Aqueous Starch Solution Research Articles

Physicochemical and technofunctional properties of high Andean native potato starch

In the high Andean areas of Peru, a diversity of native potatoes improved at the germplasm level is grown, with higher nutritional and amylose quality, for use mainly in fries. The research aimed to evaluate the rheological behavior, thermal and technofunctional starch extracted from native potato varieties (Solanum tuberosum spp Andigena), cultivated in Andahuaylas, Peru. Native potatoes of the Azul Helada (AH) and Amarilla Reyna (AR) varieties were collected from the district of Champaccocha, Andahuaylas, Peru, and the starch was extracted by hydro extraction. The AH and AR starch in aqueous solution was observed to present dilatant behavior, with a behavior index of n > 1.0; represented by the Power Law and Herschel-Bulkley model, with low retrogradation speed. The starches reported gelatinization temperatures of 61.8 and 66.4 °C and melting of 132.2 and 133.5 °C, thermal degradation with mass losses of up to 89.90 and 86.16 %, 43.56 and 42.09 % of apparent amylose for HA and AR respectively. The solubility, swelling power, water adsorption capacity, oil absorption capacity, emulsifying capacity, and apparent density were higher for HA, with aw around 0.50. The color presented L* values > 95.17, and a whiteness index greater than 94.80. The ζ potential of the starches indicates medium stability, with a granule size of 42.17 and 57.67 nm. They also respond to type B with a degree of crystallinity of 58.95 and 43.12 % and a crystal size of 6.55 and 6.01 nm for AH and AR respectively. The native high Andean potato AH and AR are potential sources for starch extraction, with good techno-functional properties.

PREPARATION AND PROPERTIES OF BIODEGRADABLE CRYOGELS BASED ON POLYVINYL ALCOHOL AND POTATO STARCH FOR USE IN SOIL EROSION CONTROL

Compositions for the formation of three-component elastic cryogels based on the aqueous solutions of polyvinyl alcohol (PVA) and potato starch are proposed. It is shown that the viscosity of aqueous solutions depends both on the kind of polymer and on the total content of polymers in the system. The elasticity modulus of three-component cryogels depends on the concentration of starch in them and increases from 5 to 15 kPa with the addition of starch in the amount of 1-5 wt. %. By introducing a dispersed material (soil) into the matrix of two-and three-component cryogels, due to the high adhesion of the polymer to the filler, the filled cryogels were obtained, with the elasticity modulus 16 times higher than that of cryogels without the filler. The introduction of potato starch in the amount of 5 wt. % into PVA cryogel caused an increase in the time of its complete drying by 24 h, and an increase in its destruction during exposure in water by 5% within a week. Two-component cryogels exhibited sharply different types of behaviour during storage in water: PVA cryogel did not lose its mass, while mass loss by the cryogel of potato starch was 11% within a week. A decrease in the mass of three-component cryogels by 75-89% due to the loss of moisture and destruction was demonstrated in the soil test under the action of aboriginal soil microflora. The mass loss by the two-component cryogel based on PVA was 60%. Soil testing for phytotoxicity after the destruction of three-component cryogels revealed a decrease in the germination capacity of white mustard (Sinapis alba L.) by 2-10% with respect to the reference experiment, depending on starch content, while for the reference two-component PVA cryogel the corresponding decrease was by 18%. Cryostructuring of the upper soil layer by PVA cryogel caused an increase in the dry above-ground mass of plants by 3.2% in comparison with the reference, while the cryogel with potato starch caused an increase by 7.1%, and cryogel based on PVA and potato starch gave 9.4%.

Starch-Directed Synthesis of Worm-Shaped Silica Microtubes

Many strategies have been adopted to prepare silica materials with highly controlled structures, typically using sol-gel chemistry. Frequently, the alkoxysilanes used in sol-gel chemistry are based on monoalcohols, e.g., Si(OEt)4. The structural control over silica synthesis achieved by these precursors is highly sensitive to pH and solvency. Alkoxysilanes derived from the sugar alcohol glycerol (diglycerylsilane) react more slowly and with much less sensitivity to pH. We report that, in the presence of cooled aqueous starch solutions, glyceroxysilanes undergo transesterification with the sugars on starch, leading to (hollow) microtubules resembling worms of about 400 nm in diameter. The tubes arise from the pre-assembly of starch bundles, which occurs only well below room temperature. It is straightforward to treat the first-formed starch/silica composite with the enzyme amylase to, in a programmed fashion, increasingly expose porosity, including the worm morphology, while washing away untethered silica and digested starch to leave an open, highly porous materials. Sintering at 600 °C completely removes the starch silane moieties.

