Search Results (17)

This review summarizes scientific advances about the sonochemical synthesis of starch nanoparticles (St-NPs) for the food industry, as well as nutraceutical and drug delivery applications. High-intensity ultrasonication (HIU) has been explored as a versatile and environmentally friendly alternative to conventional methods for synthesizing St-NPs with high yields (>90%), controlled size (~100 nm), and minimal effluent generation. Thus, HIU has been explored (pre- or post-treatment) to mitigate the inherent disadvantages (high-cost, low yields, and environmental impact) of hydrothermal gelatinization, acid/alkaline hydrolysis, enzymatic hydrolysis, enzyme branching, water-in-oil and oil-in-water emulsions, non-solvent nanoprecipitation, extrusion, high-pressure homogenization, high-energy milling, and cold plasma. Conventional sources of starch (corn [normal, waxy, high-amylose] and potato) and other unconventional sources (tubers [cassava, yam, malanga], seeds and grains [sorghum, barley, quinoa, lotus], breadfruit, pinhao seed, Araucaria angustifolia) have been subjected to single or assisted sonochemical protocols to obtain St-NPS with unique structural, physicochemical, and technological properties. The physical–mechanical effects of ultrasonication (cavitation, heat, and pressure) directly promote surface functionalization (i.e., esterification, pore formation) and impact the St-NPS’s particle size, double-helix structure, enzymatic-resistance properties, crystallinity, and intra- and intermolecular arrangements. Pickering additives in food systems, colloids in beverages, nanocomposites in biofilms for food packaging, and nanocarriers for drug and nutraceutical delivery (oral and transdermal) have been the most reported applications. Full article

This study presents an optimized and sustainable route for synthesizing cassava starch nanoparticles (CSNPs) tailored for enhanced oil recovery (EOR) applications. Conventional inorganic acid hydrolysis methods often produce low nanoparticle yields and large particle sizes due to extensive degradation of both amorphous and crystalline starch regions. To overcome these challenges, ultrasonic-assisted acetic acid hydrolysis coupled with response surface methodology (RSM) was applied. Under optimal conditions, two distinct CSNPs were produced: CSNP A (206.77 nm, 96.23% yield in 3 days) and CSNP B (99.4 nm, 96.07% yield in 7 days). Characterization via Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed enhanced crystallinity, while rheological analyses revealed shear-thickening behavior and improved viscosity, key factors for effective polymer flooding in EOR. DSC and TGA measurements highlighted robust thermal stability, essential for high-temperature reservoir conditions. A preliminary assessment suggests CSNP B’s small size (99.4 nm), high viscosity, and thermal stability make it particularly promising for EOR in low-permeability reservoirs, with future core flooding studies needed for validation. These attributes position CSNPs as sustainable alternatives for polymer flooding in challenging reservoir environments. Full article

Hybrid pigments were obtained by combining zinc oxide with the anionic dye Congo red (CR), a breakthrough with significant environmental implications. By adjusting the ratio of solid mass to dye concentration, it is possible to obtain pigments with pink hues from a white solid (ZnO) through its adsorption of CR. The process involved using ZnO, prepared at 800 °C using cassava starch suspension as a suitable fuel. The oxide was characterized using XRD, SEM, and BET, and the results showed that the textural properties are typical of nanoparticles, with a size of 50.5 nm, a pore size of 3.48 nm, and a surface area of 3.03 nm, making it suitable for molecular dye removal. Controlling the adsorbent mass (in grams) and dye concentration (in mg L⁻¹) makes it possible to consistently produce hybrid pigments in various shades of pink that exhibit good thermal resistance. When dispersed in white waterborne paint, they are chemically stable in different solvents, have excellent painted surface coverage, and resist photochemical degradation. The results demonstrate technical feasibility and compatibility with the Sustainable Development Goals, particularly Goals 6, 11, 12, 14, 15, and 17, offering a promising solution for a more sustainable future. Full article

