Search Results (14)

The steady shear rheology of suspensions of mixtures of rod-shaped cellulose nanocrystals (NCC) and spherical starch nanoparticles (SNPs) was investigated experimentally over a broad range of NCC and SNP concentrations. The NCC concentration varied from about 1 to 6.7 wt% and the SNP concentration varied from 5 to 30 wt%. The suspensions of mixtures of NCC and SNPs were pseudoplastic (shear-thinning) in nature. The viscous behavior of suspensions of mixtures of NCC and SNPs could be described adequately using the power-law model. The power-law parameters, that is, consistency index and flow behavior index, were dependent on the concentrations of both NCC and SNPs. The consistency index increased substantially with increases in NCC and SNP concentrations. The flow behavior index generally decreased with an increase in NCC and SNP concentrations; that is, the suspension mixtures became more shear-thinning with increases in NCC and SNP concentrations. However, the dependence of the consistency index and flow behavior index on NCC concentration was much stronger as compared with the SNP concentration. Full article

Quercetin (Qc) is a natural bioactive compound derived from plants, with strong anti-inflammatory and antioxidant properties. However, its extreme water insolubility limits its bioavailability and practical utility. To address this, quercetin was encapsulated in ginkgo-derived starch nanoparticles (SNPs) to enhance solubility and stability. In this study, the bioactivity and cellular effects of the SNPs/Qc system were evaluated. Results showed excellent biocompatibility with no toxicity or adverse effects observed in experimental mice. At 25 µg/mL, SNPs/Qc significantly promoted early apoptosis in 3LL cells (33%) and blocked the cell cycle at G1 and G2 phases. The system demonstrated a dose-dependent inhibitory effect on abnormal cell proliferation, with significant activity observed 6 h (hour) post-treatment. Compared with free quercetin, the SNPs/Qc system has dual advantages in improving the bioavailability of quercetin and tumor targeted penetration. After 15 days of ingestion, the survival rate of mice in the SNPs/Qc group increased by 20%, and the tumor volume was only 239 mm³, corresponding to a 49.4% decrease. At the same time, specific damage to the cell structure of tumor cells and higher intensity fluorescence accumulation were observed. This study reveals the potential of the SNPs/Qc system as a biocompatible and efficient delivery platform for natural bioactive compounds, particularly in health promotion and functional food applications. Full article

Deep eutectic solvents (DESs) have received extensive attention in green chemistry because of their ease of preparation, cost-effectiveness, and low toxicity. Pickering emulsions offer advantages such as long-term stability, low toxicity, and environmental friendliness. The oil phase in some Pickering emulsions is composed of solvents, and DESs can serve as a more effective alternative to these solvents. The combination of DESs and Pickering emulsions can improve the applications of green chemistry by reducing the use of harmful chemicals and enhancing sustainability. In this study, a Pickering emulsion consisting of a DES (menthol:octanoic acid = 1:1) in water was prepared and stabilized using starch nanoparticles (SNPs). The emulsion was thoroughly characterized using various techniques, including optical microscopy, transmission microscopy, laser particle size analysis, and rheological measurements. The results demonstrated that the DES-in-water Pickering emulsion stabilized by the SNPs had excellent stability and retained its structural integrity for more than 200 days at room temperature (20 °C). This prolonged stability has significant implications for many applications, particularly in the field of storage and transportation. This Pickering emulsion based on DESs and SNPs is sustainable and stable, and it has great potential to improve green chemistry practices in various fields. Full article

Cassava starch nanoparticles (SNP) were produced using the nanoprecipitation method after modification of starch granules using ultrasound (US) or heat–moisture treatment (HMT). To produce SNP, cassava starches were gelatinized (95 °C/30 min) and precipitated after cooling, using absolute ethanol. SNPs were isolated using centrifugation and lyophilized. The nanoparticles produced from native starch and starches modified using US or HMT, named NSNP, USNP and HSNP, respectively, were characterized in terms of their main physical or functional properties. The SNP showed cluster plate formats, which were smooth for particles produced from native starch (NSNP) and rough for particles from starch modified with US (USNP) or HMT (HSNP), with smaller size ranges presented by HSNP (~63–674 nm) than by USNP (~123–1300 nm) or NSNP (~25–1450 nm). SNP had low surface charge values and a V-type crystalline structure. FTIR and thermal analyses confirmed the reduction of crystallinity. The SNP produced after physical pretreatments (US, HMT) showed an improvement in lipophilicity, with their oil absorption capacity in decreasing order being HSNP > USNP > NSNP, which was confirmed by the significant increase in contact angles from ~68.4° (NSNP) to ~76° (USNP; HSNP). A concentration of SNP higher than 4% may be required to produce stability with 20% oil content. The emulsions produced with HSNP showed stability during the storage (7 days at 20 °C), whereas the emulsions prepared with NSNP exhibited phase separation after preparation. The results suggested that dual physical modifications could be used for the production of starch nanoparticles as stabilizers for Pickering emulsions with stable characteristics. Full article

Starch nanoparticles (SNPs) have unique attributes that make them suitable for specific applications. In this study, we assessed the optimum conditions for the fabrication of SNPs from the rice starches of low- (TCSG2) and medium-amylose rice lines (TK11) using pullulanase debranching combined with annealing treatment and evaluated their physicochemical and digestion properties. The highest crystalline SNP percent recoveries of 15.1 and 11.7% were obtained from TK11 and TCSG2, respectively, under the following debranching conditions: 540–630 NPUN/g, pH 5.0, 60 °C, and 12 h. The percent recovery of the crystalline SNPs by the combined modification of the debranching and the annealing treatment with an extended annealing incubation prepared from TK11 and TCSG2 was significantly increased to 25.7 and 23.8%, respectively. The modified starches from TK11 had better percent recovery of the crystalline SNPs than those from TCSG2. They exhibited a higher weight-average molecular weight (M_w) and a broader/bimodal molecular weight distribution with a higher polydispersity (PDI) (M_w = 92.76–92.69 kDa; PDI = 4.4) than those from TCSG2 (M_w = 7.13–7.15 kDa; PDI = 1.7). Compared to the native counterparts, the color analyses showed that the modified starches from TK11 and TCSG2 exhibited decreased brightness (L*)/whiteness index (WI) values with marked color difference values (∆E) ranging between 6.32 and 9.39 and 10.67 and 11.32, respectively, presumably due to the protein corona formed on the surface of SNPs which induced the browning reaction during the treatments. The pasting properties revealed that the modified starches displayed restricted swelling power with extremely low pasting viscosities, reflecting that they were highly thermally stable. The modified starches, especially those treated with an extended annealing incubation, exhibited marked decreases in the rate and extent of digestion and estimated glycemic index due to the honeycomb-like agglomerates comprising an assembly of densely packed SNPs. The results could provide helpful information for the preparation and characterization of the crystalline SNPs for potential applications such as emulsion stabilizers for Pickering emulsion and health-promoting ingredients. Full article

The rheology of suspensions of solid particles in aqueous matrix liquids thickened by starch nanoparticles (SNP) was investigated. The SNP concentration varied from 9.89 to 34.60 wt% based on the aqueous matrix phase. The solids concentration of suspensions varied from 0 to 47 wt% (0 to 56 vol%). The suspensions at any given SNP concentration were generally Newtonian at low solids concentrations. At high solids concentrations, the suspensions were non-Newtonian shear-thinning. With the increase in the SNP concentration, the suspensions become non-Newtonian at a lower solids concentration. The rheological behavior of non-Newtonian suspensions could be described adequately with a power-law model. The consistency index of the suspension increased with the increase in solids concentration of the suspension at any given SNP concentration. The flow behavior index of suspensions was well below unity at high solids concentrations, indicating non-Newtonian shear-thinning behavior. The value of the flow behavior index decreased with the increase in solids concentration indicating an enhancement of shear-thinning in suspensions. The experimental viscosity and consistency data for Newtonian and non-Newtonian suspensions showed good agreement with the predictions of the Pal viscosity model for suspensions. Full article

Starch nanoparticles (SNPs) are generally defined as starch grains smaller than 600–1000 nm produced from a series of physical, chemical, or biologically modified starches. Many studies have reported the preparation and modification of SNPs, which are mostly based on the traditional “top-down” strategy. The preparation process generally has problems with process complexity, long reaction periods, low yield, high energy consumption, poor repeatability, etc. A “bottom-up” strategy, such as an anti-solvent method, is proven to be suitable for the preparation of SNPs, and they are synthesized with small particle size, good repeatability, a low requirement on equipment, simple operation, and great development potential. The surface of raw starch contains a large amount of hydroxyl and has a high degree of hydrophilicity, while SNP is a potential emulsifier for food and non-food applications. Full article

Starch as a natural polymer is abundant and widely used in various industries around the world. In general, the preparation methods for starch nanoparticles (SNPs) can be classified into ‘top-down’ and ‘bottom-up’ methods. SNPs can be produced in smaller sizes and used to improve the functional properties of starch. Thus, they are considered for the various opportunities to improve the quality of product development with starch. This literature study presents information and reviews regarding SNPs, their general preparation methods, characteristics of the resulting SNPs and their applications, especially in food systems, such as Pickering emulsion, bioplastic filler, antimicrobial agent, fat replacer and encapsulating agent. The aspects related to the properties of SNPs and information on the extent of their utilisation are reviewed in this study. The findings can be utilised and encouraged by other researchers to develop and expand the applications of SNPs. Full article

Emulsion systems are widely used in various industries, including the cosmetic, pharmaceutical, and food industries, because they require emulsifiers to stabilize the inherently unstable contact between oil and water. Although emulsifiers are included in many products, excessive use of emulsifiers destroys skin barriers and causes contact dermatitis. Accordingly, the consumer demand for cosmetic products made from natural ingredients with biocompatibility and biodegradability has increased. Starch in the form of solid nanosized particles is considered an attractive emulsifier that forms and stabilizes Pickering emulsion. Chemical modification of nanosized starch via acid hydrolysis can effectively provide higher emulsion stability. However, typical acid hydrolysis limits the industrial application of starch due to its high time consumption and low recovery. In previous studies, the effects of starch nanoparticles (SNPs) prepared by treatment with acidic dry heat, which overcomes these limitations, on the formation and stability of Pickering emulsions were reported. In this study, we evaluated the safety of SNPs in skin cell lines, 3D cultured skin, and human skin. We found that the cytotoxicity of SNPs in both HaCaT cells and HDF cells could be controlled by neutralization. We also observed that SNPs did not induce structural abnormalities on 3D cultured skin and did not permeate across micropig skin tissue or human skin membranes. Furthermore, patches loaded with SNPs were found to belong in the “No irritation” category because they did not cause any irritation when placed on human skin. Overall, the study results suggest that SNPs can be used as a safe emulsifier in various industries, including in cosmetics. Full article

Starch nanoparticles (SNPs) useful for the extraction of bitumen from oil sands were obtained by modification with thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate) (PMEO₂MA) segments through RAFT (Reversible Addition–Fragmentation chain Transfer) grafting. Since PMEO₂MA exhibits a Lower Critical Aggregation Temperature (LCAT), the polymer-grafted SNPs are amphiphilic above the LCAT of the thermoresponsive polymer and can interact efficiently with bitumen in the oil sands, facilitating its extraction. The PMEO₂MA-grafted SNPs form micellar aggregates that remain dispersed in water but can shuttle the bitumen component out of the sand and silt mixture in the extraction process above the LCAT. Upon cooling, the hydrophobic PMEO₂MA domains become hydrophilic again and the grafted SNPs remain in the water phase, while the extracted oil floats on the aqueous phase and can be skimmed off. The aqueous polymer solution may be reused in other extraction cycles. Extraction by tumbling of the oil-water-SNP mixtures in vials at 45 °C reached over 80% efficiency. The synthetic methods used provide easy control over the characteristics of the grafted SNPs (number and length of grafted PMEO₂MA segments), and therefore over their hydrophilic-lipophilic balance (HLB). The SNP-g-PMEO₂MA samples were characterized by ¹H NMR, UV-visible spectroscopy and dynamic light scattering analysis, and the grafted PMEO₂MA chains were cleaved from the starch substrates for analysis by gel permeation chromatography. Full article

Starch is affected by several limitations, e.g., retro-gradation, high viscosity even at low concentrations, handling issues, poor freeze–thaw stability, low process tolerance, and gel opacity. In this context, physical, chemical, and enzymatic methods have been investigated for addressing such limitations or adding new attributes. Thus, the creation of biomaterial-based nanoparticles has sparked curiosity. Because of that, single nucleotide polymorphisms are gaining a lot of interest in food packaging technology. This is due to their ability to increase the mechanical and water vapor resistance of the matrix, as well as hide its re-crystallization during storage in high-humidity atmospheres and enhance the mechanical properties of films when binding in paper machines and paper coating. In medicine, single nucleotide polymorphisms (SNPs) are suitable as carriers in the field of drug delivery for immobilized bioactive or therapeutic agents, as well as wastewater treatments as an alternative to expensive activated carbons. Starch nanoparticle preparations can be performed by hydrolysis via acid hydrolysis of the amorphous part of a starch molecule, the use of enzymes such as pullulanase or isoamylase, or a combination of two regeneration and mechanical treatments with the employment of extrusion, irradiation, ultrasound, or precipitation. The possibility of obtaining cheap and easy-to-use methods for starch and starch derivative nanoparticles is of fundamental importance. Nano-precipitation and ultra-sonication are rather simple and reliable methods for nanoparticle production. The process involves the addition of a diluted starch solution into a non-solvent, and ultra-sonication aims to reduce the size by breaking the covalent bonds in polymeric material due to intense shear forces or mechanical effects associated with the collapsing of micro-bubbles by sound waves. The current study focuses on starch nanoparticle manufacturing, characterization, and emerging applications. Full article

In recent years, starch nanoparticles (SNPs) have attracted growing attention due to their unique properties as a sustainable alternative to common nanomaterials since they are natural, renewable and biodegradable. SNPs can be obtained by the breakdown of starch granules through different techniques which include both physical and chemical methods. The final properties of the SNPs are strongly influenced by the synthesis method used as well as the operational conditions, where a controlled and monodispersed size is crucial for certain bioapplications. SNPs are considered to be a good vehicle to improve the controlled release of many bioactive compounds in different research fields due to their high biocompatibility, potential functionalization, and high surface/volume ratio. Their applications are frequently found in medicine, cosmetics, biotechnology, or the food industry, among others. Both the encapsulation properties as well as the releasing processes of the bioactive compounds are highly influenced by the size of the SNPs. In this review, a general description of the different types of SNPs (whole and hollow) synthesis methods is provided as well as on different techniques for encapsulating bioactive compounds, including direct and indirect methods, with application in several fields. Starches from different botanical sources and different bioactive compounds are compared with respect to the efficacy in vitro and in vivo. Applications and future research trends on SNPs synthesis have been included and discussed. Full article

Emulsions stabilized by solid nanoparticles, referred to as Pickering emulsions, are becoming increasingly important in applications as they are free of surfactants. However, the bulk properties and stability of Pickering emulsions are far from being well understood. In this work, the rheological behavior and catastrophic phase inversion of emulsions in the presence of starch nanoparticles were studied using in-situ measurements of viscosity and electrical conductivity. The aqueous phase consisting of starch nanoparticles was added sequentially in increments of 5% vol. to the oil phase under agitation condition to prepare the emulsions. The emulsions were water-in-oil (W/O) type at low to moderate concentrations of aqueous phase. At a certain critical volume fraction of aqueous phase, catastrophic phase inversion of W/O emulsion to oil-in-water (O/W) emulsion took place accompanied a sharp jump in the electrical conductivity and a sharp drop in the emulsion viscosity. The W/O emulsions were nearly Newtonian at low concentrations of aqueous phase. At high concentrations of aqueous phase, prior to phase inversion, the W/O emulsions exhibited a shear-thickening behavior. The O/W emulsions produced after phase inversion were shear-thinning in nature. The comparison of the experimental viscosity data with the predictions of emulsion viscosity model revealed only partial coverage of droplet surfaces with nanoparticles. With the increase in the concentration of starch nanoparticles (SNPs) in the aqueous phase of the emulsions, the phase inversion of W/O emulsion to O/W emulsion was delayed to higher volume fraction of aqueous phase. Thus SNPs imparted some stability to W/O emulsions against coalescence and phase inversion. Full article

Cellulose nanocrystals (CNC) and starch nanoparticles (SNP) have remarkable physical and mechanical characteristics. These properties particularly facilitate their application as high-performance components of bio-based packaging films as alternatives to fossil-based counterparts. This study demonstrates a time-efficient and resource-saving extraction process of CNC and SNP by sulfuric acid hydrolysis and neutralization. The yields of the hydrolyzed products were 41.4% (CNC) and 32.2% (SNP) after hydrolysis times of 3 h and 120 h, respectively. The nanoparticle dispersions were wet-coated onto poly(lactic acid) (PLA) and paper substrates and were incorporated into starch films. No purification or functionalization of the nanoparticles was performed prior to their application. Techno-functional properties such as the permeability of oxygen and water vapor were determined. The oxygen permeability of 5–9 cm³ (STP) 100 µm m⁻² d⁻¹ bar⁻¹ at 50% relative humidity and 23 °C on PLA makes the coatings suitable as oxygen barriers. The method used for the extraction of CNC and SNP contributes to the economic production of these nanomaterials. Further improvements, e.g., lower ion concentration and narrower particle size distribution, to achieve reproducible techno-functional properties are tangible. Full article