The interactions between the two negatively charged polysaccharides: Gum Arabic and alginate

Simultaneous viscoelasticity and sprayability in antimicrobial acetic acid-alginate fluid gels

Acetic acid is a promising alternative to antibiotics for topical applications, particularly burn wounds, however its site specificity and retention are impaired by poor material properties. In this study, acetic acid was investigated as both the gelling agent and antimicrobial active in alginate fluid gels. The formed microstructure was found to be directly dependent on acetic acid concentration, leading to highly tuneable material properties. At clinically relevant concentrations of 2.5-5 % acetic acid, the fluid gels were elastically dominated at rest, with viscosities up to 7 orders of magnitude greater than acetic acid alone. These material properties imparted long term surface retention and microparticle barrier function, not seen with either acetic acid or alginate solutions. Most notably, sprayability was enhanced simultaneously with the increased viscosity and elasticity due to the introduction of a discretised microstructure, leading to a remarkable tenfold increase in spray coverage. Formulation was found not to inhibit antimicrobial activity, despite the less acidic pH, with common burn wound pathogens Staphylococcus aureus and Pseudomonas aeruginosa being equally susceptible to the fluid gels as to acetic acid solutions.

Re-entrant phase transitions in Laponite/Gum Arabic nanocomposites

A re-entrant gel transition is observed in a discotic clay, Laponite (Lap) aqueous suspensions with the addition of a complex polysaccharide, Gum Arabic (GA). For fixed concentrations of Lap (1-3 % w/v) and at low GA concentrations (CGA < 10 % w/v), the composites exhibit gel behaviour, while the suspensions undergo liquid phase separation for intermediate GA concentrations (10 % w/v < CGA < 20 % w/v). Gel behaviour is again observed in the samples at even higher GA concentrations (CGA > 30 % w/v). Here, we identify a thermodynamic phase transition in Lap/GA mixtures that is caused by a variation in GA content. The viscoelastic characteristics, phase transitions, and gelation kinetics of the Lap/GA mixtures have been studied by employing rheology, small-angle X-ray scattering, and optical investigations. Reduction of the negative values of zeta-potential and growth of the composite system's hydrodynamic size indicated the presence of interactions in Lap/GA mixtures. The phase diagram enables the apparent interactions and phase transitions between the nanoplatelets and the complex polysaccharides. Thus, our study provides new perspectives on a nanocomposite's tuneable rheological and structural features.

Alginate Beads with Encapsulated Bioactive Substances from Mangifera indica Peels as Promising Peroral Delivery Systems

Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.

Multilayer microparticles for programmed sequential release of phenolic compounds from Eugenia stipitata: Stability and bioavailability

A co-delivery system based on multilayer microparticles was developed and characterized for the sequential release of phenolic compounds (PCs) using different encapsulation processes (spray drying: SD and drying-chilling spray: SDC) and wall materials to improve the stability and bioavailability of PCs. Samples were characterized in terms of process yield (PY%), phenolic retention efficiency (PRE%), chemical structure and crystallinity (NMR, FTIR, DXR), thermal stability (DSC and FT-IR), anti-radical capacity (ORAC and ABTS) and in vitro digestion. PRE% of samples by SD were higher (p < 0.05) than SDC due to the formation of PCs from CRF (cará-roxo flour). NMR, FTIR, DXR confirmed the presence of key components and interactions for the formation of the advanced co-delivery system. The SDC particles showed crystalline regions by XRD and were stable at ∼47 °C. All samples showed good release of PC in the intestinal phase, and antiradical capacity that reached 23.66 µmol TE g-1.

