Structure, morphology and functionality of acetylated and oxidised barley starches

Acetic anhydride and vinyl acetate differentially modify the supramolecular structure of starch

The multi-scale structure changes of five underutilized starches, including waxy proso millet (PMS) and amaranth (AS) starches, non-waxy foxtail millet (FMS), buckwheat (BS) and oat (OS) starches, were investigated after modification with acetic anhydride (0.0165 mol) and vinyl acetate (0.0165 mol). Five starches exhibited a higher proportion of short chains compared to waxy and normal maize starches. Degree of substitution (DS) of acetylated starches ranged 0.03 to 0.08. Vinyl acetate modified non-waxy starches showed higher DS values than waxy starches, while acetic anhydride modified waxy starches exhibited higher DS values than non-waxy starches. Vinyl acetate reduced relative crystallinity (RC) by 1.3 % in PMS, 5.7 % in FMS, and 12.5 % in OS, whereas acetic anhydride did not significantly decrease RC for AS, FMS, BS and OS. For the non-waxy starches, gelatinization enthalpies after vinyl acetate modification were 4-22 % lower than after acetic anhydride modification. Additionally, the increase in amorphous lamellae thickness (da) of PMS, AS, BS and OS was greater with vinyl acetate than acetic anhydride, indicating that vinyl acetate more effectively disrupted crystalline lamellae. Overall, the presence of amylose influenced DS of modified starches. However, change of supramolecular structure was independent of DS but dependent on the acetylation reagent.

Exposure of Proso millet starch to superheated steam: Effect on physicochemical, techno-functional, rheological behavior, digestibility, and related mechanism

In the present study, proso millet starch (PMS) was treated with SHS (120-160 °C for 1-5 min) to investigate the molecular interactions and techno-functional, rheological, and digestible properties. Exposure to SHS induced the degradation of helical structure, and longer chains, reducing amylose, blue value, optical density, and relative crystallinity. Meanwhile, SHS treatment might have introduced hydro‑carbonyl groups, eventually increasing water absorption capacity, swelling power, and transparency. As per SEM images, SHS-treated PMS had rough and irregular polygon surfaces with small pinholes. Compared to control, SHS treatment slightly improved the elastic nature of PMS samples. Furthermore, SHS treatment at 140 and 160 °C for 3 and 5 min increased the slowly digestible and resistant starch content. Multivariate analysis suggests that SHS treatment could be performed at 140 °C for 3 min to modify the PMS.

In vitro starch digestibility and physicochemical properties of chemical and enzymatic modified Indian Teff (Eragrostis Tef) starch for industrial applications

The long-term stability, mechanical properties, and interactions of modified teff starch with food components remain unclear. The effects of dual or multiple modifications on physicochemical properties and digestibility are also unexplored. This study investigates the modification of Teff starch through oxidation (sodium hypochlorite), cross-linking (citric acid), and enzymatic treatments (α-amylase, amyloglucosidase) to enhance its structural, physicochemical, and thermal properties. Oxidation reduced swelling power and pasting viscosity, while cross-linking improved mechanical resistance with a cross-linking degree of 44.2 %-70.4 %. Enzymatic modification lowered amylose content and enhanced gelation. In vitro digestibility analysis revealed increased slowly digestible starch (SDS) and resistant starch (RS) contents for all modified starches. O2 showed SDS and RS levels of 44.64 % and 31.42 %, respectively, compared to 41.51 % and 21.28 % in NS. C2 demonstrated RS levels of 24.11 %, while AA exhibited an RS of 29.03 %. O1, O2, C1 and C2 reduced starch digestibility by introducing steric hindrance and cross-linking bridges, while AA increased branching density, slowing digestion. Structural analyses (FTIR, DSC, XRD, SEM, and 1H NMR) confirmed functional group stabilization, enhanced thermal stability, partial amorphization, and surface integrity improvements. The X-ray diffractograms showed no notable alterations, confirming that the crystalline region remained unaffected by the reaction. 1H NMR spectra revealed changes in glycosidic linkages, with oxidation reducing branching and cross-linking increasing structural complexity. PCA revealed the distinct properties of modified starches. The study highlights the synergistic effects of oxidation and cross-linking, offering insights into starch modification mechanisms and future industrial applications.

Ultrasonic assisted enzymolysis based modification of native banana starch - A comprehensive analyses of the structural, morphological, rheological and textural properties

Native banana starch (NS) has few limitations, such as poor solubility, low resistance to shear, temperature, and inconsistent retrogradation. This study investigates the effects of mono (α-amylase, pullulunase) and sequential enzymatic modifications of NS along with the application of ultrasound to enhance its functional attributes. Starch modified with α-amylase alone and along with ultrasound resulted the lowest amylose (20.23 %), resistant starch (28.22 %), higher rapidly digestible starch (48.92 %). Whereas pullulanase modification resulted in higher amylose (38.14 %), resistant starch (52.72 %) and therefore the better swelling power and water holding capacity. The retrogradation negatively associated with the solubility of these modified starches is outlined through the static viscosity measurements. Ultrasound enhanced the efficiency of enzymes by altering the structure of starch granules, confirmed through SEM analysis and provided differentiated thermal stability as observed through viscosity and enthalpy values from DSC. The dual sequential enzymatic treatment with ultrasound also significantly improved the starch solubility by altering the molecular structure as evidenced through XRD and FTIR analysis. NMR 1H spectra revealed distinct variations in the anomeric peaks and hydroxyl regions of modified starches. Cluster analysis highlighted the unique characteristics of ultrasound-assisted starches.

