Starch with a Slow Digestion Property Produced by Altering Its Chain Length, Branch Density, and Crystalline Structure

Abstract

The hypothesis of increasing the branch density of starch to reduce its digestion rate through partial shortening of amylopectin exterior chains and the length of amylose was investigated. Starch products prepared using -amylase, -amylase and transglucosidase, maltogenic R-amylase, and maltogenic R-amylase and transglucosidase showed significant reduction of rapidly digested starch by 14.5%, 29.0%, 19.8%, and 31.0% with a concomitant increase of slowly digested starch by 9.0%, 19.7%, 5.7%, and 11.0%, respectively. The resistant starch content increased from 5.1% to 13.5% in treated starches. The total contents of the prebiotics isomaltose, isomaltotriose, and panose (Isomaltooligosaccharides) were 2.3% and 5.5%, respectively, for -amylase/transglucosidase-and maltogenic R-amylase/transglucosidase-treated starches. The molecular weight distribution of enzyme-treated starches and their debranched chain length distributions, analyzed using high-performance sizeexclusion chromatography with multiangle laser light scattering and refractive index detection (HPSEC-MALLS-RI) and HPSEC-RI, showed distinctly different patterns among starches with different enzyme treatments. A larger proportion of low molecular weight fractions appeared in starches treated additionally with transglucosidase. All enzyme-treated starches showed a mixture of B-and V-type X-ray diffraction patterns, and 1 H NMR spectra showed a significant increase of R-1,6 linkages. Both the increase of the starch branch density and the crystalline structure in the treated starches likely contribute to their slow digestion property.

Starch Source Influences Dietary Glucose Generation at the Mucosal α-Glucosidase Level

“…Glucogenesis was determined by the glucose oxidase/peroxidase assay (11), and the residue structure was studied by high performance anion exchange chromatography (Ref. 12 and data not shown). wx ␣-LDx (25 g) was incubated with four subunits and at three amounts (0.05, 0.1, and 0.2 g of Nt-and Ct-MGAM; 0.25, 0.5, and 1 g of Nt-and Ct-SI), and real-time (up to 6 h) residue structure change was examined by high performance size exclusion chromatography (HP-1090, Agilent Technologies) equipped with a refractive index detector (RID-10A, Shimadzu Corp., Kyoto, Japan) using two Zorbax PSM 60S columns (50°C; Agilent Technologies) with a mobile phase of dimethyl sulfoxide containing 50 mM lithium chloride at a flow rate of 0.5 ml/min.…”

Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment

“…Among these, branching enzyme (B) and maltogenic α-amylases (MA) have been used to slow down the digestion of starches. Branching enzyme (EC 2.4.1.18) catalyzes hydrolytic and transfer reactions to form new α-1,6 linkages [8]. Meanwhile, maltogenic α-amylase (EC 3.2.1.133) hydrolyze α-1,4-glucosidic linkages of starch and its derivatives to maltose reducing the chain length of the polymer [9].…”

“…In this way, the combination of branching followed by posterior trimming through a starch-active exo-hydrolase, such as β-amylase or maltogenic α-amylase, has been attempted to change the amylopectin fine structure to create resistant structures that slow down the starch digestion properties in native and cooked matrices. These changes mainly comprise increasing the ratio of short chains (degree of polymerisation, DP<13) to long chains of amylopectin and the relative amount of α,1-6 linkages [8,9,11]. Additionally, the formation of prebiotic isomaltooligosacharides has been also reported [8,12].…”

Characterization Methods for Starch-Based Materials: State of the Art and Perspectives

“…Retrograded starch inhibits susceptibility to further enzyme attack, which can also reduce the rate of digestion. [60,61] Starch with a higher proportion of long chains is usually termed a 'high-amylose' starch. High amylose starches are correlated with a type of resistant starch (RS).…”