Development and optimization of complex coacervates based on zedo gum, cress seed gum and gelatin

Performance of spray-dried Ziziphus jujuba extract using insoluble fraction of Persian gum-sodium alginate and whey protein: Microstructural and physicochemical attributes of micro- and nano-capsules

The study focused on the impact of the insoluble fraction of Persian gum-sodium alginate and a blend of the insoluble fraction of Persian gum-sodium alginate (IFPG-Al) with whey protein isolate (WPI) on sprayed Ziziphus jujuba extract (JE) powder. The addition of whey protein led to powders with higher moisture (10%), higher solubility (99.19%), and lower powder yield (27.82%). The powders fabricated with WPI depicted the best protection of polyphenolic compounds (3933.4 mg/L) and the highest encapsulation efficiency activity (74.84%). Additionally, they had a higher T g (62.63°C), which indicates more stability of the powders during shelf life. The sphericity of the majority of the particles was noticeable in powders, but multi-sided concavities were visible in the protein-containing particles. Based on the particle size's results, IFPG-Al/WPI capsules fabricated relatively smaller particles (2.54 μm). It can be acknowledged that the presence of protein in particles can bring fruitful results by preserving valuable bioactive compounds.

Intermolecular binding of blueberry anthocyanins with water-soluble polysaccharides: Enhancing their thermostability and antioxidant abilities

This study investigated the protective effect of β-glucan (BG), konjac glucomannan (KGM) and xanthan gum (XG) on thermo-stability and antioxidant capacities of blueberry anthocyanins (ACN) and their interaction mechanisms. Twenty-six glycosylated and acylated ACN were identified, and malvidin-3-O-galactose was predominant (36.78 %) in ACN extracts. Three polysaccharides retained colour and stability and antioxidant capabilities of ACN under thermal-treatments (XG > KGM > BG). Rheological properties (shear stress, apparent viscosity) of three polysaccharides were enhanced in presence of ACN. UV-visible spectra, SEM and DLS results indicated that co-aggregation between ACN and specific zones of these polysaccharides was formed. TGA and DSC studies confirmed that introductionof three polysaccharides, especially XG could improve thermostability of ACN. FTIR, and molecular dynamics simulations revealed that thermo-stabilization of polysaccharides-ACN conjugates might be attributedto their intermolecular interactions mainly via hydrogen bindings. The protection by water-soluble polysaccharides foresees novel anthocyanins in food products with increased heat-resistant stability.

Production and characterization of Ziziphus jujuba extract-loaded composite whey protein and pea protein beads based on sodium alginate-IFPG (insoluble fraction of Persian gum)

BACKGROUND

This research was aimed at the fabrication of jujube extract (JE)-loaded beads by extrusion, using whey protein isolate (WPI), chickpea protein concentrate (PPC) and a combination of two types of hydrocolloid insoluble fraction of Persian gum (IFPG) and sodium alginate (Al).

RESULTS

JE-loaded beads with the highest encapsulation efficiency (10.87%) and polyphenol content (120.8 mg L^-1 gallic acid) were obtained using Al-IFPG/PPC at 4 °C. The Al-IFPG, Al-IFPG/WPI and Al-IFPG/PPC beads revealed 5.66, 6.85 and 5.76 mm bead size, respectively, and almost all of them demonstrated a homogeneous and spherical structure. Fourier transform infrared spectroscopy data proved that the stable structure of the Al-IFPG beads was due to hydrogen bonding and electrostatic interactions. The thermostability of beads loaded with JE based on Al-IFPG/WPI was significantly enhanced compared to pure Al-IFPG. Texture evaluation of JE-loaded beads based on Al-IFPG incorporation with WPI revealed an increment in the hardness of beads.

CONCLUSION

This study confirmed the potential of Al-IFPG complex beads for the effective delivery of jujube extract via incorporation into pea and whey proteins and for the expansion of its use in products. © 2023 Society of Chemical Industry.

