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This study evaluated the influence of the amylose and amylopectin on the physicochemical properties and printing performance of corn starch gels. Amylose in starch-based gels enhances their storage modulus and the support performance of printed products by promoting the formation of cross-linked gel structures and crystalline structures. However, the higher amylose content in starch gels makes extrusion difficult, resulting in intermittent extrusion in 3D printing. Despite the increased shear-thinning ability of high-amylose starch, its low water retention capacity leads to water loss and rough printed morphology. Additionally, starch with 72 % amylose content exhibits insufficient adhesive properties for effective layer bonding, negatively impacting structural integrity. While gels with 72 % and 56 % amylose content demonstrate higher viscosity and enhanced mechanical properties, their poor adhesion limits the quality of printed layers. Conversely, waxy starch gel demonstrates continuous extrusion and adhesion but lacks adequate support. The 27 % corn starch gel achieves the highest 3D printing accuracy at 88.12 %, suggesting an optimal amylose-amylopectin ratio for desired ink material performance. These findings enhance our understanding of the relationship between amylose content in starch and 3D printing performance, providing a theoretical basis for the development of starch-based printing products., Competing Interests: Declaration of competing interest No, (Copyright © 2024 Elsevier B.V. All rights reserved.)

The effect of corn starch-fatty (CS-FA) complexes from varying carbon chain length and degree of unsaturation on the rheological and 3D printing properties of corn CS-FA complex gels. The CS-FA complexes with longer carbon chain lengths and lower saturation enhanced the ability of gels to bind water, promoting the formation of intermolecular hydrogen bonds. The CS-FA complexes inhibit retrogradation and increase the amount of bound water, thereby reducing the structural integrity and transforming the original skeleton structure into a flake-like structure. These changes in gel structure led to lower flow stress and storage modulus for CS-FA gels containing FAs with shorter carbon chain lengths and lower saturation, resulting in reduced "extrusion swelling" of the material and facilitating its extrusion. The decreased "extrusion swelling" of gel improved print line width and printing performance. The CS-FA complex gel-printed product with a 12-carbon chain FA has the greatest printing accuracy, thanks to its moderate G', flow stress, and viscosity. This study provides important information for the CS-FA complexes for the preparation of starch-based 3D printing materials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

SBEIIb ( Sobic .004G163700), SSSIIa ( Sobic .010G093400), and GBSSI ( Sobic .010G022600) genes that regulate starch synthesis in sorghum endosperm were transferred into Escherichia coli by transgenic technology. SBEIIb, SSSIIa, and GBSSI enzymes were separated and purified through a Ni column and analyzed by electrophoresis with molecular weights and activities of 91.57 84.57, and 66.89 kDa and 551 and 700 and 587 U/μL, respectively. Furthermore, they were applied to starch modification, yielding interesting findings: the A chain content increased from 25.79 to 89.55% for SBEIIb-treated waxy starch, while SSSIIa extended the A chain to form DPs of the B chain, with A chain content decreasing from 89.55 to 37.01%, whereas GBSSI was explicitly involved in the synthesis of B1 chain, with its content increasing from 9.59 to 48.45%. Modified starch was obtained, which could be accurately applied in various industries. For instance, we prepared a sample (containing 89.6% A chain content) with excellent antiaging and antidigestion properties through SBEIIb modification. Moreover, higher RS3 (34.25%) and SDS contents (15.75%) of starch were obtained through the joint modification of SBEIIb and SSSIIa. These findings provide valuable insights for developing sorghum starch synthesis-related enzymes and offer opportunities for improving starch properties through enzymatic approaches.

