RESUMEN

Forest frog's oviduct oil (FFOO) is highly susceptible to microbial spoilage during storage, which causes serious safety concerns and economic losses. However, little information is available regarding the preservation of it up to now. The aim of this research is to understand the dominant microbial community of FFOO spoilage, and based on this, develop a kind of edible nanoemulsion coating for preserving FFOO. Microbial metagenomic analysis indicated that the Aspergillus genus increased significantly during storage. In the present study, gum arabic and whey protein isolate were chosen as the coating matrix, the natural compounds sanguinarine and glabridin were selected as antimicrobial agents to prepare double-layer nanoemulsion edible coating. When the ratio of sanguinarine and glabridin in the nanoemulsion was 1:3, it exhibited strongest storage stability and antifungal activity. The mycelial inhibition rate of 1:3 nanoemulsion against dominant microbial community (Aspergillus niger and Aspergillus glaucus) reached 88.89 ± 1.37 % and 89.68 ± 1.37 %, respectively. The experimental results indicated that the edible nanoemulsion coating not only had outstanding antifungal activity, but also had excellent fresh-keeping effect on FFOO. This nanoemulsion coating could be a promising and potential candidate for food preservation.

Asunto(s)

RESUMEN

This research focused on synthesizing an eco-friendly FeZn/GA@Cu nanocomposite using spent coffee grounds and Gum Arabic (GA). The study aimed to investigate its effectiveness as both a photocatalyst and an adsorbent, specifically for removing nitrates from aqueous solutions. The prepared nanocomposite was characterized using various analytical techniques, including XRD, TGA, FESEM with EDS, TEM, BET, FTIR, zeta potential, UV-DRS, and VSM. The RSM method, an impressive removal efficiency of 95.28 % for nitrate was projected under the specific conditions of an optimal dose of 1.82 g/L, an initial concentration of 60.00 mg/L, a pH level of 5.85, and a reaction duration of 48.90 min. It was ascertained that the peak efficiency of 98.25 % could be achieved with a carefully calibrated dose of 1.94 g/L, an initial concentration of 62.69 mg/L, a pH of 5.16, and a reaction time contained within 45.75 min. The synthesized nanocomposites have shown potential antibacterial activity against gram+ve (Staphylococcus aureus) and gram-ve (Escherichia coli) pathogens. This study suggests that the FeZn/GA@Cu nanocomposite synthesized using spent coffee grounds has potential as a photocatalyst for removing nitrate from aqueous solutions.

Asunto(s)

RESUMEN

This study investigated the effect of heat treatments on the pungency and aroma profiles of a spice oleoresin blend, and the emulsion stability with different surfactants, encapsulating agents, and homogenization mechanisms. Total pungency increased with heat until 120 °C and drastically reduced at 150 °C. Thermal processing induced aroma release, and 46 compounds were identified at 90 °C, predominantly comprising sesquiterpenes. Tween 80 dispersed the highest oleoresin mass (6.21 ± 0.31 mg/mL) and reported the maximum emulsion stability index. The oleoresin percentage significantly influenced the emulsion stability, with 1% oleoresin producing the most stable emulsion. High-pressure homogenization applied on gum Arabic resulted in a greater encapsulation efficiency, exceeding 86%, and the lowest creaming index (4.70 ± 0.06%), while Hi-Cap 100 produced the best flow properties. The findings provide insights into incorporating lipophilic spice oleoresin blends in aqueous food systems and understanding the release of flavor compounds during thermal food processing.

