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To investigate the potential of inhibiting starch retrogradation by modifying the functional groups of starch, transglucosidase (TG) was used to facilitate active hydroxyl groups to be exposed through increasing branching degree. Subsequently, hexose oxidase (HOX) advantageously promoted the oxidation of starch chains and increased spatial repulsion of starch backbone. The Fukui Function revealed that the oxygen atoms at the C3 and C4 positions on glucose units had a higher oxidation tendency. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis confirmed that the reactive hydroxyl groups underwent an oxidation process with increasing HOX treatment time. From the crystal structure parameters, the c-axis of native corn starch modified by TG for 16 h and HOX for 48 h (or TGHOX-48) was shortened from 16.92 to 16.32 Å and in the long-term retrogradation, TGHOX-48 exhibited the lowest starch retrogradation rate (0.22).

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The utilization of cold plasma can be used as an alternative method to modify the properties of starch. This research aimed to examine the use of cold plasma technology to alter the structure of corn starch and investigate how its functionality could be improved using a food model (milk dessert). Modified corn starch by plasma technology under different gas contents (dielectric-barrier discharge (DBD)) (95 % argon+5 % hydrogen (DBD1) and 90 % argon+10 % oxygen (DBD2)) was compared to the control sample of corn starch. The physicochemical characteristics of modified corn starch, DSC, XRD, SEM and FTIR tests were evaluated. The findings demonstrated that corn starch had significantly higher solubility, transparency, ash, oil absorption capacity (OAC), and resistant starch (RS) when exposed to cold plasma under the test circumstances compared to the control sample. SEM analysis confirmed that plasma affected the surface of starch granules, making the surface changes more pronounced when oxygen was added to the treatment. It was concluded that the sample should be treated with plasma containing 90 % argon and 10 % oxygen (as the best sample). The best sample (modified corn starch) was used to prepare a milk dessert as a food model, and considerable differences were found between the modified starch treated sample and control samples in terms of moisture, brix, syneresis, and organoleptic properties (p < 0.05).

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Kuey teow is one of the delicacies of Guangdong, China and is a gluten-free noodle dish made from rice. It has a short storage period and extending the shelf life by quick freezing induces quality deterioration due to temperature fluctuations. To improve its freeze-thaw frozen storage quality, this paper examined the effects of hydroxypropyl corn starch (HCS), guar gum (GG), and compound phosphates (CP) on the quality of quick-frozen kuey teow during freeze-thaw cycles. The mechanism was investigated by identifying changes in the moisture status, aging degree of the starch, and textural and cooking characteristics. The results showed that all three additions improved the toughness, chewiness and steaming characteristics of the kuey teow, with CP significantly enhancing chewiness. XRD and FTIR results revealed that GG more significantly inhibited the decrease of starch crystallinity, while HCS inhibited starch aging. GG, HCS and CP all improved the hydration characteristics and water holding capacity of rice starch. GG enhances the ability of starch to bind more tightly with water, resulting in a more uniform water distribution and a more continuous and tight structure of the kuey teow. This study will provide a theoretical basis for compounding and optimizing the quick-freezing of kuey teow.

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Endowing biodegradable plastics with easy recyclability can reduce competition with food resources and further enhance their environmental friendliness. In this work, 4-carboxyphenylboronic acid was grafted onto the side chains of hydroxyethyl cellulose and compounded with inexpensive cornstarch. Upon the introduction of tannic acid, stable and reversible borate ester bond rapidly formed, yielding composite biodegradable plastic films with outstanding mechanical properties and facile recyclability. The formation of a dynamic cross-linked network mitigates the aggregation of gelatinized starch molecules, enhancing the flexibility and durability of the crosslinked film. Testing revealed that while maintaining high tensile strength, the elongation at break of the crosslinked film increased by 952.86 %. The static water contact angle was improved from 32.74° to 78.82°, with a change of <5° within 1 min, demonstrating enhanced water resistance. Excellent antioxidant and thermal stability were also characterized, the crosslinked film can be easily dissolved by heating in water at pH = 6.5 and reshaped in water at pH = 7.2. After five times of regeneration, the tensile strength loss was as low as 5.68 %. This eco-friendly and efficient recycling process is promising during green chemistry.

