Structure Of Starch Research Articles

Unveiling lotus root processing under vacuum microwave: starch-malic acid interactions based on moisture, structure, and in vitro digestibility.

This study evaluated the effects of malic acid vacuum microwave preconditioning (MVMP) on lotus root (LR) by examining its moisture content, dielectric properties, microstructure, and starch characteristics, including modifications in starch structure and composition. Dielectric properties and LF-NMR indicated that the dielectric constant (ε') was closely associated to moisture content and state, while changes in water migration depended on microwave power and the dielectric loss factor (ε″). Increased microwave power and malic acid concentration resulted in microstructural damage (indentation and breakage of starch granules) and starch hydrolysis into smaller particles. MVMP preserved higher levels of phenolic and flavonoid compounds. FT-IR analysis revealed an additional absorption peak at 1740cm-1. The maximum degree of substitution was 0.131. Starch from MVMP-treated LR exhibited higher crystallinity, with a maximum resistant starch (RS) content of 68.3%. In addition, microwave power considerably influenced amylose content, solubility, swelling power, and thermal enthalpy.

Hydrophobic modification of starch via enzymatic grafting polymerization of fluorinated vinyl monomer.

The synthesis of starch grafted with poly (hexafluorobutyl methacrylate) (PHFBMA) was achieved using the horseradish peroxidase (HRP)/acetophenone (ACAC) green initiating system. The modified starch was characterized through FT-IR, 19F NMR, XPS and EDS to confirm the successful grafting of PHFBMA onto starch backbone. The SEM analysis revealed that the introduction of PHFBMA led to a partial disruption of the crystalline structure of starch, suggesting that PHFBMA did not undergo physical adsorption onto starch. Compared to natural starch film, the modified starch film displays a significantly enhanced hydrophobicity, which can lead to substantial improvements in both the hydrophobicity and tensile properties when applied to hydrophilic paper substrates.

Effect of (-)-epigallocatechin gallate palmitate complexation under mild temperature on the structure and nutritional functions of porous rice starch.

The correlation among the hierarchical structure, physicochemical properties, and nutritional functions of porous rice starch after absorbing and complexing with (-)-epigallocatechin gallate palmitate (P-EGCG) under mild temperatures at different reaction times were investigated. The P-EGCG loading rate (19.6%-28.5%) of porous starch increased after hydrolysis with a mixture of amyloglucosidase and α-amylase for 3 and 6h, respectively. A decrease in the melting enthalpy of the amylopectin double helix and an increase in the melting enthalpy of the V-type helices after complexation was observed with longer reaction times. The retention index of P-EGCG after 6h of incubation was 57.11% following 21 d of storage. These structural changes significantly transformed portions of the rapidly and slowly digestible starches into resistant starch (41.68%-47.84%), accompanied by enhanced thermal stability, antioxidant activity, and enteropathogenic bacteria-inhibiting ability. Therefore, porous rice starch complexed with P-EGCG may provide controlled digestion, antioxidant activity, and potential gut microbiota benefits.

Mechanism of starch multi-scale structural in determining the textural properties and formability of starch pearls

Starch pearls are widely used in bubble tea and desserts, yet the mechanistic understanding of the formation process of their textural properties remain unclear. To investigate the relationship between the multi-scale structure of starch and the textural properties of starch pearls, analyses of fine structure, crystal structure, rheological behavior, and textural profiling were conducted. The results showed that starch gels with a higher content of short-chain amylose (100 < X ≤ 1000) exhibited weaker formability during starch pearl preparation, leading to a lower flow behavior index (n*). This, in turn, positively influenced the hardness and resilience of the starch pearls. Cassava, potato, and yam starch pearls contained a large amount of long-chain amylopectin (24 < X ≤ 100) and long-chain amylose (5000 < X ≤ 20,000). The high proportion of long chains resulted in a weaker ordered structure, leading to increased peak viscosities and final viscosities and a higher consistency coefficient (k*). This structural feature enhanced the formability stability, viscosity, and chewability of starch pearls. Our findings reveal that variations in starch multi-scale structure significantly influence the textural quality and formability of starch pearls, providing valuable insights for optimizing starch selection and processing techniques in the food industry.

