Starch Layer Research Articles

Molecular Structure and Properties of Resistant Dextrins from Potato Starch Prepared by Microwave Heating.

The dextrinization of potato starch was performed using a sophisticated single-mode microwave reactor with temperature and pressure control using 10 cycles of heating with stirring between cycles. Microwave power from 150 to 250 W, a cycle time from 15 to 25 s, and two types of vessels with different internal diameters (12 and 24 mm) and therefore different thicknesses of the heated starch layer were used in order to estimate the impact of vessel size used for microwave dextrinization. The characteristics of resistant dextrins (RD) including solubility in water, total dietary fiber (TDF) content, color parameters, the share of various glycosidic bonds, and pasting and rheological properties were carried out. The applied conditions allowed us to obtain RDs with water solubility up to 74% at 20 °C, as well as TDF content up to 47%, with a predominance of low-molecular-weight soluble fiber fraction, with increased content of non-starch glycosidic bonds, negligible viscosity, and a slightly beige color. The geometry of the reaction vessel influenced the properties of dextrins obtained under the same heating power, time, and repetition amounts. Among the conditions used, the most favorable conditions were heating 10 times for 20 s at 200 W in a 10 mL vessel and the least favorable were 15 s cycles.

Relationship between internal structure and in vitro digestibility of A- and B-type wheat starch revealed by chemical surface gelatinization

In this study, the properties of remaining starch granules obtained with different degrees of exfoliation were explored by removing the outer layers of A- and B-type wheat starch (AWS and BWS) granules with chemical surface gelatinization. SEM images revealed significant morphological variations with increasing exfoliation. CLSM and amylose content analysis indicated a predominance of lipid complexes in the outer granule layers, particularly in BWS. The structural characteristics of AWS and BWS were analyzed using PLM, XRD, FT-IR and DSC, verifying the conclusion of the alternation of starch crystalline and amorphous zone. And the amorphous regions are proportionally higher in the inner starch layer. Moreover, raw AWS and BWS granules were more easily digested from the outside in, with the RS content decreasing from 80.65 % to 66.92 % and 49.06 % to 45.01 %, respectively. The RS content of cooked WS were affected by the internally structures, particularly lipid content (11.46 % – 19.09 %) in BWS outer layers and amylose content (13.59 % – 19.43 %) in the inner layers. These results revealed the internal radial structural differences and digestibility patterns of AWS and BWS granules.

Antioxidant efficacy of amino acids on vitamin A palmitate encapsulated in OSA-starch electrosprayed core-shell microcapsules

The encapsulation and the oxidative stability of vitamin retinyl palmitate (AP), a vitamin A derivative, within coaxial electrosprayed (AP) core – octenyl succinic anhydride (OSA-modified starch) shell microcapsules were investigated. The antioxidant efficiency of amino acids (AAs) (namely histidine, leucine, valine, tryptophan, tyrosine, cysteine and lysine) added to the core, on the oxidative stability of AP was evaluated using differential scanning calorimetry at the isothermal temperature of 140 °C. Confocal microscopy confirmed the location of the AP within the core with AAs microcapsules, surrounded by the shell layer of OSA starch. Scanning electron microscopy revealed that the microcapsules are uniform in size with an average diameter ranging from 2.06 ± 1.05 to 2.41 ± 1.42 μm. The AAs contributed substantially to enhance the oxidative stability of AP, with histidine being the most efficient with an improvement in oxidative stability of about 214 times, while lysine showed the lowest protection (about 3.9 times), compared to non-encapsulated AP. For the encapsulated AP, the presence of histidine or lysine enhanced the oxidative stability of the vitamin by about 70.6 or 1.3 times, respectively. The enhancement of the oxidative stability was mainly due to both the hydrophobic interactions formed between AP and AAs, and the adsorption of AP on the surface of AAs crystals (except lysine), assisted by the suspension of the AAs in ethanol antisolvent, as confirmed with attenuated total reflection–Fourier transform infrared (ATR–FTIR) and X-ray diffraction (XRD) analyses.