The study examined the impact of phase morphological transformations within the corn starch/gelatin system, induced by varying gelatin content, on its rheological properties and 3D printing performance. Gelatin addition inhibited the gelatinization and retrogradation of starch, which leaded to the transformation of continuous phase structure. The transition process from starch continuous phase to gelatin continuous phase promoted a thinner wall structure of the gel and loosed its dense network, resulting in reduced flow stress (τ f ) and storage modulus (G'). These changes improved the extrusion and "extrusion swelling" of gel ink materials, which made the print size of printed product closer to the set model. The formation of a gelatin continuous phase in the gel was helpful in increasing τ f and G', resulting in enhanced support capacity of the printed product. This study presented meaningful information for the application of 3D printing to starch-gelatin complex foods., Competing Interests: Declaration of competing interest None., (Copyright © 2023. Published by Elsevier B.V.)

To address the limitation of strong hydrophilicity of edible films, starch/gelatin (S/G) films incorporated with natural waxes (beeswax (BW), candelilla wax (CL), and carnauba wax (CB)) were fabricated by extrusion blowing. Rheological analysis demonstrated that the incorporation of natural waxes reduced storage modulus and complex viscosity of S/G blends. BW and CL weakened molecular interactions among film components, whereas CB did not. CB exhibited the strongest crystalline behavior after film formation. The degree of starch gelatinization and water vapor barrier property of films depended on wax type. The presence of waxes increased the water resistance and surface hydrophobicity of the films. However, CL and BW addition decreased the tensile strength of films. The highest water contact angle (102.6°), strongest thermal stability, and lowest water vapor permeability were found in S/G-BW film, which could be the optimal choice to produce highly hydrophobic edible films., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, starch/PBAT antimicrobial film, based on the synergistic effects of two commercial antimicrobial peptides, was fabricated by blown extrusion. The blends with nisin exhibited higher storage modulus and complex viscosity than those with ε-polylysine hydrochloride (ε-PL) alone. ATR-FTIR spectra revealed that new intermolecular hydrogen bonds were formed among starch, nisin, and ε-PL. XRD results indicated that antimicrobial peptides facilitated the destruction of the original crystalline structure of starch. Combination of ε-PL and nisin enhanced tensile strength, flexibility, moisture permeability, and oxygen barrier property of the films with more homogeneous morphology. SP-PN1/2 film (1% ε-PL + 2% nisin) exhibited over 90% inhibition rates against Staphylococcus aureus and Escherichia coli, and prolonged the shelf life of fresh peaches. The antimicrobial film with nisin and ε-PL showed high safety, cost-effectiveness, consumer acceptability, and thus it had a good application prospect in the food packaging field., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Edible antimicrobial films made from starch/gelatin (S/G) incorporated with different ε-polylysine hydrochloride (ε-PL) contents were developed by low-temperature extrusion blowing process. ε-PL addition reduced the complex viscosity and storage modulus of blends, while promoted the formation of hydrogen bonding among film components. The control film had an A-type crystalline structure, while increasing the ε-PL content promoted its transformation to B-shaped structure. Without ε-PL and under the processing temperature used, the starch granules were not sufficiently gelatinized. However, ε-PL addition significantly enhanced the gelatinization degree. Increasing ε-PL content in S/G films increased film flexibility, water contact angle value, swelling degree, antimicrobial effect, and storage period of fresh bread, but decreased water vapor permeability and tensile strength. S/G film with 4 wt% ε-PL had the highest water contact angle (94°) and elongation at break (149%). This research demonstrates the plasticizing effects of ε-PL and potential of S/G films containing ε-PL for food preservation/packaging., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The effects of various physical state lipids (rapeseed oil (RO), shortening (ST), beeswax (BW)), on the physicochemical properties of starch (S) (hydroxypropyl distarch phosphate (HP), oxidized hydroxypropyl starch (OS))/gelatin (G) blown films were studied. S/G-lipid blends showed decreased storage modulus and complex viscosity. The formation of hydrogen bonds was inhibited by the ST and BW, but facilitated by the RO. Compared with BW and ST, RO was more effective to promote the melted and fractured of starch. Lipids addition promoted the compatibility of starch and gelatin. The presence of the lipids significantly improved the surface hydrophobicity, mechanical, water vapor barrier and water resistance properties of S/G films. S/G-RO films exhibited the strongest surface hydrophobicity and tensile strength, while HP/G-BW film showed the strongest water resistance and water vapor barrier properties. These results revealed that the appropriate lipids could be used to produce S/G-lipid films with desirable physicochemical properties., (Copyright © 2021. Published by Elsevier B.V.)