Bioactive polysaccharides from Aegle marmelos fruit: Recent trends on extraction, bio-techno functionality, and food applications

Polysaccharides from non-conventional sources, such as fruits, have gained significant attention recently. Aegle marmelos (Bael), a non-conventional fruit, is an excellent source of biologically active components with potential indigenous therapeutic and food applications. Apart from polyphenolic components, this is an excellent source of mucilaginous polysaccharides. Polysaccharides are one the major components of bael fruit, having a high amount of galactose and glucuronic acid, which contributes to its potential therapeutic properties. Therefore, this review emphasizes the conventional and emerging techniques of polysaccharide extraction from bael fruit. Insight into the attributes of polysaccharide components, their techno-functional properties, characterization of bael fruit polysaccharide, emulsifying properties, binding properties, reduction of hazardous dyes, application of polysaccharides in film formation, application of polysaccharide as a nanocomposite, and biological activities of bael fruit polysaccharides are discussed. This review also systematically overviews the relationship between extraction techniques, structural characteristics, and biological activities. Additionally, recommendations, future perspectives, and new valuable insight towards better utilization of bael fruit polysaccharide have been given importance, which can be promoted in the long term.

Comparative study on chain conformations, physicochemical and rheological properties of three acidic polysaccharides from Opuntia dillenii Haw. fruits

In this study, three acidic polysaccharides (OFPP-1, OFPP-2 and OFPP-3) were isolated from the pulps of Opuntia dillenii Haw. fruits, and their chain conformations, physicochemical and rheological properties were investigated. The molecular weight and conformational parameters (Mw, Mn, Mz, Rg and Rh) of OFPPs in 0.1 M NaNO3 solution were detected by HPSEC-MALLS-RI. In addition, based on the parameters ρ and v, it was concluded that these three polysaccharide chains exhibited sphere-like conformation in 0.1 M NaNO3 solution, which was consistent with AFM and TEM observations. Furthermore, the Congo Red experiment showed that OFPP-2 had a triple-helix structure, which may be conducive to its biological activity. This study also found that OFPPs were semi-crystalline structures with high thermal and pH stability. The rheological analyses indicated that the apparent viscosity of OFPPs solutions exhibited concentration-, temperature-, and pH-dependence, and the viscoelasticity of them was affected by molecular characteristics and concentration. The results of this study are helpful to elucidate the structure-activity relationship of OFPPs. Moreover, this study can provide theoretical reference for the application of OFPPs as bioactive ingredients or functional materials in the food, pharmaceutical and cosmetic industries and the development and utilization of the O. dillenii Haw. fruits resource.

Enhanced Antibacterial Efficiency and Anti-Hygroscopicity of Gum Arabic-ε-Polylysine Electrostatic Complexes: Effects of Thermal Induction

The aim of this investigation was to scrutinize the effects of a thermal treatment on the electrostatic complex formed between gum arabic (GA) and ε-polylysine (ε-PL), with the goal of improving the antibacterial properties and reducing the hygroscopicity of ε-PL. The heated complex with a ratio of 1:4 exhibited an encapsulation efficiency of 93.3%. Additionally, it had an average particle size of 350.3 nm, a polydispersity index of 0.255, and a zeta potential of 18.9 mV. The formation of the electrostatic complex between GA and ε-PL was confirmed through multispectral analysis, which demonstrated the participation of hydrogen bonding and hydrophobic and electrostatic interactions, as well as the enhanced effect of heat treatment on these forces within the complex. The complex displayed a core-shell structure, with a regular distribution and a shape that was approximately spherical, as observed in the transmission electron microscopy images. Additionally, the heated GA-ε-PL electrostatic composite exhibited favorable antibacterial effects on Salmonella enterica and Listeria monocytogenes, with reduced minimum inhibitory concentrations (15.6 μg/mL and 62.5 μg/mL, respectively) and minimum bactericidal concentrations (31.3 μg/mL and 156.3 μg/mL, respectively) compared to free ε-PL or the unheated electrostatic composite. Moreover, the moisture absorption of ε-PL reduced from 92.6% to 15.0% in just 48 h after being incorporated with GA and subsequently subjected to heat. This research showed a way to improve the antibacterial efficiency and antihygroscopicity of ε-PL, reducing its application limitations as an antimicrobial substance to some extent.