Retrogradation inhibition and intragranular distribution in cooked rice by addition of α-glucosidase (AG) and branching enzyme (BE)

The effect of inhibiting retrogradation and changes in chain length distribution by AG and BE, which are texture-modifying enzymes, has been clarified. To ascertain in which part of the rice grain retrogradation occurs and which enzymes is most effective, the degree of retrogradation in each part of the rice grain was measured from the surface to the core of the same rice grain using a synchrotron radiation X-ray beam with a beam size of 100 μm. Retrogradation was effectively suppressed at all measurement sites by enzyme addition, although the effect of enzymes was greater at the surface. Rice grain sections were stained with iodine and eosin. A starch layer that does not easily form a complex with iodine was observed inside the protein layer at the surface of cooked rice. A starch layer with a long molecular chain that forms complexes with iodine was observed inside the rice grain.

Effects of starch gelatinisation and water migration on the hardness of parboiled rice

SummaryParboiled rice is well known for its high nutritional value, while its firm texture is still challenging to accept by consumers. In this study, the effects of starch gelatinisation and water migration on the increased hardness of parboiled rice were investigated. The hardness of parboiled rice was affected by starch gelatinisation, displaying an increasing trend with an increasing degree of starch gelatinisation (DSG). Examination of the water migration characteristics during soaking showed that the water uptake capacity of parboiled rice was significantly enhanced. Compared to white rice soaked at 90 °C, the water molecules in parboiled rice were restricted to the outer layer of starch. Significant correlations between rice hardness, DSG and moisture absorption‐related parameters were established, indicating that gelatinised starch limits the migration of water to the inside of the rice kernel, resulting in a firm rice grain. These results enhance the understanding of starch gelatinisation by parboiling and water migration properties during the cooking process of parboiled rice. This study provided new insights into the regulation of hardness by parboiled rice processing.

A comparative study on digestion and SEM based topological behaviour of six native starches hydrolysed using porcine pancreatic enzymes

The variation in structure and function of any biomolecule plays a vital role as far as the digestibility, absorption and other metabolic regulations are concerned. The amorphous to crystalline arrangement of any starchy granule reflects the polymorphic type and so-forth determines the digestion pattern as rapid, slow or resistant. The granule morphology in its native form and its ultrastructural arrangement are also crucial factors in determining the digestion behaviour of any native starch granule. The present study depicted that the digestion profile of any starchy granule is not only dictated by the compositional variation of amylose to amylopectin ratio but also the thickness of the granule layer. Although the native starch of banana and potato resisted digestion by porcine pancreatic enzymes due to the presence of thick granule layer, but the thin granule layer of taro, cassava, rice and maize starch were not able to resist the action of hydrolytic enzymes.

Dynamically Responsive and Ionic Conductive Gel Coatings to Realize the Stable Circulation of Zinc Metal Anodes for Zinc-Ion Batteries

Dendrite growth, hydrogen evolution, and corrosion reactions of zinc (Zn) metal anodes deteriorate the cyclic performance and hinder the commercial application of high-safety aqueous Zn-ion batteries. Herein, a hydroxyl-rich starch (SS) layer is rationally constructed on Zn anodes (Zn@SS) through a facile coating process to tune the Zn electroplating homogeneity and reduce adverse reactions with the electrolyte. SS layers with strong chelating ability can in situ coordinate with Zn2+ ions within the aqueous electrolyte and form ionic conductive gels, which can decrease the contact area, facilitate ion transportation from the ZnSO4 electrolyte to the metallic Zn anodes, and regulate the plating behavior for Zn2+ ions. Zn@SS symmetrical cells show a prolonged circulation of 3000 h at 2 mA cm–2. Even at a large charge/discharge depth of 5 mAh cm–2, Zn@SS symmetric cells can provide a long lifetime of 1000 h. Zn@SS-V2O5 full cells can operate for 1000 cycles at 1 A g–1. This article offers a novel approach for the surface protection of Zn metal anodes through the construction of dynamic ionic conductive gel layers and widens the applied field of renewable and biodegradable starch-based biomass materials.

Thermo-sensitive amylase-starch double-layer polymer nanoparticles with self-polishing and protein corona-free property for drug delivery applications

