In Vitro Digestibility and Predicted Glycemic Index of Chemically Modified Rice Starch by One‐Step Reactive Extrusion

Abstract

The in vitro digestibility of chemically modified rice starch by one‐step reactive extrusion (REX) via esterification, acetylation, hydroxypropylation, and cross‐linking or dual‐modification (hydroxypropylation‐cross‐linking and acetylation‐cross‐linking) is investigated. After REX processing, pasting viscosity is decreased, while the viscosity of esterification samples is lower than that of cross‐linking samples. Molecular structure analysis suggests that the degradation of starch molecules is retarded by esterification whereas enhanced by cross‐linking. Dual modification (hydroxypropylation and phosphorylation, hydroxypropylation‐cross‐linking (HP‐CL) sample) involving hydroxypropylation and phosphorylation (HP‐CL sample) is more conducive to preventing enzyme hydrolysis than the other modifications. HP‐CL sample achieves the lowest predicted glycemic index (pGI) value (88.1) and the highest RS content (15.3%). Thus, the one‐step REX is a useful method for reducing rice starch digestibility or pGI value.

Reactive Extrusion-Assisted Process to Obtain Starch Hydrogels through Reaction with Organic Acids

“…SEM micrographs also demonstrated that the sample surfaces did not contain residual starch granules, which indicated that the granules were destroyed due to the thermomechanical and chemical modification effects, which agreed with the XRD results. Other authors also reported the disintegration of the granular structure of starch subjected to reactive extrusion [29,46,47].…”

“…Alternatively, the reactive extrusion process is an efficient and versatile method for modifying starch and it is considered a green technological solution since the extruder is used as a reactor, where chemical reactions such as esterification, hydroxypropylation, and crosslinking can be performed [27][28][29][30]. Reactive extrusion combines the thermomechanical energy necessary to disintegrate the native structure of the starch granule, favoring the reaction between starch and organic acids in a single process without using other reagents.…”

In Vitro Digestibility and Physicochemical Properties of Isolated Starch from Potatoes (Solanum tuberosum and Solanum subsp. andigena) Varieties Commercialized in the Andean Region: Ecuador

“…Diets with high SDS and RS are associated with low glycemic index and hence would be important in reducing type 2 diabetes. [ 9 ]…”

“…Diets with high SDS and RS are associated with low glycemic index and hence would be important in reducing type 2 diabetes. [9] Food processing can greatly influence the content of RS and SDS in food. [10] Processing methods differ in terms of heating rate and duration, magnitude of shear forces and temperature, cooling rate and time, all these parameters affect the rate and degree of gelatinization and thus starch digestibility.…”

Influence of potato Variety on Phenolic Content, <i>In-vitro</i> Starch Digestibility and Predicted Glycaemic Index of Crisps and Chips from Nyandarua County, Kenya

“…RDS, SDS and RS have been termed the important fractions of starch in terms of GI. Diets with high SDS and RS are associated with low GI and hence would be important in reducing type 2 diabetes [15].…”