Biodefensive Based on Piper nigrum Essential Oil for Controlling of Anopheles aquasalis Larvae: Influence of Temperature (35 °C) and Preservatives

Considerable efforts have been spent on the development of biodefensives based on the encapsulation of essential oils for controlling of urban pests from their larval stage, especially as anopheline controlling agents. The larval source management of Anopheles aquasalis is important for malaria prevention. For this reason, this research proposes larvicidal biodefensives based on polymeric particles loaded with Piper nigrum essential oil, considering the influence of temperature (35 °C) and preservatives on the formulation stability. The biodefensive containing the preservative phenoxyethanol/methylisothiazolinone (PNE) resulted in 5 months of shelf-life storage with an Encapsulation Efficiency (EE%) of essential oil of 70%. The biodefensive PNE (containing 500 µg.mL−1 of encapsulated essential oil) presented a polydisperse particle size distribution, ranging from D10 = (127 ± 10) nm to D90 = (472 ± 78) nm and a particle mean size of (236 ± 34) nm. The AFM images revealed a spherical morphology with an external surface almost regular and smooth. The controlled release of the essential oil was evaluated up to 72 h according to the Korsmeyer-Peppas mathematical model, confirming the anomalous transport (n = 0.64 in pH = 3 and pH = 10, and n = 0.65 in pH = 7). The total larvae mortality on the in loco bioassays was almost reached (92%) after 24 h. However, according to the in vitro bioassays applying the in natura essential oil alone, the concentration of 454 μg.mL−1 resulted on the mortality of 70% of the larvae after 24 h. For this reason, the highest efficiency of the biodefensive PNE may be related to the encapsulation of essential oil, delivering the loaded particles more efficiently inside the larvae. From this perspective, the present study shows that a formulation based on P. nigrum essential oil may be taken into account in the integrated management of disease vector mosquitoes.

Interaction between Gelatin and Mulberry Leaf Polysaccharides in Miscible System: Physicochemical Characteristics and Rheological Behavior

In this study, the miscible system was formed by mixing gelatin (G) with mulberry leaf polysaccharides (MLPs) continuously extracted with a hot buffer (HBSS), a chelating agent (CHSS), a dilute alkali (DASS), and a concentrated alkali (CASS), and the zeta potential, turbidity, particle size, distribution, and rheological properties of the miscible systems were evaluated. Under acidic conditions, the miscible systems of four polysaccharides and gelatin were in a clear state; under alkaline conditions, G-HBSS and G-CHSS were clarified, and G-DASS and G-CASS changed from clarification to turbidity. The zeta potential changed from positive to negative with the increase in pH. When the pH was at 7, it increased with the increase in polysaccharide concentration but was still negative. The four miscible systems all showed polydispersity. The particle sizes of G-HBSS and G-CHSS decreased with the increase in pH, while the particle sizes of G-DASS and G-CASS were increased. The four miscible systems showed “shear thinning” behavior, and the addition of gelatin reduced the apparent viscosity of the four polysaccharide solutions. G-CHSS was highly stable, and G-CASS was more suitable as a stabilizer in the freezing process.

Enhanced thermal stability of anthocyanins through natural polysaccharides from Angum gum and cress seed gum

Enhanced thermal stability of anthocyanins from black barberry was obtained using an optimum concentration of Angum gum (AG) and cress seed gum (CSG). To this goal initially, the phytochemical characteristics, and the thermal stability of purified and non-purified anthocyanins were investigated to perceive the effect of the purification process. Then the effect of each gum and its concentration was evaluated on the thermal degradation kinetics of anthocyanins. Results demonstrated that both gums enhanced the thermal stability of anthocyanins, while CSG had a superior effect. Findings also revealed that the half-life of anthocyanin was increased at 60°C from 366 ± 22.8 to 432 ± 4.2 and 636 ± 52.8 min in presence of AG and CSG, respectively. TGA results confirmed that the presence of SF-AG and CSG in their optimum concentration enhanced the heat stability of anthocyanin extract. Also, physical molecular bondings were confirmed by the FTIR spectrums where some peaks attributed to both of the extract and the gums were shifted. Plateau or flake-like micro-particles were detected by SEM which correspond with the most freeze-dried microcapsules. PRACTICAL APPLICATION: The results of this study may contribute to the enhanced thermal stability of anthocyanins from barberry that can be used as a coloring agent in beverage and food systems. Moreover, it can be used in preparation of natural nutraceuticals and pharmaceuticals.