Curcumin is a hydrophobic bioactive compound, and its incorporation into lipid-based carriers can enhance its bioaccessibility and maintain its stability over time. Pickering emulsions are long-term stability systems, effective for encapsulation, protection, and delivery of bioactive compounds. This study aimed to produce Pickering oil-in-water (O/W) emulsions stabilized by cassava starch nanoparticles (native or modified by heat–moisture treatment (HMT)) with high kinetic stability to encapsulate curcumin. The effect of curcumin incorporation on emulsion features was also assessed, as well as curcumin stability over time. Native starch nanoparticles (NSNPs) were not effective stabilizers in the concentration range of 0.8 to 4 wt%. Otherwise, modified starch nanoparticles (HSNPs) at 4 wt% produced a long-term stability Pickering emulsion, which was used to encapsulate curcumin (0.07 wt%). Confocal laser scanning microscopy (CLSM) showed that HSNPs were located at the droplet’s interface. The interfacial tension for HSNPs exhibited initial values from 40 to 33 mN/m, quickly reaching equilibrium. These findings suggest that HSNPs exhibit low surface activity and the stabilization mechanism of emulsion is based on steric hindrance. The stabilization by steric hindrance is supported by the low zeta potential value (−5.39 mV). Stable emulsions showed shear thinning behavior, and the power-law model demonstrated excellent fit to experimental data (R² ≥ 0.998). The addition of curcumin reduced the interfacial tension, droplet size, apparent viscosity, and consistency index, indicating that this bioactive compound can also act at the interface. After 60 days, curcumin degradation was fully avoided. Our findings indicated that HSNP-stabilized Pickering emulsions can protect encapsulated curcumin from degradation. 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

Phenolic compounds from propolis extract (PE) have antioxidant and antimicrobial properties; however, extracts from this raw material are not water soluble. This study aimed to stabilize the phenolic compounds from green propolis extract in cassava and potato starch nanoparticles produced by the anti-solvent precipitation method. The obtained materials displayed a crystalline structure related to starch nanomaterials with a V_6h-type crystalline structure. The starch nanoparticles interacted with the phenolic compounds by means of hydrogen bonds and increased the hydrophobicity in the nanomaterials. The developed starch nanomaterials loaded with the phenolic compounds from PE could be potentially used as a novel ingredient in food packaging. Full article

One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix. Full article

Alkaline–surfactant–polymer (ASP) flooding, a recognized method for oil recovery, encounters limited use due to its expense. In addition, ASP’s best composition and injection sequence still remains uncertain today. This study explores conventional ASP flooding using PT SPR Langgak’s special surfactants, simulating Langgak oilfield conditions in Sumatra, Indonesia. By comparing the outcomes of this flooding technique with that of starch-assisted ASP performed in another study, the benefits of adding starch nanoparticles to flooding are evident. Nano-starch ASP increased oil recovery by 18.37%, 10.76%, and 10.37% for the three configurations investigated in this study. Water flooding preceded ASP flooding, and flooding operations were carried out at 60 °C. This study employed sodium hydroxide (NaOH), sodium carbonate (Na₂CO₃), and specialized surfactants from PT SPR. The adopted polymer is solely hydrolyzed polyacrylamide (HPAM) at 2000 ppm. Starch nanoparticles underwent comprehensive characterization and focused more on charge stability. Purple yam nanoparticles (PYNPs) exhibited remarkable stability at −36.33 mV, unlike cassava starch nanoparticles (CSNPs’) at −10.68 mV and HPAM’s at −27.13 mV. Surface properties affect interactions with fluids and rocks. Crystallinity, a crucial characterization, was assessed using Origin software 2019b. CSNPs showed 24.15% crystallinity, surpassing PYNPs’ 20.68%. Higher crystallinity benefits CSNPs’ thermal stability. The amorphous behavior found in PYNPs makes them less suitable if applied in harsh reservoirs. This research correlated with prior findings, reinforcing starch nanoparticles’ role in enhancing oil recovery. In summary, this study highlighted conventional ASP flooding using HPAM as the sole polymer and compared it with three formations that used two starch nanoparticles included with HPAM, assessing their impact on charge stability, crystallinity, and recovery rate to emphasize their importance in the oil recovery industry. Starch nanoparticles’ benefits and limitations guided further investigation in this study. Full article

