Weight Ratio Of Starch Research Articles

Preparation of cassava starch-gelatin yolk-shell microspheres by water-in-water emulsion method

This paper reports the preparation and characterization of gelatin-cassava starch microspheres using the water-in-water emulsion technique. The effects of different weight ratios (10: 0, 9: 1, 8: 2, 7: 3, 6: 4, 5: 5) of starch to gelatin on the morphology, structure, thermal properties, and stability of microspheres were investigated. The morphology results showed that most microspheres had spherical shapes and smooth surfaces. When the weight ratio of starch to gelatin was 5: 5, the prepared microspheres formed a stable yolk-shell structure. The swelling capacity of the microspheres increased with the proportion of gelatin, up to 682.3 %. The gelatin and starch in the microspheres were compatible but not miscible. Compared with the native starch, the crystalline structure of microspheres changed from A-type to a mixture of B-type and V-type, and the relative crystallinity decreased. Differential scanning calorimetry results showed that the melting of microspheres involved both gelatin dissolution and starch gelatinization. Due to the formation of composite microspheres, the starch content decreased, and the release of reducing sugars from the microspheres upon hydrolysis was reduced. The gelatin-cassava starch microspheres are simple to prepare, biocompatible, and can be used as a potential material for microencapsulation.

Starch/ Polyvinyl Alcohol (PVA) Blend Bioplastics: Synthesis and Physicochemical Properties

Starch-based bioplastics are prepared from the waste of food materials and are widely used as the short-lived biodegradable plastic for household and food packaging applications. In this work, glycerol plasticized starch (extracted from potato peels)bioplastics blended with Polyvinyl Alcohol (PVA) in various compositions (wt.-%) were prepared, and characterized using Fourier Transform Infrared (FTIR) spectroscopy and their physicochemical properties such as water absorption, biodegradable properties, and acid-base resistance were investigated. The FTIR spectra of starch-based bioplastics blended with PVA of the peak at 2924 cm-1 portrayed good compatibility between starch bioplastics and PVA. The water absorption test showed that the increase in starch proportion in starch/PVA blend increases water absorption capacity. The higher weight ratio of starch in starch/ PVA blend bioplastics degraded more rapidly than other bioplastics. Furthermore, the bioplastics of higher starch content resist acid and base for 45 and 42 hours respectively without being dissolved.

Sterile and Dual-Porous Aerogels Scaffolds Obtained through a Multistep Supercritical CO₂-Based Approach.

Aerogels from natural polymers are endowed with attractive textural and biological properties for biomedical applications due to their high open mesoporosity, low density, and reduced toxicity. Nevertheless, the lack of macroporosity in the aerogel structure and of a sterilization method suitable for these materials restrict their use for regenerative medicine purposes and prompt the research on getting ready-to-implant dual (macro + meso)porous aerogels. In this work, zein, a family of proteins present in materials for tissue engineering, was evaluated as a sacrificial porogen to obtain macroporous starch aerogels. This approach was particularly advantageous since it could be integrated in the conventional aerogel processing method without extra leaching steps. Physicochemical, morphological, and mechanical characterization were performed to study the effect of porogen zein at various proportions (0:1, 1:2, and 1:1 zein:starch weight ratio) on the properties of the obtained starch-based aerogels. From a forward-looking perspective for its clinical application, a supercritical CO2 sterilization treatment was implemented for these aerogels. The sterilization efficacy and the influence of the treatment on the aerogel final properties were evaluated mainly in terms of absence of microbial growth, cytocompatibility, as well as physicochemical, structural, and mechanical modifications.