Valorization of raw papaya (Carica papaya) and citrus peels for development of antimicrobial and biodegradable edible film

Most of the food packaging materials used in the market are petroleum-based plastics; such materials are neither biodegradable nor environmentally friendly and require years to decompose. To overcome these problems, biodegradable and edible materials are encouraged to be used because such materials degrade quickly due to the actions of bacteria, fungi, and other environmental effects. The present study examined that starch can be effectively used as raw material to develop biodegradable, edible films. In this regard, Raw papaya and Citrus Peel were chosen to make biodegradable plastic film blended with corn starch. Raw papaya powder was combined with citrus peel powder for the development of film in treatments of T1, T2, T3, T4 and T5. RPP and CPP blend with Corn starch (CS) to maximize the film-forming properties and characteristics. The films were subjected to various parameter analysis like thickness, optical properties and barrier properties. As per the results, T3 was an optimized film, as it had minimum thickness (0.26 ± 0.01), high tensile strength (5.79 ± 0.12), elongation at break of 11.92 ± 0.03, High transparency (1.42 ± 0.06), and high degradation temperature. From the results, it is inferred that the prepared films are ideally suitable for food packaging and their production on a larger scale can considerably cut down the plastic wastage.

Research Progress of Application and Interaction Mechanism of Polymers in Mineral Flotation: A Review

Polymers are composed of many smaller units connected by covalent bonds, with higher molecular weight and larger molecular structure. Due to their economical efficiency and easy modification, researchers have discovered the potential of polymers as the flotation reagent in mineral processing, including the roles of depressant, flocculant, and frother. This paper provides a comprehensive review of the utilization of polymers in mineral flotation, emphasizing their current applications and mechanistic investigations. The study categorizes polymers into three types: natural polymers, modified polymers, and synthesized polymers. Detailed discussions include the polymers structures, functional properties, adsorption mechanisms and specific application examples of each reagent are shown in the main text, which will provide a vital reference for the development of highly efficient and environmentally friendly reagents in mineral flotation.

Dialdehyde starch cross-linked aminated gelatin sponges with excellent hemostatic performance and biocompatibility

Developing a hemostatic material suitable for rapid hemostasis remains a challenge. This study presents a novel aminated gelatin sponge cross-linked with dialdehyde starch, exhibiting excellent biocompatibility and hemostatic ability. This aminated gelatin sponge features hydrophilic surface and rich porous structure with a porosity of up to 80 %. The results show that the aminated gelatin sponges exhibit superior liquid absorption capacity and can absorb up to 30-50 times their own mass of simulated body fluid within 5 min. Compared with the commercial gelatin hemostatic sponge and non-aminated gelatin hemostatic sponge, the aminated gelatin hemostatic sponge can accelerate the hemostatic process through electrostatic interactions, demonstrating superior hemostatic performance in both in vitro and in vivo hemostasis tests. The aminated gelatin sponge can effectively control the hemostatic time within 80 s in the in vivo rat femoral artery injury model, significantly outperforming both commercial and non-aminated gelatin sponges. In addition, the aminated gelatin sponge also exhibits good biocompatibility and certain antibacterial properties. The proposed aminated gelatin sponge has very good application prospects for the management of massive hemorrhage.

Effect of non-thermal acidic and alkaline modifications on the structural, pasting, rheological, and functional properties of cassava (Manihot esculenta) starch

This study aimed to investigate the effects of acid or alkali modification of isolated cassava starch (ICS) on its physicochemical properties. Acetic acid concentrations of 5%, 10%, and 20% v/v (0.87, 1.73, and 3.46 M, respectively) and calcium hydroxide concentrations of 0.15%, 0.20%, and 0.30% w/w (0.02, 0.025, and 0.04 M, respectively) were tested independently and compared with untreated isolated starch. The scanning electron microscope (SEM) shows starches with polyhedral and semispherical shapes; these modifications do not change the surface of the starch granules. Nanocrystals with orthorhombic crystal structure were extracted from ICS. Transmission electron microscopy (TEM) shows crystallites with a size (two-dimensional) of 20 ± 5 nm in length and 10 ± 2 nm in width and reveals that this starch contains nanocrystals with orthorhombic crystal structure. The X-ray patterns show that these nanocrystals are unaffected by acidic or alkaline treatments. The Ca+2 and CH3COO- ions do not interact with these nanocrystals. The alkaline treatment only affects the gelatinization temperature at a Ca(OH)2 concentration of 0.30%. Low concentrations of acidic and alkaline treatments affect the ability of cassava starch to absorb water and reduce the peak and final viscosity. The infrared spectra show that the modifications lead to C-H and C═C bond formations. ICS-B 0.30 can modify the amorphous regions of the starch, and the acid treatment leads to acetylation, which was confirmed by the presence of an IR band at 1740 cm-1.

