The role of the proteinaceous component on the emulsifying properties of gum arabic

Innovative biopolyelectrolytes-based technologies for wastewater treatment

Developing eco-friendly, cost-effective, and efficient methods for treating water pollutants has become paramount in recent years. Biopolyelectrolytes (BPEs), comprising natural polymers like chitosan, alginate, and cellulose, have emerged as versatile tools in this pursuit. This review offers a comprehensive exploration of the diverse roles of BPEs in combating water contamination, spanning coagulation-flocculation, adsorption, and filtration membrane techniques. With ionizable functional groups, BPEs exhibit promise in removing heavy metals, dyes, and various pollutants. Studies showcase the efficacy of chitosan, alginate, and pectin in achieving notable removal rates. BPEs efficiently adsorb heavy metal ions, dyes, and pesticides, leveraging robust adsorption capacity and exceptional mechanical properties. Furthermore, BPEs play a pivotal role in filtration membrane techniques, offering efficient separation systems with high removal rates and low energy consumption. Despite challenges related to production costs and property variability, their environmentally friendly, biodegradable, renewable, and recyclable nature positions BPEs as compelling candidates for sustainable water treatment technologies. This review delves deeper into BPEs' modification and integration with other materials; these natural polymers hold substantial promise in revolutionizing the landscape of water treatment technologies, offering eco-conscious solutions to address the pressing global issue of water pollution.

Preliminary study of physicochemical, thermal, rheological, and interfacial properties of quinoa oil

Background: The growing popularity of nutrient-rich foods, among which is quinoa, is due to the increasing demand for healthier choices. Oils and hydrolyzed proteins from these foods may help prevent various health issues. The objective of this work was to perform extraction from the endosperm of the grain from high-protein quinoa flour by physical means via a differential abrasive milling process and extracting the oil using an automatic auger extractor at 160°C, as well as characterizing extracted oil. Methods: Quinoa oil extraction and physicochemical characterization were carried out. Chemical and physical quality indexes of quinoa oil were established, and both characterizations were conducted based on international and Columbian standards. Thermal properties were evaluated by differential scanning calorimetry, and rheological and interfacial properties of the oil were evaluated using hybrid rheometers and Drop Tensiometers, respectively, to determine its potential for obtaining functional foods. Results: The result was 10.5 g of oil/ 100 g of endosperm, with a moisture content of 0.12%, insoluble impurities of 0.017%, peroxide index of 18.5 meq O 2/kg of oil, saponification index of 189.6 mg potassium hydroxide/g of oil, refractive index of 1.401, and a density of 0.9179 g/cm 3 at 20°C. Regarding contaminating metals, it presented 7 mg of iron/kg of oil, a value higher than previously established limits of 5 mg of iron/kg of oil. The oil contained 24.9% oleic acid, 55.3% linoleic acid, and 4% linolenic acid, demonstrating antioxidant capacity. Quinoa oil showed thermal properties similar to other commercial oils. Conclusions: The interfacial and rheological properties were suitable for the stabilization of emulsions, gels, and foams, which are important in various industrial applications and could facilitate the development of new products. The extracted quinoa oil presented similar characteristics to other commercial oils, which could make it a potential product for commercialization and application in different industries.

Fabrication, Characterization, and Microbial Biodegradation of Transparent Nanodehydrated Bioplastic (NDB) Membranes Using Novel Casting, Dehydration, and Peeling Techniques