Study on Manufacturing and Applicability of Natural Adhesive for Paper Craft Using Corn Starch

A natural adhesive of starch (corn) that can be used to make and repair paper crafts was manufactured. The purpose of this study was to explore a composition of an adhesive having maximum adhesive strength while controlling a catalyst, a reaction initiator, and an oxidizing agent added to an aqueous starch solution at room temperature. The best composition was when a 35% starch aqueous solution was used. The 2.0% NaOH aqueous solution was added to the 35% starch aqueous solution to adjust pH from 10.0 to 11.0, and 0.20 g NiSO4, 20.0 g NaOCl, 30.0 g of 30.0% NaOH solution, and 3.0 g of 1.0% sodium thiosulfate were sequentially added. In the last step, the 3.0% HCl aqueous solution was added to adjust the pH of the adhesive to 7.5, and the adhesive strength of the prepared adhesive was 213 kgf/㎠. It was stable at room temperature for more than 60 days without physical changes such as viscosity, phase separation, precipitation, etc. In addition, TVOC, HCHO, and heavy metals were not detected, and the excellent result was found in antibacterial and reversible tests. This adhesive is an excellent natural adhesive that can be easily used by the user and does not contain harmful substances. It was an adhesive that could maintain the reputation of traditional materials in addition to their production and preservation.

FILM-FORMING AND DESTRUCTION POWERS OF COMPOSITIONS BASED ON MODIFICATIONS OF NATURAL POLYMERS

On the basis of the conducted literature review of biodegradable film-forming compositions using modified natural polymers, using the example of starch, it can be seen that the range of possibilities for its modification and the choice of suitable synthetic polymers depend on the method of production and the field of use, and are generaily aimed at protecting the environment. The physico-mechanical and structural characteristics of film-forming polymers polybutyrate PBAT and polycaprolactone PCL, which belong to biodegradable polymers processed by the extrusion method with the addition of thermoplastic starch, were studied. The destructive properties of film-forming compositions obtained from aqueous solutions of plasticized starch after UV irradiation for 90 days were studied. The maximum loss of strength reaches 86%, and the loss of elasticity is 93%.The structural changes of the compositions were investigated by the mass spectrometric method.

Enabling the aqueous solution sensing of skin-conformable organic field-effect transistor using an amphiphilic molecule

Research on aqueous solution sensor has immense demand in biological sensing applications. While traditional organic field-effect transistors (OFETs) have shown promising prospect in the field of sensing, their application in the aqueous solution sensing far lag behind since the aqueous environment strongly limits the organic materials to work. Here, we design, somewhat counterintuitively, an approach to increase the affinity of OFET to aqueous solution by adding amphiphilic molecule in the hydrophobic semiconductor. This method enables the aqueous solution sensing of the OFET through providing a good wettability between the OFET and the aqueous environment. Benefiting from this, the OFET can detect glucose aqueous solution in the human blood range (0.5–2 mg/mL) and the strongest response derived from the variation of mobility is as high as 5600% when applied 1 mg/mL glucose solution. Under a curvature radius of 7.5 mm, the OFET still maintains the sensitivity to glucose down to 0.5 mg/mL. The sensing performance is tunable through changing the amphiphilic molecule with different Hydrophile-Lipophile Balance value and introducing dielectric material in semiconductor. In addition, the selective detection to aqueous solutions of glucose, raffinose, starch, and lactic acid is realized. Portable real-time detection is achieved by integrating the OFET with wireless transmission and a smartphone. When the glucose concentration exceeds the limit, a red-light signal can be triggered as a warning. The work develops a simple approach for OFET to achieve aqueous solution detection.

Passive Fire Protection of Taeda pine Wood by Using Starch-Based Surface Coatings.