Starch/chitosan/glycerol films produced from low-value biomass: effect of starch source and weight ratio on film properties

Films based on chitosan from giant squid (Dosidicus gigas) residual endoskeleton, starch from different low-value agroindustrial byproducts and glycerol were successfully obtained. Four starch sources and three different weight ratios (1/1, 2/1 and 5/1 of starch/chitosan) were used. Applying a statistical design of completely randomized blocks, the effect of starch source and weight ratio on the film properties were evaluated. The starch source did not affect any of the tested properties. However, film properties such as thickness, water solubility, water vapor permeability, elongation, and tensile strength revealed significant differences (p<0.01) related to the starch weight ratio in the films. A higher starch weight ratio led to lower water solubility; nevertheless, the higher starch weight ratio led to films with higher thickness, water vapor permeability and tensile strength.

Performance of binders in briquetting of durian peel as a solid biofuel

As a consequence of an increasing in durian season in a year, many durian peels become a garbage. However, the valuable contents in durian peel namely lignin and cellulose are wasted away. These contents have high possibility to be modified as a biofuel. The purpose of this current study is to investigate the effect of binders on briquetting of durian peel, particularly modification of starch composition as a binder. In this study, the durian peel was treated by drying, milling and carbonization at 370 oC. The binders were starch and calcium hydroxide. The ratio between durian peel and various binders was 4 % of weight. In binding with starch, the weight ratio of starch and water as a solvent was modified by 1:4, 1:8 and 1:12 respectively. The durian peels were mixture physically with binders and formed into cylindrical shape. Analysis on briquette involved proximate analysis, theoretical calorific value and compressive test. The calorific value revealed that briquette non-carbonized has highest theoretical calorific value (18.62 MJ/kg) and its compressive test was 130.19 MPa. The present study has found that starch and calcium hydroxide could be applied as a binder for briquetting of durian peel as a solid biofuel

Highly-sensitive electrochemical sensing platforms for food colourants based on the property-tuning of porous carbon

It is very challenging to develop highly-sensitive analytical platforms for toxic synthetic colourants that widely added in food samples. Herein, a series of porous carbon (PC) was prepared using CaCO3 nanoparticles (nano-CaCO3) as the hard template and starch as the carbon precursor. Characterizations of scanning electron microscopy and transmission electron microscopy indicated that the morphology and porous structure were controlled by the weight ratio of starch and nano-CaCO3. The electrochemical behaviours of four kinds of widely-used food colourants, Sunset yellow, Tartrazine, Ponceau 4R and Allura red, were studied. On the surface of PC samples, the oxidation signals of colourants enhanced obviously, and more importantly, the signal enhancement abilities of PC were also dependent on the starch/nano-CaCO3 weight ratio. The greatly-increased electron transfer ability and accumulation efficiency were the main reason for the enhanced signals of colourants, as confirmed by electrochemical impedance spectroscopy and chronocoulometry. The prepared PC-2 sample by 1:1 starch/nano-CaCO3 weight ratio was more active for the oxidation of food colourtants, and increased the signals by 89.4-fold, 79.3-fold, 47.3-fold and 50.7-fold for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. As a result, a highly-sensitive electrochemical sensing platform was developed, and the detection limits were 1.4, 3.5, 2.1 and 1.7 μg L−1 for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. The practical application of this new sensing platform was demonstrated using drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography.

Tuning the Pore Size of Monodisperse SBA-15 Spheres

A flexible, controllable and facile synthesis route was presented in the synthesis of spherical particles of mesoporous SBA-15 with diameter up to 28 nm, and particle diameter of 3-5 µm. The structures and morphology of these materials were characterized by powder X-ray diffraction (XRD), nitrogen adsorption analysis and scanning electron micrographs (SEM). The relationship between the porous property of silica and the weight ratio of starch to TMB were discussed. It indicates that the weight ratio of starch to TMB have a significant effect on the pore size, the surface area and also contribute to a narrow pore size distribution.

Preparation of corn starch-g-polystyrene copolymer in ionic liquid: 1-ethyl-3-methylimidazolium acetate.