NDBs were fabricated from gum Arabic (GA) and polyvinyl alcohol (PVA) in different ratios using novel techniques (casting, dehydration, and peeling). The GA/PVA blends were cast with a novel vibration-free horizontal flow (VFHF) technique, producing membranes free of air bubble defects with a homogenous texture, smooth surface, and constant thickness. The casting process was achieved on a self-electrostatic template (SET) made of poly-(methyl methacrylate), which made peeling the final product membranes easy due to its non-stick behavior. After settling the casting of the membranous, while blind, the sheets were dried using nanometric dehydration under a mild vacuum stream using a novel stratified nano-dehydrator (SND) loaded with P2O5. After drying the NDB, the dry, smooth membranes were peeled easily without scratching defects. The physicochemical properties of the NDBs were investigated using FTIR, XRD, TGA, DTA, and AFM to ensure that the novel techniques did not distort the product quality. The NDBs retained their virgin characteristics, namely, their chemical functional groups (FTIR results), crystallinity index (XRD data), thermal stability (TGA and DTA), and ultrastructural features (surface roughness and permeability), as well as their microbial biodegradation ability. Adding PVA enhanced the membrane's properties except for mass loss, whereby increasing the GA allocation in the NDB blend reduces its mass loss at elevated temperatures. The produced bioplastic membranes showed suitable mechanical properties for food packaging applications and in the pharmaceutical industry for the controlled release of drugs. In comparison to control samples, the separated bacteria and fungi destroyed the bioplastic membranes. Pseudomonas spp. and Bacillus spp. were the two main strains of isolated bacteria, and Rhizobus spp. was the main fungus. The nano-dehydration method gave the best solution for the prompt drying of water-based biopolymers free of manufacturing defects, with simple and easily acquired machinery required for the casting and peeling tasks, in addition to its wonderful biodegradation behavior when buried in wet soil.

Triumfetta cordifolia Gum as a Promising Bio-Ingredient to Stabilize Emulsions with Potentials in Cosmetics

The cosmetics industry is searching for efficient and sustainable substances capable of stabilizing emulsions or colloidal dispersions that are thermodynamically unstable because of their high surface energy. Therefore, surfactants are commonly used to stabilize the water/oil interface. However, the presence of a surfactant is not always sufficient to obtain stable emulsions on the one hand, and conventional surfactants are often subject to such controversies as their petroleum origin and environmental concerns on the other hand. As a consequence, among other challenges, it is obvious that research related to new-natural, biodegradable, biocompatible, available, competitive-surfactants are nowadays more intensive. This study aims to valorize a natural gum from Triumfetta cordifolia (T. cordifolia) as a sustainable emulsifier and stabilizer for oil-in-water (O/W) emulsions, and to evaluate how the nature of the fatty phase could affect this potential. To this end, O/W emulsions were prepared at room temperature using three different oils varying in composition, using a rotor-stator mixer. Resulting mixtures were characterized using optical microscopy, laser granulometry, rheology, pH and stability monitoring over time. The results demonstrated good potential for the gum as an emulsifying agent. T. cordifolia gum appears efficient even at very low concentrations (0.2% w/w) for the preparation and stabilization of the different O/W emulsions. The best results were observed for cocoglyceride oil due to its stronger effect of lowering interfacial tension (IFT) thus acting as a co-emulsifier. Therefore, overall results showed that T. cordifolia gum is undoubtedly a highly promising new bio-sourced and environmentally friendly emulsifier/stabilizer for many applications including cosmetics.

Composition and Charge Compensation in Chitosan/Gum Arabic Complex Coacervates in Dependence on pH and Salt Concentration

In this study, complex coacervates of the biopolyelectrolytes chitosan and gum arabic were investigated with respect to their composition and charge compensation depending on the pH and salt concentration. Individual polyelectrolyte yields were deduced from thermogravimetric analysis and chitosan quantification via enzymatic hydrolysis/HPLC-ELSD. The polyelectrolyte mass ratio in the complex coacervate is found to remain approximately constant irrespective of the pH, despite the latter's effect on the polyelectrolyte charge ratio. Two regimes are identified, including either chitosan charges in excess (at pH < 6.0) or gum arabic charges in excess (at pH > 6.0). The amount of extrinsic charge compensation in the complex coacervates is discussed in detail. We show for the first time that the doping level, a quantity traditionally used to describe salt-induced changes of the charge compensation in polyelectrolyte complexes, is also suitable for the description of pH-induced extrinsic charge compensation in such systems.