Polyhydroxy starch with abundant hydroxyls and a unique structure enables uniform Zn deposition.

Zinc metal is a promising anode material for zinc-ion batteries (ZIBs), but severe side reactions and dendrite formation hinder its commercialization. In this study, starch is introduced into the ZnSO4 electrolyte for stabilizing the Zn anode. With abundant hydroxyl groups, starch can reconstruct the H-bond system in the electrolyte, suppressing side reactions. Moreover, the unique ring and double-helix structures of starch show strong interactions with Zn2+ ions. The large molecule structure also exhibits a steric hindrance effect, regulating the diffusion and reduction of Zn2+. Additionally, starch molecules can adsorb onto the Zn anode, promoting the formation of a solid-electrolyte interphase (SEI) and resulting in uniform Zn deposition along the (002) plane. Consequently, this approach enhances the stability and reversibility of the Zn anode.

Variations in the Impact of Gingerols' Conversion to Shogaols on the Properties of Corn Starch with Different Amylose Contents.

The polyphenol-starch complex has become a hot research topic since it is evident that this modification method can alter the physicochemical properties of starch as well as improve its nutritional value. This work aimed to evaluate the effect of ginger polyphenol gingerols (GNs) and shogaols (SNs) on the structure of starch with different amylose content (WCS, CS, G56, G80). Textural and rheological results indicated that GNs and SNs had more pronounced inhibitory retrogradation effects for relative low-level amylose starches (WCS and CS) compared to relative high-level amylose starches (G56 and G80). GNs and SNs improved the freeze-thaw stability of starch gels. FT-IR and XRD results revealed that GNs and SNs decreased the (short- and long-range) ordered structure of starches through a non-covalent interaction. Moreover, DSC results proved that the gelatinisation temperature of CS/G56/G80 significantly increased, and the enthalpy (ΔH) decreased by the incorporation of GNs and SNs. Overall, this in-depth study is beneficial in providing valuable pathways for starch-polyphenol interactions to improve the quality of starchy foods.

Silanization of Starch and Its Effect on Cross-Linking and Mechanical, Dynamic, Hydrophobic, and Aging Properties of Polymeric Compositions Containing Natural Rubber.

In recent years, the search for more sustainable fillers for elastomeric composites than silica and carbon black has been underway. In this work, silanized starch was used as an innovative filler for elastomeric composites. Corn starch was chemically modified by silanization (with n-octadecyltrimethoxysilane) via a condensation reaction to produce a hydrophobic starch. Starch/natural rubber composites were prepared by mixing the modified starch with elastomer. The morphology, hydrophobicity, and chemical structure of starch after and before modification were studied. The results showed that starch after silanization becomes hydrophobic (θw = 117.3°) with a smaller particle size. In addition, FT-IR spectrum analysis confirmed the attachment of silane groups to the starch. The modified starch dispersed better in the natural rubber matrix and obtained a more homogeneous morphology. The composite achieved the best dynamic (ΔG' = 203.8 kPa) and mechanical properties (TSb = 11.4 MPa) for compositions with 15 phr of modified starch. In addition, the incorporation of silanized starch improved the hydrophobicity of the composite (θw = 117.8°). The higher starch content allowed the composites to achieve a higher degree of cross-linking, resulting in better resistance to swelling in organic solvents. This improvement is due to enhanced elastomer-filler interactions and reduced spaces that prevent solvent penetration into the material's depths. The improved mechanical properties and good dynamic properties, as well as improved hydrophobicity, were mainly due to improved interfacial interactions between rubber and starch. This study highlights the potential and new approach of silane-modified starch as a sustainable filler, demonstrating its ability to enhance the mechanical, dynamic, and hydrophobic properties of elastomeric composites while supporting greener material solutions for the rubber industry.