Asunto(s)

RESUMEN

Erythromycin (ERY) molecules are robust to the environment and hard to remove due to their aromatic structure. Nowadays, numerous researches have reported that the ERY amount in water is above the standard level and its removal is necessary. Here, we prepared three solid adsorbents: graphitic carbon nitride (g-C3N4), potassium carrageenan beads (Cr), and graphitic carbon nitride/gum Arabic/potassium carrageenan composite (g-ACr). Several techniques such as XRD, SEM, TEM, TGA, ATR-FTIR, Zeta potential, and N2 adsorption were employed to characterize the fabricated adsorbents. Five essential factors of adsorbent dose, initial ERY concentration, contact time, temperature, and pH were optimized to investigate the batch adsorption of ERY. The maximum adsorption capacity of 356.12 mg/g was attained by g-ACr composite at an adsorbent dose of 1.25 g/L, contact time of 6 h, and pH 7 at 15 °C. The data showed that the experimental findings exhibited the best agreement with Langmuir, Temkin, and DR isotherm models, in addition to the kinetic models of pseudo-second-order, Elovich, and intra-particle diffusion. The evaluated thermodynamic factors designated that the ERY adsorption is endothermic, physisorption, favorable, and spontaneous process. The g-ACr reusability displayed a decline in the adsorption capacity after seven adsorption/desorption runs by 5.7 %. Finally, this work outcomes depict that g-ACr composite is an efficient reusable adsorbent for ERY elimination from wastewater.

Asunto(s)

RESUMEN

This study explores the synthesis and characterization of superabsorbent hydrogels derived from chemically modified gum Arabic, designed for controlled folic acid release. The synthesis involves a two-step process: carboxymethylation followed by grafting with 2-hydroxyethyl methacrylate via gamma irradiation. The resulting hydrogels exhibit enhanced mechanical strength and controlled diffusivity, essential for nutrient delivery systems. Key factors such as copolymer composition and irradiation dose are investigated, affecting the synthesis process. Systematic studies of swelling behaviors reveal that the hydrogel achieves a maximum swelling of 888.1% at 40 °C. The hydrogels are loaded with folic acid, and in vitro, sustained release profiles are examined under various pH conditions. The maximum release of 83.3% is observed after 24 h at pH 7.0, following a Korsmeyer-Peppas release mechanism. Different characterization techniques, confirm the successful synthesis and unique properties of the superabsorbent hydrogels. Rheological behavior analysis, scanning electron microscopy, and biocompatibility assessments provide a comprehensive understanding of the hydrogel structures. Gamma irradiation ensures a homogeneous network structure, crucial for optimal swelling behavior and mechanical properties. This research highlights the potential of eco-friendly biopolymer hydrogels in precise drug delivery applications, leveraging the safety and process control benefits of gamma irradiation.

RESUMEN

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

RESUMEN

The objective of this research was to explore the viability of pea protein as a substitute for gelatin in the complex coacervation process, with a specific focus on understanding the impact of incorporating an emulsifier into this process. The study involved the preparation of samples with varying polymer mixing ratios (1:1, 1:2, and 2:1) and emulsifier content. As core substances, black pepper and juniper essential oils were utilized, dissolved beforehand in grape seed oil or soybean oil, to minimize the loss of volatile compounds. In total, 24 distinct samples were created, subjected to freeze-drying to produce powder, and then assessed for their physicochemical properties. Results revealed the significant impact of emulsifier addition on microcapsule parameters. Powders lacking emulsifiers exhibited higher water solubility (57.10%-81.41%) compared to those with emulsifiers (24.64%-40.13%). Moreover, the emulsifier significantly decreased thermal stability (e.g., without emulsifier, Ton = 137.21°C; with emulsifier, Ton = 41.55°C) and adversely impacted encapsulation efficiency (highest efficiency achieved: 67%; with emulsifier: 21%).

Asunto(s)

RESUMEN

The inadequate water resistance and mechanical properties of waterborne anticorrosive coatings is a serious problem that leads to coating failure. When the bark of acacia trees sustains damage, the liquid Gum Arabic (GA) that oozes from the trunk coagulates at the site of injury to safeguard it, which is called "gummosis" self-protection. Inspired by this, biomimetic GA microgel-based waterborne anticorrosive coatings are designed. Microgel exhibits a crosslinked polymer network structure with a combination of advantageous characteristics derived from both solids and liquids. By encapsulating the liquid corrosion inhibitors (MeBT) within the solid microgel matrix, the coating system is endowed with self-protective capabilities. The as-prepared GAMG-MeBT microgels are introduced into waterborne epoxy (WE) matrix and sprayed onto the surface of Q235 steel. Corrosion studies reveal the 3.0-wt% GAMG-MeBT/WE coating exhibits an impedance modulus value in the low-frequency region (Z0.01Hz) of 1.37 × 109 Ω cm2 after immersing in 3.5-wt% NaCl solution for 60 days, which is nearly two orders of magnitude higher than that of the pure WE coatings. Moreover, the coatings display improved water resistance, enhanced abrasive resistance, and active corrosion protection. This work provides a new approach to solving the failure of WE anticorrosive coatings.