Potential of Wood Hemicelluloses and Their Derivates as Food Ingredients

A holistic utilization of all lignocellulosic wood biomass, instead of the current approach of using only the cellulose fraction, is crucial for the efficient, ecological, and economical use of the forest resources. Use of wood constituents in the food and feed sector is a potential way of promoting the global economy. However, industrially established food products utilizing such components are still scarce, with the exception of cellulose derivatives. Hemicelluloses that include xylans and mannans are major constituents of wood. The wood hemicelluloses are structurally similar to hemicelluloses from crops, which are included in our diet, for example, as a part of dietary fibers. Hence, structurally similar wood hemicelluloses have the potential for similar uses. We review the current status and future potential of wood hemicelluloses as food ingredients. We include an inventory of the extraction routes of wood hemicelluloses, their physicochemical properties, and some of their gastrointestinal characteristics, and we also consider the regulatory route that research findings need to follow to be approved for food solutions, as well as the current status of the wood hemicellulose applications on that route.

Method to prepare aqueous propolis dispersions based on phase separation

Propolis has many benefits for human health. To facilitate its oral consumption, we designed propolis-in-water dispersions to be used as nutraceuticals. Propolis was first dissolved either in ethanol or in a hydroalcoholic solution. Water being a non-solvent for propolis, its addition produced propolis precipitation. We explored the ternary phase diagram of water, propolis and ethanol to identify the line separating the one phase region where propolis is fully dissolved, and the two-phase region where a concentrated propolis solution coexists with a dilute one. Droplets rich in propolis were produced during the phase separation process under mechanical stirring induced by a rotor-stator device or a microfluidizer, and they were stabilized using gum Arabic as an emulsifier. Ethanol was finally removed by distillation under reduced pressure. Propolis dispersions in the micron and submicron size range could be obtained. They contained between 1.75 and 10.5 wt% polyphenols relative to the total mass.

Assessment of Pharmacological Potential of Novel Exopolysaccharide Isolated from Marine Kocuria sp. Strain AG5: Broad-Spectrum Biological Investigations

With more than 17 clinically approved Drugs and over 20 prodrugs under clinical investigations, marine bacteria are believed to have a potential supply of innovative therapeutic bioactive compounds. In the current study, Kocuria sp. strain AG5 isolated from the Red Sea was identified and characterized by biochemical and physiological analysis, and examination of a phylogenetic 16S rRNA sequences. Innovative exopolysaccharide (EPS) was separated from the AG5 isolate as a major fraction of EPS (EPSR5, 6.84 g/L⁻¹). The analysis of EPSR5 revealed that EPSR5 has a molecular weight (Mw) of 4.9 × 10⁴ g/mol and number average molecular weight (Mn) of 5.4 × 10⁴ g/mol and contains sulfate (25.6%) and uronic acid (21.77%). Analysis of the monosaccharide composition indicated that the EPSR5 fraction composes of glucose, galacturonic acid, arabinose, and xylose in a molar ratio of 2.0:0.5:0.25:1.0, respectively. Assessment of the pharmacological potency of EPSR5 was explored by examining its cytotoxicity, anti-inflammatory, antioxidant, and anti-acetylcholine esterase influences. The antioxidant effect of EPSR5 was dose- and time-dependently increased and the maximum antioxidant activity (98%) was observed at 2000 µg/mL after 120 min. Further, EPSR5 displayed a significant repressive effect regarding the proliferation of HepG-2, A-549, HCT-116, MCF7, HEP2, and PC3 cells with IC₅₀ 453.46 ± 21.8 µg/mL, 873.74 ± 15.4 µg/mL, 788.2 ± 32.6 µg/mL, 1691 ± 44.2 µg/mL, 913.1 ± 38.8 µg/mL, and 876.4 ± 39.8 µg/mL, respectively. Evaluation of the inhibitory activity of the anti-inflammatory activity of EPSR5 indicated that EPSR5 has a significant inhibitory activity toward lipoxygenase (5-LOX) and cyclooxygenase (COX-2) activities (IC₅₀ 15.39 ± 0.82 µg/mL and 28.06 ± 1.1 µg/mL, respectively). Finally, ESPR5 presented a substantial hemolysis suppressive action with an IC₅₀ of 65.13 ± 0.89 µg /mL, and a considerable inhibitory activity toward acetylcholine esterase activity (IC₅₀ 797.02 μg/mL). Together, this study reveals that secondary metabolites produced by Kocuria sp. strain AG5 marine bacteria serve as an important source of pharmacologically active compounds, and their impact on human health is expected to grow with additional global work and research.