The present paper reports the preliminary results relating to the development, subsequent application, and testing of environmentally benign starch-based formulations for passive fire protection of wood substrates. This study evaluated the effectiveness of starch colloid coatings applied onto the wood surface with a view to improving its performance when exposed to the external heat flux (35 kW/m2) during cone calorimetric tests. The formulations were prepared from aqueous colloid solutions of either starch alone, or in combination with inorganic salts, such as: sodium carbonate, Na2CO3, potassium carbonate, K2CO3, and diammonium hydrogen phosphate, (NH4)2HPO4. The fire performance of Taeda pine wood samples, where their top surfaces were treated with these formulations, was compared with the control sample. The thermal and combustion characteristics of the tested samples were determined with the aid of thermo-gravimetric analysis (TGA), bomb and cone calorimetric techniques, and a steady state tube furnace coupled to an FT-IR spectrometer. A significant boost of fire protection was observed when starch formulations with added inorganic salts were applied onto the wood surfaces, compared with the control sample. For example, the presence of K2CO3 in starch colloid solutions resulted in a notable delay of the ignition and exhibited a reduction in the heat release parameters in comparison with the untreated wood substrate.

Preparation and characterization of nanoparticles from cereal and pulse starches by ultrasonic-assisted dissolution and rapid nanoprecipitation

Starch nanoparticles (SNPs) were prepared for the first time via a combination of ultrasonic-assisted dissolution of starch and subsequent rapid nanoprecipitation. Purified starches from cereal (regular corn and wheat) and pulse (faba bean and field pea) grains that significantly differ in amylose content were used. The effects of starch source, concentration and amylose content as well as the ratio between antisolvent to solvent (i.e., aqueous starch solution) on the SNPs morphological, molecular, and physicochemical properties were investigated. The morphology was evaluated by scanning electron microscopy (SEM) to observe shape and surface details and dynamic light scattering (DLS) to analyze particle size and poly dispersity index (PDI). Molecular properties of the native starch and SNPs were determined by a high-performance size-exclusion chromatography equipped with a multi angle laser light scattering and a differential refractive detector (HPSEC-MALLS-RI). Physicochemical characterization of the SNPs was performed via measuring the crystallinity by X-ray diffraction (XRD), molecular order by Fourier-transform infrared spectroscopy (FTIR), and thermal properties by differential scanning colorimeter (DSC). Results showed that SNPs from all starches were spherical in shape, where pulse SNPs had smaller and more uniform size than cereal SNPs. Across all starch types, the molecular weight of amylopectin and amylose in SNPs was smaller and more uniform than in the respective native starches. Pulse SNPs with higher amylose content showed greater relative crystallinity, enhanced short-range molecular order, and better thermal stability. A schematic diagram has been proposed to explain the variations in SNP size, where amylose-amylopectin ratio plays an important role.

Ultrasonic investigation on physico-chemical behavior of starch at different temperature

In this present study, the bio-polymer material starch was used to understand the behaviour of bio-polymer material under ultrasonic investigation at different temperatures. In our regular foods, Starch is also found there and it is a bio-polymer which is produced by plants. For the starch soluble bio-polymer with double distilled water at 303K, 308K, 313K, 318K, 323K, 328K & 333K over the entire range the ultrasonic velocity and also the other acoustical properties have also been studied and with these useful data related with sound’s speed, viscosity, free volume and internal pressure the Auerbach surface tension were calculated. From 303K to 333K, the Thermodynamic interaction of starch solution was studied experimentally by using the ultra-sonic interferometer at 2MHz. For the different temperature regions, the other parameters such as density, viscosity were also measured. In addition to this, adiabatic compressibility (βa), free volume (Vf), Acoustic Impedance (Z), Intermolecular free length (Lf), Internal Pressure (πi) and Enthalpy (H) were calculated. Based on these values, the variations of interactions in aqueous starch solution have been analyzed. The analysis of the experimental results suggests the weak existence of intermolecular interactions between the components of molecules. It is concluded that the concentration of the solute and the nature of the solvent play an important role in determining such molecular interactions. This study also highlights the factor involved in solute-solvent interactions and opens up a new method of investigation for the biomedical applications of starch. This conclusion highlights the importance of the ultrasonic velocity measurement in the given medium for detecting the molecular interactions and also for characterizing the thermo-acoustical properties of the medium.

