Starch Nanoparticles Research Articles

High Stability and Reusability of Papain Immobilized on the Non‐Toxic Magnetic Dialdehyde Starch Nanoparticles

AbstractPapain is widely used in food, drug, and bioactive peptide production and must be immobilized onto carriers with biocompatibility. Dialdehyde starch (DAS) can be a good biocompatible cross‐linker according to its active aldehyde groups. In the present study, the magnetic nanoparticles dialdehyde starch (MDASN), synthesized by DAS and Fe3O4 magnetic nanoparticles (Fe‐MNP), are successfully used to immobilize papain to improve the enzymic activity. The structure and morphology of DAS, MDASN, and immobilized papain onto magnetic dialdehyde starch nanoparticles (papain‐MDASN) are characterized detailly. The morphology of DAS is like a flat ball, and that of Fe‐MNP and papain‐MDASN are spherical and clumpy. The particle size of Fe‐MNP and papain‐MDASN are small, resulting in a large surface electrostatic effect and partial agglomeration. Enzymic activity studies of papain‐MDASN exhibit that the immobilized papain on MDASN represents better temperature resistance, alkaline resistance, thermal stability, and reusability, and its activity recovery is up to 68.21%. Papain onto magnetic dialdehyde starch nanoparticles (MDASN) may enhance its potential application in production processes.

Unveiling the synergistic effect of octenyl succinic anhydride and pulsed electric field on starch nanoparticles

In this study, guinea starch nanoparticles (GSNP) were prepared by nanoprecipitation technique and modified with octenyl succinic anhydride (3 %) and pulsed electric field (1.5, 3.0, and 4.5 kV/cm). The effect of dual modification on the physicochemical, structural, morphological, thermo-pasting, and rheological properties of GSNP was investigated. The dual modification successfully incorporated octenyl groups into GSNP, as confirmed by 1H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The degree of substitution increased from 0.0254 to 0.0347, with particle size ranging from 241.30 to 292.50 nm and zeta potential of −23.11 to −29.98 mV. TEM micrographs revealed that all SNP samples had self-aggregated granules with a mean size below 120 nm, and XRD confirmed a V-type crystalline structure. The amylose content and water absorption capacity decreased from 34.02 % to 24.63 % and from 2.45 to 1.91 g/g, respectively, while the oil absorption capacity and relative crystallinity increased from 3.42 to 4.01 g/g and from 17.82 % to 34.76 %, with modification. The gelatinization and degradation temperature of modified samples were higher while pasting properties exhibited variation with modification. The rheological properties of modified SNP samples exhibited more pronounced shear thinning, attributed to their weaker gel structure and fluid-like gel network. Overall, results suggested that modified GSNPs have potential for stabilizing Pickering emulsion and delivery of carrier materials for active functional substances.

Resistant Starch Nanoparticles Induce Colitis through Lysosomal Exocytosis in Mice.

Resistant starch (RS) is present in various natural and processed foods as well as medications. It has garnered significant attention from both scientists and consumers due to its notable health benefits. However, there is a limited understanding of how RS particles are absorbed at the cellular level and their metabolic behavior, resulting in a lack of clarity regarding the intestinal safety implications of prolonged RS exposure. Here, we demonstrate that rice-derived RS nanoparticles (RSNs) can lead to colitis in mice by triggering lysosomal exocytosis. The research shows that RSNs enter the cells through macropinocytosis and clathrin- and caveolin-mediated endocytosis and activate TRPML1 thereafter, causing the release of lysosomal calcium ions. This, in turn, triggered the TFEB signaling pathway and thus upregulated the lysosomal exocytosis level, leading to lysosomal enzymes to be released to the intestinal lumen. As a result, a decreased number of intestinal goblet cells, diminished tight junction protein expression, and imbalanced intestinal flora in mice were observed. These damages to the intestinal barrier ultimately led to the occurrence of colitis. Our study offers important insights into the cellular bioeffects and detrimental effects on intestinal health caused by RS particles and emphasizes the need to re-evaluate the safety of long-term RS consumption.

Optimization of Cassava-Peel Derived Nanostarch Via Sulphuric Acid Hydrolysis Using Taguchi Method

Untreated cassava peel waste generated during harvesting and processing poses significant environmental challenges. Synthesis of starch nanoparticles from cassava peels for various applications offers a sustainable solution to waste reduction and contributes to environmental conservation. The unique characteristics of nanostarch such as thermal stability, high solubility, non-toxicity, and low cost enable its application in the food industry, cosmetics, enhanced oil recovery, and textiles. The current study employed the Taguchi method design to optimize sulphuric acid hydrolysis in synthesizing cassava peel-derived nanostarch. Additionally, the derived cassava peel nanostarch was characterized using Fourier Transform Infrared Spectroscopy (FTIR). Starch was extracted from cassava peels, followed by synthesizing starch nanoparticles via sulphuric acid hydrolysis. Optimization of nanostarch synthesis was based on randomized experimental runs using the Taguchi method generated by the Minitab software, with the experiments conducted in duplicates. The optimum conditions for the experiment were found to be 3 hours, at 25°C using an H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M. These conditions produced a yield of 92.28%. ANOVA analysis identified sulphuric acid concentration as the most significant factor that affected cassava nanostarch yield, with p-values of 0.026 and 0.003 for the signal to noise (S/N) ratios and means, respectively. The least significant factor based on the analysis was the hydrolysis time. However, according to the S/N ratios main effect plot, the most optimum conditions predicted by the Taguchi method design was 9 hours, 25°C using H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M. A confirmation experiment conducted at 25°C, using an H<sub>2</sub>SO<sub>4 </sub>acid concentration of 2M for 9 hours gave a nanostarch yield of 97.01%. In conclusion, the Taguchi method design identified sulphuric acid concentration as the most significant factor in synthesizing cassava peel-derived nanostarch via acid hydrolysis.

Bioinspired core-shell microparticle for dual-delivery of prebiotic and probiotic for the treatment of ulcerative colitis

Lactiplantibacillus plantarum (LP) is a well-known probiotic strain that has a beneficial effect in preventing ulcerative colitis. However, delivering a sufficient number of viable LP to the colon still face challenges due to its vulnerability to the highly complex intestinal flora ecosystem. Herein, we present a centrifuge-driven micronozzle system designed for double-layered core-shell alginate microcapsules (DAM), which can serve as an effective carrier for dual delivery of resistant starch nanoparticles (RSNP, prebiotic) and LP (probiotics) for the treatment of colitis. This system enables precise loading of LP and RSNP within the core and shell regions of DAM, respectively. The resulting LP/RS@DAM exhibited a high encapsulation efficiency of LP (108 CFU per bead), in which the dense distribution of RSNP in the shell effectively protected LP against acidic conditions (pH 2) and maintained the cell viability up to 52 % even after long-term storage for 30 days. Furthermore, LP/RS@DAM effectively enhances the production of short-chain fatty acids, leading to a reduction in inflammatory cytokines and restoration of intestinal microbial diversity in dextran sulfate sodium (DSS)-induced colitis. We believe that this innovative approach would offer a potential solution for improving colitis management and paving the way for tailored therapeutic interventions in gastrointestinal disorders.

Green synthesis of silver, starch, and zinc oxide mediated nanoparticles with probiotics and plant extracts, their characterization and anti-bacterial activity

Nanotechnology has various applications in all branches of science, including engineering, medicine, pharmacy, and other related fields. Conventional techniques, such as the chemical reduction approach, which produces nanoparticles (NPs) using various hazardous chemicals, offer several health risks due to their toxicity and raise serious environmental concerns. In contrast, other techniques are expensive and need a lot of energy. More than 70 % of pathogenic bacterial strains have developed resistance to at least one class of antibiotics, leading to an increase in life-threatening bacterial infections that pose a significant health risk. However, the creation of NPs by biogenic synthesis is risk-free for the environment and clean enough for biological use. This study was aimed at synthesis of novel Moringa oleifera mediated starch capped silver-zinc NPs and green synthesis of ZnO nanoparticles from Aloe vera, papaya, and Lactobacillus plantarum. Antimicrobial activity of both NPs was tested against Gram-negative antibiotic-resistant bacteria Pseudomonas aeruginosa, Gram-positive bacteria Staphylococcus aureus (ATCC 6538), and two foodborne pathogens Listeria monocytogenes and Campylobacter jejuni. Ultraviolet–visible spectroscopy, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy were used for characterization. Majority of the research studies stress the flexibility, repeatability, and desirable features of the metals, polymers, and plant components employed in the production of biomedical nanoparticles. Such an intuitive approach provides several advantages, particularly a reasonable total expense, compliance with healthcare and pharmaceutical implementations, and the ability to produce massive volumes for industrial use. The novelty of the presented work lies in the unusual combination of silver, starch, and zinc oxide nanoparticles using Moringa oleifera, which is an eco-friendly alternative to chemical-based methods. This research exhibits the formation of well-defined nanoparticles with strong antibacterial activity against a wide range of pathogens, giving us insights into their potential applications in various biomedical fields.

Characterization of exopolysaccharide / starch composite film incorporated with TiO2 nanoparticles and its application in chilled meat preservation

Multifunctional food packaging composite films were prepared using Pediococcus acidilactici J1 exopolysaccharide (EPS), potato starch (PS) and TiO2 nanoparticles by casting method. The microstructure, physicochemical properties and antibacterial activity of EPS/PS composite films with different weight ratio of TiO2 nanoparticles were characterized. Transmission electron microscope (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the uniform distribution of TiO2 nanoparticles in the EPS/PS matrix. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results indicated that the interaction between polymers and nanoparticles through non-covalent bonds. When TiO2 nanoparticles were added at 1 % (wt), the composite film had higher barrier properties against water vapor and UV–vis light, and better mechanical properties then EPS/PS film. Notably, EPS/PS/1%TiO2 composite film exhibited good antioxidant and antibacterial activity against Escherichia coli and Staphylococcus aureus. Through the analysis of the quality indexes and microbial community structure during the storage of chilled meat, the composite film slowed the oxidation rate of chilled meat and inhibited the growth of dominant spoilage bacteria, effectively extending its shelf life. All results suggested that EPS/PS/1%TiO2 composite film could serve as an effective packaging material for chilled meat, providing a novel approach to solve its limited shelf-life problem.

Elucidating siRNA Cellular Delivery Mechanism Mediated by Quaternized Starch Nanoparticles.

Starch-based nanoparticles are highly utilized in the realm of drug delivery taking advantage of their biocompatibility and biodegradability. Studies have utilized Quaternized starch (Q-starch) for small interfering RNA (siRNA) delivery, in which quaternary amines enable interaction with negatively charged siRNA, resulting in self-assembly complexation. Although reports present numerous applications, the demonstrated efficacy is nonetheless limited due to undiscovered cellular mechanistic delivery. In this study, a deep dive into Q-starch/siRNA complexes' cellular mechanism and kinetics at the cellular level is revealed using single-particle tracking and cell population level using imaging flow cytometry. Uptake studies depict the efficient cellular internalization via endocytosis while a significant fraction of complexes' intracellular fate is lysosome. Utilizing single-particle tracking, it is found that an average of 15% of cellular detected complexes escape the endosome which holds the potential for the integration in the cytoplasmatic gene silencing mechanism. Additional experimental manipulations (overcoming endosomal escape) demonstrate that the complex's disassembly is the rate-limiting step, correlating Q-starch's structure-function properties as siRNA carrier. Structure-function properties accentuating the high affinity of the interaction between Q-starch's quaternary groups and siRNA's phosphate groups that results in low release efficiency. However, low-frequency ultrasound (20kHz) application may have induced siRNA release resulting in faster gene silencing kinetics.

Fabrication of millet starch nanocapsules loaded with beta carotene using acid hydrolysis and ultrasonication: Characterisation, release behaviour and bioactivity retention

The acid hydrolysis process was used to create novel millet starch-based nanoparticles from three different sources: sorghum, foxtail millet and pearl millet. An environment-friendly, risk-free ultrasonication technique was used for encapsulating beta carotene in starch nanoparticles to create nanocapsules that will shield the bioactivity of beta carotene in gastrointestinal conditions and increase its accessibility after consumption. Formulated nanocapsules were examined for zeta potential, particle size and encapsulation efficiency. The particle dimensions of beta carotene-loaded sorghum (SSB), foxtail millet (FSB), and pearl millet (PSB) starch nanoparticles were 416, 399 and 587 nm with zeta potential of −17.98, −19.03 and –22.31 mV respectively. Encapsulation efficiencies of nanocapsules were found to be 85.83, 89.65 and 78.32 % for SSB, FSB and PSB respectively. Scanning electron microscopy (SEM) was also harnessed as a confirmatory tests towards the presence of beta carotene in nanocapsules. Beta carotene encapsulation in starch nanoparticles was also demonstrated using ATR-FTIR which revealed broad characteristic peaks at 3000, 1086 and 885 cm−1 that occur without any discernible interaction. Intestinal juice with higher beta carotene content ensured controlled release in the intestine. Encapsulated beta carotene showed more bioactive properties in terms of antioxidant activity as compared to free beta carotene form

Folic acid functionalized Ag@MOF(Ag) decorated carboxymethyl starch nanoparticles as a new doxorubicin delivery system with inherent antibacterial activity

Considering the benefits of controlled drug delivery in cancer treatment, as well as the importance of biological macromolecules in this area, herein, the pre-synthesized carboxymethyl starch (CMS) was converted to CMS nanoparticles (CMS NPs) in one easy nanoprecipitation way. Thereafter, the Ag@MOF(Ag) was in situ synthesized in the presence of pre-prepared CMS NPs (CMS NPs/Ag@MOF(Ag)). Eventually, the functionalization with folic acid (FA) obtained the CMS NPs/Ag@MOF(Ag)-FA. The success of the accomplished process was approved by doing several techniques, including FT-IR, XRD, EDX, AFM, etc. The SEM analysis showed a combination of rod-like and spherical-like morphology for the fabricated bio-nanocomposite. The generated CMS NPs/Ag@MOF(Ag)-FA with a surface area of 10.595 m2/g displayed a pore size of 13.666 nm and 82.99 % of doxorubicin (DOX) loading efficiency (DOX@CMS NPs/Ag@MOF(Ag)-FA). The 38.46 % and 58.19 % of loaded DOX were released respectively within 240 h at pH 7.4 and pH 5.0, referring to the pH-responsivity of the constructed system. 27.25 % of inhibitory effects on HeLa cells were obtained for the drug-loaded bio-nanocomposite. The CMS NPs/Ag@MOF(Ag)-FA also displayed an inherent antibacterial activity towards two common gram-negative and gram-positive bacteria. All of these results can contribute to developing polysaccharide-based porous systems in controlled cancer therapy.

Influence of ultrasound frequency, processing time, and cold temperature on quality characteristics of mutton subjected to ultrasonic nano-cooling with a preservative film

Refrigeration slows down microbial growth and oxidation in mutton, but it is not enough on its own to fully prevent spoilage. To promote preservation, this research evaluated the effectiveness of combining ultrasound treatment, nanocomposite packaging, and cold storage ― a method known as ultrasonic nano-cooling (UNC) on quality of mutton. Various ultrasound frequencies (40 and 80 kHz) and processing times (2–4 minutes) were applied to process the mutton. Thereafter, the products were packaged in nanocomposite film, made from sorghum starch and Azadirachta indica gum nanoparticles, and then stored under cold temperature condition: 2°C, 4°C, and 6°C. Analysis of the physical and biochemical properties revealed significant improvements in quality due to UNC preservation compared to the control (p < 0.05). Notably, the total bacterial load dropped from 5.4 × 10⁶ CFU/g in the control to 1.9 × 10⁶ CFU/g at 2°C with 80 kHz ultrasound after 4 minutes. This effect may be due to enhanced cavitation effects at higher frequencies, which, according to previous studies, can disrupt microbial cell walls. Lipid oxidation reduced from 0.45 mg MDA/kg to 0.20 mg MDA/kg, likely due to minimized thermal degradation and oxidative reactions, facilitated by lower temperatures and effective packaging. Water holding capacity increased from 70 % to 85 %, due to improved muscle fiber structure from ultrasound treatment, which aids moisture retention. The pH remained steady between 5.8 and 6.0, reflecting minimal spoilage and effective microbial control. This study demonstrates that UNC preservation is an effective method for extending mutton shelf life, aligning with the demand for high-quality, long-lasting mutton products.

Betanin-encapsulated starch nanoparticles: synthesis and cytotoxic effect on colon cancer.

Colorectal cancer (CRC) is a common and life-threatening neoplastic disease that continues to pose a formidable challenge to global health. The present work was performed to evaluate the anticancer properties of betanin and betanin (BT) loaded starch nanoparticles (S-BT). The BT and S-BT were characterized by DLS, SEM, UV spectroscopy, XPS and FTIR. The cytotoxic effect was assessed by MTT and LDH assay. The apoptotic potential of BT and S-BT was assessed by DCFDA, Rh123, AO/EB and DAPI staining methods. Cell cycle arrest was depicted using flow cytometry. The antimetastatic potential of BT and S-BT was evaluated by wound healing assay. The S-BT showed a spherical morphology with a size of 175nm. The betanin contained SNPs were found to have strong encapsulation efficiency and favorable release profiles. Both BT and S-BT exhibited cytotoxicity in SW480 cells but S-BT displayed increased cytotoxicity when compared to BT alone. Loss of mitochondrial membrane potential, nuclear fragmentation, chromatin condensation and generation of ROS, all indicative of apoptotic mode of cell death, were revealed by fluorescence imaging. The cells were arrested in the G2M phase. Moreover, both BT and S-BT were able to inhibit the migratory potential of SW480 cells. Overall, our results indicated that both BT and S-BT were able to induce anticancer effects; and, S-BT was found to have increased therapeutic efficacy when compared to BT alone.

Efficacy Assessment of Molecularly Imprinted Polymer Incorporated with Starch and Macadamia Capped Silver Nanoparticles for the Removal of Multi‐Class Pharmaceuticals in Wastewater

AbstractThe presence of pharmaceuticals in water bodies has been reported to be mainly due to their incomplete removal by the conventional wastewater treatment processes, resulting to their release into the aquatic environment where they thratens to human health and aquatic life. Therefore, it is important to remove these pollutants from the aquatic environment using affordable highly efficient materials. The goal of this study was to incorporate silver nanoparticles (AgNPs) into MIPs for selective removal of sulfamethoxazole, nevirapine, and ibuprofen in wastewater. The AgNPs were synthesized using starch (St) and macadamia (MCD) as both reducing and stabilizing agents. Thermogravimetric analysis showed high stability for the St/MCD‐nanoMIPs. The ANOVA analysis revealed that the parameters affecting adsorption of St/MCD‐nanoMIPs have a significant difference (p&lt;0.05). The St/MCD‐AgNPs experimental data fitted to both Langmuir and Freundlich adsorption isotherms, however, the non‐linear Langmuir isotherm model yielded a better fit based on the higher R2 value (0.999). The non‐linear Freundlich model best fitted for the St/MCD‐nanoMIPs. The linear pseudo‐second order model shown best fit for St/MCD‐nanoMIPs, the thermodynamic results revealed that the adsorption process was spontaneous and endothermic. The St/MCD‐nanoMIPs showed improved qualities and were highly selective (&gt;70 %) and effective in removing the selected pharmaceuticals from wastewater.

Effect of cationized guar gum on stability and bioaccessibility of curcumin-loaded Pickering emulsion stabilized by starch nanoparticles

To enhance stability and bioaccessibility of curcumin in Pickering emulsions stabilized by starch nanoparticles (SNP), cationized guar gum (CGG) was incorporated into the emulsion. Zeta potential results revealed that SNP and CGG formed electrostatic interactions, resulting in stable interfacial layer with higher hydrophobicity. Adding 0.4 % CGG maintained a homogeneous phase without significant droplet size change for up to one month. The emulsion with 0.4 % CGG demonstrated stable storage under varying pH (4–10), ionic strength (0–10 mM NaCl), and freeze-thaw cycles (up to 3). When optimized Pickering emulsion system was applied to curcumin encapsulation, curcumin-loaded emulsions were stably maintained for up to one month. The curcumin retained approximately 100 % stability under thermal (90 °C) and UV (12h) treatments. In the optimized emulsion, starch components resisted digestion in oral and gastroenteric phases but were primarily digested in small intestine, resulting in an increasing bioaccessibility from 88.23 to 96.92 %.