The effect of combining basil seeds and gum Arabic on the healing process of experimental acetic acid-induced ulcerative colitis in rats

Background & aim

Ulcerative colitis (UC) is a chronic recurrent inflammatory disease of the large intestine and rectum that oxidative stress and severe inflammation are the main features of this disease. Previous studies have shown that separate consumption of basil and gum arabic can reduce inflammation and oxidative stress. The aim of the study was evaluating the effect of treatment with basil seeds given together with gum arabic on healing, inflammation and oxidative stress in the course of experimental colitis in rats.

Experimental procedure

A total number of 50 male rats were used, randomly assigned to five groups of 10 rats each. Colitis was induced in rats by enemas with 4% solution od acetic acid. Four days after induction of colitis, rats were treated for next 4 days with saline or combination of basil seeds plus gum arabic (1 mg/kg) or sulfasalazine (100 mg/g) rectally. The experiment was terminated after last dose of treatment. Rats without induction of colitis were used as a sham group.

Results

Acetic acid-induced colitis increased the macroscopic and histopathological damage scores of the colon as well as colon levels of MDA(Malondialdehyde), MPO(Myeloperoxidase), TNFα(Tissue necrosis factor α), IL6 (Interleukin 6)and IL17(Interleukin 17) and decreased SOD(Superoxide Dismutase), GPx (Glutathione Peroxidase) and IL10 (Interleukin 10) levels compared with the control group(P < 0.001). Treatment with basil and gum arabic reduced macroscopic and histopathological damage scores (P < 0.01) of the colon, MDA, MPO, TNFα, IL6(P < 0.001) and IL17 (P < 0.01) levels of the colon and increased SOD, GPx and IL10 levels compared to the colitis group (P < 0.01).

Conclusion

Rectal administration of combination of basil seeds plus gum arabic after induction of colitis, exhibits antioxidant and anti-inflammatory effects, and accelerates the healing of the colon in experimental colitis evoked by acetic acid.

Gum Arabic in combination with IFN-γ promotes the M1 polarization in macrophage

Gum Arabic, a mixture of polysaccharide and glycoprotein, is used as an emulsifying stabilizer in the food industry. It might have immunomodulatory effects. We hypothesized that the combination of IFN-γ and Gum Arabic promotes the production of pro-inflammatory factors in RAW 264.7 cells. Treatment of RAW 264.7 cells with the combination of 3% Gum Arabic and 40 ng/mL IFN-γ resulted in a drastic increase (320%) in nitric oxide production compared with that induced by IFN-γ alone. PGE-2 was produced after the cells were treated with 3% Gum Arabic and 40 ng/mL IFN-γ for 6 h. Gum Arabic and IFN-γ increased the production of iNOS and COX-2 proteins, and triggered TNF-α release. Apart from TNF-α, the release of both G-CSF and IL-6 increased by more than 100 times. The release of IL-3, RANTES, and IL-10 increased by more than ten times. Gum Arabic and IFN-γ also increased the secretion of IL-10, IL-1α, IL-1β, IL-13, KC, IL-5, IL-4, IL-12, Eotaxin, IL-9, MCP-1, and ROS. Cytokines associated with M1 polarization of macrophages such as TNF-α, IL-1β, IL-12, NO, and ROS were induced by Gum Arabic and IFN-γ. Our findings help to explore the inflammatory reaction caused by Gum Arabic in cosmetics.

Characterization of Microwave-Controlled Polyacrylamide Graft Copolymer of Tamarind Seed Polysaccharide