Design and characterization of PANI/starch/Fe2O3 bio composite for wastewater remediation

A new synthesized polyaniline/starch/hematite bio composite (PANI/S/Fe2O3 BC) has been studied as an effective material for on-site water remediation. PANI/S/Fe2O3 BC was developed by combining the techniques of co-precipitation and interfacial polymerization in the presence of aqueous starch solution in an acidic medium under ultrasonic irradiation. The nano-morphologies and structures of the designed PANI/S/Fe2O3 BC were evaluated by various techniques relative to PANI and Fe2O3 nanoparticles. In single and multiple systems, PANI/S/Fe2O3 BC was evaluated as a possible adsorbent for different heavy metals, including As3+, Zn2+, and Co2+, relative to PANI and Fe2O3 nanoparticles. In terms of pH value, operating temperature, initial heavy metal concentration, contact time, adsorbent dose and competitive ions in the solutions, the adsorption process was optimized. For 92% overall adsorption of Co2+ and 100% overall adsorption of both As3+ and Zn2+, the adsorption equilibrium was achieved within 60 and 120 min, respectively. In addition, adsorption thermodynamic analysis shows that the As3+ ions adsorption process was not random and the pseudo-second-order fitted with experimental results. Moreover, PANI/S/Fe2O3 BC was evaluated as an antibacterial agent against Gram-negative bacteria (Salmonella typhimurium) and Gram-positive bacteria (S. aureus, Methicillin-Resistant Staphylococcus, Aureus Clinical isolate and Bacillus subtilis). The reported performances indicated that the PANI/S/Fe2O3 BC is a potent candidate for industrial water bioremediation.

The impact of various exogenous type starch on the structural properties and dispersion stability of autoclaved lotus seed starch

In order to investigate the effects of exogenous V-type starch on the structural properties and dispersion stability of lotus seed starch after autoclave treatment, the crystal structure, molecular structure, and dispersion stability were analyzed and discussed, as well as compared with exogenous A-type and B-type starches. Analysis of structural properties indicated that the addition of different crystal nuclei led the crystallization of disordered helices to a specific direction. The B- and V-type starch addition increased the crystallinities of starch and enhanced the ordered arrangement of disordered helices, whereas A-type starch had no significant positive influence on the stability of starch system. The microstructure observation showed that A- and B-type starch addition led to a rough and porous morphology of starch particles; the presence of V-type starch retarded the agglomeration and retrogradation of starch after autoclaving. Analysis of contact angle and dispersion stability revealed that the addition of various exogenous starch increased the contact angle of starch particles in different extent, suggesting the enhancement of hydrophobicity. But B-type starch addition resulted in the poor dispersion stability compared to A-type starch, instead V-type starch addition improved the dispersion stability of starch in aqueous solution, allowing the particles to stay dispersed for 141.12 ± 6.52 min. These results provided a theoretical basis for the effects of exogenous type starch on original starch properties, and revealed the potential of V-type starch as dispersion stabilizer.

Polyetherols and polyurethane foams from starch

New method of synthesis of polyetherols from starch in aqueous solution was elaborated. Starch was converted into polyetherols by reactions with alkylene carbonates. The products are mixtures of starch-derived polyetherols and products of hydroxyalkylation of water. The elaborated method can be useful, eco-friendly synthetic route avoiding burdensome solvents. The polyetherols were characterized by IR, H NMR and MALDI-ToF spectroscopes and used to obtain rigid polyurethane foams. The properties of polyurethane foams obtained from such polyetherols were investigated. The polyurethane foams have apparent density, water uptake and polymerization shrinkage similar to the classic polyurethane foams. Some of obtained PUFs show improved thermal resistance; they stand long term heating at 175 °C. Furthermore, thermal exposure of obtained PUFs results in increase of their compression strength, which renders them valuable material for isolation. The polyurethane foam obtained from polyetherols synthesized in a reaction of starch with propylene carbonate showed moderate availability to biodegradation as was demonstrated by bioavailability tests with Bacillus subtilis.