Design of Novel Knot-like Structures Based on Ovotransferrin Fibril-Gum Arabic Complexes: Effective Strategies to Stabilize Pickering Emulsions

This work aimed to clarify the effects of gum arabic (GA) on the morphology and properties of ovotransferrin fibrils (OVTFs). By constructing OVTF-GA complexes and exploring the dispersion stability, turbidity and the ζ-potential of the complexes, the optimum mass ratio of OVTFs to GA and pH for complex formation were confirmed as being 1:1 and pH 4.6, respectively. The interaction between OVTFs and GA was determined to be predominantly driven by electrostatic attraction. The OVTF-GA complexes exhibited a knot-like structure when observed using atomic force microscopy. Then, OVTFs and OVTF-GA complexes were compared in terms of contact angle, surface hydrophobicity and dynamic interfacial tension. The combination of OVTFs and GA decreased the contact angle of OVTFs from 80.85° to 70.36°. In comparison with OVTFs, OVTF-GA complexes reduced the oil-water interfacial tension to a lower level (8.14 mN/m). Furthermore, the capacities of OVTF-GA complexes in stabilizing emulsions were explored. OVTF-GA complex-stabilized oleogel-based Pickering emulsion (OGPE) was constructed, and OVTF-stabilized oleogel-based Pickering emulsion (OPE) was used as the control. OGPE had a higher emulsified phase volume fraction (EPVF) and stability index (SI). The EPVF of OGPE was 100.0% and 99.4% before and after one-month storage, respectively, compared with 98.3% and 95.7% of OPE. This work can provide some useful references for the design of biopolymers with novel structures composed of protein fibrils and polysaccharides, which may also help to construct and apply protein fibril-polysaccharide complexes under specific needs.

Synthesis and Characterization of Environmentally Friendly Chitosan-Arabic Gum Nanoparticles for Encapsulation of Oregano Essential Oil in Pickering Emulsion

The encapsulation of bioactive agents through the utilization of biodegradable nanoparticles is a topic of considerable scientific interest. In this study, microcapsules composed of chitosan (CS) and Arabic gum (GA) nanoparticles were synthesized, encapsulating oregano essential oil (OEO) through Pickering emulsions and subsequent spray drying. The optimization of hybrid chitosan and Arabic gum (CS-GA) nanoparticle formation was carried out via complex coacervation, followed by an assessment of their behavior during the formation of the emulsion. Measurements of the size, contact angle, and interfacial tension of the formed complexes were conducted to facilitate the development of Pickering emulsions for encapsulating the oil under the most favorable conditions. The chitosan-Arabic gum capsules were physically characterized using scanning electron microscopy and fitted to the Beerkan estimation of soil transfer (BEST) model to determine their size distribution. Finally, the OEO encapsulation efficiency was also determined. The optimum scenario was achieved with the CS-GA 1-2 capsules at a concentration of 2% wt, featuring a contact angle of 89.1 degrees, which is ideal for the formation of oil/water (O/W) emulsions. Capsules of approximately 2.5 μm were obtained, accompanied by an encapsulation efficiency of approximately 60%. In addition, the hybrid nanoparticles that were obtained showed high biodegradability. The data within our study will contribute fundamental insights into CS-GA nanoparticles, and the quantitatively analyzed outcomes presented in this study will hold utility for forthcoming applications in environmentally friendly detergent formulations.

Development and characterization of rice bran-gum Arabic based encapsulated biofertilizer for enhanced shelf life and controlled bacterial release

Introduction

Currently, microbe-based approaches are being tested to address nutrient deficiencies and enhance nutrient use efficiency in crops. However, these bioinoculants have been unsuccessful at the commercial level due to differences in field and in-vivo conditions. Thus, to enhance bacterial stability, microbial formulations are considered, which will provide an appropriate microenvironment and protection to the bacteria ensuring better rhizospheric-colonization.

Methods

The present study aimed to develop a phosphobacterium-based encapsulated biofertilizer using the ion-chelation method, wherein a bacterial strain, Myroid gitamensis was mixed with a composite solution containing rice bran (RB), gum Arabic (GA), tricalcium phosphate, and alginate to develop low-cost and slow-release microbeads. The developed microbead was studied for encapsulation efficiency, shape, size, external morphology, shelf-life, soil release behavior, and biodegradability and characterized using SEM, FTIR, and XRD. Further, the wheat growth-promoting potential of microbeads was studied.

Results

The developed microbeads showed an encapsulation efficiency of 94.11%. The air-dried beads stored at 4°C were favorable for bacterial survival for upto 6 months. Microbeads showed 99.75% degradation within 110 days of incubation showing the bio-sustainable nature of the beads. The application of dried formulations to the pot-grown wheat seedlings resulted in a higher germination rate, shoot length, root length, fresh weight, dry weight of the seedlings, and higher potassium and phosphorus uptake in wheat.

Discussion

This study, for the first time, provides evidence that compared to liquid biofertilizers, the RB-GA encapsulated bacteria have better potential of enhancing wheat growth and can be foreseen as a future fertilizer option for wheat.

Exploration of curcumin-incorporated dual anionic alginate-quince seed gum films for transdermal drug delivery

The idea of combining bioextracted polymers for wound healing applications has emerged in hopes of developing highly flexible and mechanically stable hydrogel films with controlled drug delivery, biocompatibility, and high collagen deposition. In the present research, polysaccharide films composed of Alginate and Quince Seed Gum (QSG) were fabricated by ionic crosslinking, and their potential for curcumin delivery and wound healing were examined. In this regard, microstructure, mechanical properties, thermal stability, physiochemical properties, and biocompatibility of films with three different QSG amounts (25 %, 50 %, and 75 %) were studied. Because of the optimum properties of 25 % QSG films like better transparency (Opacity = 6.1 %), higher flexibility (Elongation = 28.9 %), less water solubility (Water solubility = 66.6 %), proper absorbance (Swelling degree = >600 %), and suitable biocompatibility (Cell viability = >85 %), they were used for drug delivery examination. Curcumin administration through films with and without stearic acid modification was investigated. Stearic Acid (SA) modified samples demonstrated superior compatibility between hydrophobic drug and hydrophilic film. Stearic acid-modified film could prolong the curcumin release up to 48 h and showed increased collagen synthesis and TGF-β expression, making it an excellent candidate for transdermal drug delivery and wound healing applications.

Development of Films from Spent Coffee Grounds' Polysaccharides Crosslinked with Calcium Ions and 1,4-Phenylenediboronic Acid: A Comparative Analysis of Film Properties and Biodegradability

Most polymeric materials are synthetic and derived from petroleum, hence they accumulate in landfills or the ocean, and recent studies have focused on alternatives to replace them with biodegradable materials from renewable sources. Biodegradable wastes from food and agroindustry, such as spent coffee grounds (SCGs), are annually discarded on a large scale and are rich in organic compounds, such as polysaccharides, that could be used as precursors to produce films. Around 6.5 million tons of SCGs are discarded every year, generating an environmental problem around the world. Therefore, it was the aim of this work to develop films from the SCGs polysaccharide fraction, which is comprised of cellulose, galactomannans and arabinogalactans. Two types of crosslinking were performed: the first forming coordination bonds of calcium ions with polysaccharides; and the second through covalent bonds with 1,4-phenylenediboronic acid (PDBA). The films with Ca²⁺ ions exhibited a greater barrier to water vapor with a reduction of 44% of water permeability vapor and 26% greater tensile strength than the control film (without crosslinkers). Films crosslinked with PDBA presented 55-81% higher moisture contents, 85-125% greater permeability to water vapor and 67-150% larger elongations at break than the films with Ca²⁺ ions. Film biodegradability was demonstrated to be affected by the crosslinking density, with the higher the crosslinking density, the longer the time for the film to fully biodegrade. The results are promising and suggest that future research should focus on enhancing the properties of these films to expand the range of possible applications.

