Abstract19 Starch digestion rate is strongly related to metabolic diseases such as obesity and diabetes.20 Starchy foods always contain non-starch components, which can affect starch digestibility.21 Mixtures of ungelatinized corn starch with a common non-starch component, pectin, were 22 used to investigate pectin's effect on starch digestibility rate and evolution of starch molecular 23 structure during digestion using amyloglucosidase and pancreatin. The whole-molecule size 24 distribution and the chain-length distribution of chains were measured by size-exclusion 25 chromatography and fluorophore-assisted carbohydrate electrophoresis. Digestion profiles 26 and changes in molecular size distributions of whole and debranched digesta during digestion 27 show that addition of pectin significantly decreased starch digestion rates. While pectin did 28 not change the amylose/amylopectin ratio during most of the digestion, it decreased the 29 digestion rate of short amylopectin chains compared to long ones. UV-visible spectral data 30 suggested that a major contributor to this digestion rate change is from substantial 31 pectin/amyloglucosidase interaction. This suggests an approach to designing nutritionally 32 more beneficial starch-based foods by taking account of interactions between pectin and 33 digestive enzymes.

X., A starch molecular basis for aging-induced changes in pasting and textural properties of waxy rice, Food Chemistry (2019), doi: