Starch Nanocrystals Research Articles

Avocado Seed Starch-Based Films Reinforced with Starch Nanocrystals

Biopolymers derived from biomass can provide the advantages of both biodegradability and functional qualities from a circular economy point of view, where waste is transformed into raw material. In particular, avocado seeds can be considered an interesting residue for biobased packaging applications due to their high starch content. In this work, avocado seed starch (ASS)-based films containing different glycerol concentrations were prepared by solvent casting. Films were also reinforced with starch nanocrystals (SNCs) obtained through the acid hydrolysis of ASS. The characterization of the extracted starch and starch nanocrystals by scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis has been reported. Adding 1% of SNCs increased elastic modulus by 112% and decreased water vapor permeability by 30% with respect to neat matrix. Interestingly, the bioactive compounds from the avocado seed provided the films with high antioxidant capacity. Moreover, considering the long time required for traditional plastic packaging to degrade, all of the ASS-based films disintegrated within 48 h under lab-scale composting conditions. The results of this work support the valorization of food waste byproducts and the development of reinforced biodegradable materials for potential use as active food packaging.

Adsorption behavior of cationic dyes on starch nanocrystals: Kinetic, isotherm, and thermodynamic insights from single to multi-component systems

The adsorptive potential of starch nanocrystals (SNCs) was evaluated for the elimination of methylene blue (MB), crystal violet (CV), and malachite green (MG) from aqueous media in single, binary, and ternary dye systems using batch mode experiments. SNCs were extracted using mild acid hydrolysis to remove the amorphous parts of native granular starch, and they were characterized using different physicochemical methods, such as FESEM, XRD, FTIR, BET, TGA, and pHZPC. The results revealed that the optimal pH for dye removal in both single and mixed dye systems was found to be 9.0. The equilibrium time increased from 5 to 20 min when the system was changed from single to binary, and then further increased to 30 min when the system was changed to ternary. The equilibrium data for single-dye systems exhibited a good fit with the Langmuir isotherm model (R2 > 0.98, SEE <3.52 mg g−1), whereas for binary and ternary dye mixtures, the extended Langmuir model provided an accurate representation of the experimental data (R2 > 0.99, SEE <1.33 mg g−1). Among the single, binary, and ternary systems, the highest adsorption capacities were observed for MB, MB in the (MB + MG) binary system, and MB in the (MB + CV + MG) ternary system. The respective adsorption capacities were recorded as 79.55 mg g−1, 61.91 mg g−1, and 43.59 mg g−1. The adsorption of dyes onto the SNCs was inherently spontaneous and endothermic, and adhered to the pseudo-second-order kinetic model in single dye systems as well as mixed dye systems. It can be concluded that the SNCs are capable of being utilized for five consecutive cycles in the adsorption-desorption process for single dye systems and three consecutive cycles for mixed dye systems. This suggests that the SNCs have potential as a sustainable and efficient option for dye removal in mixture systems.

Thermal stability and in vitro digestive behavior of Pickering emulsion stabilized by high-amylose starch nanocrystals

In this study, high-amylose starch (HAS) was processed using sulfuric acid-ultrasonic cross-linking to produce high-amylose starch nanocrystals (HASNC). These nanocrystals were used to stabilize Pickering emulsions and assess their effectiveness in encapsulating β-carotene. Normal starch nanocrystals (NSNC) were prepared similarly for comparison. The HASNC retained key HAS properties, such as heat and enzyme resistance, providing several advantages to HASNC-stabilized emulsions. First, after exposure to 100 °C heat and in vitro tests simulating the mouth and stomach, the HASNC-stabilized emulsions demonstrated significantly greater stability and higher β-carotene retention compared to the NSNC-stabilized emulsions. This enhanced stability is attributed to the lower gelatinization degree and increased resistance to α-amylase hydrolysis of HASNC, which provides stronger steric stabilization of the oil droplets. Second, during in vitro small intestine tests, the greater enzyme resistance of HASNC allowed for the formation of a denser barrier around the oil droplets, effectively preventing lipase and bile salts from contacting the oil droplets. This led to a reduced rate and extent of lipid digestion and facilitated a sustained-release effect. Consequently, HASNC, as a starch-based emulsifier, show great potential as an effective delivery system for the sustained release of bioactive compounds.