This study aimed to address the challenges faced by mature oilfields in extracting substantial oil quantities. It focused on improving the efficiency of alkaline–surfactant–polymer (ASP) flooding technique, which is a proven tertiary recovery technology, to overcome scaling issues and other hindrances in its large-scale implementation. Appropriate materials and their suitable concentrations were selected to enhance the ASP flooding technique. Special surfactants from Indonesia were introduced to improve the interfacial tension reduction and wettability alteration. Reservoir rock model that resembling Langgak oilfield in Sumatra was utilized, and low-salinity water was employed to mimic the oilfield conditions. Starches derived from cassava nanoparticles (CSNPs) and purple yam nanoparticles (PYNPs) were combined separately with conventional hydrolyzed polyacrylamide (HPAM) polymer to enhance its performance. Sodium hydroxide and sodium carbonate were used as alkaline in final ASP formula. It was demonstrated from this research that only two combinations of ASP formulations have led to improved oil recovery. One combination utilizing PYNPs resulted in 39.17% progressive recovery, while the other combination incorporating CSNPs achieved 35% incremental oil recovery. The ASP combination that resulted in recovery rate of 39.17% was composed of sodium hydroxide (NaOH) at a concentration of 1.28 wt.%, PSC EOR 2.2 (0.98 wt.%), and a combined polymer consisting of HPAM (0.2 wt.%) and PYNPs nano-starch (0.6 wt.%). The second combination led to 35% recovery rate and involved NaOH also at concentration 1.28 wt.%, PSC HOMF (0.63 wt.%), and a combined polymer comprising from HPAM (0.2 wt.%) and CSNPs nano-starch (0.8 wt.%). These findings of this study highlighted the potential of this modified ASP flooding to enhance oil recovery in mature oilfields, thereby offering valuable insights for oil industry. Full article

Significant amounts of oil remain in the reservoir after primary and secondary operations, and to recover the remaining oil, enhanced oil recovery (EOR) can be applied as one of the feasible options remaining nowadays. In this study, new nano-polymeric materials have been prepared from purple yam and cassava starches. The yield of purple yam nanoparticles (PYNPs) was 85%, and that of cassava nanoparticles (CSNPs) was 90.53%. Synthesized materials were characterized through particle size distribution (PSA), Zeta potential distribution, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The performance of PYNPs in recovering oil was better than CSNPs, as found from the recovery experiments. Zeta potential distribution results confirmed the stability of PYNPs over CSNPs (−36.3 mV for PYNPs and −10.7 mV for CSNPs). The optimum concentration for these nanoparticles has been found from interfacial tension measurements and rheological properties, and it was 0.60 wt.% for PYNPs and 0.80 wt.% for CSNPs. A more incremental recovery (33.46%) was achieved for the polymer that contained PYNPs in comparison to the other nano-polymer (31.3%). This paves the way for a new technology for polymer flooding that may replace the conventional method, which depends on partially hydrolyzed polyacrylamide (HPAM). Full article

Biodegradable polymers have been strongly recognized as an alternative to replace traditional petrochemical plastics, which have become a global problem due to their long persistence in the environment. In this work, the effect of the addition of titanium dioxide nanoparticles (TiO₂NP) on the morphology, physicochemical properties and biodegradation under industrial composting conditions of cassava starch-based nanocomposites obtained by extrusion at different screw speeds (80 and 120 rpm) were investigated. Films performed at 120 rpm (S₁₂₀ and S₁₂₀-TiO₂NP) showed completely processed starch and homogeneously distributed nanoparticles, leading to much more flexible nanocomposites than those obtained at 80 rpm. The incorporation of TiO₂NP led to an increase in storage modulus of all films and, in the case of S₁₂₀-TiO₂NP, to higher strain at break values. From the Kohlrausch–Williams–Watts theoretical model (KWW), an increase in the relaxation time of the nanocomposites was observed due to a decrease in the number of polymer chains involved in the relaxation process. Additionally, S₁₂₀-TiO₂NP showed effective protection against UV light, greater hydrophobicity and faster biodegradation in compost, resulting in a promising material for food packaging applications. Full article

Starch can be found in the stems, roots, fruits, and seeds of plants such as sweet potato, cassava, corn, potato, and many more. In addition to its original form, starch can be modified by reducing its size. Starch nanoparticles have a small size and large active surface area, making them suitable for use as fillers or as a reinforcing material in bioplastics. The aim of reinforcing material is to improve the characteristics of bioplastics. This literature study aims to provide in-depth information on the potential use of starch nanoparticles as a reinforcing material in bioplastic packaging. This study also reviews starch size reduction methods including acid hydrolysis, nanoprecipitation, milling, and others; characteristics of the nano-starch particle; and methods to produce bioplastic and its characteristics. The use of starch nanoparticles as a reinforcing material can increase tensile strength, reduce water vapor and oxygen permeability, and increase the biodegradability of bioplastics. However, the use of starch nanoparticles as a reinforcing material for bioplastic packaging still encounters obstacles in its commercialization efforts, due to high production costs and ineffectiveness. Full article