The main objective of the study was to prepare tamarind seed polysaccharide grafted copolymers of polyacrylamide (TSP-g-Am) using a 32 factorial design. Tamarind seed polysaccharide (TSP) was extracted, and grafted copolymer of TSP was prepared using polyacrylamide as copolymer and ceric ammonium nitrate as initiator. Various batches (F1-F9) of TSP-g-Am were prepared, among which F1 showed highest grafting efficiency; hence, the prepared TSP-g-Am (F1) was evaluated for grafting efficiency, conversion, effect of initiator and further characterized using SEM analysis, contact angle determination, DSC analysis, swelling index, swelling and deswelling, and chemical resistance. The contact angle of TSP was found to be 81 ± 2, and that of TSP-g-Am (F1) was found to be 74 ± 2, which indicates that the wetting ability of the grafted copolymer was less than that of the native polymer. The results of thermal analysis indicated that TSP-g-Am had a more stable molecular structure than TSP. The morphology of the grafted polymer was observed from SEM images, and it was observed that the particles was asymmetrical. Antimicrobial activity was also found in the grafted copolymer. The present study concludes that the TSP-g-Am showed an excellent performance in thermal stability and swelling capacity compared with TSP. The detailed structural characteristics, as well as the excellent thermal stability and swelling capacities, will make it beneficial to use the synthesised copolymer as a precursor for the production of large-scale eco-friendly advanced materials with a wide range of applications, acting as a stabiliser, thickener, binder, release retardant, modifier, suspending agent, viscosity enhancer, emulsifying agent, or carrier for novel drug delivery systems in oral, buccal, colon, and ocular systems, and in nanofabrication and wound dressing, and it is also becoming an important part of food, cosmetics, confectionery, and bakery.

In Vitro Assessment of Antistaphylococci, Antitumor, Immunological and Structural Characterization of Acidic Bioactive Exopolysaccharides from Marine Bacillus cereus Isolated from Saudi Arabia

A strain of Bacillus cereus was isolated from the Saudi Red Sea coast and identified based on culture features, biochemical characteristics, and phylogenetic analysis of 16S rRNA sequences. EPSR3 was a major fraction of exopolysaccharides (EP_S) containing no sulfate and had uronic acid (28.7%). The monosaccharide composition of these fractions is composed of glucose, galacturonic acid, and arabinose with a molar ratio of 2.0: 0.8: 1.0, respectively. EPSR3 was subjected to antioxidant, antitumor, and anti-inflammatory activities. The results revealed that the whole antioxidant activity was 90.4 ± 1.6% at 1500 µg/mL after 120 min. So, the IC₅₀ value against DPPH radical found about 500 µg/mL after 60 min. While using H₂O₂, the scavenging activity was 75.1 ± 1.9% at 1500 µg/mL after 60 min. The IC₅₀ value against H₂O₂ radical found about 1500 µg/mL after 15 min. EPSR3 anticytotoxic effect on the proliferation of (Bladder carcinoma cell line) (T-24), (human breast carcinoma cell line) (MCF-7), and (human prostate carcinoma cell line) (PC-3) cells. The calculated IC50 for cell line T-24 was 121 ± 4.1 µg/mL, while the IC₅₀ for cell line MCF-7 was 55.7 ± 2.3 µg/mL, and PC-3 was 61.4 ± 2.6 µg/mL. Anti-inflammatory activity was determined for EPSR3 using different methods as Lipoxygenase (LOX) inhibitory assay gave IC₅₀ 12.9 ± 1.3 µg/mL. While cyclooxygenase (COX-2) inhibitory test showed 29.6 ± 0.89 µg /mL. EPSR3 showed potent inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci. The exposure times of EPSR3 for the complete inhibition of cell viability of methicillin resistant S. aureus was found to be 5% at 60 min. Membrane stabilization inhibitory gave 35.4 ± 0.67 µg/mL. EPSR3 has antitumor activity with a reasonable margin of safety. The antitumor activity of EPSR3 may be attributed to its content from uronic acids with potential for cellular antioxidant and anticancer functional properties.

Effects of pH and Electrolytes on Castor Oil Emulsions with Various Stabilisers Using Khaya senegalensis Gum as an Emulsifier

Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evaluated, and an effort was made to improve the stability by incorporating Tween 80, hydroxypropyl methylcellulose, and xanthan gum. From the results, it can be inferred that Tween 80 (0.5%) was able to stabilise the emulsion. Addition of xanthan gum worsened the creaming. The effects of pH (4.0, 5.5, 7.2, 9.0, and 11.0) and electrolytes (0.1 M of NaCl, KCl, and CaCl₂) on the physical stability of oil-in-water emulsions were studied during 12 weeks of storage. Percentage creaming volume and whether there was phase inversion were the criteria used as the evaluation parameter. From the percentage creaming volume data, emulsions formulated with both gums showed the lowest creaming volumes at pH of 7.2, followed by the acidic regions (pH 4.0, 5.5), with the basic regions (pH 9.0, 11.0) recording the highest creaming volumes. The effects of the various electrolytes at a constant concentration of 0.1 M on the o/w emulsions were found in this order NaCl < KCl < CaCl₂. This study proves that Khaya senegalensis gum can successfully be employed as an emulsifying agent in pharmaceutical formulations.