Acid Hydrolysis of Quinoa Starch to Stabilize High Internal Phase Emulsion Gels.

Starch nanocrystals (SNCs) to stabilize high internal phase emulsions (HIPEs) always suffer low production efficiency from acid hydrolysis. Due to its small granule size, Quinoa starch (QS) was selected to produce SNCs as a function of acid hydrolysis time (0-4 days), and their structural changes and potential application as HIPEs' stabilizers were further explored. With increasing the acid hydrolysis time from 1 day to 4 days, the yield of QS nanocrystals decreased from 30.4% to 10.8%, with the corresponding degree of hydrolysis increasing from 51.2% to 87.8%. The occurrence of QS nanocrystals was evidenced from the Tyndall effect and scanning electron microscopy with particle size distribution. The relative crystallinity of QS subjected to different hydrolysis times (0-4 days) increased from 22.27% to 26.18%. When the acid hydrolysis time of QS was 3 and 4 days, their HIPEs showed self-standing after inversion, known as high internal phase emulsion gels (HIPE gels), closely related to their densely packed interfacial architecture around oil droplets, seen on an optical microscope, and relatively high apparent viscosity. This study could provide a theoretical guidance for the efficient production and novel emulsification of SNCs from QS to HIPE gels.

A Novel Pickering High Internal Phase Emulsion Gels Fabricated by Starch Nanocrystals and Bovine Serum Albumin Complexes

A Novel Pickering High Internal Phase Emulsion Gels Fabricated by Starch Nanocrystals and Bovine Serum Albumin Complexes

Ozone modification of waxy rice starch nanocrystals: Effects on the multi-scale structural and surface properties

The rich active hydroxyl groups on starch nanocrystals (SNC) surface limits its dispersion and stability in the aqueous phase. To address this issue, ozone modification for 0 (SNC), 0.5 (SNC-1), 1 (SNC-2), 1.5 (SNC-3), and 2 h (SNC-4) as compared to conventionally chemical methods was applied to functionally modify the SNC. The impact of ozone treatment on the structural and surface characteristics of waxy rice starch nanocrystals. The findings revealed that longer ozone treatment durations favored the formation of carbonyl groups in starch molecules. Initially, ozone oxidized the hydroxyl group of the macromolecule. Once the carbonyl groups formed, the cross-linking reaction occurred among starch nanocrystals through condensation reactions, leading to the increasing molecular orderliness. X-ray photoelectron spectroscopy, X-ray diffraction and Small-angle X-ray scattering analyses of SNC-2 supported this finding with a reduced O/C ratio, and implied that surface oxidation did not alter the crystal type but rather enhanced molecular hydration in an aqueous system, leading to increased interfacial thickness and fractal dimension. Additionally, ozone oxidation improved surface properties such as charge and hydrophobicity. Oxidized SNC also exhibited altered gelatinization properties due to surface degradation. This study offers a promising strategy for enhancing SNC surface properties, crucial for food science applications.

Innovative packaging solutions for paneer shelf stability: chitosan, montmorillonite, and starch nanocrystals reinforced gluten based bionanocomposite films

Innovative packaging solutions for paneer shelf stability: chitosan, montmorillonite, and starch nanocrystals reinforced gluten based bionanocomposite films

Stearic acid enhanced starch nanocrystal integration in cassava starch film

SummaryStarch nanocrystals (SNCs) have emerged as promising biodegradable nanomaterial for the enhancement of biopolymer films' properties. Nevertheless, using SNCs alone is difficult due to restricted capacity for nanocrystal integration within the film's matrix. The objective of this study was to enhance the properties of biopolymer films using waxy corn starch nanocrystals supplemented with stearic acid. Cassava starch films containing varying proportions of SNCs (0–20 wt.% starch) and steric acid (2%) were prepared and characterised. The inclusion of stearic acid substantially improved SNC integration from 5% to 15%, yielding nanocomposite films with better tensile strength, thermal stability and barrier properties than those prepared with native starch or starch‐fatty acid alone. The improvement in film properties was attributed to V‐amylose complexes formation, increased crystallinity and hydrophobicity. Microscopy images revealed homogenous film surfaces, depicting greater nanocrystal dispersibility. The supplementation of lipid additives offers a valuable strategy to improve the integration of SNCs in film matrices.

Progress in nanocomposites based on starch nanocrystals graft polycaprolactone and modified clay: synthesis, characterization, thermal and antibacterial properties

This research presents a new approach for the fabrication and the characterization of nanocomposites materials, consisting of corn starch nanocrystals, polycaprolactone and, Maghnite–CTA+ (organophilic modified montmorillonite clay intercalated by cetyltrimethylammonium cations). The latter displayed two distinct roles: Maghnite acts as a catalyst for the in situ graft copolymerization through the ring opening of caprolactone with starch macromolecules and, also served at the same time as a nanofiller. The structural of the obtained materials was identified by FT-IR, Moreover, the dispersion state of Maghnite particles was examined by XRD, SEM, TEM, TGA, and DLS (particle size), thermogravimetric results indicate that the incorporation of the Maghnite organophilic in to the copolymer (SNCs-g-PCL) enhanced the thermal properties of the nanocomposites. Additionally, the nanocomposites show significant behavior against gram positive bacterial (Bacillus cereus, Staphylococcus aureus, Klebsiella pneumonia) and gram negative bacterial (Pseudomonas aeruginosa,). The synergistic effects of SNC, PCL, and Maghnite–CTA+ contribute to the development of multifunctional nanocomposites, positioning them for potential applications in areas such as packaging and biomedical materials. This research bridges the gap between renewable resources and advanced materials, offering a sustainable solution with versatile functionalities . These findings underscore the potential of the SNCs-g-PCL/Mag-CTA+ nanocomposites as environmental friendly materials with improved thermal and antimicrobial properties.

Effectiveness of Starch Nanocrystals on Mechanical and Shape Memory Behaviour of Smart Rubber

Shape memory rubber (SMR) is a type of smart rubber that can undergo reversible changes when exposed to external stimuli such as temperature, solvent, pH, light, magnetic field and oxidation. Lightly crosslinked rubber demonstrated shape memory behaviour without any initial heat treatment. However, the strength of lightly crosslinked natural rubber latex (NRL) film cured by sulphur is relatively low. With the concept of sustainability in mind, the idea of fabricating green smart material for continuous development has motivated researchers to explore the realms of sustainable materials. This research aims to investigate the mechanical behaviour of starch nanocrystals (SNC) reinforced rubber composite films. To this end, the emphasis is laid on evaluating the effectiveness of SNC on shape memory effect (SME) of rubber nanocomposite films. In the current work, up to 8 wt% of SNC synthesized by acid hydrolysis was incorporated into NRL and the mixture was cast to form rubber nanocomposite films. SNC effectively increased the modulus and energy-storing potential of the rubber nanocomposite films. Moreover, the shape memory behaviour of the rubber nanocomposite films improved significantly with SNC content, leading to increased shape fixity (Sf) and full shape recovery (Sr).

Synergistic stabilization of a menthol Pickering emulsion by zein nanoparticles and starch nanocrystals: Preparation, structural characterization, and functional properties

Synergistic stabilization of a menthol Pickering emulsion by zein nanoparticles and starch nanocrystals: Preparation, structural characterization, and functional properties

Optimization Mechanism of Mechanical Properties of Basalt Fiber-Epoxy Resin Composites by Interfacially Enriched Distribution of Nano-Starch Crystals

Fibre reinforced polymer composites have become a new generation of structural materials due to their unique advantages such as high specific strength, designability, good dimensional stability and ease of large-area monolithic forming. However, the problem of interfacial bonding between the resin matrix and the fibres limits the direct use of reinforcing fibres and has become a central difficulty in the development of basalt fibre-epoxy composites. This paper proposes a solution for enhancing the strength of the fibre-resin interface using maize starch nanocrystals, which are highly yield and eco-friendly. Firstly, in this paper, corn starch nanocrystals (SNC) were prepared by hydrolysis, and were deposited on the surface of basalt fibers by electrostatic adsorption. After that, in order to maximize the modification effect of nano-starch crystals on the interface, the basalt fiber-epoxy resin composite samples were prepared by mixing in a pressureless molding method. The test results shown that the addition of basalt fibers alone led to a reduction in the strength of the sample. Deposition of 0.1 wt% SNC on the surface of basalt fibers can make the strength consistent with pure epoxy resin. When the adsorption amount of SNC reached 0.5 wt%, the tensile strength of the samples was 23.7% higher than that of pure epoxy resin. This is due to the formation of ether bond homopolymers between the SNC at the fibre-epoxy interface and the epoxy resin, which distorts the originally smooth interface, leading to increased stress concentration and the development of cracks. This enhances the binding of basalt fibers. The conclusions of this paper can provide an effective, simple, low-cost and non-polluting method of interfacial enhancement modification.

Preparation and Application of High Internal Phase Pickering Emulsion Gels Stabilized by Starch Nanocrystal/Tannic Acid Complex Particles.

Herein, the starch nanocrystal/tannic acid (ST) complex particles, which were prepared based on the hydrogen bond between starch nanocrystal (SNC) and tannic acid (TA), were successfully used to stabilize the HIPPE gels. The optimal TA concentration of the ST complex particles resulted in better water dispersibility, surface wettability, and interfacial activity as compared to SNC. The hydrogen bond responsible for the formation of ST complex particles and subsequent stable emulsions was demonstrated by varying the pH and ionic strength of the aqueous phase. Notably, the HIPPE gels stabilized via the ST complex particles can maintain long-term stability for up to three months. The HIPPEs stabilized via the ST complex particles all displayed gel-like features and had smaller droplets and denser droplet networks than the SNC-stabilized HIPPEs. The rheological behavior of HIPPE gels stabilized via the ST complex particles can be readily changed by tuning the mass ratio of SNC and TA as well as pH. Finally, the prepared HIPPE gels used to effectively protect encapsulated β-carotene against high temperatures and ultraviolet radiation and its controllable release at room temperature were demonstrated. It is anticipated that the aforementioned findings will provide new perspectives on the preparation of Pickering emulsion for delivery systems.

Enhancing litchi shelf life with gluten-based nanocomposite films: A comparative study of montmorillonite and starch nanocrystals reinforced with chitosan

This study investigates the efficacy of gluten films incorporated with montmorillonite (MMT) and starch nanocrystals (SNCs), further enriched with chitosan, in preserving the quality of litchis over a 20-day storage period at 4 °C. The addition of MMT/SNCs along with chitosan boosts the tensile strength (52.44 to 57.00 MPa) and surface uniformity of the films while also decreasing water vapour transmission rates (0.77 to 0.68 × 10−3 g/m2/h). Notably, litchis wrapped in these nanocomposite films demonstrate superior shelf stability compared to untreated litchis, which undergo considerable deterioration. Among the film variants, SNCs/chitosan films (GSL2) outperform MMT/chitosan (GML2) due to their superior barrier properties. By the 20th day of storage, litchis packaged in GSL2 films display reduced antioxidant enzyme activity (polyphenol oxidase: 3.18 to 8.08 unit/min/g fruit weight; peroxidase: 0.94 to 5.29 unit/min/g fruit weight) and higher retention of bioactive compounds, including anthocyanin (9.15 to 9.90 mg/100 g), phenolics (347.7 to 362.07 mg/100 g), and ascorbic acid (28.21 to 29.09 mg/100 g) in litchi pericarps during last intervals. Similarly, less alteration was observed in the firmness (8.47 % and 7.36 %) and weight loss (24.04 % and 19.86 %) of the litchis packaged in GML2 and GSL2, respectively as compared to unpackaged litchis. Notably, litchi pericarp exhibits negligible functional group changes when packed in GML2 and GSL2 films until the 15th day of storage. In summary, GML2 and GSL2 films effectively maintain acceptable litchi quality for three weeks.