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Phytic acid (PA) and malic acid (MA), as environmentally friendly, plant-based water-soluble acids, were applied to normal corn starch during dry heating at mildly acidic pH to improve its gelatinization and retrogradation behaviors. A significant increase in peak viscosity (5011-6338 mPa·s) was observed in starch treated with MA compared to native corn starch (1162 mPa·s). The treatment with PA and MA further increased the peak viscosity (8140-8621 mPa·s). The interactions of PA and MA with starch were analyzed using ICP-OES, FTIR, and 13C CP/MAS NMR. Swelling power and solubility increased in MA and PA + MA starches. After storage at 4 °C for 14 d, MA and PA + MA starches produced transparent and fluid gels without forming B-type crystals, which indicated inhibition of starch retrogradation by PA and MA treatments. In conclusion, dry heating with PA and MA produced starch with remarkably superior paste viscosity, swelling, and inhibition of retrogradation.

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This study investigated the effects of ultrasonic and three chemical individual and dual modification treatments on corn starch's physicochemical, thermal, and rheological properties. Ultrasonication and the three chemical treatments disrupted the starch granules with a decrease in particle size and a significant increase in the ζ-potential. The hydrophilicity of ultrasonic-oxidized dual-modified starch (U-O-CS) was the highest, at 0.854 g/g. The lipophilicity of ultrasonic-esterified dual-modified starch (U-E-CS) was the highest, at 1.485 g/g. The gelatinization temperature of ultrasonic, oxidation, and cross-linking modified starches increased significantly, with cross-linking starches being the largest. Oxidative treatment significantly decreased the starch's G' and G" and weakened the textural properties. The rheological properties of U-O-CS were further weakened. The G' of the starch decreased after the esterification treatment, while the G" increased, and the textural properties were cut. The maximum rheological and textural properties were obtained for crosslinked modification, with a hardness value of 284.70 g.

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In this study, carbon nanodot (CD)-corn starch (CS) nanocomposite films are fabricated for active food packaging applications. First, ginkgo biloba leaves (GBL) were used as a biomass-derived carbon precursor, and a facile hydrothermal method was employed to synthesise environmentally sustainable CDs. The GBL-derived carbon nanodots (gCDs) were then characterised and incorporated into a CS matrix via an extrusion process to fabricate the CS/gCD nanocomposite film. The effects of various gCD concentrations on the physicochemical and functional properties of CS/gCD composite films were systematically investigated. The gCD exhibited non-cytotoxic effect against human colorectal adenocarcinoma cell line (Caco-2) cells when exposed up to 1000 µg/mL. The incorporation of gCDs into the CS film improved its mechanical properties, with the toughness of the CS/gCD2% nanocomposite film exhibiting 198 % superiority compared to the CS film. In addition, the oxygen barrier and UV-blocking properties were significantly improved. Furthermore, the CS/gCD nanocomposite film significantly extended the shelf life of ω-3 oils owing to the superior antioxidant activity of the gCDs, exhibiting only 9 meq/kg during the 15-day storage period. Our results suggest that the developed CS/gCD active composite film is a promising candidate for environmentally sustainable solutions to enhance food shelf life and reduce food waste.

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High hydrostatic pressure (HHP) was used to synthesize corn starch (CS) and ferulic acid (FA) complex (CS-FA). Its effects on the structure of the complex at multiple scales and its digestibility were examined. The results demonstrated that HHP significantly influenced the digestibility of the CS-FA complex, decreasing the content of rapidly digestible starch (RDS) while increasing slowly digestible starch (SDS) and resistant starch (RS). Notably, the combined SDS and RS content in the HHP-treated CS-FA complex with 2.0 % FA addition (38.13 %) was significantly higher (p < 0.05) than those in the CS-FA complex without HHP treatment (29.21 %) and pure CS (21.72 %). The results indicated that HHP treatment reduced the enthalpy change (ΔH), number of short-range order structures, and relative crystallinity (RC) while increasing the average particle size of these CS-FA complexes. This treatment also increased the proportion of amorphous starch regions and the degree of agglomeration between the starch and FA. HHP treatment-induced CS-FA complexes exhibited a denser fractal structure and higher short-range order, affecting the interaction sites between the starch and digestive enzymes. These findings suggest the potential application of HHP treatment and FA in modulating the postprandial glycemic response to starchy food.