Proanthocyanidins from Chinese berry leaves modified the physicochemical properties and digestive characteristic of rice starch

Proanthocyanidins extracted from Chinese berry leaves (CBLPs) were heated with rice starch in aqueous solution to prepare polyphenols-starch complexes. The physicochemical properties of the complexes were characterized with XRD, DSC, RVA and FT-IR and starch constituents were also analyzed with an enzyme method. Results indicated that the addition of CBLPs destroyed the long ordered structure of rice starch rather than the short ordered structure, since the crystallinity decreased from 21.96% to 18.90% and the ratio of 1047 cm−1/1022 cm−1 showed little difference, consistent with the lower ΔH of complexes with higher CBLPs content. Additionally, the CBLPs-rice starch complexes showed a significantly lower content of rapidly digested starch (RDS, 45.64 ± 3.25%) than that of the native rice starch (67.76 ± 2.15%). These results indicated that CBLPs complexes with rice starch might be a novel way to prepare functional starch with slower digestion.

Synthesis of boron carbide powders from mono- and polysaccharides

Boron carbide powders are usually synthesized by carbothermal or magnesiothermic reduction of boron oxy-compounds, a carbon source is usually graphite or some organic phases. The aim of the work is using of mono- and polysaccharides for synthesis of boron carbide powders in which the final grains are separated from each other by an unreacted excess of carbon preventing both grain growth and formation of strong aggregates. Aqueous solutions of glucose, fructose, dextrin or hydroxyethyl starch and boric acid were dried, pyrolyzed at 850 °C for 1 h and then heat-treated at temperatures from 1300 to 1700 °C for 1 h. The amount of boron carbide in the powders depends both on the saccharide and on the temperature. The grains prepared from precursors containing monosaccharides had oval shapes whereas polysaccharides were applied they had rhombohedral shapes corresponding to the boron carbide structure. This effect can be attributed to presence of molten boron oxide.

Antimicrobial and swelling behaviors of novel biodegradable corn starch grafted/poly(4-acrylamidobenzoic acid) copolymers

Novel antimicrobial copolymers resulted from free radical copolymerization of gelatinized corn starch in aqueous solution with different amounts of 4-acrylamidobenzoic acid monomer using ammonium persulfate (APS)/sodium bisulfite (NaHSO3) as a redox initiator. The grafting copolymerization was evidenced by FTIR, 1HNMR, scanning electron microscopy (SEM) and X-ray diffraction. The thermal stability was improved after the grafting reaction as detected from IPDT values calculated from the thermogravimetric analysis. The effect of changing grafting parameters (initiator concentration, monomer concentration, reaction time and temperature) on graft copolymerization were studied by measuring the grafting percentage (%G), grafting efficiency (%GE) and homopolymer percentage (%H). The optimum grafting conditions were determined as follows: Initiator concentration [I] = 3 × 10-2 mol/L, monomer concentration [M] = 0.25 mol/L, reaction temperature = 65 °C and reaction time = 2 h. The prepared copolymers exhibited swelling ability in both water and 0.9% saline solution. The antimicrobial study revealed a high degree of inhibition against different strains of Gram-positive bacteria, Gram-negative bacteria and fungi when compared with neat starch.

Coupling effect of starch coated fibers for recycled polymer/wood composites

In this work is proposed the use of starch gum (SG) as a coupling agent for polymer matrix composites (virgin and recycled) reinforce with wood flour. The coupling agent is prepared using an aqueous starch solution containing 3 and 5 %wt. forming a coating over the reinforcement, and compared with maleic anhydride grafted (MAPP), a usual coupling agent. The starch gum coating characterization indicates that 5%wt. presents more cohesive coating on the reinforcement. The mechanical properties of the composites also indicate that 5 %wt. produces higher properties than 3 %wt. The starch coupling agent presents a lower performance compared to MAPP for the virgin polymer; however, for the recycled polymer, it increases the elastic modulus in 37%, overcoming MAPP. Computational tomography indicates that the starch gum promotes compatible interaction at the interface with a low formation of empty spaces in the recycled polymer, indicating that it can be an exciting alternative to produce low-cost composites with eco-friendly solutions.