Combination of α-lactalbumin and gum Arabic for microencapsulation of L-menthol: The effects on flavor release during storage and rehydration

L-menthol-containing food products generally show the flavor loss during storage due to their high volatility. The hydrophobicity of L-menthol also causes the inadequate flavor release during rehydration. In this study, the stability of L-menthol was enhanced by microencapsulation and the effect of different powder drying techniques was also investigated. The highest efficiency (76.58-78.66 %) and loading content (18.58-28.35 mg/g) of encapsulations were obtained by using a mass ratio of 2:1(α-LA: GA). Then they were dried by non-thermal spray freeze drying (SFD) technique compared to spray drying (SD) and freeze-drying (FD) process. The SFD particles were shown to be spherical and porous with the highest porosity (86.82 %). α-LA/GA based microparticles with spherical shapes were demonstrated to largely enhance flavor retention during high humidity storage. In addition, the porous structures of SFD powders could cause rapid rehydration in liquid models, and the release behaviors of loaded L-menthol followed the Fickian diffusion. Consequently, the SFD technique shows great potential to produce microparticles by regulating the release behaviors of L-menthol during storage and rehydration.

Naringin-loaded Arabic gum/pectin hydrogel as a potential wound healing material

Wound healing is a complicated cellular process with overlapping phases. Naringin (NAR); a flavanone glycoside, possesses numerous pharmacological effects such as anti-inflammatory, antioxidant and anti-apoptotic effects. In the current study, Arabic gum (AG)/pectin hydrogel was utilized to encapsulate NAR. Drug-loaded AG/pectin hydrogel exhibited excellent EE% of about 99.88 ± 0.096 and high DL% of about 16.64 ± 0.013. The formulated drug-loaded hydrogel was characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Zetasizer analyzer, besides determination of equilibrium degree of swelling (EDS%). Afterwards, wound healing potential of NAR-loaded AG/pectin hydrogel was evaluated in an in vivo animal model. Results manifested that NAR-loaded AG/pectin hydrogel was able to accelerate wound healing in terms of enhanced angiogenesis, re-epithelialization and collagen deposition. Furthermore, it significantly (P < 0.001) down-regulated the mRNA expression of inflammatory mediators (TNF-α) and apoptosis (BAX). In addition, NAR-loaded AG/pectin hydrogel was found to possess potent antioxidant activity as it enhanced the levels of SOD and GSH, besides decreasing the levels of MPO, MDA and nitrite. These data suggest that NAR-loaded AG/pectin hydrogel could be utilized in wound healing applications.

Stability evaluation of gardenia yellow pigment in the presence of different antioxidants or microencapsulating agents

The chemical instability of gardenia yellow pigment (GYP) limits its utilization in the food industry. In this study, the effects of different antioxidants (0.2% of tea polyphenols, sodium phytate, potassium citrate, and ascorbic acid) and microencapsulating agents (gum Arabic, maltodextrin, inulin, and gum Arabic/maltodextrin) on the degradation of GYP under different conditions (heat, light, and ferric iron) were evaluated. Then, the characteristic properties of microcapsules coated with gum Arabic/maltodextrin, gum Arabic/maltodextrin/tea polyphenols, maltodextrin, and maltodextrin/tea polyphenols were investigated. Furthermore, food models were simulated to evaluate the GYP stability of the microcapsules. The results showed that tea polyphenols, maltodextrin, and gum Arabic/maltodextrin significantly improved the GYP stability. Moreover, the presence of GYP in microcapsules was confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopy. In addition, GYP-MD/TP possessed high thermal stability under different cooking methods. PRACTICAL APPLICATION: Gardenia yellow pigment (GYP) is easily degraded under light and high-temperature conditions, which limits its applications in the food industry. This study will provide effective clues for expanding the practical applications of GYP in the natural pigment industry.