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The escalating environmental crisis posed by single-use plastics underscores the urgent need for sustainable alternatives. This study provides an approach to introduce biodegradable polymer blends by blending synthetic polyvinyl alcohol (PVA) with natural polymers-corn starch (CS) and hydroxypropyl methylcellulose (HPMC)-to address this challenge. Through a comprehensive analysis, including of the structure, mechanical strength, water solubility, biodegradability, and thermal properties, we investigated the enhanced performance of PVA-CS and PVA-HPMC blends over conventional polymers. Scanning electron microscopy (SEM) findings of pure PVA and its blends were studied, and we found a complete homogeneity between the PVA and both types of natural polymers in the case of a high concentration of PVA, whereas at lower concentration of PVA, some granules of CS and HMPC appear in the SEM. Blending corn starch (CS) with PVA significantly boosts its biodegradability in soil environments, since adding starch of 50 w/w duplicates the rate of PVA biodegradation. Incorporating hydroxypropyl methylcellulose (HPMC) with PVA not only improves water solubility but also enhances biodegradation rates, as the addition of HPMC increases the biodegradation of pure PVA from 10 to 100% and raises the water solubility from 80 to 100%, highlighting the significant acceleration of the biodegradation process and water solubility caused by HPMC addition, making these blends suitable for a wide range of applications, from packaging and agricultural films to biomedical engineering. The thermal properties of pure PVA and its blends with natural were studied using diffraction scanning calorimetry (DSC). It is found that the glass transition temperature (Tg) increases after adding natural polymers to PVA, referring to an improvement in the molecular weight and intermolecular interactions between blend molecules. Moreover, the amorphous structure of natural polymers makes the melting temperature ™ lessen after adding natural polymer, so the blends require lower temperature to remelt and be recycled again. For the mechanical properties, both types of natural polymer decrease the tensile strength and elongation at break, which overall weakens the mechanical properties of PVA. Our findings offer a promising pathway for the development of environmentally friendly polymers that do not compromise on performance, marking a significant step forward in polymer science's contribution to sustainability. This work presents detailed experimental and theoretical insights into novel polymerization methods and the utilization of biological strategies for advanced material design.

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Although starch has been intensively studied as a raw material for 3D printing, the relationship between several important process parameters in the preparation of starch gels and the printing results is unclear. In this study, the relationship between different processing conditions and the gel printing performance of corn starch was evaluated by printing tests, rheological tests and low-field nuclear magnetic resonance (LF-NMR) tests, and a back-propagation artificial neural network (BP-ANN) model for predicting gel printing performance was developed. The results revealed that starch gels exhibited favorable printing performance when the gelatinization temperature ranged from 75 °C to 85 °C, and the starch content was maintained between 15 % and 20 %. The R2adj of the BP-ANN models were all reached 0.894, which indicated good predictive ability. The results of the study not only provide theoretical support for the application of corn starch gels in 3D food printing, but also present a novel approach for predicting the printing performance of related materials. This method contributes to the optimization of printing parameters, thereby enhancing printing efficiency and quality.

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On the basis of revealing the interaction mechanism between corn starch (CS) and water-extractable arabinoxylan (WEAX) with high/low molecular weight (H-WEAX, L-WEAX), the degree of gelatinization (DG) on structural behaviors and in vitro digestibility of CS-WEAX complexes (CS/H, CS/L) was evaluated. With the increased DG from 50 % to 95 %, the water adsorption capacity of CS/L was increased 64 %, 58 %, 47 %, which were higher than that of CS/H (39 %, 54 %, 33 %). The gelatinization of starch was inhibited by WEAX, resulting in the enhancement of crystallinity, short-range ordered structure and molecular size of CS-WEAX complexes. Stronger interaction was detected in CS/L than with CS/H as proved by the increased hydrogen bonds and electrostatic force. Complexes exhibited higher resistant starch content (RS) at diverse DG, especially for CS/L. Notability, RS content of samples with 50 % DG were increased from 27.72 % to 32.89 % (CS/H), 36.96 % (CS/L). Except for the reduction of gelatinization degree by adding WEAX, the other possible mechanisms of retarding digestibility were explained as the small steric hindrance of L-WEAX promoted encapsulation of starch granules, limiting enzyme accessibility. Additionally, the fragmentation of CS granules with high DG promoted the movement of H-WEAX, reducing the difference in digestibility compared to CS/L.