The copolymer of starch grafted with polystyrene (starch-g-PS) was synthesized with high grafting percentage by utilizing the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) as solvent and potassium persulfate as initiator. The effect of various parameters upon the polymerization were studied including: initiator concentration, styrene:starch weight ratio, the reaction time and temperature. Grafting percentages were calculated using an FT-IR calibration method, with values up to 114%. The resulting copolymer was characterized using FT-IR, SEM, WAXD and TGA, which demonstrated that polystyrene side chains were evenly distributed on the starch backbone. Our results indicate that ionic liquid dissolution of starch, prior to polystyrene grafting, is a versatile methodology for the synthesis of amphiphilic, polysaccharide-based graft copolymers, having high grafting percent.

Utilization of Cassava Starch in Copolymerisation of Superabsorbent Polymer Composite (SAPC)

Cassava starch was used as the main chain in the copolymerization of a superabsorbent polymer composite (SAPC) based on acrylic acid and bentonite. The SAPC was synthesized through graft polymerization using nano-sized bentonite as reinforcement. The variables in this experiment were: bentonite concentration, acrylic acid to starch weight ratio, concentration of initiator, and cross linker. The product was characterized using FTIR, SEM and TGA-DSC. The results show that the polymerization reactions involved processes of incorporating starch chains as polymer backbone and grafting acrylic acid monomers onto it. The use of cassava starch in the polymerisation produced a very short reaction time (10-15 minutes), which led to SAPC production with higher efficiency and lower cost. Bentonite interacts with monomers via hydrogen and weak bonding, thus improving the thermal properties of the product. The maximum absorbance capacity obtained was at an acrylic acid to starch weight ratio of 5 and a concentration of initiator, cross linker and bentonite of 0.5, 0.05 and 2 weight percent, respectively. The product is suitable for agricultural and medical applications as well as common superabsorbent polymer applications.

Optimization of reaction conditions for resistant Canna edulis Ker starch phosphorylation and its structural characterization

Response surface methodology was employed to study phosphorous (P) and resistant starch (RS) content of resistant Canna edulis Ker starch phosphate monoester by starch phosphorylation with sodium mono- and dihydrogen orthophosphate. A five-level-four-factor central composite design was used for maximizing the P and RS content. The optimal reaction conditions obtained were NaH 2PO 4·2H 2O to Na 2HPO 4·12H 2O molar ratio of 1:0.44, phosphate sodium to starch weight ratio of 1.76:1, reaction temperature of 131.6 °C and reaction time of 2.43 h. The theoretical P and RS content were attained to about 0.58 and 73.17%, respectively. P and RS content experimentally obtained were 0.55 and 71.93%, in agreement with the predicted values. In addition, the structural characteristic of the purified starch phosphate monoester was investigated by 31P-nuclear magnetic resonance ( 31P-NMR), fourier transform-infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).

Synthesis and characterization of starch-modified polyurethane

Corn starch was reacted with urethane prepolymer in order to modifying starch and preparing new hydrophobic copolymers. These copolymers were prepared by two-step reactions. The polycaprolactone terminated hexamethylene diisocyanate (HDI) (as prepolymer) was prepared by introducing diisocyanate on both ends of PCL at a molar ratio of 1:2 (PCL:HDI). The grafting was performed by addition of polycaprolactone based prepolymer to starch solution of DMSO with different weight ratio of starch and prepolymer. The samples were characterized and examined by FTIR and 1H NMR spectroscopy, DSC analysis, and scanning electron microscopy (SEM). By introducing NCO groups onto the PCL terminals, the FTIR spectrum shows a new sharp peak, representing the NCO groups and formation of prepolymer. By grafting this prepolymer onto starch a NH and urethane band were appeared. The effect of prepolymer percentage on hydrophobicity was measured through contact angle and it was found that increases with increasing amount of prepolymer. Glass transition temperature ( T g) is also affected with increasing amount of urethane linkages. Surface morphology of modified starch was studied by SEM. It was observed that the surfaces of modified starch are rougher and disordered than the surface of unmodified starch particles. This confirms the grafting and modification of starch. This modified starch can be used as filler in biodegradable starch based polymers.

Starch-chitosan hydrogels prepared by reductive alkylation cross-linking.