Protein corona formation can lead to obstructive screening of targeting groups of nanoparticles (NPs). Also, the targeting groups are subjected to physiochemical interactions when exposed to solvents. Here, these two factors can influence NP targeting efficiency. Therefore, it is necessary to prepare a general method of preparing an anti-fouling NPs with protected targeting groups. Here, we designed α-amylase-starch double-layer coated poly (methyl methacrylate-co-acrylic acid) NPs (α-ams-SCMMA NPs), functionalized with aptamer targeting groups and doped with Tetrakis(para-hydraoxylphenyl) porphyrin (TPPOH) as a payload drug. Natural polysaccharide starch and enzyme α-amylase were applied here for thermo-sensitive activation of starch hydrolyzation in order to render the NPs' self-polishing from protein corona effects. During incubation with serum media, the protein corona was formed at the exterior shell of NPs, while the self-polishing process was activated to remove the “protein fouling” when the incubation temperature increased to 37 °C (body temperature). Mechanistically, the starch layer of α-ams-SCMMA NPs was readily hydrolysed by α-amylase, whereby the adsorbed protein corona could be efficiently eliminated and the targeting groups were then presented. With this unique self-polishing NP design, we believe our method can be applied for potential NP applications in cancer therepy due to excellent antifouling property and protected targeting groups.

Characteristics of corn starch-based edible coating enriched with curry leaf extract on quality of the strawberry (Fragaria x ananassa Duch.)

Strawberry is one of the most popular tropical fruits in Indonesia. The fruit has a concise shelf life and quickly deterioration after harvesting due to mechanical injury, physiological disorders, water loss, fungal growth, and high respiration rates. Postharvest technology is one technique that can maintain fruit quality and extend shelf life, one of which is a coating technique called edible coating. The edible coating layer of corn starch with the addition of curry leaf extract has antibacterial activity that can inhibit the growth rate of microorganisms. This study aimed to determine the characteristics of the edible coating solution produced from corn starch with the addition of curry leaf extract to produce the best edible coating layer. This study used a factorial completely randomized design experimental method, which consisted of treatment with curry leaf extract concentration (8%, 10%, and 12%) and dipping time (4, 5, and 6 minutes) with three repetitions. The result showed a significant delay in weight loss and total dissolved solids in strawberries compared to the uncoated control strawberries. In addition, the edible coatings had positive results in organoleptic based on panelists’ acceptance of color, aroma, taste, texture, and overall. These findings suggest that using 8% curry leaf extract with 4 minutes dipping time could be favorable to extend the shelf-life and maintain the quality of strawberry fruit.

Starch Capped Atomically Thin CuS Nanocrystals for Efficient Photothermal Therapy (Small 47/2021)

Starch Capped CuS Nanocrystals In article number 2103461, Christian Engelbrekt, Lixin Ma, and co-workers report a one-pot synthesis of starch-capped ultrathin CuS nanocrystals with efficient cancer photothermal therapy capacity. The starch layer endows CuS nanocrystals with enhanced photothermal efficacy by increasing the free carrier density and effectively assigning the localized surface plasmon resonance at specific optical wavelength.

Starch Capped Atomically Thin CuS Nanocrystals for Efficient Photothermal Therapy.

Photothermal therapy requires efficient plasmonic nanomaterials with small size, good water dispersibility, and biocompatibility. This work reports a one-pot, 2-min synthesis strategy for ultrathin CuS nanocrystals (NCs) with precisely tunable size and localized surface plasmon resonance (LSPR), where a single-starch-layer coating leads to a high LSPR absorption at the near-IR wavelength 980nm. The CuS NC diameter increases from 4.7 (1nm height along [101]) to 28.6nm (4.9nm height along [001]) accompanied by LSPR redshift from 978 to 1200nm, as the precursor ratio decreases from 1 to 0.125. Photothermal temperature increases by 38.6°C in 50mg L-1 CuS NC solution under laser illumination (980nm, 1.44 W cm-2 ). Notably, 98.4% of human prostate cancer PC-3/Luc+ cells are killed by as little as 5mg L-1 starch-coated CuS NCs with 3-min laser treatment, whereas CuS NCs without starch cause insignificant cell death. LSPR modeling discloses that the starch layer enhances the photothermal effect by significantly increasing the free carrier density and blue-shifting the LSPR toward 980nm. This study not only presents a new type of photothermally highly efficient ultrathin CuS NCs, but also offers in-depth LSPR modeling investigations useful for other photothermal nanomaterial designs.

Characteristics of Pigment Distribution in the Pigmentized Surface-Sizing Films

The distribution of inorganic pigments in the pigmentized sizing layer was investigated to understand the basic behavior of pigment particles in the surface-sizing layer. The distribution and arrangement of two ground calcium carbonates and two kaolin clays in the surface-sized starch layer were investigated using scanning electron microscopy and image analysis. When coarse ground calcium carbonate or clay with a low aspect ratio was used, the tendency of the pigment to be exposed to the outside of the starch film increased. The plate-shaped clay had a significantly higher surface retention than ground calcium carbonates, which greatly improved the coverage of the base paper by pigment.