Polysaccharide-Based Materials Created by Physical Processes: From Preparation to Biomedical Applications

Polysaccharide-based materials created by physical processes have received considerable attention for biomedical applications. These structures are often made by associating charged polyelectrolytes in aqueous solutions, avoiding toxic chemistries (crosslinking agents). We review the principal polysaccharides (glycosaminoglycans, marine polysaccharides, and derivatives) containing ionizable groups in their structures and cellulose (neutral polysaccharide). Physical materials with high stability in aqueous media can be developed depending on the selected strategy. We review strategies, including coacervation, ionotropic gelation, electrospinning, layer-by-layer coating, gelation of polymer blends, solvent evaporation, and freezing-thawing methods, that create polysaccharide-based assemblies via in situ (one-step) methods for biomedical applications. We focus on materials used for growth factor (GFs) delivery, scaffolds, antimicrobial coatings, and wound dressings.

Hydrolyzed Karaya Gum: Gelatin Complex Coacervates for Microencapsulation of Soybean Oil and Curcumin

This is the first report on utilizing hydrolyzed karaya gum (HKG) as a novel polyanion material for complex coacervation with gelatin A. With negative zeta potentials at pH > 2.5, HKG formed the complex coacervate with a maximum yield at pH 3.75 and 1 : 1 HKG:gelatin ratio. The optimal complex coacervates were used to encapsulate soybean oil containing curcumin using different shell:core ratios, homogenization speeds, concentrations of emulsifier, and drying techniques. Optical microscopy showed that increasing homogenization speed and Tween 80 concentration produced smaller and more uniform coacervate particles. Increasing the shell:core mass ratio from 1 to 4 resulted in a linear increase in encapsulation efficiencies for both soybean oil and curcumin. Accelerated peroxidation tests on the microcapsules showed enhanced protective effects against oil peroxidation when increasing shell:core ratios and using freeze-drying instead of oven-drying at 50 oC. In vitro release of curcumin in simulated gastric and intestinal fluids was faster when using freeze-drying and decreasing shell:core ratio. This study shows perspective novel applications of HKG in microencapsulating active ingredients for food and pharmaceutical industries.

Gum arabic and collagen hydrolysate extracted from hide fleshing wastes as novel wall materials for microencapsulation of Origanum onites L. essential oil through complex coacervation

Renewable resource-based biodegradable materials attract more attention than petroleum-based biodegradable materials to support the sustainable development of ecology. Obtaining collagen hydrolysate (CH) from hide fleshing wastes of leather industry is an environmentally friendly way to develop multifunctional materials that can contribute to technological advances in different industries. In this study, 2:1, 1:1, and 1 2 ratios of gum arabic (GA) and CH extracted from hide fleshing waste were used as wall materials to encapsulate Origanum onites L. essential oil (OOEO) using the complex coacervation method. The encapsulation yield and efficiency, functional group composition, particle size, morphology, and thermal stability of the obtained OOEO microcapsules were characterized. The results showed that the obtained microcapsules had high encapsulation yield and efficiency, as well as good functional properties such as uniform morphology and low water activity. The best mass ratio for the biopolymers (GA:CH) was 1:1. Scanning electron microscopy analysis showed that OOEO microcapsule samples had a spherical shape. FTIR analysis was performed on obtained microcapsules, confirming the molecular interactions between GA and CH. These findings can be useful in designing an ideal wall material using GA and CH for microencapsulation of essential oils by the complex coacervation method.

Vitamin D3 cress seed mucilage -β-lactoglobulin nanocomplexes: Synthesis, characterization, encapsulation and simulated intestinal fluid in vitro release

Vitamin D₃ (VD₃) as an essential lipid-soluble active ingredient with numerous applications in food and pharmaceutical sectors; however, poor water solubility reduces its bioavailability significantly. Application of protein-polysaccharide complexes as a promising way to protect and trigger programmed release of bioactive molecules has established an optimal window in nutraceutical delivery systems. In this study, complexes of β-lactoglobulin (Blg) and cress seed mucilage (CSM) were used to retain VD₃ at undesirable circumstances, such as acidic pH values. The interaction of CSM-Blg was studied by rheological tests and the best formulation was chosen for encapsulation of VD₃ via crosslinking with calcium ions (2-10 mM). The results demonstrated that complexation protect VD₃ at low pH values with the maximum encapsulation efficiency of 84.2 %. The in vitro study indicated that Blg-CSM-VD₃ was more stable in simulated gastric fluid, and in turn VD₃ was released in simulated intestinal fluid; the complexes treated with calcium ions had a slower release rate than normal complexes. The release trend of VD₃ followed the diffusion-Fickian law and the principal interactions included hydrophobic, electrostatic and hydrogen bonding. The results indicated that Blg-CSM complexes can retain VD₃ at acidic environment and induce sustained release, which brings about practical advantages for vitamin delivery in the food and pharmaceutical sectors.