Effects of rolling on eating quality, starch structure, and water distribution in cooked indica rice dough.

Given the composition of rice and its lack of gluten proteins, rice flour fails to form a cohesive and elastic dough when mixed directly with water. Consequently, many rice products rely on rice sheets (RS) made by rolling cooked rice dough. Limited research exists on how the rolling process impacts the properties and structure of cooked indica rice dough. This study investigated the effect of the number of rolling passes on the eating quality, starch structure, and water distribution of cooked fermented indica RS formed by dough. When the number of rolling passes reached six, the RS (RP-6) that was obtained exhibited the lowest cooking loss, the highest hardness, adhesiveness, and chewiness, and optimal stretchability. It also demonstrated the lowest water loss after freezing. Dense microstructures were observed on both the surface and cross-section of RP-6. More ordered starch crystal structures and double helix structures were formed. The relative peak area of tightly bound water significantly increased in RP-6, indicating a stronger bonding status between the starch and water molecules. However, excessive rolling passes (more than six) led to a partial disruption of the internal RS structure, resulting in a decline in eating quality. The study demonstrated the importance of the rolling process in improving the performance of RS. It was found that a moderate number of rolling passes was conducive to producing excellent RS, providing a theoretical basis for the production of high-quality rice-based products such as rice noodles, dumplings, and cakes. © 2024 Society of Chemical Industry.

Multiscale structural characterization, physicochemical properties, and in vitro digestibility of pea starch produced by two different processes

AbstractBackground and ObjectivesDry grinding pea starch (DG) and wet grinding pea starch (WG) are two primary industrial starches with significantly different structures, physicochemical properties, and application potentials. To date, there have been no detailed studies examining these differences. Therefore, the aim of this study was to (i) investigate the effects of dry grinding and wet grinding on the structure of pea starch, and (ii) examine how the structure of pea starch influences its physicochemical properties and digestibility.FindingsThe crystallinity (35.75%), medium and long amylopectin (AP) chains (22.00%), swelling power (17.23 g/g), gelatinization temperature (76.4°C), and gelatinization viscosity (5585.0 cP) of WG were higher than those of DG (24.29%, 20.36%, 16.90 g/g, 75.9°C, and 5196.3 cP). In contrast, the average particle size (APS) (24.31 μm), resistant starch content (45.80%), and gel hardness (509.70 g) were lower than those of DG (25.68 μm, 52.13%, and 617.53 g).ConclusionsSignificant structural differences exist between WG and DG, with APS and AP chain length distribution being the primary factors contributing to the distinct physicochemical characteristics of the two pea starches.Significance and NoveltyThis is the first detailed comparison of the properties of commercial pea starch produced by two different processes. The results provide theoretical insights that underpin the use of pea starch in functional foods and promote the development of new starch‐based products.

Extraction and characterization of rubberwood starch for accurate structural and physicochemical properties analysis

Rubberwood has high starch content and is susceptible to fungal and microbial attack. The modification of starch can prevent it from becoming a nutrient source of microorganisms and realize the purpose of anti-mildew and anti-corrosion of rubber wood. Understanding the structure and physicochemical properties of rubberwood starch aids to explore suitable methods for starch modification. This study investigates the distribution of starch in rubberwood and explores the feasibility of extracting starch by three different methods (water extraction, sodium metabisulfite extraction and ethanol extraction). The results showed that the distribution of rubberwood starch was consistent with the typical distribution of wood starch, mainly distributed in thin-walled cells. Three extraction methods proved the feasibility of extracting starch from rubberwood thin-walled cells. The microstructure, physical and chemical properties and structure of rubberwood starch were investigated by means of scanning electron microscope, X-ray diffraction, polarizing light microscope and nuclear magnetic resonance analysis. The results showed that compared with the internal starch of rubberwood, the shape of the starches extracted by the three methods did not change significantly, and they were all spherical and elliptical, with stable A-type crystal structure and obvious Malta cross diffraction pattern. However, it is worth noting that sodium metabisulfite and ethanol will increase the swelling power of rubberwood starch, which provides new insights into other uses of rubberwood starch. This work not only enriched our understanding of the characteristics of rubberwood starch, but also laid a theoretical basis and practical guidance for the development of efficient mildew prevention technology of rubberwood products.