RESUMEN

BACKGROUND: Gum arabic, a polysaccharide exudate from Acacia senegal (L.) Willdenow trees, has already been used by African native people in natural medicine. METHODS: Using whole-blood samples from young (20-35 years) and older (>80 years) healthy volunteers (each group n = 10), the effect of an aqueous solution of GA on phagocytosis of Escherichia coli was examined with a gentamicin protection assay. Whole-blood samples of each volunteer were stimulated with GA and as a control with CpG oligodeoxynucleotides (Toll-like receptor -9 agonists) for 2 h, then co-incubated with E. coli for 30 min and thereafter treated with gentamicin for up to 240 min to kill extracellular bacteria. Then, whole-blood cells were lysed with distilled water, and colony-forming units were counted by quantitative plating. Cytokine enzyme-linked immunosorbent assay for the detection of TNF-α and IL-6 was performed using the blood supernatant. RESULTS: The GA concentration tested (20 mg/mL) did not affect the viability of eukaryotic cells. Phagocytosis of E. coli by whole-blood leukocytes derived from young (p = 0.008) and older (p = 0.004) healthy volunteers was increased by 120.8% (young) and 39.2% (old) after stimulation with GA. In contrast, CpG only stimulated the bacterial phagocytosis by cells derived from young volunteers (p = 0.004). Stimulation of whole blood with GA increased the intracellular killing of E. coli in young (p = 0.045) and older volunteers (p = 0.008) and induced a TNF-α release in whole blood collected from older volunteers but not from younger ones (p = 0.008). CONCLUSIONS: These data encourage the isolation of active compounds of GA and the initiation of clinical trials addressing the preventive effect of GA on bacterial infections.

RESUMEN

In this study, gum arabic (GA) coating was employed to mitigate chilling injury in peach fruit, and it was observed that 10% GA coating exhibited the most favorable effect. GA coating significantly inhibited the decline of AsA content and enhanced antioxidant enzyme activity in peach fruit, thereby enhancing reactive oxygen species (ROS) scavenging rate while reducing its accumulation. Simultaneously, GA coating inhibited the activity of oxidative degradation enzymes for phenolics and enhanced synthase activity, thus maintaining higher levels of total phenolics and flavonoids in fruits. Additionally, compared to the control fruit, GA-coated fruits demonstrated higher concentrations of sucrose and sorbitol, accompanied more robust activity of sucrose synthase and sucrose phosphate synthase, as well as reduced activity of acid invertase and neutral invertase. Our study demonstrates that GA coating can effectively enhance the cold resistance of peach fruit by regulating ROS, phenolics, and sugar metabolism, maintaining high levels of phenolics and sucrose while enhancing antioxidant activity.

Asunto(s)

RESUMEN

Granular hydrogels have emerged as a new class of materials for 3D printing, tissue engineering, and food applications due to their extrudability, porosity, and modularity. This work introduces a convenient method to prepare granular hydrogel with tunable properties by modulating the interaction between gum Arabic (GA) and whey protein isolate (WPI) microgels. As the concentration of GA increased, the appearance of the hydrogel changed from fluid liquid to moldable solid, and the microstructure changed from a macro-porous structure with thin walls to a dense structure formed by the accumulation of spherical particles. At a GA concentration of 0.5 %, the hydrogels remained fluid. Granular hydrogels containing 1.0 % GA showed mechanical properties similar to those of tofu (compressive strength: 10.8 ± 0.5 kPa, Young's modulus: 16.7 ± 0.4 kPa), while granular hydrogels containing 1.5 % GA showed mechanical properties similar to those of hawthorn sticks and sausages (compressive strength: 300.4 ± 5.8 kPa; Young's modulus: 200.5 ± 3.4 kPa). The hydrogel with 2.0 % GA was similar to hawthorn sticks, with satisfactory bite resistance and elasticity. Such tunability has led to various application potentials in the food industry to meet consumer demand for healthy, nutritious, and diverse textures.