Unraveling the Hidden Potential of Barley (Hordeum vulgare): An Important Review

Barley (Hordeum vulgare) is a winter crop well known for its small-seeded grains and self-pollinating characteristics. The flour derived from barley grains plays a crucial role in numerous processed food items, contributing to their taste and nutritional value. Barley consists of complex carbohydrates (80%), proteins (11.5-14.2%), lipids (4.7-6.8%), β-glucans (3.7-7.7%), and ash (1.8-2.4%). Beyond its other nutrients, barley boasts a good reservoir of phenolic compounds (1.2-2.9 mg/g GAE). This abundance of beneficial compounds positions barley as an attractive industrial substrate. In this review, the nutritional composition and bioactive profile of barley are discussed in a systemic manner, emphasizing its potential in the development of innovative barley-based products that promote health and well-being. By incorporating barley into various food formulations, industries can not only boost nutritional content but also offer consumers a wide range of health benefits. In conclusion, barley's diverse applications in food and health highlight its essential role in promoting healthier living.

Recent advances on the preparation conditions, structural characteristics, physicochemical properties, functional properties and potential applications of dialdehyde starch: A review

Starch, a natural storage polysaccharide of plant kingdom, has many industrial applications. However, native starch has some inherent shortages, which can be overcome by structural modification. Dialdehyde starch, one kind of oxidized starch produced by periodate oxidation, has good physical properties and bioactivities with wide applications in different fields. Dialdehyde starch is typically achieved by oxidizing native starch slurry through periodate oxidation under controlled reaction conditions. Several factors including the source of starch, the type of oxidant, the molar ratio of oxidant to starch, reaction temperature, reaction time and solution pH value can influence the synthesis of dialdehyde starch. Dialdehyde starch shows different spectroscopic/chromatographic characters and physicochemical properties from native starch. Moreover, dialdehyde starch exhibits good antioxidant activity, antimicrobial activity and cross-linking property. Based on these functional properties, dialdehyde starch has shown application potentials in food packaging, thermoplastic production, enzyme immobilization, heavy metal ion adsorption, drug delivery, wood adhesion and leather tanning. In this review, the preparation conditions, structural characteristics, physicochemical properties, functional properties and potential applications of dialdehyde starch are summarized for the first time. The future research and development prospects of dialdehyde starch are also discussed.

Investigation of ultrasound-assisted starch acetylation by single- and dual- frequency ultrasound based on rheology modelling, non-isothermal reaction kinetics, and flow/acoustic simulation

To achieve wheat starch acetylation (AC) with a high degree of substitution (DS), the acetylation process was carried out using various ultrasonication frequencies, including 25 kHz, 40 kHz, and 25 + 40 kHz. In the second step, wheat starch's ultrasound-assisted acetylation (UAA) is simulated using various approaches including the rheology models, non-isothermal reaction kinetics, and flow/acoustic modelling. The computational fluid dynamics (CFD) simulation solves the non-linear acoustic governing equation to determine the flow field and the amount of delivered ultrasound energy. The acetylated starch increased peak and final viscosity, with the highest values observed for the 25 + 40 kHz frequency than other single frequencies (25 kHz and 40 kHz). The viscosity of the starch is specified based on the experimental data using Herschel-Bulkley, power law, and Casson rheology models. According to differential scanning calorimetry (DSC) analysis, the gelatinization parameters and enthalpy of gelatinization (ΔHgel), were found to be lower in acetylated starches at the frequency of 25 + 40 kHz compared to those at frequencies of 25 kHz and 40 kHz, as well as native starches (NS). Moreover, the gelatinization process is examined by implementing the non-isothermal reaction kinetics to obtain the activation energy and reaction order. Based on the results obtained, implementing sonication at 25 kHz reduces the activation energy by 70.3 % compared to native starch. However, the same parameter is obtained to be 69.9 % and 67.1 % for the application of 40 and 25 + 40 kHz transducers, respectively. Additionally, during the sonication treatment, the yield shear stress increases between 24.1 and 31.8 %, based on the applied frequency. Morphology analysis determined by scanning electron microscopy (SEM) revealed that the surfaces and small granules underwent more damage in acetylated starches at frequencies of 25 kHz and 40 kHz. However, in acetylated starches at 25 + 40 kHz, the larger granules were more affected than the smaller ones.

A combined recrystallization and acetylation strategy for resistant starch with enhanced thermal stability and excellent short-chain fatty acid production

In this study, resistant starch (RS) with enhanced thermal stability and excellent short-chain fatty acid production was obtained using recrystallization at 50 °C of debranched waxy maize starch followed by an acetylation strategy. RS sample obtained by debranching with a 25% high concentration of native starch combined with recrystallization at 50 °C (25DBS-50 °CP) and acetylated RS (25DBS-50 °CPA) exhibited high relative crystallinity of 69.4% and 64.2%, respectively. And the peak gelatinization temperature values of them reached 116.8 °C and 111.4 °C, and the RS contents of them after cooking for 30 min remained at 35.1% and 40.0%, respectively. The acetic acid yield of 25DBS-50 °CPA was higher than that of the control group. These results indicated that recrystallization at 50 °C combined with acetylation for debranched starch could be used as a new method for regulating the digestibility and fermentation properties while developing food with a low glycemic response and specific nutritional benefits.