Using Eco-Friendly Nano-Polymers in Industrial Wastewater Treatment

Abstract The major target of this research is to synthesize an eco-friendly coagulant, based on a biomaterial (potato starch) that contribute in industrial wastewater treatment. From this work an eco-friendly nano-polymer was produced from potato starch. Successfully not only the potatoes were used, but also the potato peel, which has an economic impact on reducing the amount of water wasted in planting such an important crop as the potatoes all over the world. Because of increasing the need for food production and changing the dietary pattern, the development of potato industry has become the first among all food crops in most of the countries. As a result potato starch became the most popular type among the polysaccharides. To achieve this, the experimental work started by extracting the starch from the potato and potato waste (peels). In order to enhance the potato starch characteristics, the synthesis of starch nano-particles (StNPs) was conducted by gelatinization using a mixture of sodium hydroxide along with glycerol in aqueous medium throughout the reaction process, while settling down the StNPs which was done by homogenization at ambient temperature. Characterization was done on both native potato starch and starch nano-particles using Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDX). The second part of the experimental work is to test the eco-friendly starch nano-particles (starch-based coagulants) in industrial wastewater treatment, and to evaluate its effectiveness as a coagulant against the most commonly used synthetic polymer (PolyDADMAC) playing the same roll in industry and whether it can really replace it or not.

Starch Nanoparticles Based on Ultrasonication Pretreatment and Enzyme Posttreatment: Preparation, Optimization, and Biophysical Characterization

AbstractStarch nanoparticles (SNPs), due to their minimum particle size and maximum surface to volume ratio do not have starch limitations such as low solubility and digestibility. SNPs in colloidal form were enzymatically produced using enzyme of α‐amylase in combination toultrasinication technique to accomplished SNPs gelatinization. Results indicated that SNPs with smallest particle size (109 nm) and polydispersity index (0.560), and highest zeta potential (−32.16 mV) and antioxidant activity (30%) values was obtained using 2.10 mL enzyme and ultrasonication time of 69 s. SNPs in powder form were produced using obtained optimum conditions and a laboratory freeze dryer with chamber temperature and pressure of −70 °C and 100 Pa, for 24 h, and characterized Results indicated that the provided native starch had particle size of ranging 6 to 10 µm with zeta potential value of −4.50 mV, prepared SNPs powder had spherical shape and flat surface with mean particle size, zeta potential and specific surface area values of 105 nm, −26.7 mV and 4.70 m2 g−1, respectively. Furthermore, oil separation time for the emulsions having starch and powder of SNPs, were 43 and 297 s, respectively. While, for the sample without emulsifier (control), this time was 22 s.

Bioresponsive hydroxyethyl starch-flurbiprofen nanoparticles targeted to inflammatory microenvironments for post-operative pain management

Post-operative pain can hinder post-operative recovery by activating the neuroendocrine stress response to surgery, caused by inflammation. Preemptive analgesia using flurbiprofen preoperatively is a potential treatment option to avoid hyperalgesia and prevent post-operative pain. However, the hydrophobicity and short in vivo elimination half-life of flurbiprofen are limitations. In this study, a strategy is presented for targeting inflammatory microenvironments using bioresponsive nanoparticles that simultaneously alleviate inflammation and inhibit hyperalgesia, effectively managing post-operative pain in rats. Our study demonstrates that flurbiprofen-conjugated hydroxyethyl starch can self-assemble into nanoparticles in water, imparting flurbiprofen with higher solubility in water and a longer half-life. Additionally, these biocompatible flurbiprofen-conjugated hydroxyethyl starch nanoparticles accumulate in the incision. Pathological analysis of nerves indicates that hyperalgesia was effectively inhibited by the preoperative administration of HES-Flurbiprofen nanoparticles in the rat incisional pain model. This hydroxyethyl starch-based nanoparticle system also suggests a promising and straightforward strategy for developing biocompatible and bioresponsive formulations for post-operative pain management.

