Dialdehyde Starch Research Articles

Preparation optimization by response surface and performance characterization of PEG-urea-dialdehyde starch adhesive

In this study, a new kind of green, pollution-free, renewable and formaldehyde-free starch adhesive was prepared by using corn starch as raw material, which was oxidized into dialdehyde starch by sodium periodate, and then grafted and cross-linked with polyethylene glycol (PEG) and urea. The PEG-urea-dialdehyde starch adhesive has good dry shear strength and certain hydrophobicity. The preparation parameters of PEG-urea-dialdehyde starch adhesive were optimized by response surface methodology and it characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM) and X-ray spectroscopy (EDAX). The results showed that when the dosage of PEG was 54% (w/w, dry starch basis), the dosage of urea was 70% (w/w, dry starch basis), the reaction time was 2.4 h, and the reaction temperature was 40 °C, the comprehensive properties of the adhesive were better. The dry shear strength of the PEG-urea-dialdehyde starch adhesive can reach 3.01 MPa, and the water contact angle was 61.76°. When the adhesive was used to bond paper-based materials, the tensile strength, burst strength and ring crush strength of the paper were increased by 17.0%, 16.0% and 42.0%, respectively. This paper provided a new idea for the preparation of the high quality starch-based adhesive, which has a wide application prospect in paper adhesive.

Novel Biomass-Based Polymeric Dyes: Preparation and Performance Assessment in the Dyeing of Biomass-Derived Aldehyde-Tanned Leather.

High-performance chrome-free leather production is currently one of the most concerning needs to warrant the sustainable development of the leather industry due to the serious chrome pollution. Driven by these research challenges, this work explores using biobased polymeric dyes (BPDs) based on dialdehyde starch and reactive small-molecule dye (reactive red 180, RD-180) as novel dyeing agents for leather tanned using a chrome-free, biomass-derived aldehyde tanning agent (BAT). FTIR, 1H NMR, XPS, and UV-visible spectrometry analyses indicated that a Schiff base structure was generated between the aldehyde group of dialdehyde starch (DST) and the amino group of RD-180, resulting in the successful load of RD-180 on DST to produce BPD. The BPD could first penetrate the BAT-tanned leather efficiently and then be deposited on the leather matrix, thus exhibiting a high uptake ratio. Compared with the crust leathers prepared using a conventional anionic dye (CAD), dyeing, and RD-180 dyeing, the BPD-dyed crust leather not only had better coloring uniformity and fastness but it also showed a higher tensile strength, elongation at break, and fullness. These data suggest that BPD has the potential to be used as a novel sustainable polymeric dye for the high-performance dyeing of organically tanned chrome-free leather, which is paramount to ensuring and promoting the sustainable development of the leather industry.

Antibacterial Activity of Carboxymethyl Chitosan Dialdehyde Starch Schiff Base and its Metal Complex

AbstractCarboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) and its metal complexes are synthesized by corn starch (St), sodium periodate, carboxymethyl chitosan, and metal ions (copper, zinc, nickel, silver), and are characterized by Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), energy dispersive spectroscopy (EDS), and X‐ray powder diffraction (XRD). The antibacterial activities of carboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) increase according to their increasing nitrogen content, and the best minimum inhibitory concentrations (MIC) against E. coli and S. aureus are 30 mg mL−1, respectively. Furthermore, the minimum inhibitory concentrations (MIC) of the metal complexes (copper, nickel, silver, and zinc) against S. aureus are 7.50, 30, 30, and 1.88 mg mL, respectively; and against E. coli are 7.50, 15, 15, and 0.94 mg mL−1, respectively.

A dialdehyde starch-based adhesive for medium-density fiberboards

Bio-based adhesives have gained considerable attention in the last years as more sustainable and healthier alternatives to the formaldehyde-based adhesives used today in wood-based panel manufacturing. In this study, dialdehyde starch (DAS) with various aldehyde contents was prepared by using sodium metaperiodate as an oxidizing agent. Characterizations were performed by employing Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and thermal stability analysis. Different adhesive compositions were used for making medium-density fiberboard (MDF) panels. They were based on DAS (12 wt% based on fiber), emulsifiable diphenylmethane diisocyanate (eMDI, 2-4 wt% based on DAS), and microfibrillated cellulose (MFC, 0.5-1.0 wt% based on DAS). Fibers and the adhesive components were mixed with a combination of dry mixing and wet spraying. The physical and mechanical properties of MDF panels bonded with different DAS-based adhesives were compared with those of melamine urea-formaldehyde (MUF) adhesive and sole eMDI. The results showed that the MDF panels made with DAS-MFC-eMDI of 99.52% bio-based content showed comparable properties to standard panels with a commercial MUF adhesive. It was implied that DAS in the presence of small amount of eMDI can create strong bonds with wood fibers, while an additional positive effect on bonding was due to the contact surface enlargement of MFC.

Investigation into the magnetic immobilization of lipase and its application in the synthesis of structured triacylglycerols

In this paper, sn-1,3-specific lipase from Rhizomucor miehei (RML) was immobilized with dialdehyde starch (DAS) as a support activating agent and nano-sized Fe3O4 as a magnetic carrier. The structured triacylglycerol as human milk fat substitutes enriched with OPO was produced. The results showed that the fixed load of lipase was 52.41 mg/g. The enzyme activity recovery was 57.82%. Compared with free lipase, the relative enzyme activity of RML immobilized in magnetic particle was kept at 92% when placing 10 h in a methanol solution. The lipase immobilized in magnetic particle had an average particle diameter of 169 nm and was applied in the synthesis reaction of 1,3-dioleoyl-2-palmitoylglycerol (OPO) by using tripalmitin (PPP) and oleic acid (OA) as raw materials. Under the optimal reaction conditions of 10% immobilized lipase, 5:1 substrate molar ratio (OA/PPP), 50 °C reaction temperature and 7 h reaction time, the product's OPO content was 43.97%, and the content of triacylglycerols rich in palmitic acid at the sn-2 position was 83.32%. After eight repeated uses at 50 °C, the relative activity of RML immobilized in magnetic particle remained above 71%. The synthesized OPO has potential to be used in infant formulas.

A Melamine–Dialdehyde Starch Wood Particleboard Surface Finish without Formaldehyde

A Melamine–Dialdehyde Starch Wood Particleboard Surface Finish without Formaldehyde

Inhibitory effect of pre-gelatinized dialdehyde starch on heat-induced deterioration of sea cucumber.

This study sought to investigate the inhibitory effect of pre-gelatinized dialdehyde starch (P-DAS) on the deterioration of sea cucumber during high-temperature sterilization. It was found that pre-gelatinization reduced crystallinity and average molecular weight of dialdehyde starch (DAS), exposed free aldehyde groups, improved the solubility, and unified the particle sizes. According to the texture profiles of sea cucumber, the crosslinking power of P-DAS was higher than that of DAS. The results of free amino content, total soluble substance, water retention, water distribution, relaxation time and scanning electron microscopy all showed that the crosslinking effect was dose-dependent on crosslinking agent. These results have proved that large molecules such as P-DAS, when properly handled, could also efficiently enter collagen hydrogels and perform crosslinking, providing reference for the development of new protein food stabilizing agents. © 2022 Society of Chemical Industry.

Molecular and Interactions Modelling of PETase and Its Variant with Different Types of Crosslinker in Enzyme Immobilization


 
 
 
 Plastics are made from non-renewable resources and due to the tremendous production of plastics nowadays, they can lead to high levels of pollution. Biodegradation of plastic by utilizing enzymatic catalytic reaction is an environmentally friendly strategy that produce less or no negative carbon footprint. PETase from Ideonella sakaiensis (IsPETase) is an enzyme that able to degrade polyethylene terephthalate (PET), a building block of plastic. However, free enzyme has several limitations such as unstable in harsh conditions and lack of reusability. One of the strategies to overcome this drawback is through enzyme immobilization that able to improve the enzymatic properties. A suitable crosslinker is very important as it would determine the interactions of the enzymatic particles. Crosslinker should be chosen before performing the enzyme immobilization and this can be accomplished by molecular docking. Thus, the purpose of this research is to determine the suitability of glutaraldehyde, chitosan, dialdehyde starch (DAS) and ethylene glycol as the crosslinker for IsPETase and its variant. Three-dimensional structure of the enzymes was built and docked with different types of crosslinkers. Binding affinity and interactions between the enzymes and the crosslinkers were analyzed and it was found that chitosan has the lowest binding affinity (-7.9 kcal/mol) and the highest number of interactions. This is followed by DAS, ethylene glycol and glutaraldehyde. By using computational analysis, suitable crosslinker for IsPETase could be determine and this would a cost-effective practice in enzyme immobilization strategy. 
 
 
 

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.

INDIRECT ELECTROCATALYTIC OXIDATION OF STARCH BY REACTIVE OXYGEN SPECIES IN SITU GENER-ATED ON Pb/PbO2 ANODE AND BORON-DOPED DIAMOND ELECTRODE IN AQUEOUS ELECTROLYTES

The indirect electrocatalytic oxidation of starch by reactive oxygen species (ROS) generated in situ on lead dioxide anodes and a boron-doped diamond electrode in an acidic aqueous electrolyte has been studied. The influence of the current density, concentration and state of aggregation of the reagent, the scheme of introduction of ROS on the kinetics and yields of the product of indirect oxidation of starch dialdehyde karazmal has been established. The optimal conditions for obtaining oxidized starch were determined: anode – Pb/PbO2, current density – 25 mA/cm-2, electrolyte pH 2–3, electrolysis time – 80 min, 25 °C. Starch oxidation products were analyzed by the following methods: spectrophotometry after deratization with dinitrophenylidrazine, gas chromatography-mass spectrometry after hydrolysis and silylation, and IR spectroscopy. Glucose tautomers, as well as ethylene glycol oligomers, were found in the hydrolyzates of the reaction products by GCMS, indicating the breaking of C-C bonds in the monosaccharide units during the oxidation process.

Chitosan/dialdehyde starch hybrid in situ forming hydrogel for ocular delivery of betamethasone

Ocular drug therapy remains to be a major pharmaceutical challenge due to the presence of ocular barriers. The development of novel ophthalmic delivery systems is an immense necessity to overcome such biological and physiological barriers. Hydrophilic gels are considered an ideal candidate for such purposes owing to their favorable characteristics such as rapid in situ gelation, biodegradability, biocompatibility, and high encapsulation capacity. In the current study, we report on the development of an in situ forming composite hydrogel formulated using natural polymers, including dialdehyde starch (DAS) and chitosan (CS), to deliver betamethasone to the eye. The modification of starch and composite hydrogel structure was evaluated by FT-IR spectroscopy. The effect of the different ratios of CS to DAS on the gelation time, surface microstructure morphology, swelling ratio, rheological behavior, and in vitro degradation was evaluated. Our findings demonstrated that the high content of DAS could result in fast gelation, improved mechanical strength, larger pore size, and optimized degradation with a fast in vitro and ex vivo release rate. Furthermore, the developed composite hydrogel displayed excellent biocompatibility in cell models in vitro. Altogether, the obtained data suggest that the developed hydrogel-based delivery system could be well suited for local administration of betamethasone to control ocular inflammation and consequent complications.

Co-immobilization of electron mediator and laccase onto dialdehyde starch cross-linked magnetic chitosan nanomaterials for organic pollutants' removal.

In this study, an amino-functionalized ionic liquid-modified magnetic chitosan (MACS-NIL) containing 2,2-diamine-di-3-ethylbenzothiazolin-6-sulfonic acid (ABTS) was used as a carrier, and dialdehyde starch (DAS) was used as a cross-linking agent to covalently immobilize laccase (MACS-NIL-DAS-lac), which realized the co-immobilization of laccase and ABTS. The carrier was characterized by Fourier infrared transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction analysis, electron paramagnetic resonance, etc. The immobilization efficiency and activity retention of MACS-NIL-DAS-lac could reach 76.7% and 69.8%, respectively. At the same time, its pH stability, thermal stability, and storage stability had been significantly improved. In the organic pollutant removal performance test, the removal rate of 2,4-dichlorophenol (10mg/L) by MACS-NIL-DAS-lac (1 U) could reach 100% within 6h, and the removal efficiency could still reach 88.6% after six catalytic runs. In addition, MACS-NIL-DAS-lac also showed excellent degradation ability for other conventional phenolic pollutants and polycyclic aromatic hydrocarbons. The research results showed that MACS-NIL-DAS fabricated by the combination inorganic material, organic biomacromolecules, ionic liquid, and electron mediator could be used as a novel carrier for laccase immobilization and the immobilized laccase showed excellent removal efficiency for organic pollutants.

Antioxidant packaging films developed by in-situ cross-linking chitosan with dialdehyde starch-catechin conjugates

In this study, four dialdehyde starch-catechin (DAS-catechin) conjugates were prepared by conjugating (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) with dialdehyde starch. Then, DAS-catechin conjugates were used as antioxidant and cross-linking agents to produce chitosan (CS) based antioxidant packaging films. The functionality of CS/DAS-catechin conjugate films was determined. Results showed four DAS-catechin conjugates formed Schiff-base linkages and hydrogen bond interactions with CS, resulting in improved film uniformity. Compared with plain CS film, CS/DAS-catechin conjugate films owned higher UV–vis light, water vapor and oxygen barrier ability, lower swelling degree, and stronger tensile strength, thermal stability and antioxidant activity. The cross-linking between CS and DAS-catechin conjugates delayed the biodegradable process of CS film. CS/DAS-catechin conjugate films showed good performance on inhibiting sunflower seed oil oxidation. Notably, CS/DAS-ECG conjugate film had the highest oxygen barrier, mechanical and antioxidant performances among four CS/DAS-catechin conjugate films. Therefore, CS/DAS-ECG conjugate film is an antioxidant packaging candidate for edible oil.

Application of magnetic immobilized enzyme of nano dialdehyde starch in deacidification of rice bran oil

Glutaraldehyde is usually used as a cross-linking agent in the immobilization of enzymes, but this will have a negative effect on the enzyme. Dialdehyde starch can effectively replace glutaraldehyde as a cross-linking agent, but the large particle size of dialdehyde starch affects the performance of immobilized enzyme. In this study, dialdehyde starch nanoparticles (DSNP) were combined with modified Fe3O4 to obtain magnetic carrier (MDSNP), and Candida Antarctica lipase B (CALB) was crosslinked to the carrier to obtain magnetic immobilized enzyme (MDSNPCALB). The characterization results show that the functional groups of each material have obvious characteristic absorption peaks, strong diffraction peaks and typical crystal structures, high magnetism, no coercivity, relatively good dispersion and nano particle size. MDSNPCALB was added to degummed rice bran oil (RBO) and ethanolamine was used as an acyl receptor for acylation and deacidification. After repeated use for 10 times, MDSNPCALB remained highly active, indicating that MDSNPCALB can be effectively used for the deacidification of RBO.

Dialdehyde Starch Nanocrystals as a Novel Cross-Linker for Biomaterials Able to Interact with Human Serum Proteins

In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5–15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.

Sensor Modified with Gold Nanoparticles Stabilized in Dialdehyde Starch/DMSO Matrix for Methyldopa Detection

AbstractIn this study, gold nanoparticles (AuNP) were synthesized using a novel stabilizer based on dialdehyde starch polymer (DAS) and dimethyl sulfoxide (DMSO) and the nanomaterial was applied to develop a sensor for methyldopa detection. The nanoparticles were characterized by transmission electron microscopy and the proposed sensor was electrochemically characterized by electrochemical impedance spectroscopy, chronocoulometry and square‐wave voltammetry. Under optimized conditions (0.1 mol L−1 McIlvaine buffer solution at pH 3.5 and 50 μL AuNP/DAS‐DMSO), using square‐wave voltammetry, the calibration curve presented a linear range of 0.99 to 19.60 μmol L−1, with a detection limit of 0.50 μmol L−1. The sensor showed good accuracy, with coefficients of variation of 7.8 % (inter‐day; n=6) and 5.9 % (intra‐day; n=3), and recovery values in the range of 95.3 to 105.2 %. The methyldopa content in a pharmaceutical sample was determined and the results show good correlation with the label value and the method recommended by the Pharmacopoeia, representing a fast and accurate alternative for detecting methyldopa in pharmaceutical products.

Starch-Based Rehealable and Degradable Bioplastic Enabled by Dynamic Imine Chemistry

The increasingly serious environmental pollution caused by petroleum-based nondegradable plastics has evoked intense research interest in the development of sustainable and degradable bioplastics. Starch is one of the most promising biopolymers for the preparation of bioplastic. However, it is still a great challenge to develop starch bioplastics with high strength, low water sensitivity, and excellent water resistance. Herein, we reported a facile chemical modification method for the synthesis of a novel starch bioplastic. In this process, an easily available starch derivate, dialdehyde starch (DAS), is cross-linked using diamine based on dynamic imine chemistry to prepare DAS-based polyimine (DAS-PI). This DAS-PI exhibits excellent thermal malleability, and it can be easily thermoformed into novel starch bioplastic without using any plasticizer. The resulting starch bioplastic shows high mechanical strength (40.6 MPa), high thermal stability, and excellent water/chemical resistance, as well as heat-induced self-healing ability. Moreover, it can be easily chemically degraded and recycled. This work provides a novel method of producing high-performance starch bioplastics without using plasticizers.