Tuning Local Order in Starch Nanoparticles Exploiting Nonsolvency with "Green" Solvents.

Starch is a renewable biopolymer that can be sourced from agricultural waste and used to produce nanoparticles (SNPs). In particular, amorphous SNPs have potential application in numerous fields, including the consolidation of weakened paintings in the cultural heritage preservation. Starch dissolution followed by nanoprecipitation in nonsolvents is an advantageous synthetic route, but new methodologies are needed to feasibly control the physicochemical properties of the SNPs. Here, we explored nanoprecipitation by nonsolvency using a set of "green" solvents to obtain amorphous SNPs, rather than starch nanocrystals already reported in the literature. The effect of the nonsolvent on the ordering of polymer chains in the obtained SNPs was studied. The recovery of local order (e.g., isolated V-type helices) after dissolution was shown to depend on the type of solvents used in the dissolution and precipitation steps, while long-range order (extended arrays of helices) is lost. Aqueous dispersions of the SNPs provided effective consolidation of powdery painted layers, showing that the selection of particle synthetic routes can be dictated by sustainability and scalability criteria. These "green" formulations are candidates as new consolidants in art preservation, and the possibility of tuning local order in amorphous starch assemblies might also impact fields like food chemistry, pharmaceutics, and nanocomposites, where SNPs with tunable amorphousness are more advantageous than nanocrystals.

Formulation and characterization of ibuprofen solid dispersions using native and modified starches

Background: Ibuprofen is an anti-inflammatory analgesic drug that is weakly water-soluble with a poor bioavailability.Objectives: The aim of this study is to formulate ibuprofen solid dispersions by solvent evaporation method using natural polymers (native cassava and genetically modified cassava (GMS), Cassava nanocrystal and corn starches) as possible hydrophilic carriers at varying weight proportions to optimize ibuprofen solubility and dissolution.Material and Methods: Solvent evaporation method was used to formulate the ibuprofen solid dispersions at different drug polymer ratios. The pure drug and solid dispersions were characterized using Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffractometer (XRD), particle size, and in vitro drug release.Results: Solid dispersions formulated with starch nanocrystals showed the highest solubility. All solid dispersions prepared with drug:polymer ratio 1:2 generally showed highest solubility. According to the FTIR, the chemical structure of ibuprofen remained intact in the amorphous solid dispersion, but the structure changed from crystalline to amorphous, according to the XRD and the DSC also confirmed this. The scanning electron microscopy showed the solid dispersions were more porous than the pure drug. Higher dissolution rate was observed with nanocrystal solid dispersions with T50 (time required for 50% of the medication to be released) between 1.8 and 4.1 minutes.Conclusion: This study has shown that using these natural polymers increased the solubility and dissolution rate of ibuprofen.