Complex wall materials of polysaccharide and protein effectively protected numb-taste substance degradation of Zanthoxylum bungeanum

BACKGROUND

Hydroxyl-sanshools are mainly responsible for the numb taste and biological activities of Zanthoxylum bungeanum, but they show low water solubility, high volatility and easy degradation, which limit their application in the catering and food industries. Thus microcapsules of Z. bungeanum essential oil (ZBEO) were prepared to prevent numb-taste substance attenuation.

RESULTS

The complex effects of hydroxypropyl-β-cyclodextrin (HPCD) with other materials, such as konjac glucomannan octenyl succinate (KGOS), octenyl succinic anhydride-modified starch (OSAS), soy protein isolate (SPI) and gum arabic (GA), on the protection of the main numb-taste substance of ZBEO were investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that ZBEO was successfully encapsulated in the complex wall materials. X-ray diffraction indicated that the loaded essential oil did not affect the crystalline form of the wall material. The stability of the numb-taste substance α-sanshool in the microcapsules prepared with the complex microcapsule wall materials was higher than that in single-wall microcapsules. Storage stability evaluation indicated that microcapsules prepared with a combination of HPCD and SPI showed the greatest effect in maintaining the stability of the main numb-taste substance α-sanshool in ZBEO at room temperature, low pH and in high-salt conditions.

CONCLUSION

Complex wall materials of polysaccharide and protein could effectively protect the numb-taste substance degradation of Z. bungeanum during processing and storage. © 2021 Society of Chemical Industry.

Modification of EDC method for increased labeling efficiency and characterization of low-content protein in gum acacia using asymmetrical flow field-flow fractionation coupled with multiple detectors

1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) is widely used as a crosslinker for fluorescence labeling of protein in the fields of biochemistry and food analysis. Many natural polysaccharides often contain some proteins or peptides that are very low in content but play a vital role in their biological function as well as technical applications. Determination of these low-content proteinaceous matters requires a highly sensitive and selective method. In this study, a methodological approach for investigations of the presence of proteinaceous material over the molar mass distribution (MD) of polysaccharides was developed using gum acacia (GA) as a model polysaccharide. EDC fluorescence-labeling method was modified by changing the pH (7, 9, and 11) of the solution for the analysis of low-content protein in food materials. Fluorescence spectroscopy and asymmetrical flow field-flow fractionation (AF4) were employed for characterizing the labeling efficiency and physiochemical properties of unlabeled and fluorescence-labeled GA. AF4 provided molar mass (M) and the radius of gyration (r_G) of arabinogalactan (AG) and arabinogalactan protein complex (AGP) and determined the presence of proteinaceous matter over the MD. The labeling efficiencies of GA at pH 7, 9, and 11 determined by fluorescence spectroscopy were 56.5, 68.4, and 72.0%, respectively, with an increment of 15.5% when pH was increased from 7 to 11. The modified EDC fluorescence-labeling method allows highly sensitive and selective analysis of low-content proteinaceous matters and their distribution in natural polysaccharides.