Asunto(s)

RESUMEN

Gum arabic finds extensive application and typically undergoes sterilization prior to utilization in the food industry. This study explored the impact of steam sterilization temperature and duration on the physicochemical and emulsification characteristics of gum arabic, accompanied by proposed mechanisms elucidating observed effects. The results showed that when gum arabic was treated with high temperature sterilization (110 °C âˆ¼ 140 °C), the emulsion prepared turned unstable. The interfacial tension decreased from 8.26 mN/m to 6.77 mN/m after sterilization, while the elastic modulus decreased from 23.65 mN/m to 16.16 mN/m. Moreover, the circular dichroic chromatographic results indicated that the arabinogalactan protein (AGP) structure of gum arabic was more relaxed after high temperature treatment with ß-sheets content decreased from 36.2 % to 29.8 % and random coil content increased from 41.3 % to 51.8 %. Quartz crystal microbalance with dissipation (QCM-D) results demonstrated that emulsion surface film thickness and toughness decreased after sterilization treatment of gum arabic. The study indicates that high temperature sterilization may change protein structure in gum arabic and reduce the stability of prepared emulsions.

Asunto(s)

RESUMEN

Photochromic wood materials are very important and appealing for smart windows. Herein, we describe the development of transparent photochromic wood that can change its color under ultraviolet and visible lights. Photoluminescent transparent wood was prepared by delignification of wood followed by infiltration with a combination of gum Arabic/chitosan/acrylic acid (ACA), lanthanide-activated aluminum strontium oxide (LASO) as a photoluminescent, and Genipin as a cross-linking agent. The produced mixture was then infused into the lignin-modified wood substrate. In order to develop a luminescent colorless wood, the LASO phosphor must be well-distributed in the ACA solution without aggregation. According to the colorimetric parameters and photoluminescence spectra, this optically active wooden window switched color from transparent in daylight to green when UV-irradiated. Transmission electron microscopy (TEM) was employed to examine the morphological features of phosphor nanoparticles. The morphological features of the developed smart wooden window were investigated by scanning electron microscopy (SEM), X-ray fluorescent spectroscopy (XRF), and energy-dispersive X-ray analyzer (EDX). The mechanical performance was explored by investigating both hardness and resistance to scratches. The luminescent woods displayed an emission band at 518 nm when excited at 365 nm. The superhydrophobic performance and ultraviolet shielding of woods were improved upon increasing the phosphor content.

RESUMEN

Heteropolysaccharides are among the most widely distributed compounds in nature, acting as both tissue building blocks and as a source of nutrients. Their physicochemical and biological properties have been studied thoroughly; however, the microstructural properties of heteropolysaccharides are still poorly understood. This study aims to investigate the micro-structural peculiarities of agarose, gum arabic, hyaluronic and alginic acids by means of confocal laser scanning microscopy (CLSM) and cryogenic scanning electron microscopy (cryo-SEM). Herein, attention is paid to layered complexity of the microstructure differentiating surface, under surface, inner, and substrate interface layers. The scale and pattern of the polysaccharide's microstructure depend on the concentration, changing from lamellae to cell-like porous structures. This work provides the insight into micro- and nanoscale mechanisms of self-healing and substrate-induced reorganisation. Thus, investigation of the self-healing mechanism revealed that this diffusion-based process starts from the fibres, turning into lamellae, following by cell-like structures with smaller dimensions. Investigation of the substrate-induced reorganisation ability showed that nano-to-micro (scale) porous substrate causes reorganisation in the interface layer of the studied heteropolysaccharides. This work contributes to understanding the structural peculiarities of heteropolysaccharides by looking at them through a supramolecular, micro-level prism.

