Effects of starch multiscale structure on the physicochemical properties and digestibility of Radix Cynanchi bungei starch

Modulation of rice starch physicochemical properties and digestibility: The role of highland barley non-starch polysaccharide fractions

Highland barley non-starch polysaccharides (HBNP), particularly β-glucans, are known for their health-promoting effects, including modulation of glycemic response and enhancement of gut health. This study investigated the impact of different HBNP fractions on the properties and digestibility of high-glycemic index rice starch. HBNP was segmented into five fractions (HBNP-15, HBNP-30, HBNP-45, HBNP-60, and HBNP-75) using gradient ethanol precipitation, and these fractions exhibited varying molecular weights, monosaccharide compositions, and β-glucan contents. All fractions reduced rice starch's pasting viscosity, with 1 % HBNP-75 leading to a 99.1 % decrease in final viscosity. Morphological and size distribution analyses showed that HBNP fractions limited granule swelling and disrupted starch's continuous phase structure. HBNPs also reduced starch digestibility and increased the formation of resistant starch from 10 % to 28 %. These results suggest potential uses for HBNP fractions in developing low-glycemic starch-based foods.

Three nonconventional starch: Comparison of physicochemical properties and in vitro digestibility

Extraction of starch from waste is also an effective way to recover resources and provide new sources of starch. In this study, starch was isolated from white kidney bean residue, chickpea residue, and tiger nut meal after protein or oil extraction, and the morphology of starch particles was observed to determine their physicochemical properties and in vitro digestibility. All these isolated starches had unique properties, among which white kidney bean starch (KBS) had a high amylose content (43.48%), and its structure was better ordered. Scanning electron microscopy revealed distinct granular morphologies for the three starches. KBS and chickpea starch (CHS) were medium-granular starches, whereas tiger nut starch was a small granular starch. Fourier transform infrared spectroscopy analysis confirmed the absence of significant differences in functional groups and chemical bonds among the three starch molecules. In vitro digestibility studies showed that CHS is more resistant to enzymatic degradation. Overall, these results will facilitate the development of products based on the separation of nonconventional starches from waste.

Structure and functional characteristics of starch from different hulled oats cultivated in China

This work aimed to evaluate the structure and functional characteristics of starch from ten hulled oat cultivars grown in different locations in China. The protein, phosphorus, amylose, and starch contents were 0.2-0.4 %, 475.7-691.8 ppm, 16.2-23.0 %, and 93.6-96.7 %, respectively. All the starches showed irregular polygonal shapes and A-type crystallization with molecular weights ranging from 7.2 × 107 to 4.5 × 108 g/mol. The amounts of amylopectin A (DP 6-12), B1 (DP 13-24), B2 (DP 25-36), and B3 (DP > 36) chains were in the ranges of 10.3-16.0 %, 54.5-64.8 %, 16.5-21.1 %, and 4.9-13.1 %, respectively. The starches differed significantly in gelatinization temperatures, pasting viscosity, solubility, swelling power, rheological properties, and digestion parameters. The results revealed that the larger particle size could increase the peak viscosity of the starch paste. The presence of phosphorus increased the gelatinization temperature and enhanced the resistant starch content. The starch granules with higher crystallinity contained a higher proportion of phosphate, which increased final viscosity and setback viscosity but decreased rapidly digestible starch. Overall, oat starch with a high phosphorus content could be used to prepare low-glycemic-index food for diabetes patients.