BACKGROUND: Poor mechanical and water barrier properties of starch‐based films severely restrict their applications as packaging materials. In this study, glycerol was combined with various small molecular esters (SMEs) with different molecular structures to plasticize high‐content starch/poly(butylene adipate‐co‐terephthalate) (80/20, w/w) films (SPFs) prepared by extrusion blowing. The effects of co‐plasticization on the physicochemical properties and film‐forming mechanism of SPFs were investigated. RESULTS: The addition of glycerides to SPFs reduced intermolecular interaction, increased molecular chain mobility, and decreased glass transition, melting temperatures, and crystallinity. Mechanical and water barrier properties of SPFs were improved significantly with the co‐plasticization of glycerol and SMEs. The incorporation of triacetate glyceride increased tensile strength of SPFs by 54% and the water contact angle by up to 95°. The SPF with diacetate glyceride exhibited the minimum water vapor permeability, which decreased by 39%. CONCLUSION: The levels of hydrophilic/hydrophobic groups in SMEs and their molecular weights were essential for the plasticizing effects. Glycerides tended to infiltrate into starch for effective plasticization compared with citrates. The combination of glycerol and glycerides had better plasticizing effects on starch. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Although the changes in molecular structure during starch gelatinization has been intensively investigated, how a relationship between starch rheological properties, printability, and starch molecular structure changes during starch gelatinization remains unclear. This research is focused on the molecular structure changes of corn starch (CS) gels caused by different treatment temperatures and their effects on CS gel rheological and 3D printing properties. With increasing treatment temperature, the leached amylose content and short linear chains (DP 6–12) of CS increase, whereas the contents of long linear chains (DP > 12) decrease, which influences the rheological and 3D printing properties of starch. Due to the presence of the original granules and crystalline structure, the CS-65 starch gel presented a poor storage modulus (G′), indicating poor 3D printing performance. The leaching of amylose induced the formation of new crystal and cross-linked network structures, which is beneficial for increasing its G′. However, the increase in short amylopectin linear chains (DP 6–12) reduced the degree of short-range order and hydrogen bonding interactions, which was detrimental to its G′ and yield stress (τf). CS-80 starch gel exhibited the largest G′ and shear recovery rate, showing the highest self-supporting properties and printing precision. Extremely high temperatures contributed to the densification of the starch gel structure, which led to an increase in τf and difficult extrusion. Overall, molecular structural changes caused by starch gelatinization are critical to its ideal rheological properties for 3D printing. [Display omitted] • Starch with different treatment temperature were processed by extrusion 3D printing. • Higher temperature increases leached amylose and short chains (DP 6–12) contents. • The chains with DP between 6 and 12 were detrimental to G′ and τf. • The leached amylose was conducive to the mechanical strength. • Extremely high temperatures leaded to the densification of the starch gel structure. [ABSTRACT FROM AUTHOR]