Formation of the rosette-like starch with enhanced V-type crystallization via modified solvent-shifting method.

This research investigated the effect modified solvent-shifting method on the formation, ordered structure, and morphology of V-type starch. Ionic liquid (IL) dissolution and hot ethanol aqueous incubation in gradient concentrations from 30% to 80% (v/v) were applied to optimize the relative crystallinity of V-type starch. The results showed that this new method worked in producing V-type conformation, and higher ethanol concentration tended to yield V-type starch with higher crystallinity and more disk-like shape structure within the ethanol range of 30-50% (v/v). Notably, the crystalline order of V-type starch reached the maximum with a specific rosette-like morphology under the condition of an ethanol concentration of 50% (v/v). While the grown crystals organized into small-size flower-like assemblies and this morphology even disappeared accompanied by the V-type crystallization weakening when starch chains co-crystallized with the ethanol concentrations of 60%-80% (v/v). The molecular structure analysis indicated no significant correlation between the relative crystallinity of V-type starch and its fine structure. IL served to promote the formation of V-type starch, while it didn't participate in the formation process and could be removed during the washing process. The findings can provide new insights into developing a bottom-up pathway for regulating crystallization and morphology of V-type starch.

Starch-Tannin Interactions: Influence of Grape Tannins on Structure, Texture, and Digestibility of Starches from Different Botanical Sources

Starch-Tannin Interactions: Influence of Grape Tannins on Structure, Texture, and Digestibility of Starches from Different Botanical Sources

Influence of the induced Na+/Cl- ionic polarization effects on multi-scale structures of maize starch during radio frequency heating.

Structural modification/unfolding of starch molecules can be improved by radio frequency (RF) treatment. This necessitates a better understanding of its action mechanism through rapid heating and dipolar/ionic molecular vibration effects. Native maize starch (NS) was subjected to RF heating in a NaCl solution to five target temperatures, and its effect on structural modifications was evaluated. Results showed that the conductivity, particle size distribution and zeta potential of RF heated starch increased with increasing temperature. RF energy had a significant effect on the vibration intensity of other skeleton modes. No new chemical bonds/groups were formed in the starch even though there was the effect of sodium/chloride ions with the added vibration intensity of the ions and the dipolar rotation movements resulted in changes in the disordered and/or ordered structures. The RF treatment at 70°C had the highest energy (10.4kJ) of inter-strand hydrogen bond, crystallinity (36.6%) and trough viscosity (2480 cp), but had the lowest crystallite dimension (13.7nm), full width at half maximum (14.4) of peak at 480cm-1, and breakdown (534 cp) and setback (784 cp) viscosities based on X-ray diffraction, Fourier transform infrared, and Raman and rapid viscos analyzer observations.

Unraveling the key structural characteristics enhancing digestion resistance of wheat starch-mung bean hull polyphenols complexes.

Mung bean hull polyphenols (MBPs) have the potential to retard starch digestion by altering its multi-scale structures. However, the regulatory mechanism and the key structural characteristics that contribute to digestion resistance remain unclear. In this study, MBPs were non-covalently interacted with wheat starch (WS) under hydrothermal treatments. The digestibility of WS was negatively correlated with the addition of MBPs. The multi-scale structures investigated by 13C CP/MAS NMR, FT-IR, XRD, SAXS, and SEM unveiled the formation of single helix, short-range ordered, and V-type crystalline structures. Notably, MBPs could also induce the entanglements of glucan chains to form compact aggregates that were non- or weakly-crystalline. Correlation and stepwise regression analyses demonstrated that ordered structures were prerequisites for digestion resistance of WS-MBPs complexes, with tightly packed amorphous aggregates playing a secondary yet significant role. This study provides new insights into the relation between starch multi-scale structures and digestion resistance.