Structure and surface properties of ozone-conjugated octenyl succinic anhydride modified waxy rice starch: Towards high-stable Pickering emulsion

In the present work, a dual-modified waxy rice starch (OOWRS) fabricated with OSA and ozone was successfully used to stabilize the O/W Pickering emulsion. The molecular structure, surface properties, and underlying stabilizing mechanism were systematically investigated. The results showed that oxidation occurring on the surface of OSA-modified waxy rice starch (OSAWRS) resulted in the presence of indentations and cracks. The relative crystallinity of starch was generally decreased with increasing degree of oxidation. Due to the introduction of carbonyl and the variation in surface structure, the hydrophobicity and acidity of OSAWRS were significantly enhanced after the ozone treatment. Remarkably, OOWRS stabilized Pickering emulsion exhibited a feature of typical O/W emulsion, and the 0.5 h and 1 h OOWRS emulsion exhibited a more uniform droplet size as well as a higher surface potential. We also noted that a weak-gel network was formed within the OOWRS emulsion system as the hydrophilic starch chains played a bridging role. Two reasons for the improved stability of the emulsion were the special gel structure and the enhanced electrical repulsion among the droplets. This research provides that ozone-conjugated OSA modification is a promising strategy for improving the emulsion ability of starch-based Pickering emulsions.

Modifications of native lotus (Nelumbo nucifera G.) rhizome starch and its overall characterization: A review

Lotus (Nelumbo nucifera G.) rhizomes are an under-utilized and sustainable starch source that constitutes up to 20 % starch. The review mainly focused on the extraction methods of starch, the chemical composition of LRS, and techno-functional characteristics such as swelling power, solubility, in vitro digestibility, pasting property, and gelatinization is highlighted in LRS review. Lotus rhizome starch (LRS) is also used as a water retention agent, thickening, gelling, stabilizing, and filling in food and non-food applications. Native starch has limited functional characteristics in food applications so by modifying the starch, functional characteristics are enhanced. Single and dual treatment processes are available to enhance microstructural properties, resistant starch, techno-functional, morphological, and, film-forming properties. Compared with other starch sources, there is a lack of systematic information on the LRS. Many industries are interested in developing food products based on starch such as nanoparticles, hydrogels, edible films, and many others. Additionally, there are several recommendations to improve the applications in the food industry. Finally, we provide an outlook on the future possibility of LRS.

Influence of oxidation, acetylation and hydrothermal treatment on structure and functionality of common buckwheat starch

The set aim of present work was to investigate the effects of acetylation, oxidation and heat moisture treatment on physicochemical, pasting, gel texture, structural, thermal and morphological properties of common buckwheat starch. Swelling power and solubility of starches reduced after modification except acetylation. Color of buckwheat starch improved after oxidation and acetylation. Paste clarity increased while syneresis reduced following modification with the exception of oxidation. Pasting properties of buckwheat starch revealed increased peak viscosity and breakdown viscosity following modification treatments. Gel texture analysis depicted increased hardness and reduced springiness, chewiness and cohesiveness for modified starches of buckwheat. Diffractograms of starches showed variation in intensity of some bands. Heat moisture treatment increased agglomeration and oxidation caused slight depression on surface of some granules. Relative crystallinity reduced following oxidation and hydrothermal treatment of starch. The gelatinization temperatures were increased in hydrothermal treated starch samples while oxidation and acetylation reduced the gelatinization temperature. The findings of this work would favor the new applications of modified starch from common buckwheat.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

Preparation and characterization of the bonding performance of a starch-based water resistance adhesive by Schiff base reaction

Starch is one of the important raw materials for the preparation of biomass adhesives for its good viscosity and low-cost properties. However, the drawbacks of poor water resistance and bonding performance seriously restrict its application in the wood industry. To resolve those problems, an environment-friendly renewable, and high water resistance starch-based adhesive (OSTH) was prepared with oxidized starch and hexanediamine by Schiff base reaction. In order to optimize the adhesive preparation process, the effect of different oxidation times and oxidant addition on the mechanical performance of plywood were investigated. In addition, the curing behavior characteristics, thermomechanical properties, and thermal stability of the OSTH adhesives were analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TG). Fourier-transform infrared (FTIR) spectrometry and Liquid Chromatography-Mass Spectrometry (LC-MS) were used to explain the reaction mechanisms involved. The results show this adhesive has an excellent bonding performance at the oxidation time of 12 h with 11 % (w/w, dry starch basis) NaIO4 as an oxidant. The dry shear strength, 24-hour cold water, and 3-hour hot water (63 °C) soaking shear strength of the plywood bonded with this resin were respectively 1.87 MPa, 0.96 MPa, and 0.91 MPa, which satisfied the standard requirement of GB/T 9846-2015 (≥0.7 MPa). Thus, this study provided a potential strategy to prepare starch-based wood adhesives with good bonding performance and water resistance.