In this study, two green synthesis routes were used for the synthesis of Ag/ZnO nanoparticles, using cassava starch as a simple and low-cost effective fuel and Aloe vera as a reducing and stabilizing agent. The Ag/ZnO nanoparticles were characterized and used for bacterial disinfection of lake water contaminated with Escherichia coli (E. coli). Characterization indicated the formation of a face-centered cubic structure of metallic silver nanoparticles with no insertion of Ag into the ZnO hexagonal wurtzite structure. Physicochemical and bacteriological analyses described in “Standard Methods for the Examination of Water and Wastewater” were used to evaluate the efficiency of the treatment. In comparison to pure ZnO, the synthesized Ag/ZnO nanoparticles showed high efficiencies against Escherichia coli (E. coli) and general coliforms present in the lake water. These pathogens were absent after treatment using Ag/ZnO nanoparticles. The results indicate that Ag/ZnO nanoparticles synthesized via green chemistry are a promising candidate for the treatment of wastewaters contaminated by bacteria, due to their facile preparation, low-cost synthesis, and disinfection efficiency. Full article

Based on the characteristics of charge reversal around the isoelectric point (pI) of amphoteric starch-containing anionic and cationic groups, amphoteric cassava starch nanoparticles (CA-CANPs) are prepared by a W/O microemulsion crosslinking method using (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride as a cationic reagent and POCl₃ as an anionic reagent, and the effects of preparation conditions on the particle size of the CA-CANPs are studied in detail in the present study. CA-CANPs with a smooth surface and an average diameter of 252 nm are successfully prepared at the following optimised conditions: a crosslinking agent amount of 15 wt%, an aqueous starch concentration of 6.0 wt%, an oil–water ratio of 10:1, a total surfactant amount of 0.20 g·mL⁻¹, and a CHPTAC amount of 4.05 wt%. The pH-responsive value of the CA-CANPs can be regulated by adjusting the nitrogen–phosphorus molar ratio in the CA-CANPs. By using CA-CANPs with a pI of 6.89 as drug carriers and the paclitaxel (PTX) as a model drug, the maximum loading rate of 36.14 mg·g⁻¹ is achieved, and the loading process is consistent with the Langmuir isotherm adsorption, with the calculated thermodynamic parameters of ΔH° = −37.91 kJ·mol⁻¹, ΔS° = −10.96 J·mol⁻¹·K⁻¹ and ΔG° < 0. By testing the release rate in vitro, it is noted that the release rates of PTX in a neutral environment (37.6% after 96 h) and a slightly acidic environment (58.65% after 96 h) are quite different, suggesting that the CA-CANPs have the possibility of being a targeted controlled-release carrier with pH responsiveness for antitumor drugs. Full article

Biodegradable polymers can be used for eco-friendly, functional, active packaging to preserve food quality. Incorporation of titanium dioxide (TiO₂) nanoparticles into polymer packaging enhances ethylene-scavenging activity and extends the shelf-life of fresh produce. In this study, TiO₂ nanoparticles were incorporated into biodegradable poly(butylene adipate-co-terephthalate) (PBAT)- and thermoplastic cassava starch (TPS)-blended films to produce nanocomposite packaging via blown-film extrusion. The effects of TiO₂ on morphology, packaging properties, and applications as functional packaging for fresh produce were investigated. Increased TiO₂ in the film packaging increased amorphous starch content and hydrogen bonding by interacting with the TPS phase of the polymer blend, with negligible chemical interaction with the PBAT component and identical mechanical relaxation in the PBAT phase. Surface topography indicated void space due to non-homogeneous dispersion causing increased oxygen and carbon dioxide permeability. Homogeneous dispersion of fine TiO₂ nanoparticles increased mechanical strength and reduced oxygen, carbon dioxide, and water vapor permeability. Films containing TiO₂ also showed efficient oxygen-scavenging activity that removed residual oxygen from the package headspace dependent on the levels and morphology of nanoparticles in the film matrices. Banana fruit packaged in films containing TiO₂ recorded slower darkening color change and enhanced shelf-life with increasing TiO₂ content. Full article