Pengaruh Penyetelan Squeezing Roll Pada Mesin Sizing Terhadap Kekuatan Benang

The process of applying starch to the warp yarn in order to increase the weaving power of the warp yarn in the presence of a starch layer, is expected to increase the strength of the yarn and reduce the yarn hairs. One of the factors that influence the sizing process is the amount of pressure in the squeezing roll. In this process, the sizing machine uses a double size box and each size box has 2 (two) squeezing rolls. The material used is Combed Ne 40 yarn with construction ,which is the amount of tetal or the density of the yarn with the construction included in the tetal of the dense warp yarn. The method used by comparing the pressure of squeezing roll process 1 and process 2. In the first process, the squeezing roll 1 is set at 3 kN and squeezing roll 2 is 3.5 kN, while in the second sizing process, the squeezing roll 1 is set at 4 kN and squeezing roll 2 for 5kN. After the experimental process was carried out, the starch warp yarn strength was obtained which was higher, namely 351.93gr and compared to process 2 which was 345.84 gr. The higher from the strength of the starchy yarn, can make it better for weaving process.

Study of Cassava Starch Layer on Zinc Anode by Electrochemistry Method for Zinc-air Fuel Cell System

In this study, cassava starch was prepared as conductive biodegradable material on zinc anode in zinc-air fuel cell system by using electrochemistry method. Successful formation of cassava layer on zinc anode was determined by its conductivity values by using four-point probe instrument and the enhancement of conductivity of anode after the deposition of cassava starch was proven. The optimization of conductivity study was further carried out in different concentrations of cassava. It was shown the increment about 30% from 0.079 to 0.105 Scm−1 of conductivity values from original conductivity of pure zinc. Moreover, SEM analysis exhibits the morphology of cassava coated on zinc plate with distinct particle structure was observed, proving the successful formation of cassava layer via electrochemical method. Hence, the discharge profile analysis highlighted the composition of C3 of CS performed best performance in ZAFC system.

The Influence of Multilayer, “Sandwich” Package on the Freshness of Bread after 72 h Storage

The goal of this research was to evaluate a polymeric system, including biopolymers, as a multi-component material coating on paperboard for bread. The main aim of the research was to create a humidity-controlling packaging material. This means that the packaging material should contain filler which will absorb water or water vapour from the bread. The ideal packaging should have high barrier qualities against water vapour, enabling the possible release of water from the product (to maintain proper humidity inside the packaging). The preliminary storage tests made of the bread confirmed that the freshness of a product kept in a climatic chamber in RH = 70% was the highest. To summarise, the obtained packaging should maintain the required humidity (in the case of bread, the optimal humidity is 70%) within the packaging to keep the bread fresh after more than 72 h of storage. A “sandwich” form of (multilayer) packaging was indicated as a solution to this problem. The main objective of this packaging was to obtain two paper layers and one starch layer to increase water absorption from the bread. It was also important to obtain a thin, external hydrophobic layer to decrease the water vapour transmission rate of the packaging (WVTR). A number of ‘’sandwich” packaging types were prepared, consisting of two sheets of paper with an external aquaseal coating and an internal starch coating (with a NaCl filler). The covered ‘’sandwich” papers were then used to create packaging that could be used for the bread storage tests. The study results confirmed that the bread stored for 72 h in the “sandwich” packaging was found to be fresher than the same product stored in commercial paper packaging.

Biodegradable sandwich-architectured films derived from pea starch and polylactic acid with enhanced shelf-life for fruit preservation

The development of biopolymer films is crucial for the replacement of conventional plastics. Tremendous effort is made to improve their performances by introducing biopolymers through the film manufacturing process. Herein, a sandwich-architectured film was proposed to efficiently improve the adhesion between the PS and PLA layers by using octenyl succinic anhydride-modified pea starch (OMPS) layer as the interlayer, leading to a highly mechanically enhanced interpenetrating network. Accordingly, the properties of the films were enhanced due to the synergism effect of sandwich architecture. In particular, the WVP value of the sandwich-architectured films (0.25 ∼ 0.89×10−10g·m-1·s-1·Pa-1) decreased more than 7-fold compared with the OMPS20 film, and the OP value of the sandwich-architectured films (0.256 ∼ 1.229×10-12cm3·m·m-2·s-1·Pa-1) decreased more than 10-fold in comparison to the PLA film. Benefitting from the characteristics investigated above, the films exhibited a favorable effect on strawberry storage. Overall, the fabricated eco-friendly sandwich-architectured films have shown great potential for biodegradable packaging applications.