Insight into how E-beam pretreatment promotes sodium hypochlorite oxidation for structure-property improvement of cassava starch: A molecular-level modulation mechanism

To investigate the role of E-beam treatment on the structure-properties of oxidized starch, this study investigated the influence of E-beam (1, 3, 6 kGy) pretreatment combined with NaClO oxidation (1% and 3%) on the multi-scale structural, physicochemical, and digestive properties of cassava starch. Results showed that E-beam treatment did not affect the starch surface, but the oxidative modification increased granule surface roughness. Also, the synergistic modification preserved starch growth rings, FT-IR patterns and crystal types. Further investigations revealed that E-beam induced starch molecular degradation, leading to decreased molecular weight, depolymerization of long chains, and a loss of short-range order. Moreover, oxidation treatment exacerbated the disruption in starch molecular structure, as evidenced by crystallinity loss, viscosity, and enthalpy reduction. Notably, E-beam induces starch yellowing; however, oxidative modification increases starch whiteness. Additionally, the synergistic modification improved native starch's lower solubility and enhanced the resistant starch content. Results suggest that E-beam pretreatment can enhance oxidative modification by promoting the exposure of active sites of starch molecules without destroying starch structure and can be considered an advanced, green, and efficient pretreatment for modified starch in the future.

Influence of chemical modifications on dynamic rheological behaviour, thermal techno-functionalities, morpho-structural characteristics and prebiotic activity of banana starches

Banana starch is explored for its use in food and pharmaceutical applications. In this study, in order to improve the techno-functional properties of native banana starch (NS), different chemical modifications namely acid thinning (AT), oxidation (OX), sodium-trimetaphosphate method (STMP), cross linking phosphorylation (CLP), hydroxypropylation (HYP) were employed. Among the modified starches, amylose content was higher in CLP starch and the least was observed in AT. Resistant starch (RS) of HYP (65.38 %) and CLP starches (62.76 %) were significantly higher than other modified starches. Lesser amylose, higher water solubility and lower swelling of AT starch resulted in inferior paste clarity and inability to make a firm gel. Non-Newtonian behaviour of starch gels were observed from static viscosity observations. The dynamic rheological behaviour of the starch gels affirmed the higher gel strength of STMP (0.46) and CLP (0.56) starches. Imperfection and exo-corrosion in starch morphology was observed through SEM and influence of chemicals on the starch structure was elucidated through FTIR and XRD analyses. Except AT starch, modified starches with higher RS resulted in lowering glycemic index (57-69 %). STMP starches recorded highest prebiotic activity score of 0.88. Chemical modifications enable to enhance the functionalities of banana starch and offers potential industrial uses.

PLA/modified-starch blends and their application for the fabrication of non-woven fabrics by melt-blowing

Blends of polylactic acid (PLA) and thermoplastic starch (TS) with and without chemical modification were obtained by melt extrusion and used to obtain non-woven fabrics by melt-blowing for the first time. Different TS were obtained by reactive extrusion from native cassava, oxidized, maleated, and dual modified (oxidized and maleated) starch. The chemical modification of starch decreases the difference in viscosity and favors blending, resulting in more homogeneous morphologies, unlike the blends with unmodified TS, which displayed a visible phase separation with large TS droplets. The dual modified starch showed a synergistic effect to process TS by melt-blowing. Regarding non-woven fabrics, values in diameter (2.5-82.1 μm), thickness (0.4-0.6 mm), and grammage (49.9-103.8 g/m²) were explained due to differences in viscosity of the components, and to the fact that during melt the hot air preferentially stretches and thins the areas without large droplets of TS. Moreover, plasticized starch acts as a flow modifier. The porosity of the fibers increased with the addition of TS. Further studies and optimization of blends with low contents of TS and type starch modification will be necessary to completely understand these systems with very complex behavior to obtain non-woven fabrics with improved properties and application.

Modification of Starches and Flours by Acetylation and Its Dual Modifications: A Review of Impact on Physicochemical Properties and Their Applications

Various modification treatments have been carried out to improve the physicochemical and functional properties of various types of starch and flour. Modification by acetylation has been widely used to improve the quality and stability of starch. This review describes the effects of acetylation modification and its dual modifications on the physicochemical properties of starch/flour and their applications. Acetylation can increase swelling power, swelling volume, water/oil absorption capacity, and retrogradation stability. The dual modification of acetylation with cross-linking or hydrothermal treatment can improve the thermal stability of starch/flour. However, the results of the modifications may vary depending on the type of starch, reagents, and processing methods. Acetylated starch can be used as an encapsulant for nanoparticles, biofilms, adhesives, fat replacers, and other products with better paste stability and clarity. A comparison of various characteristics of acetylated starches and their dual modifications is expected to be a reference for developing and applying acetylated starches/flours in various fields and products.