Starch Film as a Carrier of a Model Drug Substance from the Group of Non-Steroidal Anti-Inflammatory Drugs

The article describes the production of starch film as a carrier of a model drug substance from the group of non-steroidal anti-inflammatory drugs (NSAIDs). An analgesic/anti- inflammatory drug was put into aqueous starch solution, and next a film was formed. The following solid drug substances were included in the tests: acetylsalicylic acid, salicylic acid, ibuprofen lysine salt, naproxen in the form of acid, and sodium salt. Solutions were obtained from ibuprofen lysine salt and naproxen sodium, whereas the other drugs enabled to obtain aqueous suspensions. Such a drug substance was mixed with aqueous starch solution to obtain a film. Forming a film under laboratory conditions involved spreading aqueous starch solution containing a drug on a flat heated surface and evaporating water. The films obtained were transparent. They were then dried for a period of 24 hours at a temperature of 20 °C and 50% relative air humidity. Next their mechanical properties were studied. Starch films which contained therapeutic substances were characterised by Fourier transform infrared spectroscopy (FTIR). There were slight differences between the spectra of films containing a drug substance and those of films containing both starch and a drug substance, which implies weak intermolecular reactions. Scanning electron microscope (SEM) images of cross-sections of the starch films with a drug substance were taken, which indicated their uniform morphological structure. The release rate of the drug from each film to an acetate buffer pH 4.5 (acetylsalicylic acid and salicylic acid) or phosphate buffer pH 7.38 (ibuprofen lysine salt and naproxen) was determined in vitro with the paddle method. This procedure took up to 90 min. Acetylsalicylic acid and salicylic acid were almost completely released from the starch film as early as in the first minutes of the procedure, with a maximum value of around 90%. The release of ibuprofen lysine salt and naproxen in the form of acid from the starch film was partial, about 40%. The release of naproxen sodium from the starch film was time-proportional, and there was a tendency towards further release.

Rheology, dynamic light scattering and physicochemical characterization of octenyl succinic anhydride (OSA) modified starch in aqueous solution.

Physicochemical and rheological properties of hydrophobically modified starch by octenyl succinic anhydride (OSA) have been evaluated in order to investigate the effects of concentration and temperature on its aggregation phenomenon in an aqueous solution. The analysis of particle size distribution showed the existence of two modes of aggregation by intramolecular bonds, whereas beyond the critical aggregation concentration a second population appears which seems to be induced by the intermolecular interactions. From the rheological analysis of OSA starch solutions, three behaviour classes were observed. The first class presents a non-Newtonian shear-thinning behavior characterized by two Newtonian regions. The second class exhibits a gel like behavior due to the entanglement of the macromolecular chains by intermolecular bonds, where its destructuring makes it possible to find the first morphology of the aggregated macromolecules. The third class exhibits a liquid behavior in a concentrated domain due to the phase separation between the modified and unmodified parts. Otherwise, the thermo-rheological analysis demonstrated indeed the presence of a thermosensitive behavior in tangled solutions of OSA starch.

Lignin-containing coatings for packaging materials

Abstract The mechanical properties and chemical stability in water of self-supporting films made from aqueous solutions of starch and lignin, and the barrier properties of paperboard coated with solutions of these polymers have been studied. The dissolution of starch from the starch-lignin films in contact with the model liquids was decreased significantly when lignin was added to the starch films. The addition of ammonium zirconium carbonate (AZC) to the formulations as a crosslinking agent substantially increased the storage modulus of the starch-lignin films, which indicated that crosslinking had occurred. The addition of AZC to the formulations also led to a decrease in dissolution of both starch and lignin from the starch-lignin films in contact with model liquids. The effect of AZC on the water stability of the films was greater when the pH of the starch-lignin-AZC solution was adjusted with ammonia rather than NaOH. The addition of NH4Cl solution as a presumed catalyst to the recipe when the pH adjustment was performed with NaOH did not improve the effect of AZC on the water stability of the films. The water vapour transmission rate of the coated paperboard decreased slightly when AZC was added to the coating formulation.

Investigations of benzo[a]pyrene encapsulation and Fenton degradation by starch nanoparticles

Starch nanoparticles were produced by dialysis method from octenyl succinic anhydre (OSA) and 1,4-butane sultone (BS). The properties of the self-assembled nanoparticles were characterized by NMR spectroscopy (DOSY), fluorescence spectroscopy and dynamic light scattering (DLS). In order to investigate the formation of hydrophobic microdomains, the Nile Red dye was used as a fluorescent probe to evaluate the critical aggregation concentration (CAC) of modified starch in aqueous solution. The results show that the entrapment of the molecular guest was effective and only restricted by the solubility limit of the starch. Then, the modified starch was applied to solubilize benzo[a]pyrene (BaP) in view of degradation by Fenton process. Finally, it has been shown that 95% of BaP was degraded when it was encapsulated in OSA-BS-starch nanoparticles.