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The effect of ultrasound/CaCl2 co-treatment on aggregation structure, thermal stability, rheological, and film properties of high amylose corn starch (HACS) was investigated. The scanning electron microscopy (SEM) images revealed the number of starch fragments and malformed starch granules increased after co-treatment. The differential scanning calorimetry (DSC) results showed the co-treated HACS got a lower gelatinization temperature (92.65 ± 0.495 °C) and enthalpy values (ΔH, 4.14 ± 0.192 J/g). The optical microscope images indicated that lesser Maltase crosses were observed in co-treated HACS. The results of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated ultrasound influenced the compactness of amorphous zone and CaCl2 damaged the crystalline region of HACS granules. Additionally, the rheology properties of HACS dispersion demonstrated the apparent viscosity of co-treated dispersion increased as the ultrasound time prolonged. The mechanical strength and structural compactness of HACS films were improved after ultrasound treatment. The mechanism of ultrasound/CaCl2 co-treatment improved the gelatinization and film-forming ability of HACS was that (i) ultrasound wave loosened the HACS granules shell, promoted the treatment of CaCl2 on HACS granules, and (ii) ultrasound wave improved the uniform distribution of HACS dispersion, increased the interaction between CaCl2 and starch chains during the process of film-forming.

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This study aimed to investigate the impact of alginate (AG) on the retrogradation properties of corn starch (CS) in conjunction with three phenolic compounds, including naringin (NA), rutin (RT), and soy isoflavones (SI). The findings indicated that AG, NA, RT, and SI collectively resulted in a significant reduction in the hardness, retrogradation enthalpy, and relaxation time of CS gel. This effect was more pronounced when compared to NA, RT, and SI individually. The findings suggested that the elemental system comprising AG, phenolic compounds, and CS yielded enhanced water retention capacity and thermal stability. Moreover, a noticeable decrease in the short-range ordered structure and crystallinity was observed, indicating that AG and phenolic compounds effectively inhibited the retrogradation of CS; notably, the synergistic interaction between AG and SI resulted in the most favorable outcome. The results of this study provide new ideas for the design, development, and quality improvement of starch-based food.

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An edible colorimetric label has been developed to determine the freshness level of mushrooms, i.e. white oyster mushrooms (Pleurotus ostreatus). The edible indicator label has been fabricated based on purple sweet potato (Ipomoea batatas L.) anthocyanins (PSPA) immobilized onto an edible film made of chitosan and cornstarch with added PVA. The freshness parameters of the mushrooms were pH, weight loss, texture, and sensory evaluation. The results showed that the colorimetric label was dark purple when the mushroom was fresh, and turn to light purple when the mushroom was still fresh, and finally green when the mushroom was no longer fresh. The color value (mean Red) of the label was measured using the ImageJ program, where its color value (mean Red) increased with decreasing freshness level of the mushrooms. The edible label can distinguish fresh mushrooms from spoilage, making it suitable to be used in a packaged mushroom as a freshness indicator.

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This study aimed to explore the effects of various lipids on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles (EBNs) with and without 20% high-amylose corn starch (HACS). Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction revealed that lauric acid bound more strongly to starch than did stearic acid and oleic acid, and the binding capacity of fatty acids with starch was stronger than that of glycerides. The presence of HACS during extrusion facilitated increased formation of starch-lipid complexes. Evaluations of cooking quality and digestion characteristics showed that EBNs containing 20% HACS and 0.5% glycerol monooleate demonstrated the lowest cooking loss (7.28%), and that with 20% HACS and 0.5% oleic acid displayed the lowest predicted glycemic index (pGI) (63.54) and highest resistant starch (RS) content (51.64%). However, excessive starch-lipid complexes were detrimental to EBNs cooking quality and the resistance of starch to digestive enzymes because of the damage to the continuity of the starch gel network. This study establishes a fundamental basis for the development of EBNs with superior cooking quality and a relatively lower GI.

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This study prepared resistant starch (RS) from waxy corn starch and normal corn starch and analyzed the effects of its molecular and microstructural characteristics on RS content. The RS content of waxy corn resistant starch (RS-WCS) was highest at 57.8%, whereas that of normal corn resistant starch (RS-NCS) was 41.46%. The short-chain amylose contents of RS-WCS and RS-NCS were 47.08% and 37.24%, respectively, proportional to their RS content. Additionally, RS content positively correlated with crystallinity, short-range order degree, and degree of polymerization (DP), exceeding 25. Electron microscopic images, before and after enzymolysis, revealed that RS-WCS was hydrolyzed from the surface to the center by pancreatic α-amylase, while RS-NCS underwent simultaneous hydrolysis at the surface and center. These results indicate that the higher RS content in RS-WCS, compared to RS-NCS, is attributable to the synergistic effects of molecular structure and microstructure.