Regulating effects of citric acid and pregelatinized starch on selective flocculation flotation of micro-fine siderite

To improve the beneficiation efficiency of carbonate-bearing iron ore, a selective-flocculation flotation method was developed to separate micro-fine siderite with citric acid and pregelatinized starch, which serve as the dispersant and the flocculant, respectively. Given that pregelatinized starch may have adverse effects on dispersion effect of citric acid, the regulating effects of these two species on the selective flocculation flotation of micro-fine siderite were examined by micro-flotation of artificially mixed ores and molecular dynamics simulations. The analyses of particle-size distribution and aggregation behaviour showed that citric acid effectively decreased the attachment of micro-fine siderite to hematite and quartz. In contrast, micro-fine siderite formed flocs selectively with pregelatinized starch. Molecular dynamics calculations revealed that citric acid and pregelatinized starch could co-adsorb on siderite. Collector molecules of sodium oleate penetrated the adsorption layer and thus were adsorbed onto siderite. However, sodium oleate was unable to penetrate the dense pregelatinized starch layer on hematite. Furthermore, both pregelatinized starch and sodium oleate were barely adsorbed onto quartz. The regulating effects of citric acid and pregelatinized starch improved the selective flocculation flotation of micro-fine siderite. The FeO content of the ore was 5.15%, and this was increased to 20.15% by the above treatment, with a recovery rate of 71.08%.

Mechanical characterization of functional graphene nanoplatelets coated natural and synthetic fiber yarns using polymeric binders

ABSTRACT Fabrication of electrically conductive yarns (glass, flax and polypropylene fibers) coated with graphene nanoparticles (GNP) were characterized for their mechanical properties and compared with their electrical properties. The composites were produced with the use of polymeric binders (epoxy resin and thermoplastic starch) and two different dip-coating methodologies were developed to create the coating layers. Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio, which was coated on the yarns. The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface, coating method and effective binder. Tensile properties of the yarns were measured by an appropriate standard, and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa. The composites of starch-based showed poor mechanical performance compared to those of epoxy ones. This was due to poor adhesion between the surface and starch layer (interphase) where the Van der Wall’s force was quite low. Electrical conductivity, glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.

Cold plasma treatment to improve the adhesion of cassava starch films onto PCL and PLA surface

Since starch hydrophilicity makes it difficult to be used as packaging material, its combination with synthetic biodegradable polymers is an alternative of interest. In this work, atmospheric air cold plasma was used as an adhesion improver between polycaprolactone (PCL) or poly(lactic acid) (PLA) and starch layers, in order to produce multilayer films. For this, a barrier dielectric discharge plasma reactor was used, at ambient temperature and atmospheric pressure. The treatment of PCL and PLA films resulted in increase of the surface roughness and decrease of the water contact angle. Multilayer films (PCL-, PLA-starch) were produced after plasma treatment. Adhesion of starch films onto both PCL and PLA surfaces was improved with plasma treatment, and the delamination resistance increased with treatment time. The best adhesion was obtained for PLA-starch film with 10 min of plasma treatment, resulting in no delamination. The water vapor barrier of the multilayer films was significantly higher than of starch films, while the mechanical properties were similar to those found for PCL/PLA films, showing that these multilayer films are promising for package applications.

Preparation and properties of paper coating based bilayer of starch and shellac composites

The preparation and properties of paper coating based bilayer of starch and shellac composites has been investigated in the present report. The bilayer coating were prepared by coating the surface of the paper using starch as first layer then shellac was coated on the surface of the starch layer. Composition of the bilayer composites of starch/shellac was 20:80, 30:70, 40:60, 50:50; 60:40; 70:30; 80:20; % w/w. The Payne Cup Analysis showed that the water vapour barrier properties of starch/shellac increased with the increased of shellac concentration, and very significant improvement was achieved when shellac concentration was above 50 wt%. The grease resistance of the sample was better than that of conventional paper coating. The Diffuse Reflectance UV showed that the transparency of the samples did not change by the presence of the bilayer composites. XRD indicatedd that the stability of shellac was improved by the presence of starch.