Facile synthesis of Persian gum-graphene oxide composite as a novel adsorbent for CO2 capture: characterization and optimization

Burning fossil fuels releases toxic gases into the environment and has negative effects on it. In this study, Persian gum@Graphene oxide (Pg@GO) was synthesized and used as a novel adsorbent for CO2 capture. The characterization of materials was determined through XRD, FTIR, FE-SEM, and TGA analysis. The operating parameters including temperature, Pressure, and adsorbent weight were studied and optimized by response surface methodology via Box-Behnken design (RSM-BBD). The highest amount of CO2 adsorption capacity was 4.80 mmol/g, achieved at 300 K and 7.8 bar and 0.4 g of adsorbent weight. To identify the behavior and performance of the Pg@GO, various isotherm and kinetic models were used to fit with the highest correlation coefficient (R2) amounts of 0.955 and 0.986, respectively. The results proved that the adsorption of CO2 molecules on the adsorbent surface is heterogeneous. Based on thermodynamic results, as the value of ΔG° is - 8.169 at 300 K, the CO2 adsorption process is exothermic, and spontaneous.

Properties of OSA-esterified insoluble fraction of Persian gum and its application in dairy cream

BACKGROUND

In the present study, the insoluble fraction of Persian gum (IFPG) was modified with octenyl succinic anhydride (OSA) and its various properties were assessed. In addition, the effect of OSA-IFPG on the rheological and textural properties of dairy cream was investigated.

RESULTS

Suitable conditions for achieving a degree of substitution (DS) of 0.023 were found at pH 9, IFPG concentration 4 wt%, OSA concentration 10 wt% and a temperature of 40 °C, within 120 min. The carbonyl group attachment in OSA-IFPG was also confirmed via Fourier transform infrared and H-nuclear magnetic resonance spectroscopy (1 H-NMR). While the X-ray diffraction test indicated no significant changes in the structure of the IFPG after modification with OSA, esterification increased the negative charge density, decreased thermal decomposition temperature and increased the emulsifying capacity to 100%, which was obtained for the first time. The use of OSA-modified IFPG in creams augmented the complex viscosity, loss and storage modulus, while also demonstrating the creation of a pseudo-gel network. The hardness and adhesiveness of the texture increased, which can be explained by the formation of a compact structure and reduced particle size.

CONCLUSION

Overall, OSA-IFPG with hydrophilic and hydrophobic sections may function as an emulsifier and be recommended as a safe source of hydrocolloids for emulsion stability. It can also provide a positive physical structure when added to dairy cream, even if the fat concentration is lower than usual. © 2023 Society of Chemical Industry.

Fabrication of ɛ-Polylysine-Loaded Electrospun Nanofiber Mats from Persian Gum-Poly (Ethylene Oxide) and Evaluation of Their Physicochemical and Antimicrobial Properties

In the present study, electrospun nanofiber mats were fabricated by mixing different ratios (96:4, 95:5, 94:6, 93:7, and 92:8) of Persian gum (PG) and poly (ethylene oxide) (PEO). The SEM micrographs revealed that the nanofibers obtained from 93% PG and 7% PEO were bead-free and uniform. Therefore, it was selected as the optimized ratio of PG:PEO for the development of antimicrobial nanofibers loaded with ɛ-Polylysine (ɛ-PL). All of the spinning solutions showed pseudoplastic behavior and the viscosity decreased by increasing the shear rate. Additionally, the apparent viscosity, G', and G″ of the spinning solutions increased as a function of PEO concentration, and the incorporation of ɛ-PL did not affect these parameters. The electrical conductivity of the solutions decreased when increasing the PEO ratio and with the incorporation of ɛ-PL. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectra showed the compatibility of polymers. The antimicrobial activity of nanofibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated, and the samples loaded with ɛ-PL demonstrated stronger antimicrobial activity against S. aureus.

Improving the functional properties of wild almond protein isolate films by Persian gum and cold plasma treatment

The application of edible films in food packaging is limited due to their poor functional properties. Cold plasma treatment (CPT) is an emerging technology for the modification of edible films. In this study, edible films were developed from different ratios of wild almond protein isolate (WAPI) and Persian gum (PG). The characterization of films revealed that the sample containing 90 % WAPI and 10 % PG had the highest elongation at break (E), the highest tensile strength (TS), and the lowest water vapor permeability (WVP). Therefore, it was selected as having the best WAPI:PG ratio and exposed to CPT for 5, 10, and 15 min. The results revealed that the application of CPT significantly increased the thickness, TS, and E of edible films, while WVP and solubility were not affected. FTIR spectra showed slight increases in peak intensities at 1628, 1538, and 1400 cm^-1. The micrographs revealed that the roughness of composite films increased with increased cold plasma treatment time. In general, edible films treated by CPT for 10 min demonstrated the best functional properties.