Modulating the assembly of starch-lecithin inclusion complexes and its underlying mechanism for controlling starch digestibility under the dense system

Starch-lipid inclusion complexes were used to regulate starch digestibility by changing the binding affinity of digestive enzymes such as α-amylase and α-glucosidase. However, when above a critical aggregation concentration (CAC) of starch and lipid molecules, they tended to self-assemble into double helices or normal micelles respectively, rather than interacting with each other to form starch-lipid complexes. Thus, how to enhance the complexation efficiency under a dense system is the key approach for the improvement of starch bioaccessibility and nutritional function. Herein, based on the dimethyl sulfoxide (DMSO) reverse solvent method, the effect of water/DMSO ratios and starch chain structures on the interaction and assembly behaviors between starch and lecithin molecules in high concentrations were systematically investigated. The results revealed that water/DMSO in a ratio of 1.5:1 promoted the interactions between cavities of starch helices and long alkyl chains of lecithin molecules, with higher level of complexed lecithin content, relative crystallinity (RC), enthalpy (ΔH) (Tp＞100°C), ordered-aggregation structures and resistant starch (RS) content. In this kind of solvent, starch samples with higher content of amylose and longer chains (degree of polymerization (DP) of B2 chains and B3+ chains) is advantageous to the formation of VII-type inclusion starch-lecithin complexes, with a rise in RS from 14.17% to 43.64%. It provided an effective method to modulate starch digestibility under the dense system of starch and lecithin via modulating the water/DMSO ratios and starch fine structures and lay the foundation for the large-scale preparation and application of starch-lecithin complexes.

Li-ion batteries with poly[poly(ethylene glycol) methyl ether methacrylate]-grafted oxidized starch solid and gel polymer electrolytes

Polymer electrolytes are considered in lithium-ion batteries because of their high safety and properties such as flexibility, easy moldability, etc. Starch is one of these polymers from renewable resources. Considering the semi-crystal structure of starch and ion conduction in amorphous phase, herein starch is oxidized and then modified with poly[poly(ethylene glycol) methyl ether methacrylate]. Solid polymer electrolytes (SPEs) are prepared by dissolution of lithium salt within polymer while gel polymer electrolytes (GPEs) as crosslinked structures are swollen in lithium salt solution. After validation of successful syntheses, all SPEs and GPEs with different oxidation state and various PEGMA/oxidized starch are evaluated in Li-ion battery performance. The synthesized GPEs and SPEs show the highest ionic conductivity of 5.5 × 10−3 and 2.19 × 10⁻⁴ S cm⁻1, respectively at room temperature. Lithium ion transfer number (t+) of 0.6–0.9 and electrochemical stability window of 4.4–4.9 V are obtained for SPEs and GPEs. The discharge capacity is ∼180 mAh g−1 at 0.2 C with capacity retention of 75 % after 100 cycles.

The physicochemical properties of oat starch-fatty acid complexes and application in Lactiplantibacillus plantarum microencapsulation

