the mechanism of starch resistance to digestion has not been clarified. We found that waxy rice starch consisting almost entirely of amylopectin has some resistance to enzymic hydrolysis in the concentrated starch gel. While RS content is properly determined in vivo, in vitro methods have been developed to mimic starch digestion in the human. The objective of this study was to investigate the effect of starch characteristics on the in vitro digestibility of a waxy rice starch gel.