Fabrication and characterization of Persian gum-based hydrogel loaded with gentamicin-loaded natural zeolite: An in vitro and in silico study

The main purpose of this study is to synthesize and characterize Persian gum-based hydrogel composited with gentamicin (Gen)-loaded natural zeolite (Clinoptilolite) and to evaluate its biological properties. Clinoptilolite (CLN) was decorated with Gen, and the conjugation was confirmed using computational and experimental assessments. The Monte Carlo adsorption locator module was used to reveal the physicochemical nature of the adsorption processes of Gen on CLN and ALG and gum on Gen@ CLN in Materials Studio 2017 software. Based on the high negative results, the adsorption process was found to be endothermic in all studied cases, and the interaction energies were in the range of physisorption for Gen on CLN and ALG and gum on Gen@CLN. Dynamic light scattering (DLS) and zeta potential analysis showed that the size of pristine CLN was around 2959 nm and the conjugation decreased the size significantly to approximately 932 nm. The hydrogel characterizations showed that the Gen-decorated CLNs are homogenously dispersed into the hydrogel matrix, and the resultant hydrogels have a porous structure with interconnected pores. The release kinetics evaluation showed that around 80 % of Gen was released from the nanocomposite drug during the first 10 h. In vitro studies revealed hemocompatibility and cytocompatibility of the nanocomposite. Microbial assessments indicated dose-dependent antibacterial activity of the hydrogel against gram (+) and gram (-) bacteria. The results showed that the fabricated hydrogel nanocomposite exhibits favorable physicochemical and biological properties.

Evaluation of physicomechanical properties of gluten-based film incorporated with Persian gum and Guar gum

This study aimed to optimize the formulation of gluten-based composite film incorporated with Persian gum and Guar gum using the response surface method. The effects of three variables gluten (37%wt), Persian gum (1-2%wt), and guar gum (1-2%wt) on the physicochemical properties of the films (thickness, color parameters (L*, ΔE, WI, YI), swelling, solubility, water vapor permeability (WVP) and mechanical properties of the film were investigated. The results confirmed that gluten is compatible with Persian gum and Guar gum. Optimization was determined, and then the morphological properties and interaction of the film components were investigated with SEM and FTIR, respectively. Results showed that all three variables significantly affected the films' mechanical and physical properties (P < 0.05). Increasing the number of gums in the film solution led to a decrease in the thickness of the films, and improved solubility and WVP of films. Moreover, the yellowness index of films raised with an increasing amount of gluten and Guar gum. Increasing the number of gums, Young's modulus and modulus of elasticity decreased significantly (P < 0.05). The optimum level of the variables with desirability of 0.992, obtained by the software, was 5 % gluten, 1.5 % Persian gum, and 1.5 % Guar gum (% w/w). Intensifying and shifting some absorption peaks of FTIR spectra pattern confirmed the interaction of gums and gluten chain functional groups. The current research outcomes demonstrated that proper interaction was established between gluten protein and gums and improved the physical properties of the films. High amounts of gum reduced the thickness of the film.

Design and characterization of Persian gum/polyvinyl alcohol electrospun nanofibrous scaffolds for cell culture applications

Biocompatible electrospun nanofiber scaffolds were fabricated in this study using Persian gum (PG) and poly (vinyl alcohol) (PVA) to build an artificial extracellular matrix for cell growth. The preparation procedure involves mixing various ratios of PG/PVA to be electrospun and seeded with L929 fibroblasts. Upon addition of PG up to 60% to the solutions, a 30% decrease to around 240 μs·cm^-1 is found in electrical conductivity which is in the range of semi-conductive polymers, whereas the surface tension is increased to around 3%. The fabricated scaffolds were characterized by morphological, chemical, thermal and structural analyses including SEM, FTIR spectroscopy, DSC, XRD, and tensile stress. The results showed that incorporation of 50% PG to the polymer solutions causes the formation of nanofibers with the least bead-shaped segments. All ratios of nanofibers containing PG showed significant biocompatibility with the cultured cells, which is presumably due to the radical scavenging feature of PG. The MTT and SEM analyses demonstrated that the scaffolds containing 50% PG possess the optimal cell compatibility, adhesion and proliferation properties. The fabricated PG/PVA cell culture scaffolds are potentially appropriate for wound dressing and cell culture applications in biomedicine.