Spectroscopic, molecular docking and molecular dynamic simulation studies on the complexes of β-lactoglobulin, safranal and oleuropein

Herbal bioactive compounds have captured pronounced attention considering their health-promoting effects as well as their functional properties. In this study, the binding mechanism between milk protein bovine β-lactoglobulin (β-LG), oleuropein (OLE) and safranal (SAF) found in olive leaf extract and saffron, respectively via spectroscopic and in silico studies. Fluorescence quenching information exhibited that interactions with both ligands were spontaneous and hydrophobic interactions were dominant. Also, the CD spectroscopy results demonstrated the increase in β-sheet structure and decrease in the α-helix content for both ligands. Size of β-LG-OLE complex was higher than β-LG-SAF due to the conformation and larger molecular size. Molecular docking and simulation studies revealed that SAF and OLE bind in the central calyx of β-LG and the surface of β-LG next to hydrophobic residues. Lastly, OLE formed a more stabilized complex compared to SAF based on the molecular dynamic simulation results.

Novel complex coacervates based on Zedo gum, cress seed gum and gelatin for loading of natural anthocyanins

This study aimed to characterize novel complex coacervates based on Zedo gum and cress seed gum as natural polysaccharides with gelatin (type-A and type-B) as potential wall materials for encapsulation of anthocyanins. The coacervates were prepared under optimum conditions (pH and gum to gelatin ratio), freeze-dried, and the resulted powders were analyzed in terms of thermal stability, morphology, and molecular interactions. The thermogravimetric analysis revealed that molecular interaction between polysaccharides and gelatins led to enhance the thermal stability of gums. The morphology of coacervates showed that while ZG-gelatin and CSG-gelatin coacervates resulted in cubic and irregular particles, freeze-drying severely changed the morphology of coacervates. Moreover, SEM images at lower magnification showed big voids for lyophilized coacervates, while SEM images confirmed a compact and dense microstructure of coacervates at higher magnification and BET method. Also, the molecular interaction of polysaccharides and gelatin in aqueous media was assessed using Raman spectroscopy. Furthermore, findings showed that the type-A of gelatin is a more suitable protein to form coacervates with polysaccharides. In the next step, natural anthocyanins from barberry were encapsulated by proposed coacervates as wall material. The encapsulated extract had elevated thermal stability and showed a lower degradation rate.

Synthesis of Nano-Scale Biopolymer Particles from Legume Protein Isolates and Carrageenan

Research background

Food proteins and polysaccharides can be used for the synthesis of nano-scale biopolymer particles with potential applications in the fields of food and pharmaceuticals. This study focuses on utilizing legume proteins for the production of biopolymer particles via regulation of their electrostatic interactions with carrageenan.

Experimental approach

Protein isolates were obtained from mung bean (Vigna radiata), cowpea (Vigna unguiculata) and black gram (Vigna mungo) and their protein profiles were determined. Next, these isolates were allowed to interact with carrageenan at pH=5.0-7.0 to determine optimum conditions for obtaining nano-scale biopolymer particles. Selected biopolymer mixtures were then subjected to a heat treatment (85 °C for 20 min) to enhance the interactions among biopolymers.

Results and conclusion

Nano-scale biopolymer complexes were obtained at pH=6.5. They were roughly spherical in shape with a majority having a diameter in the range of approx. 100-150 nm. Heating of the biopolymer mixtures increased the diameter of the biopolymer particles by approx. 2.5-fold. In addition, their negative surface charge was increased, stabilizing them against aggregation over a broader pH range (4.0-7.0), enhancing their potential to be utilized in food matrices.

Novelty and scientific contribution

This study reports the applicability of mung bean, cowpea and black gram proteins for the synthesis of stable biopolymer particles. These biopolymer particles can be potentially used for the encapsulation and delivery of bioactive components.