The Effect of the Liposomal Encapsulated Saffron Extract on the Physicochemical Properties of a Functional Ricotta Cheese

In this study, the encapsulation of saffron extract (SE) was examined at four various concentrations of soy lecithin (0.5%–4% w/v) and constant concentration of SE (0.25% w/v). Particle size and zeta potential of liposomes were in the range of 155.9–208.1 nm and −34.6–43.4 mV, respectively. Encapsulation efficiency was in the range of 50.73%–67.02%, with the stability of nanoliposomes in all treatments being >90%. Encapsulated SE (2% lecithin) was added to ricotta cheese at different concentrations (0%, 0.125%, 1%, and 2% w/v), and physicochemical and textural properties of the cheese were examined. Lecithin concentration significantly (p ≤ 0.05) affected the particle size, zeta potential, stability, and encapsulation efficiency of the manufactured liposomes. In terms of chemical composition and color of the functional cheese, the highest difference was observed between the control cheese and the cheese enriched with 2% liposomal encapsulated SE. Hardness and chewiness increased significantly (p ≤ 0.05) in the cheeses containing encapsulated SE compared to the control cheese. However, there was no significant difference in the case of adhesiveness, cohesiveness, and gumminess among different cheeses. Overall, based on the findings of this research, liposomal encapsulation was an efficient method for the delivery of SE in ricotta cheese as a novel functional food.

Characterization of alginate extracted from Sargassum latifolium and its use in Chlorella vulgaris growth promotion and riboflavin drug delivery

Alginates derived from macroalgae have been widely used in a variety of applications due to their stability, biodegradability and biocompatibility. Alginate was extracted from Egyptian Sargassum latifolium thallus yielding 17.5% w/w. The chemical composition of S. latifolium is rich in total sugars (41.08%) and uronic acids (47.4%); while, proteins, lipids and sulfates contents are 4.61, 1.13 and 0.09%, respectively. NMR, FTIR and TGA analyses were also performed. Crystallinity index (0.334) indicates alginate semicrystalline nature. Sodium alginate hydrolysate was evaluated as Chlorella vulgaris growth promoter. The highest stimulation (0.7 g/L biomass) was achieved by using 0.3 g/L alginate hydrolysate supplementation. The highest total soluble proteins and total carbohydrates were 179.22 mg/g dry wt and 620.33 mg/g dry wt, respectively. The highest total phenolics content (27.697 mg/g dry wt.), guaiacol peroxidase activity (2.899 µmol min-1 g-1) were recorded also to 0.3 g/L alginate hydrolysate supplementation. Riboflavin-entrapped barium alginate-Arabic gum polymeric matrix (beads) was formulated to achieve 89.15% optimum drug entrapment efficiency (EE%). All formulations exhibited prolonged riboflavin release over 120 min in simulated gastric fluid, followed Higuchi model (R2 = 0.962-0.887) and Korsmeyer-Peppas model with Fickian release (n ranges from 0.204 to 0.3885).

Insight into anti-oxidative carbohydrate polymers from medicinal plants: Structure-activity relationships, mechanism of actions and interactions with bovine serum albumin

Recently, research associated with natural anti-oxidants leads to the chemical characterization of many compounds possessing strong anti-oxidant activity. Among these anti-oxidants, naturally occurring carbohydrate polymers containing pectic arabinogalactans esterified with phenolic acids in monomeric and dimeric forms are noteworthy. The presence of highly branched arabinogalactan type II side chains and sugar linked phenolic acid residues have been resolved as important parameters. The anti-oxidant activity of these compounds depend on their ability to convert free radicals into stable by-products and themselves oxidized to more stable and less reactive resonance stabilized radicals. Moreover, these carbohydrate polymers form water soluble stable complexes with protein. Such findings support their applications in a diversity of fields including food industry and pharmacy. This review highlights experimental evidences supporting that the carbohydrate polymers containing phenolic polysaccharides may become promising drug candidate for the prevention of aging and age related diseases.