Oat starch (OS) is the primary component in oat kernels, playing a crucial role in the sensory attributes and functionality of oat products. This study aimed to improve the functional properties of OS by forming oat starch-fatty acid complexes (OS-FAs). Four OS-FAs were prepared using OS and different FAs (stearic acid, palmitic acid, myristic acid, and oleic acid), resulting in OS-S, OS-P, OS-M, and OS-O, respectively. The chemical, functional, and structural properties of these OS-FAs were analyzed and compared with unmodified OS. OS-M was selected for further application in the fabrication of Lactiplantibacillus plantarum (L. plantarum) microcapsules, in combination with sodium alginate and chitosan. The results showed that as the FA carbon chain length and the degree of saturation decreased, the degree of substitution (DS), total resistant starch (RS), water absorption capacity and oil absorption capacity (WAC and OAC), emulsification activity and stability (EA and ES), solubility (SB), and swelling capacity (SC) of the OS-FAs all significantly improved (p < 0.05). The OS-M exhibited the highest DS (0.055), total RS (11.11%), WAC (361.64%), OAC (94.34%), EA (60.87%), ES (61.63%), and best SB (41.22% at 37 °C) and SC (6.13% at 37 °C). The FTIR analysis confirmed that the substitution reactions occurred during complex formation, while the basic starch structure was maintained. XRD and SEM analyses revealed a transformation in crystal morphology from type A to type V, along with a porous network structure and increased specific surface area. Starting from approximately 9.40 log CFU/g, the viability of L. plantarum in OS-M microcapsules was retained at 6.94 and 8.85 log CFU/g in wet and dry capsules, respectively, after simulated gastrointestinal digestion, outperforming microcapsules without OS-M. Additionally, OS-M enhanced L. plantarum protection during 4-week storage at −20 °C (2.91 log CFU/g), 4 °C (8.81 log CFU/g), and 25 °C (6.70 log CFU/g). These findings suggest that modifying OS by forming OS-FA complexes improves its functionality and that OS-FAs hold potential for use in probiotic encapsulation to enhance bacterial viability.

Insight into Oil-in-Water Emulsions Stabilized by Cross-Linked and Pregelatinized Starches: The Effect of Molecular Structure, Surface Activity and Proton Molecular Dynamics.

Effective formation and stabilisation of emulsions while meeting high consumer requirements, including the so-called green label, is still a technological challenge. This is related to the multitude of emulsion destabilization mechanisms and the vastness of methods used to study them, which implies the need to develop an understanding of the phenomena occurring in emulsions. Commercial starch preparations obtained by physical and chemical modification were used to prepare model emulsions that were studied in terms of their stability. Native potato starch was the reference material. The analytical methods used included rheology, low field nuclear magnetic resonance (LF NMR), size exclusion chromatography with triple detection (SEC), and surface/interfacial tension measurements. The results showed that chemical and physical modification improved the functionality of starch in emulsions. This is due to not only chemical but also physical modifications, i.e., pregelatinization causes changes in the molecular structure of starch, including an increase in the molecular weight and the degree of branching. As a consequence, the conformation of starch macromolecules changes, which results in a change of the dynamics of protons in the continuous phase of the emulsion and the thermodynamics of starch adsorption at the water/oil interface.

Synergistic Effects of Freeze‐Thaw Pretreatment and Ultrasound on the Structure and Digestibility of Starch–Lipid Complexes

Synergistic Effects of Freeze‐Thaw Pretreatment and Ultrasound on the Structure and Digestibility of Starch–Lipid Complexes

γ-irradiation of wheat flour dough: The influence of starch hierarchical structure and physicochemical properties

Irradiation has been shown to cause a change in physicochemical properties and starch depolymerization of wheat flour. However, the impact of starch hierarchical structure and physicochemical properties on dough's viscoelastic behavior during irradiation treatment remains unexplored. Therefore, this study investigated the effect of γ-irradiation (0, 5, 10, 15, and 20 kGy) on the viscoelastic properties of dough and the hierarchical structure and physicochemical characteristics of starches isolated from irradiated dough. Irradiation weakened the gluten network structure and decreased the starch-gluten interaction. Moreover, irradiation reduced the dough's elasticity, viscosity, deformation-resistant capacity, hardness, springiness, cohesiveness, and resilience. Irradiation treatment disrupted the short-range ordered structure, reduced the crystalline lamellae thickness and crystallinity, and dissociated the double helix structure of starch, thus increasing solubility and decreasing peak, trough, and final viscosities. Correlation analysis revealed that the lamellar structure, crystalline structure, short-range ordered structure, and pasting viscosities of starch were the key factors affecting the dough's viscoelastic properties during irradiation treatment.