Utilization of chickpea protein isolate and Persian gum for microencapsulation of licorice root extract towards its incorporation into functional foods

This study aimed at the fabrication of licorice extract (LE)-loaded microparticles by complex coacervation, using chickpea protein isolate (CPI) and soluble fraction of Persian gum (SFPG). The LE-loaded microparticles with the highest encapsulation efficiency (97.87%) and loading capacity (11.35%) were obtained at pH 3 and CPI: SFPG ratio, core: coating ratio, and polymer concentration of 2, 1.5, and 2, respectively. The LE-loaded microparticles (2-15 μm) possessed heterogeneous microstructure, and the Fourier-transform infrared spectroscopy data confirmed the pronounced effect of electrostatic interactions and hydrogen bonding. The thermostability, amorphous structure, and color of the LE-loaded microparticles were significantly enhanced, compared to free LE. The sensory evaluation of the model beverages containing LE-loaded microparticles revealed that the microencapsulation was able to mask the bitter aftertaste and color of the extract. Thus, the results of this research confirm the potential of CPI-SFPG complex coacervates for the efficient delivery of glycyrrhizin via incorporation into functional food products.

The Effect of Microencapsulation of Phenolic Compounds from Lemon Waste by Persian and Basil Seed Gums on the Chemical and Microbiological Properties of Mayonnaise

Natural preservatives with high level of phenolic compounds, antioxidants and antimicrobial activities are used in mayonnaise to improve quality and safety due to their potential health benefits. Application of these compounds in production processes highlights many difficulties due to instability of their physical and chemical properties. Microencapsulation is used to address these restrictions. In this study, phenolic compounds from lemon waste were encapsulated with Persian gum (PG) and basil seed gum (BSG) as coating materials at different ratios (0:1, 1:0, and 1:1) at 15% (w/w) total biopolymer. We confirmed microencapsulation by scanning electron microscopy, and evaluate phenolic content, antioxidant activity, encapsulation efficiency, morphology, water solubility indexes, and water absorption indexes. Sample mayonnaise was prepared using microencapsulated polyphenols from lemon waste and extract (1,000 ppm of concentration), and control samples without extracts or microcapsules. All samples were subjected to chemical (measuring the peroxide, thiobarbituric acid, acidity, and color) and microbial (total count of microorganisms and Escherichia coli) analysis during 30 days of storage. BSG samples exhibited the highest antioxidant activity (61.19%) and encapsulation efficiency (70.72%), and PG/BSG microcapsules had the highest capability to prevent oxidative deterioration during storage. Addition of microcapsules led to increases in parameter b^* and decreases in parameters a^* and L^*. In general, PG/BSG microcapsules were considered optimal samples for production of mayonnaise, since they prevented mayonnaise deterioration and exhibited antioxidant and antimicrobial properties.

On the Use of Persian Gum for the Development of Antiviral Edible Coatings against Murine Norovirus of Interest in Blueberries

In the last decades, berries have been identified as important vehicles for the transmission of foodborne viruses and different strategies are being explored to eliminate or reduce viral contamination in these fruits. The aim of this work was to develop novel edible coatings with antiviral properties for inactivating and reducing murine norovirus (MNV). Firstly, the effect of gelatin (G) addition on Persian gum (PG) films was studied in terms of microstructural, mechanical, optical, and water barrier properties. The following PG:G ratios were considered: 100:0, 75:25, 50:50, 25:75, and 0:100. Microstructure analysis revealed the compatibility of both hydrocolloids since no phase separation was observed. The addition of G to PG films provided stiffer and more deformable films than pure PG, with lower water vapor permeability values. Specifically, films prepared with 50:50 PG:G ratio presented better mechanical and barrier performance. Interestingly, pure PG showed antiviral activity on murine norovirus, probably due to the presence of some impurities (mainly tannins). Adding allyl isothiocyanate (AITC) enhanced the PG antiviral activity at refrigerated temperatures in blueberries, not being affected by the AITC concentration. This effect was not observed at ambient temperature, probably due to the volatilization of AITC.

pH-Induced structural transitions in whey protein isolate and ultrasonically solubilized Persian gum mixture

The present work evidently reports that ultrasonic depolymerization strongly enhanced complex coacervation between Persian gum (PG) and whey protein isolate (WPI). PG was sonicated at 60 °C, operating frequency of 20 kHz and nominal power output of 800 W for various times followed by mixing with WPI. Acid-induced interaction between the two biopolymers was studied by turbidity, light scattering, zeta potential and viscosity measurements over a wide pH range. Sonication of intact PG (IPG) for 10 min considerably reduced the molecular weight from 4.12 × 10⁶ to 0.76 × 10⁶ g/mol. Besides, ultrasonic fragmentation of water insoluble fraction of PG drove protein containing chains into the soluble phase. Sonicated PG (SPG) was shown to be more flexible with higher number of carboxyl groups available for electrostatic interaction with WPI, such that the complete neutralization did not occur even at protein to polysaccharide ratio of 50: 1. Additionally, scattered light intensity and viscosity measurements revealed two maxima in the pH ranges of 4.4-4.85 and 3.27-4.0, being highly intense for the gum sonicated for 10 min and longer. Considering the pH-behavior of WPI components, the former peak was related to interpolymer complex formation between β-lactoglobulin and long chain fraction of SPG, while the latter was attributed to intrapolymer association of α-lactalbumin with the short chain oligosaccharides arising from ultrasonic degradation of PG.