Asunto(s)

RESUMEN

The aim of this study was to optimize the formation of sodium caseinate (CS) and gum arabic (GA) complexes through the Maillard reaction and to evaluate their effectiveness in improving the emulsification properties and stability of docosahexaenoic acid (DHA) nanoemulsions. First, the best target polysaccharides were selected, and the best modification conditions were determined using orthogonal experiments. Secondly, the response surface experiments were used to optimize the preparation process of the emulsion. The stability, in vitro digestion characteristics, and rheological characteristics of the emulsion prepared by means of CS-GA were compared with the emulsion prepared using a whey protein isolate (WPI). After the orthogonal test, the optimal modification conditions were determined to be a reaction time of 96 h, a CS-GA mass ratio of 1:2, a reaction temperature of 60 °C, and a degree of grafting of 44.91%. Changes in the infrared (IR), Raman, ultraviolet (UV), and endogenous fluorescence spectra also indicated that the complex structure was modified. The response surface test identified the optimal preparation process as follows: an emulsifier concentration of 5 g/L, an oil-phase concentration of 5 g/L, and a homogenization frequency of five, and the emulsion showed good stability. Therefore, the use of a nanoemulsion as a nanoscale DHA algal oil delivery system is very promising for extending the shelf life and improving the stability of food.

RESUMEN

This paper introduces a hybrid enhanced oil recovery (HEOR) method that combines a low-salinity water flooding (LSWF) and nanoparticles (NPs) stabilized with a green surfactant. We experimentally investigated the use of combinations of silica (SiO2) and gamma alumina (γ-Al2O3) nanohybrids stabilized with Gum Arabic (GA) at different water salinities. Nanofluids (NFs) were prepared by dispersing γ-Al2O3 and SiO2 NPs (0.1 wt%) in deionized water (DW), synthetic seawater (SSW), 2, 5, and 10 times diluted samples of synthetic seawater (in short 2-DSSW, 5-DSSW and 10-DSSW, respectively). The challenge is that NPs become unstable in the presence of cations in saline water. Moreover, an attempt was made to introduce NFs with high stability for a long period of time as the optimal NFs. The effects of temperature on the behaviour of optimal NFs in the presence of different base fluids, distinct mass ratios of γ-Al2O3/SiO2 and various concentrations of surfactant were analysed via interfacial tension (IFT) and viscosity measurements. The results of the viscosity measurement showed that with increasing temperature, the NPs dispersed in DW had lower viscosity than NPs dispersed in various salinities. However, the IFT measurement for NPs dispersed in different base-fluids revealed that with increasing temperature and presence of cations in saline water, IFT values decreases. Although, the minimum IFT for hybrid nanofluid (HNF) γ-Al2O3/SiO2 modified with GA and dispersed in 10-DSSW was reported 0.99 mN/m. Finally, according to the micromodel flooding results, in oil-wet conditions, the highest oil recovery for combination γ-Al2O3/SiO2 modified with GA and dispersed in 2-DSSW was reported 60.34%. It was concluded that NFs modified with GA could enhanced applicability of LSWF via delay in breakthrough time and improving sweep efficiency.

RESUMEN

Drilling through shale formations can be expensive and time-consuming due to the instability of the wellbore. Further, there is a need to develop inhibitors that are environmentally friendly. Our study discovered a cost-effective solution to this problem using Gum Arabic (ArG). We evaluated the inhibition potential of an ArG clay swelling inhibitor and fluid loss controller in water-based mud (WBM) by conducting a linear swelling test, capillary suction timer test, and zeta potential, fluid loss, and rheology tests. Our results displayed a significant reduction in linear swelling of bentonite clay (Na-Ben) by up to 36.1% at a concentration of 1.0 wt. % ArG. The capillary suction timer (CST) showed that capillary suction time also increased with the increase in the concentration of ArG, which indicates the fluid-loss-controlling potential of ArG. Adding ArG to the drilling mud prominently decreased fluid loss by up to 50%. Further, ArG reduced the shear stresses of the base mud, showing its inhibition and friction-reducing effect. These findings suggest that ArG is a strong candidate for an alternate green swelling inhibitor and fluid loss controller in WBM. Introducing this new green additive could significantly reduce non-productive time and costs associated with wellbore instability while drilling. Further, a dynamic linear swelling model, based on machine learning (ML), was created to forecast the linear swelling capacity of clay samples treated with ArG. The ML model proposed demonstrates exceptional accuracy (R2 score = 0.998 on testing) in predicting the swelling properties of ArG in drilling mud.