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Currently, petroleum-derived plastics are widely used despite the disadvantage of their long degradation time. Natural polymers, however, can be used as alternatives to overcome this obstacle, particularly cornstarch. The tensile properties of cornstarch films can be improved by adding plant-derived nanofibers. Sisal (Agave sisalana), a very common low-cost species in Brazil, can be used to obtain plant nanofibers. The goal of this study was to obtain sisal nanofibers using low concentrations of sulfuric acid to produce thermoplastic starch nanocomposite films. The films were produced by a casting technique using commercial corn starch, glycerol, and sisal nanofibers, accomplished by acid hydrolysis. The effects of glycerol and sisal nanofiber content on the tensile mechanical properties of the nanocomposites were investigated. Transmission electron microscopy findings demonstrated that the lowest concentration of sulfuric acid produced fibers with nanometric dimensions related to the concentrations used. X-ray diffraction revealed that the untreated fibers and fibers subjected to acid hydrolysis exhibited a crystallinity index of 61.06 and 84.44%, respectively. When the glycerol and nanofiber contents were 28 and 1%, respectively, the tensile stress and elongation were 8.02 MPa and 3.4%. In general, nanocomposites reinforced with sisal nanofibers showed lower tensile stress and higher elongation than matrices without nanofibers did. These results were attributed to the inefficient dispersion of the nanofibers in the polymer matrix. Our findings demonstrate the potential of corn starch nanocomposite films in the packaging industry.

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This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of corn starch and glycerol. Changes in the microstructure were analyzed to understand how they relate to the physical and chemical properties of these films. Specifically, we found that increasing the gelatinization time decreased the film thickness, solubility, water vapor permeability, and maximum degradation temperature and increased the water content. A gradual increase in the water contact angle of the corn starch-glycerol films was observed with increasing gelatinization time. This trend is likely due to the disruptive effect of gelatinization on the crystalline and amorphous structures inherent in corn starch, resulting in reduced film crystallinity, degree of order (DO) and degree of double helix (DD).

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In this study, corn starch was used as the raw material, and modified starch was prepared using a method combining plasma-activated water and ultrasound treatment (PUL). This method was compared with treatments using plasma-activated water (PAW) and ultrasound (UL) alone. The structure, thermal, physicochemical, pasting, and functional properties of the native and treated starches were evaluated. The results indicated that PAW and UL treatments did not alter the shape of the starch granules but caused some surface damage. The PUL treatment increased the starch gelatinization temperature and enthalpy (from 11.22 J/g to 13.13 J/g), as well as its relative crystallinity (increased by 0.51 %), gel hardness (increased by 16.19 %) compared to untreated starch, without inducing a crystalline transition. The PUL treatment resulted in a whitening of the samples. The dual treatment enhanced the thermal stability of the starch paste, which can be attributed to the synergistic effect between PAW and ultrasound (PAW can modify the starch structure at a molecular level, while ultrasound can further disrupt the granule weak crystalline structures, leading to improved thermal properties). Furthermore, FTIR results suggested significant changes in the functional groups related to the water-binding capacity of starch, and the order of the double-helical structure was disrupted. The findings of this study suggest that PUL treatment is a promising new green modification technique for improving the starch structure and enhancing starch properties. However, further research is needed to tailor the approach based on the specific properties of the raw material.

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Proteins impact starch digestion, but the specific mechanism under heat-moisture treatment remains unclear. This study examined how proteins from various sources-white kidney bean, soybean, casein, whey-altered corn starch's structure, physicochemical properties, and digestibility during heat-moisture treatment (HMT). HMT and protein addition could significantly reduce starch's digestibility. The kidney bean protein-starch complex under HMT had the highest resistant starch at 19.74 %. Most proteins effectively inhibit α-amylase, with kidney bean being the most significantly (IC50 = 1.712 ± 0.085 mg/mL). HMT makes starch obtain a more rigid structure, limits its swelling ability, and reduces paste viscosity and amylose leaching. At the same time, proteins also improve starch's short-range order, acting as a physical barrier to digestion. Rheological and low-field NMR analyses revealed that protein enhanced the complexes' shear stability and water-binding capacity. These findings enrich the understanding of how proteins from different sources affect starch digestion under HMT, aiding the creation of nutritious, hypoglycemic foods.

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