Pickering emulsions stabilized by starch nanocrystals prepared from various crystalline starches by ultrasonic assisted acetic acid: Stability and delivery of curcumin

Ultrasonic assisted acetic acid hydrolysis was applied to prepare starch nanocrystals (SNCs) from native starches with different crystalline structures (A, B, and C types). The structure properties, morphology, Pickering emulsion stability and curcumin deliver capacity of both SNCs and native starches were investigated and compared. Compared with native starches, SNCs showed smaller size and higher crystallinity. The size of SNCs varied with different crystalline types, with C-type starch exhibiting the smallest SNCs (107.4 nm), followed by A-type (113.8 nm), and B-type displaying the largest particle size (149.0 nm). SNCs-Pickering emulsion showed enhanced stability with smaller emulsion droplets, higher static stability, and denser oil/water interface. SNCs-Pickering emulsions displayed higher curcumin loading efficiency (53.53 %–61.41 %) compared with native starch-Pickering emulsions (13.93 %–19.73 %). During in vitro digestion, SNCs-Pickering emulsions proved to be more proficient in protecting and prolonging the biological activity of curcumin due to their smaller size and better interfacial properties. These findings demonstrated the potential of SNCs for application in Pickering emulsion and delivery of bioactive components.

Native and modified starch nano-crystals loaded with doxorubicin mediated apoptosis in human breast cancer MCF7 cells

The present study was aimed at evaluating the effect of doxorubicin (Dox) loaded nanocrystals starch in human breast cancer MCF7 cells. A model for breast cancer, MCF7 cells, were treated with Dox loaded in S (native starch), NS (starch nanocrystal), ANS (acetylated starch nanocrystal) extracted from Oryza glaberrima Steud and compared with Dox (diluted in water). MTT assay, Hoechst33342, H2DCFDA, Live Death, and Rhodamine123 staining, and Western Blot were used to detect different signaling protein expressions and apoptosis. Hoechst33342 staining showed cellular apoptosis of MCF7 after treating with DOX loaded S, NS, ANS or Dox alone. Intracellular ROS levels, p53 and Bax/ Bcl2 expressions, and decrease in mitochondrial membrane potential were also higher in MCF7 cells treated with Dox loaded S, NS, ANS or Dox alone. To ensure Dox loaded S, NS or ANS did not cause any cellular damages to normal cells, HEK-293 kidney cells were used as control. Dox loaded S, NS, or ANS were as effective formulations as Dox alone to decrease progression and metastasis of breast cancer in MCF7 cells. This study provides a novel approach for further investigation since Dox loaded starch nanocrystals are effective and can prevent side effects of cardiotoxicity when using Dox alone.

Potential of arrowroot (Maranta arundinacea) starch nanocrystal in edible bioplastic straw production

Potential of arrowroot (Maranta arundinacea) starch nanocrystal in edible bioplastic straw production

A smart thermoresponsive macroporous 4D structure by 4D printing of Pickering-high internal phase emulsions stabilized by plasma-functionalized starch nanomaterials for a possible delivery system

Hierarchically porous structures combine microporosity, mesoporosity, and microporosity to enhance pore accessibility and transport, which are crucial to develop high performance materials for biofabrication, food, and pharmaceutical applications. This work aimed to develop a 4D-printed smart hierarchical macroporous structure through 3D printing of Pickering-type high internal phase emulsions (Pickering-HIPEs). The key was the utilization of surface-active (hydroxybutylated) starch nanomaterials, including starch nanocrystals (SNCs) (from waxy maize starch through acid hydrolysis) or starch nanoparticles (SNPs) (obtained through an ultrasound treatment). An innovative procedure to fabricate the functionalized starch nanomaterials was accomplished by grafting 1,2-butene oxide using a cold plasma technique to enhance their surface hydrophobicity, improving their aggregation, and thus attaining a colloidally stabilized Pickering-HIPEs with a low concentration of each surface-active starch nanomaterial. A flocculation of droplets in Pickering-HIPEs was developed after the addition of modified SNCs or SNPs, leading to the formation of a gel-like structure. The 3D printing of these Pickering-HIPEs developed a highly interconnected large pore structure, possessing a self-assembly property with thermoresponsive behavior. As a potential drug delivery system, this thermoresponsive macroporous 3D structure offered a lower critical solution temperature (LCST)-type phase transition at body temperature, which can be used in the field of smart releasing of bioactive compounds.