The effects of pulsed electric fields treatment on the structure and physicochemical properties of dialdehyde starch

The structural and physicochemical properties changes of corn starch oxidized by sodium periodate under the assistance of pulsed electric fields (PEF) were studied. It was found that dialdehyde starch (DAS) particles produced by PEF-assisted oxidation exhibited shrinkage and pits, and had a larger particle size when compared to the control without PEF. The solubility of the DAS (12 kV/cm PEF- assisted oxidation) improved by 70.2% when compared to the native starch. Increment in the strength of the PEF, led to a decrease in the viscosity of the DAS. In addition, the aldehyde group content of the DAS produced by PEF-assisted oxidation exhibited shrinkage and pits, and had a larger particle size when compared to the control increased by 11.6% when compared with the traditional oxidation method. PEF is an effective method to promote oxidation reaction of starch.

Physico-chemical, structural, and adsorption properties of amino-modified starch derivatives for the removal of (in)organic pollutants from aqueous solutions

In this study, an environmentally sustainable process of crystal violet, congo red, methylene blue, brilliant green, Pb²⁺, Cd²⁺, and Zn²⁺ ions adsorption from aqueous solutions onto amino-modified starch derivatives was investigated. The degree of substitution, elemental analysis, swelling capacity, solubility, and FTIR, XRD, and SEM techniques were used to characterize the adsorbents. The influence of pH, contact time, temperature, and initial concentration has been studied to optimize the adsorption conditions. The amino-modified starch was the most effective in removing crystal violet (CV) (65.31-80.46 %) and Pb²⁺ (67.44-80.33 %) within the optimal adsorption conditions (pH 5, 10 mg dm^-3, 25 °C, 180 min). The adsorption of CV could be described by both Langmuir and Freundlich adsorption isotherms, while the adsorption of Pb²⁺ ions was better described by the Langmuir isotherm. The pseudo-second order model can be used to describe the adsorption kinetics of CV and Pb²⁺ on all tested samples. The thermodynamic study indicated that the adsorption of CV was exothermic, while the Pb²⁺ adsorption was endothermic. The simultaneous removal of CV and Pb²⁺ from the binary mixture has shown their competitive behavior. Thus, the amino-modified starch is a promising eco-friendly adsorbent for the removal of dyes and heavy metals from polluted water.

Reinvention of starch for oral drug delivery system design

Starch is a polysaccharide with varying amylose-to-amylopectin ratios as a function of its biological sources. It is characterized by low shear stress resistance, poor aqueous/organic solubility and gastrointestinal digestibility which limit its ease of processing and functionality display as an oral drug delivery vehicle. Modulation of starch composition through genetic engineering primarily alters amylose-to-amylopectin ratio. Greater molecular properties changes require chemical and enzymatic modifications of starch. Acetylation reduces water solubility and enzymatic digestibility of starch. Carboxymethylation turns starch acid-insoluble and aggregative at low pHs. The summative effects are sustaining drug release in the upper gut. Acid-insoluble carboxymethylated starch can be aminated to provide an ionic character essential for hydrogel formation which further reduces its drug release. Ionic starch can coacervate with oppositely charged starch, non-starch polyelectrolyte or drug into insoluble, controlled-release complexes. Enzymatically debranched and resistant starch has a small molecular size which confers chain aggregation into a helical hydrogel network that traps the drug molecules, protecting them from biodegradation. The modified starch has been used to modulate the intestinal/colon-specific or controlled systemic delivery of oral small molecule drugs and macromolecular therapeutics. This review highlights synthesis aspects of starch and starch derivatives, and their outcomes and challenges of applications in oral drug delivery.

Sonochemical effect on the degree of substitution of octenyl-succinic anhydride into waxy rice starch nanoparticles and study of gastro-intestinal hydrolysis using INFOGEST in vitro digestion method

Octenyl succinylation of starch nanoparticles has been proven to be effective in a variety of food industry applications such as fat replacement, thickening agents, emulsion formation, and delivery of bioactive compounds. In this study, waxy rice starch was debranched with pullulanase to obtain short glucans, which were then modified with octenyl succinic anhydride (OSA) to obtain amphiphilic short glucans (ASG) using high (400 W) and low (200 W) ultrasonic power intensity at 30 and 60 cycles. Developed ASG were characterized by nanoparticle size (ca. < 50 nm), surface hydrophobicity and gastro-intestinal stability. Ultrasonic intervention progressively increased the degree of substitution (DS) of OSA into hydrolysed starch. A significant molecular exchange between starch and OSA was confirmed with shoulder peak at 1.07 ppm by ¹H NMR, and 1560 and 1727 cm^-1 peaks in FTIR spectral image, and broad band at 1260 cm^-1 by Raman spectroscopy. The XRD analysis confirmed the change in crystalline structure, and the emergence of new peaks at 2θ angles of around 5.81° which represent the development of B-type structure following pullulanasehydrolysis, and minor peaks at 13.92° and 19.83°, which imply the production of V_h type structures in ASG. Gastro-intestinal hydrolysis of starch after modification was analyzed in a sequential digestion process using INFOGEST method. The gastro-kinetic studies unveiled the reduction in the digestibility constant in the oral-gastric phase, with significantly enhanced value of kinetic constants in the intestinal phase, proving a sustained gastro-intestinal stability. The OSA-modified starches with greater DS havemore rigid and compact surface structure, which provides superior protection against biochemical conditions in the stomach fluid.