Starch-chitosan hydrogels were produced by oxidation of soluble starch to produce polyaldehyde and subsequently cross-linked with chitosan via reductive alkylation. The swelling ratio of starch-chitosan membranes was increased gradually with increasing starch ratio, but it was always lower than the native chitosan. In dry state, starch-chitosan membranes with low starch ratio (0.16, 0.38) showed similar tensile strength values to those of native chitosan while these values decreased with increasing starch ratios (0.73-1.36). Membranes in physiological buffer solution (PBS) gave a tensile modulus between 2.8 and 1.0 MPa, decreasing with increasing starch ratio (0.16-1.36 (Wstarch/Wchitosan)). When the membranes were incubated in PBS only, a moderate weight loss was observed for the first two weeks. Original weights of low starch weight ratio membranes (0-0.38) were at near 85%, while high ratio samples (0.73-1.55) were kept around 70% after three months. However, for the membranes incubated in alpha-amylase solution, very fast weight loss was observed. For low starch ratio membranes (0.16, 0.38, 0.73), the residual original weights were measured to be 11%, 6%, 20%, while for high ratio membranes (1.04 and 1.36) these were 45% and 30%, respectively, after two months of enzyme incubation. Scanning electron microscopy analysis of alpha-amylase degraded membranes exhibited rough surface morphology.

Effect of polyhydroxy compounds on structure formation in waxy maize starch gels: a calorimetric study

The effects of polyhydroxy compounds (PHCs) on structure formation in ageing waxy maize starch gels were investigated by measuring the retrogradation endotherm ( ΔH) using calorimetry. Changes in retrogradation kinetics observed by addition of PHCs at a weight ratio of starch: PHC: water of 1 : 0·5 : 1·5 were solute specific. In the homologous series of glucose oligomers, maltotriose exhibited the largest inhibitory effect, while maltooctaose promoted retrogradation. Among various pentose and hexose sugars, ribose and talose, respectively, were the most effective in retarding retrogradation. Fructose led to increased rates of chain ordering, particularly at high concentrations. The results were correlated with literature data of several physicochemical properties of PHCs in solution. Strong linear relationships were shown between the effect of sugars on retrogradation endotherm and the hydration characteristics of these solutes. It was further suggested that compatibility of sugar with the water structure, as governed by the stereochemistry of the main sugar conformers in solution, is an important determinant of amylopectin stability in the composite gel matrix; i.e. PHCs which disturb very little the hydrogen-bonded network of water are also effective in inhibiting retrogradation.

Starch‐g‐Poly(Methyl Acrylate) Latexes for Stabilizing Soil to Water Erosion: Extending the Range of Polymer Add‐On

AbstractCationic starch‐g‐polymer latexes stabilize soil particles to water. To extend the study of such utility of starch latexes we prepared starch‐g‐poly(methyl acrylate) (S‐g‐PMA) and cationic starch‐g‐poly(methyl acrylate) (CS‐g‐PMA) latexes by the ceric‐initiation procedure, varying the weight ratio of starch or cationic starch to methyl acrylate from (10 to 1) to (1 to 1) in the preparation step. The percent add‐on (percent synthetic polymer in the graft copolymer) ranged from 0.5% to 41% for S‐g‐PMA, and from 4.6% to 43% for CS‐g‐PMA. Application rates required to obtain stable soil are dictated by the amount of PMA in the graft copolymer. For instance, wet sieve testing showed that 10S‐g‐1PMA and 10CS‐g‐1PMA latexes required dose levels of 0.4 g/100 g soil to fully stabilize the test soils. (6–8)S‐g‐1PMA and (6–8)CS‐g‐1PMA latexes gave full stabilization when applied at 0.1 g or 0.2 g/100 g soil rate. Latexes with highest (24.4%–43%) add‐on stabilized soil fully at an application rate of 0.1 g/100 g soil or less. There was no clear advantage of CS‐g‐PMA over S‐g‐PMA.