Structural changes to starch after acid hydrolysis, debranching, autoclaving‐cooling cycles, and heat moisture treatment (HMT): A review

Abstract

Starch is a carbohydrate polymer consisting of glucose monomers with alpha-glycosidic bonds comprising amylose (linear chains) and amylopectin (linear and branched chains). Starch modification is generally carried out for two reasons. First, native starch has limited applications. Second, functional properties can be added to starch through the modification to produce resistant starch for use in functional foods. Resistant starch has been revealed to show several health benefits including increasing faecal bulk, lowering colonic pH, and reducing glycaemic response. Acid hydrolysis, debranching, autoclaving-cooling cycles, and heat moisture treatment (HMT) are the common methods involved in resistant starch production. These modifications can lead to changes in the structure of starch related to its resistance to human digestion. Here, the structural changes observed by gel-permeation/filtration chromatography (GPC/GFC), Fourier transform infra-red (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) are discussed.

Resistant Starch from Isolated White Sorghum Starch: Functional and Physicochemical Properties and Resistant Starch Retention After Cooking. A Comparative Study

“…Compared to native WS starch, all the four RS‐ingredients had greater ( p < 0.05) transition temperatures ( T 0 , T p , and T c ) and enthalpies (Δ H ), thus indicating a greater thermal stability. Even if discrepancies among studies exist, primarily related to disparities in the selected starch sources and hydrothermal methods and conditions, applied treatments can alter starch gelatinization properties in dissimilar ways by: 1) affecting the hydrogen bond in the starch structure; 2) influence starch crystallite perfection and molecular interaction within the crystalline and amorphous regions; and 3) increase the overall granule stability . The results conformed with Sun et al's findings, which reported greater gelatinization transition temperatures and Δ H values in sorghum starch after subjecting to heat‐moisture treatment.…”

“…The FT‐IR spectra of native and modified starches, and the ratio 1047 cm −1 /1022 cm −1 , have been reported in Figure A and B, respectively. The FT‐IR technique provides information on the structural changes at the molecular level near the surfaces of starch granules, since the IR beam penetrates only to a depth of 2 μm into the granule . Moreover, the IR absorbance bands at 1047 and 1022 cm −1 are sensitive to ordered or crystalline structures and amorphous structures of starch, respectively and thus the ratio 1047 cm −1 /1022 cm −1 has been used to estimate the amount of ordered crystalline to amorphous domains in starches .…”

“…Based on the rate of in vitro glucose release and absorption within the human gastrointestinal tract, starch has been classified into three categories: rapidly digestible (RDS), slowly digestible (SDS), and resistant starch (RS) . In particular, owing to the nutraceutical importance and associated health benefits, starch sources rich in RS are considered as promising ingredients for novel food formulation, and there has been an increasing trend of including commercial preparations of RS in processed cereal‐based food products …”

Improving Properties of Arrowroot Starch (Maranta arundinacea)/PVA Blend Films by Using Citric Acid as Cross-linking Agent

“…(Figure 7) shows that non-modified cross-linking film (P1C1) shows an endothermic peak at <100°C which is the temperature of gelatinizing arrowroot starch. These results were consistent with the thermogram of DSC starch arrowroot resulted by the study of Pratiwi [32] where the gelatinized temperature was at 69.17-80.03 °C, likewise Valencia et al [36] obtained the temperature of gelatinization of arrowroot starch is 65.5 ± 0.1°C. Inter and intra molecules interaction between the starch and PVA were developed by cross-linking due to the changes of structure of arrowroot starch so that there is no endothermic peak at that temperature.…”

Higher Chain Length Distribution in Debranched Type‐3 Resistant Starches (RS3) Increases TLR Signaling and Supports Dendritic Cell Cytokine Production

“…Type‐3 (RS3) is obtained by a cooking and cooling process that makes it the most resistant form, fully resistant to human digestive enzymes . The final physicochemical structural properties of the RS3 are likely to provide direct immune effects …”