The microstructure and thermal properties of pulsed electric field pretreated oxidized starch

The structure and thermal properties of pulsed electric field (PEF) assisted sodium hypochlorite oxidized starch were investigated. The carboxyl content of the oxidized starch was increased by 25 % when compared with the traditional oxidation method. Dents and cracks were evident on the surface of the PEF-pretreated starch. Compared with native starch, the peak gelatinization temperature (T_p) of PEF-assisted oxidized starch (POS) was reduced by 10.3 °C, while that of the oxidized starch without PEF treatment (NOS) was only reduced by 7.4 °C. In addition, PEF treatment further reduces the viscosity and improve the thermal stability of the starch slurry. Therefore, PEF treatment combined with hypochlorite oxidation is an effective method to prepare oxidized starch. PEF showed great potential in expanding starch modification, to promote a wider application of oxidized starch in the paper, the textile and the food industry.

Highland Barley Starch: Structures, Properties, and Applications

Highland barley (HB) is a nutritious crop with excellent health benefits, and shows promise as an economically important crop with diverse applications. Starch is the main component of HB and has great application potential owing to its unique structural and functional properties. This review details the latest status of research on the isolation, chemical composition, structure, properties, and applications of highland barley starch (HBS). Suggestions regarding how to better comprehend and utilize starches are proposed. The amylopectin content of HBS ranged from 74% to 78%, and can reach 100% in some varieties. Milling and air classification of barley, followed by wet extraction, can yield high-purity HBS. The surface of HBS granules is smooth, and most are oval and disc-shaped. Normal, waxy, and high-amylose HBS have an A-type crystalline. Due to its superb freeze-thaw stability, outstanding stability, and high solubility, HBS is widely used in the food and non-food industries. The digestibility of starch in different HB whole grain products varies widely. Therefore, the suitable HB variety can be selected to achieve the desired glycemic index. Further physicochemical modifications can be applied to expand the variability in starch structures and properties. The findings provide a thorough reference for future research on the utilization of HBS.

Effect of chemical treatments on the functional, morphological and rheological properties of starch isolated from pigeon pea (Cajanus cajan)

Different chemical treatments (cross-linking, oxidation, and hydroxypropylation) were used to modify pigeon pea starch, and its effect on physiochemical, pasting and rheological properties were studied. Cross-linking and oxidation decreased while hydroxypropylation increased the swelling power of pigeon pea starch. All starch samples showed a decrease in their paste clarities. FTIR spectra of all starch samples displayed characteristic absorption bands of starch at wave numbers 1076, 1148, 1376, and 1632 cm-1. A significant reduction occurred in peak, cold paste, hot paste, and setback viscosity after chemical modification. Rheological determinations showed that starch pastes had viscoelastic behaviour. G' and G″ of all starch paste increased after chemical modification. Native and chemically treated starches revealed oval to elliptical-shaped granules and no change was observed after modification when examined in SEM. These results confirmed that the undesirable properties of native pigeon starch can be suitably altered via chemical treatments to make them suitable for several food applications.

3D-printing of oxidized starch-based hydrogels with superior hydration properties

High-hydration hydrogels based on carbohydrate polymers and green preparation methods have attracted intensive research focus recently. Driven by the attractive functions of starch, oxidized maize starch (OMS) was chosen and the related hydrogel (3D-OMS) was constructed by hot-extrusion 3D printing (HE-3DP). Meanwhile, the effect of different OMS concentrations (11 %-19 %) on its printability, structure and hydration properties were systematically investigated. The results showed that the formation of porous structure during HE-3DP environment contributed to rapid water absorption and well water holding capacity of 3D-OMS. Interestingly, as the OMS concentration increased from 11 % to 19 %, the 3D-OMS presented great hydration properties, with its maximum water absorption capacity and water holding capacity reaching 3013.43 % (11-OMS) and 93.53 % (19-OMS), respectively. Among them, 13 % was the best concentration for HE-3DP. Besides, 3D-OMS also exhibited good biodegradability and cytocompatibility. These results demonstrated potential for developing new starch-based biomedical hydrogel with great hydration properties through HE-3DP technology.

The Properties, Modification, and Application of Banana Starch

Banana is a tropical fruit crop that is consumed at large, not only because of the quantity produced but also because it serves the calorific needs of millions of people. Banana is a potential source of high starch content (more than 60%). The application of starch for various purposes is dependent upon its structural, physicochemical, and functional properties. A native starch does not possess all required properties for specific use in the food product. To improve its application, starch can be modified physically, chemically, and enzymatically. Each of these modification methods provides different characteristics to the modified starch. This review aims to examine the chemical composition, granule morphology, crystallinity, pasting, thermal properties, and digestibility of banana starch, and discusses the various modifications and potential applications of banana starch in the food industry.