The effects of various Bloom values (120, 160, 200, 230, and 250) of gelatins on the properties of starch/gelatin–beeswax (S/G-BW) films fabricated by extrusion blowing were investigated. The S/230G-BW blend exhibited the highest storage modulus and complex viscosity determined by rheological analysis. The results of dynamic mechanical analysis and scanning electron microscopy images demonstrated that starch granules could be more effectively melted and fractured in the composite films with higher Bloom values. Attenuated total reflectance–Fourier transform infrared and X-ray diffraction spectra revealed that gelatin Bloom values strongly affected the migration and crystalline properties of beeswax in the film matrix, while the S/230G-BW film had more triple helical structures, as shown by the results of circular dichroism analysis. In addition, lower water solubility and higher thermal stability of the produced films was obtained from the gelatins with higher Bloom values. The highest water contact angle (87°) of the outer film surface and lowest water vapor permeability (0.88 × 10−10 g m−1·s−1·Pa−1) were obtained for the S/200G-BW sample. The S/230G-BW film had the maximum values of tensile strength, elongation at break, and Young's modulus that exceeded those of the S/120G-BW film by 90.9%, 96.8%, and 102.4%, respectively. Finally, the extremely high Bloom values enhanced the interfacial interactions between the starch and gelatin components in the films, which negatively affected their performance. Hence, the gelatins with an appropriate Bloom values could be used to produce S/G-BW films with desirable physicochemical properties. Image 1 • Starch/gelatin-beeswax films were successfully prepared by extrusion blowing. • The Bloom value of gelatin significantly affected the performance of the S/G-BW film. • The higher Bloom values facilitated the plasticization of starch. • The Bloom value of gelatin affected the migration and crystallization of beeswax. [ABSTRACT FROM AUTHOR]

This study investigated the changes in the structure and properties of starch derived from waxy, stick, and H37 sorghum varieties at various stages of development. The results indicated that as sorghum plants matured, the shape of starch granules became distorted, their size gradually increased from 5 µm to 20 µm, and distinct porous and inner growth rings developed. Furthermore, there were irregular fluctuations in the levels of amylose and CLD. Notably, it was observed that the amylose content (>20%) played a limiting role in the crystallinity of H37 starch, as confirmed by XRD, 13C CP/MAS NMR, and SAXS analyses. Interestingly, the influence of CLD on factors such as lamellar thickness (6.4–7.1 nm), degree of crystalline order, double-helix structure, and the ratio of crystalline to amorphous starch granules (26–31%) harvested at different developmental stages in various sorghum varieties was more pronounced than the impact of amylose content. The study also conducted an in-depth correlation analysis between the structural and property aspects, including thermodynamics, viscoelasticity, and hydrolysis rate, which provides valuable insights for the precise modification of starch structure. • Sorghum starch granules undergo shape distortion and size increase as plants mature (5–20 µm). • Developmental stages of sorghum varieties lead to distinct porous and inner growth rings in starch granules. • Amylose content (>20%) limits crystallinity in H37 starch, confirmed by XRD NMR, and SAXS analyses. • Impact of CLD on lamellar thickness, crystalline order, and granule ratio is more pronounced than amylose content. • Correlation analysis reveals insights into starch structure modification for improved thermodynamics and hydrolysis. [ABSTRACT FROM AUTHOR]

KT and Nuo sorghum are planted in saline‐alkali (SA) soil (KT‐S, Nuo11‐S) and nonsaline‐alkali (NSA) soil (KT‐S, Nuo11‐NS) to demonstrate the impact of SA stress on the structure and properties of sorghum starch. SA decreases the amylose content (27.57%–20.43%) but increases the B2 + B3 chain content of branched amylopectin (18.86%–19.57%) in KT, in contrast to Nuo. The X‐ray diffraction (XRD) and small‐angle X‐ray scattering (SAXS) results confirms the crystallinity of sorghum starch, and the degree of ordering in semicrystalline lamellae is arranged as follows: Nuo11‐S > Nuo11‐NS > KT‐S > KT‐NS. Differential scanning calorimetry (DSC) confirms that SA improves thermal stability of starch granules. The noodles made of sorghum starch exhibit significant hydrolysis resistance compared to common noodles, and a higher hydrolysis rate is shown in SA‐starch noodles. Overall, it is essential to understand the fine structure and physicochemical properties of starch isolated from sorghum planted in different soils to help determine its appropriate applications. [ABSTRACT FROM AUTHOR]