Highly absorbent antibacterial chitosan-based aerogels for shelf-life extension of fresh pork

In this study, the CS-DAS aerogels were prepared using chitosan (CS) crosslinked by dialdehyde starch (DAS), with the best absorption and mechanical properties at the weight ratio of CS to DAS being 7:3. The copper nanoparticles (CuNPs) were first prepared by green reduction method, then encapsulated by liposomes (Lip-CuNPs) for controlling their sudden release. The antibacterial aerogels (CD/Lip-CuNPs) were developed by incorporating the Lip-CuNPs into the aerogel (7:3). The porous network structure of aerogels realized the further gradual release of CuNPs. The CD/Lip-CuNPs aerogels had good antimicrobial properties, which could preserve fresh pork for 14 d at 4 °C without spoilage. Moreover, the CuNPs migrated from the aerogels into fresh pork was at a safe level of 3.38 mg/kg after 14 d at 4 °C. The obtained antibacterial CD/Lip-CuNPs aerogels had the potential for extending the shelf life of fresh meat. • Dialdehyde starch significantly improved the quality of chitosan-based aerogels. • The liposomes encapsulated copper nanoparticles (Lip-CuNPs) were prepared. • S uperabsorbent antibacterial aerogels were developed by incorporating Lip-CuNPs. • Selected aerogels realized the gradual release of copper nanoparticles. • Superabsorbent antibacterial aerogels extend the shelf life of fresh pork.

Structure, stability and antioxidant activity of dialdehyde starch grafted with epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate.

Catechins, a member of the flavonoids, exist widely in teas, and have health benefits. However, catechins have poor stability, which greatly limits their application. In order to improve the stability of catechins, different catechins including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) were conjugated onto dialdehyde starch by acid-mediated coupling method. The structure, stability and antioxidant activity of dialdehyde starch-catechin conjugates were determined. Thin-layer chromatography and ultraviolet-visible spectroscopy, fluorescence, nuclear magnetic resonance and infrared spectra revealed that catechins were successfully conjugated onto dialdehyde starch, coupling between 6-H/8-H of catechins' A ring and dialdehyde starch's aldehyde groups. The conjugates presented an amorphous structure and sheet-like and/or blocky morphologies. As compared to dialdehyde starch, the conjugates showed enhanced thermal stability. Furthermore, the stability of catechins in pH 7.4 phosphate-buffered saline was improved after conjugating onto dialdehyde starch. The conjugates exhibited significantly higher antioxidant activities than dialdehyde starch, decreasing in the following order: dialdehyde starch-ECG, dialdehyde starch-EGCG, dialdehyde starch-EC, dialdehyde starch-EGC and dialdehyde starch. Dialdehyde starch-catechin conjugates have great potential as stable antioxidant agents. © 2022 Society of Chemical Industry.

New approach for starch dialdehyde preparation using microwave irradiation for removal of heavy metal ions from water

This work presents a new and simple approach to prepare Dialdehyde Starch (DAS) in one step under microwave irradiations and using, a mild and safer oxidizing agent, potassium iodate. Aldehyde content was evaluated to compare the synthesis results with DAS prepared using potassium periodate as an oxidizing agent for starch. To optimize the synthesis parameters of the new approach, the effect of the quantity of oxidizing agent and the effect of reaction time on the content of aldehyde in DAS were evaluated. According to the results, the optimized time was 10 min at the power of 300 W, and the number of moles of oxidizing agent was 0.014 mol per 2 g of starch. After that, DAS was used to prepare two Schiff bases by reaction with urea (DASU) and thiourea (DASTU), respectively. DAS, DASU and DASTU were characterized by FTIR, XRD, and SEM. Furthermore, DAS, DASU and DASTU were investigated for removing Cu(II), Pb(II), Hg(II), Cd(II), and Cr(III) ions from water. DAS showed the highest removal efficiency towards Pb(II) ions, whereas DASTU exhibited excellent ability for removing the Hg(II) ions. The removal efficiencies of DAS for Pb(II) ions and DASTU for Hg(II) ions are 95.25% and 89.45%, respectively from aqueous solutions containing 100 ppm of respective ions. Adsorption isotherm study suggests that adsorption follows Langmuir isotherm model, (correlation factors (R2) for Langmuir and Freundlich models for DAS/Pb are equal to 0.984 and 0.799, respectively, and for DASTU/Hg they are 0.995 and 0.813, respectively). The theoretical maximum adsorption capacity for DAS/Pb and DASTU/Hg are 245.09 and 180.83 mg/g, respectively.