Upcycling of industrial pea starch by rapid spray nanoprecipitation to develop plant-derived oil encapsulated starch nanoparticles for potential agricultural applications

Starch is one of the natural encapsulant materials widely used in food, pharmaceutical and cosmetic industries. Starch with high amylose content (above 40 %, w/w) is prone to form single helices V-type allomorph with a hydrophilic outer surface and a hydrophobic inner cavity making them suitable for encapsulation of hydrophobic compounds such as essential oils, fatty acids, and vitamins. Pea starch obtained from pea protein processing industries have a high amylose content (40 %, w/w) rendering them unsuitable for direct food applications as ingredients. Therefore, in this study, an in-house spraying procedure was used to synthesize nanoparticles using pea starch, to encapsulate neem oil, a natural antimicrobial compound obtained from neem plant (Azadirachta indica) seed. The synthesis of the oil-encapsulated starch nanoparticles (OESNP) was optimized using a Box-Behnken experimental design to study the influence of the processing parameters such as the initial starch concentration, homogenization speed, duration of homogenization, sample injection rate, and quantity of antisolvent (ethanol). The optimized sample showed an 80–90 % encapsulation efficiency and particle size of <500 nm. The spherical OESNPs also demonstrated sustained release of the oil compared to free oil when dispersed in water. X-ray diffraction analysis revealed the coexistence of C-type and V-type polymorphs in the loaded and unloaded nanoparticles. It is concluded that the synthesized OESNPs with controlled release hold the potential to utilize industrial pea starch waste for the delivery of natural pesticides in agriculture.

Starch nanoparticle preparation by the nanoprecipitation technique: Effects of formulation parameters

This study investigates how key formulation parameters influence the formation of starch nanoparticles using the nanoprecipitation technique. When loaded with different compounds, starch nanoparticles present a promising option for controlled drug delivery in food, biomedical, and pharmaceutical applications. The work thoroughly examines factors such as polymer concentration, NaOH concentration, solvent ratios, stirring speed, injection flow, and properties of the non-solvent phase. Characterization is conducted using dynamic light scattering, laser Doppler electrophoresis, and scanning electron microscopy, followed by statistical analysis. Increasing the stirring speed notably decreases nanoparticle size, yielding dimensions of 161.5±2.1 nm, 157.6±2.5 nm, and 136.0±0.8 nm at 500, 700, and 900 rpm, respectively. Higher starch concentrations slightly increase the zeta potential of starch nanoparticles to values of −1.97±0.4 mV, −3.1±0.7 mV, and −3.9±1.5 mV for concentrations of 0.5 %, 1 %, and 2 %, respectively. This charge can be attributed to the hydroxyl functional groups in starch monomers. The study also assesses the stability of starch nanoparticles at different pH levels (4, 7.4, and 9) and explores the use of cryoprotectants during freeze-drying. Remarkably, nanoparticles show enhanced stability at pH 7.4, maintaining their initial sizes over six weeks. Cryoprotectants, even in small amounts, effectively preserve nanoparticle size post-freeze-drying. By adjusting formulation parameters, researchers can tailor the physicochemical characteristics of nanoparticles to achieve specific sizes and ensure stability.

Enzymatically and chemically starch nanoparticles preparation using ultrasonication, precipitation and lyophilization post-treatments: Screening and characterization

Starch nanoparticles (SNPs) have been used in food emulsions as natural stabilizer and emulsifier. SNPs in colloidal form were produced using enzymatically, acidic and alkaline hydrolyses in combination to ultrasonication and precipitation methods. X-Ray diffraction test for produced SNPs indicated that enzymatically and acidic prepared SNPs had amorphous structure while, the resulted SNPs using alkaline hydrolysis had lower relatively crystallinity. Results indicated that, enzymatically prepared SNPs, had minimum particle size (225 ± 10 nm) and polydispersity index (0.472 ± 0.05), and maximum zeta potential (−26.3 ± 1 mV), antioxidant activity (3.36 ± 0.05 %) and specific surface area (1.8 ± 0.1 m2g−1). Transmission electron microscopy revealed that prepared SNPs had spherical shape and enzymatically prepared SNPs had mean particle size of <100 nm. SNPs in powder form were prepared using freeze drying (pressure and temperature of 100 Pa and − 70 °C). Atomic force microscopy results demonstrated that starch granules had smooth surface, with polyhedral shape and particle size ranging 5 to 25 μm, and after hydrolysis, SNPs had particle size in nanometer scale. Emulsion ability test indicated that oil separation time from the prepared emulsions containing 10 % (W/V) starch, and enzymatically, acidic and alkaline prepared SNPs powder were 41, 70, 82 and 101 s, respectively.