Preparation and characterization of a new edible film based on Persian gum with glycerol plasticizer

A new type of biodegradable film was formulated and characterized when based on the water-soluble-phase of Persian gum (SPG). The edible film was formulated optimally by using different concentrations of SPG (2.0, 2.5, 3.0, 3.5 and 4%) and glycerol as plasticizer (25, 35, and 35% based on dried SPG). Further examinations involved evaluating the manufactured films in terms of the barrier and physical properties, mechanical qualities, optical indices, microstructural properties and Fourier transform. The results showed that the increase in SPG and plasticizer content caused increases in thickness, moisture uptake, water vapor permeability and density of films (p < 0.05). Water solubility increased in response to higher concentrations of glycerol but decreased by higher amounts of dry matter (p < 0.05). The highest levels of the tensile strength (59.95%) and elongation at break (40.3 MPa) were obtained by SPG (3.5%) + 35% glycerol treatment. The L*, a* and opacity values decreased, while there was an increase in the b* value, as a result of increasing the plasticizer content (p < 0.05). A reduction occurred in the L* value of films, while the a* and b* values increased when using higher amounts of dry matter (p < 0.05). By analyzing the samples with field emission scanning electron microscopy, no cracks were observed on films when the contents of glycerol and dry matter were higher than 30% and 2.5%, respectively. The findings demonstrated that creating edible films from SPG can be an effective approach to the production of edible films.

Formulation, development and characterization of a novel functional fruit snack based on fig (Ficus carica L.) coated with sugar-free chocolate

The aim of the present investigation was to explore the possibility of developing a fruit snack formulation based on dried fig powder and chocolate-coated. Dried Fig (Ficus carica L.) powder with a maximum particle size of 354 μm and the lowest compaction force was formulated as the core. Persian gum was prepared at the concentrations of 1.5, 2 and 2.5% and xanthan gum was prepared at the levels of 0.25, 0.39 and 0.54% as the middle layer to the coating of the core. Regarding rheological assessments, sugar-free chocolate containing 29.3% isomalt was selected for the coating of the outer chocolate shell in the entitled snack. Textural analysis showed that coating of the core with hydrocolloids decreased hardness and adhesiveness of the samples (p < 0.05). It was also observed that increasing the xanthan gum and Persian gum concentration led to the reduction of adhesiveness in the snacks (p < 0.05). Coating of cores with hydrocolloids resulted in lower thickness of the chocolate outer shell, as well (p < 0.05). Results of the sensory evaluation tests demonstrated that, the samples with hydrocolloid coating were the most preferred ones by the panelists.

Ultrasonic degradation of Persian gum and gum tragacanth: Effect on chain conformation and molecular properties

The present study introduces the ultrasonic modification of two Iranian native gum exudates, Persian gum (PG) and gum tragacanth (GT) for the first time. They were sonicated at a constant frequency of 20 kHz and temperature of 60 °C for various times (0, 2, 5, 10, 20, 30 and 40 min) and the changes in their molecular properties were investigated using oven drying, gel permeation chromatography-multiangle laser-light scattering (GPC-MALLS), rheometery and FTIR analysis. Results indicated that the soluble dry mass of both hydrocolloids was extensively enhanced (from less than 10% at time zero to more than 90% at the end of treatment time) by sonication. Moreover, the molecular weight and viscosity of gums dispersions were decreased with the increase of the treatment time. Fracture in polysaccharide chains was confirmed by analysis of the molecular weight parameters. Calculation of chain breaks and polydispersity index (PDI) revealed that scissions occurred at the backbone as well as the side branches. PG, owing to its higher molecular weight, displayed more extensive and faster degradation than GT. However, the chain rupture of GT was twice more than that of PG at the end of sonication time. The specific volume for gyration (SV_g) and molecular density (ρ) showed that intact PG contains compactly packed molecules with greater number of cross-linked bonds compared to GT. Furthermore, the conformational changes into semi-flexible chains and worm-like coils were determined for both gums after 40 min sonication. Variation of the molecular density along with the results of FTIR analysis demonstrated that ultrasonication broke C-O-C bonds in both PG and GT leading to more flexible chains.