Impact of microwave irradiation on chemically modified talipot starches: A characterization study on heterogeneous dual modifications

In this study, the effect of chemical modifications such as oxidation, esterification and crosslinking was investigated alone and in combination with microwave irradiation on a non-conventional starch with 76% starch yield acquired from the trunk of matured talipot palm. The single- and dual-modifications imparted significant changes in the morphological, crystalline, pasting and rheological properties and digestibility of talipot starch. Characteristic peaks were observed in single- and dual-oxidized, esterified and crosslinked starches indicating their respective functional groups. All modifications significantly decreased (p ≤ 0.05) the relative crystallinity (RC) of talipot starches except for crosslinking, and the least RC (11.33%) was observed in microwave irradiated esterified starch. Microwave irradiation prior to chemical modifications showed a significant impact in the swelling and solubility of talipot starches. The decreased setback viscosity and increased light transmittance in single- and dual-microwave irradiated talipot starches showed their lowered retrogradation tendency, suitable for frozen foods. The resistant starch (RS) content was majorly improved in all heterogeneously dual modified talipot starches by incorporating more functional groups owed to structural and crystalline destruction in starch granules upon microwave irradiation. The highest RS content (45.02%) was observed in microwave irradiated esterified uncooked talipot starch.

Rheological and Physicochemical Properties of Oleogel with Esterified Rice Flour and Its Suitability as a Fat Replacer

The objectives of this study were to produce oleogel using esterified rice flour with citric acid (ERCA), to evaluate physicochemical and rheological properties of oleogels, and to investigate their suitability as a fat replacer. Rice flour was esterified with citric acid (30%, w/w) to produce ERCA. Emulsions and oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. In the steady shear rheological analysis, it was found that the values of apparent viscosity (ηa, 100) and consistency index (K) of emulsions were significantly increased by increasing the concentrations of ERCA. Oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. All oleogels showed a hydrophobic carbonyl bond in the Fourier transform infrared (FT-IR) spectra. The peaks on new hydrogen bonds and amorphous regions, which did not appear in oleogel prepared with 0% ERCA, were observed at 3300–3400 cm−1 and 1018 cm−1, respectively, in oleogels prepared with ERCA. With the increase in ERCA concentrations in oleogels, oil loss values were significantly decreased. In a time-dependent test, it was found that all oleogels exhibited thixotropic properties. The frequency sweep test revealed that storage modulus (G′), loss modulus (G″), and complex viscosity (η*) values of oleogels were elevated with an increase in the concentration of ERCA. Oleogels prepared with 15% ERCA exhibited the lowest peroxide, p-Anisidine, and Total Oxidation(TOTOX) values. The addition of oleogels to cookies did not considerably affect appearance. However, it increased the content of unsaturated fatty acid. These results indicate that oleogels prepared with ERCA can be used as a fat replacer in food industry.

Rheological behaviors, structural properties and freeze-thaw stability of normal and waxy genotypes of barley starch: a comparative study with mung bean, potato, and corn starches

The rheological behaviors, structural properties and freeze-thaw stability of starch isolated from Tetonia barley (Normal genotype, Reg. No. CV-334, PI 646199) and Transit barley (Waxy genotype, Reg. No. CV-348, PI 660128) were investigated, along with other common starch sources for comparison. Transit barley starch showed the highest loss tangents (tan δ) during a frequency sweep test, which suggested a predominance of elastic properties over viscous properties. However, the tan δ of Tetonia barley starch was similar to that of potato starch, which indicated more solidity in comparison to Transit barley starch. Transit barley starch had the highest gelatinization temperature and the lowest gelatinization enthalpy (P < 0.05). Moreover, Tetonia and Transit barley starches displayed weak diffraction peak intensities by X-ray diffraction analysis. Additionally, Transit barley starch showed the lowest % syneresis even when freeze-thawed up to five cycles (P < 0.05). However, Tetonia barley starch had the worst freeze-thaw stability (P < 0.05), which was verified via scanning electron microscopy analysis of freeze-thawed starch gels. The results of present study indicate that barley starch can be practically applied as a functional ingredient in some specialty starchy foods.

Effect of dual modification sequence on physicochemical, pasting, rheological and digestibility properties of cassava starch modified by acetic acid and ultrasound

Dual modification of cassava starch was carried out using ultrasonication and acetylation by acetic acid by altering the sequence. The results revealed that the type of modification and sequence of modification for dual modified starches significantly affected the properties of starch. The swelling decreased for all the modified starches whereas solubility decreased for ultrasonicated starches but increased for acetylated starch and dual modified starch where acetylation was done after ultrasonication. The paste viscosities of all the modified starches were found to be significantly lower compared to native starch and the lowest viscosities were observed for dual modified starch where ultrasonication was done after acetylation. The resistant starch and slowly digestible starch content of the modified starches were significantly higher than in native starch, and the type of modification and sequence of modification for dual modified starches seemed to affect the digestibility of starches.