RESUMEN

The incorporation of different amounts of Gum Arabic (GA) in thermoplastic starch (TPS) obtained by extrusion and subsequent thermocompression has been studied. The sheets have been characterized by means of XRD, FTIR, TGA, moisture content, SEM, mechanical properties, antimicrobial activity and biodegradability via composting. The FTIR analysis of the sheets shows the presence of ester groups, while the TGA shows the presence of new processes and a residue much higher than expected is obtained. No changes in crystallinity are observed by XRD. The inclusion of GA confers antimicrobial properties to thermoplastic starch against the Gram + and Gram - bacteria studied even at the smaller concentrations. For a low GA content (0.5 and 1 g GA/100 g TPS) a homogeneous material is observed by SEM, as well as an important increase in tensile strength, modulus and deformation at break, which are very interesting properties facing the applicability of this material in single use plastics which are in contact with food or other consumable goods. At higher contents of GA, hollows and cracks appear in the material, compromising the mechanical properties. In all cases, the inclusion of GA delays the biodegradation process in soil, which can be related to its antibacterial capacity and especially in case of GA concentrations of 2 and 5 g/100 g of TPS with lower humidity of these TPS sheets.

RESUMEN

Gum Arabic underwent enzymatic modification with curcumin oxidation products, prompting self-assembly in water at lower concentrations than native gum Arabic, which was fully soluble. The resulting particles displayed a narrow size distribution, suggestive of a micellization mechanism akin to Critical Micellization Concentration (CMC) in surfactants or Critical Aggregation Concentration (CAC) in polymers. Accurately determining CAC is vital for utilizing polymers in molecule encapsulation, but precise measurement is challenging, requiring multiple techniques. Initially, CAC was probed via turbidity measurements, dynamic light scattering (DLS), and isothermal calorimetric titration (ITC), yielding a range of 0.0015 to 0.01 %. Micro-scale thermophoresis (MST) was then employed for the first time to define CAC more precisely, facilitated by the intrinsic fluorescence of modified gum Arabic. Using MST, CAC was pinpointed at 0.001 % (w/v), a novel approach. Furthermore, MST revealed a low EC50 value of 0.007 % (w/t) for self-assembly, signifying uniformity among GAC sub-units and assembly stability upon dilution.

Asunto(s)

RESUMEN

This study explores the effect of spray-drying (SD) inlet temperatures (Tinlet 120 and 150 °C) and wall material on the chemical and physico-chemical properties of microencapsulated hop extracts (MHE). Hop extract was formulated with maltodextrin (MD) and gum Arabic (GA) used in single or in combination with ß-cyclodextrin (ßCD). MHE were evaluated for physical properties, bitter acids (BA), total polyphenol content (TPC) and encapsulation efficiency (TPC EE), and antioxidant capacity (AOC). Powders produced at Tinlet 150 °C exhibited the highest flowability and generally higher TPC yield. Besides Tinlet, MD enabled the obtaining of MHE with the highest encapsulation efficiency. Other physico-chemical and antioxidant properties differently varied depending on the Tinlet. Overall, the ßCD addition positively affected α-acids, and ß-acids of MHE obtained at Tinlet 120 °C. ATR-FTIR analysis showed hydrogen bond formation between hop compounds and ßCD. Multifactorial ANOVA highlighted that Tinlet, W, and their interaction influenced almost all the chemical and physico-chemical properties of MHE.