Polymer functionalization through an enzymatic process: Intermediate products characterization and their grafting onto gum Arabic

The modification of gum Arabic with ferulic acid oxidation products was performed in aqueous medium, at 30 °C and pH 7.5, in the presence of Myceliophthora thermophila laccase as biocatalyst. First, this study aimed to investigate the structures of the oxidation products of ferulic acid that could possibly be covalently grafted onto gum Arabic. HPLC analyses revealed that this reaction produced several oxidation products, whose structures were investigated using LC-MS/MS analyses (liquid chromatography-mass spectrometry with mass fragmentation analyses) and NMR experiments. The chemical structure of one intermediate reaction product was fully elucidated as the 2-(4-hydroxy-3-methoxyphenyl)-4-[(4-hydroxy-3-methoxyphenyl) methylidene] cyclobutane-1, 3-dione, called by the authors cyclobutadiferulone. Secondly, this study aimed to locate the grafting of the oxidation products onto gum Arabic by performing several NMR experiments. This study did not determine how much and specifically which oxidation products were grafted but some of them were undeniably present onto modified gum Arabic, close to the glucuronic acid C5 carbon or close to the galactose C6 carbon.

Emulsifying properties of Acacia senegal gum: Impact of high molar mass protein-rich AGPs

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Reconstitution of gums from arabinogalactan proteins (AGP) of Acacia gum.

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Experimental design to optimize their emulsions properties.

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Relevant adsorption of high molar protein-rich AGPs at the interface.

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Combined effect of high molar protein-rich AGPS and total concentration.

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Role of apparent viscosity of bulk to long-term stability.

The impact of high molar mass protein-rich arabinogalactan-proteins (AGPs) on emulsifying properties of Acacia senegal gums were studied using reconstituted gums obtained with two distinct fractions: one containing these specific high molar mass AGPs and the other protein-poor low molar mass AGPs. To produce and stabilize limonene emulsions, the experimental design emphasized not only the role of high molar mass protein-rich AGPs, but also the importance of high total concentration. At low protein contents, reconstituted gums required a slightly higher content in high molar mass protein-rich AGPs than original A. senegal gum, that confirmed the role of low molar mass protein-rich AGPs in the adsorption at interfaces. The comparison of the creaming index between original and reconstituted gums as well as the monitoring of instability phenomena by turbiscan up to 30 days clearly demonstrated the prevalent impact of the bulk apparent viscosity in the long-term stability of emulsions.

Encapsulation of black pepper seed oil using maltodextrin and pea protein

The goal of this research was to determine the physicochemical and emulsifying properties of pea protein, gum arabic, and maltodextrin and to investigate their potential for stabilizing black pepper seed oil emulsions and acting as carrier materials for spray dried microcapsules. The moisture content and water activity of pea protein and maltodextrin (∼5.5 g/100 g and ∼0.22) were found to be significantly lower than that of gum arabic (11.5 g/100 g and 0.46) whereas the glass transition temperatures of pea protein and maltodextrin (∼99.4 ℃) was significantly higher than that of gum arabic (72 ℃). Pea protein showed the highest viscosity (53.8 mPa s), the lowest surface tension (42.5 mN/m), and interfacial tension (10.5 mN/m) among the biopolymer materials studied. A mixture design was employed to investigate the effect of biopolymer formulation on droplet size and creaming stability of black pepper seed oil emulsions. Stable emulsions with relatively smaller droplet size were spray dried to produce microcapsules. Spray dried black pepper seed oil microcapsules produced with 1% pea protein and 39% maltodextrin had low surface oil (∼0.8%) and high encapsulation efficiency (95%). The results of this study suggest that pea protein in combination with maltodextrin can be used as carrier materials in encapsulation of black pepper seed oil.

Chickpea Cultivar Selection to Produce Aquafaba with Superior Emulsion Properties

Aquafaba (AQ), a viscous by-product solution produced during cooking chickpea or other legumes in water, is increasingly being used as an egg replacement due to its ability to form foams and emulsions. The objectives of our work were to select a chickpea cultivar that produces AQ with superior emulsion properties, and to investigate the impact of chickpea seed physicochemical properties and hydration kinetics on the properties of AQ-based emulsions. AQ from a Kabuli type chickpea cultivar (CDC Leader) had the greatest emulsion capacity (1.10 ± 0.04 m²/g) and stability (71.9 ± 0.8%). There were no correlations observed between AQ emulsion properties and chickpea seed proximate compositions. Meanwhile, AQ emulsion properties were negatively correlated with AQ yield and moisture content, indicating that AQ with higher dry-matter content displayed better emulsion properties. In conclusion, the emulsification properties of aquafaba are greatly influenced by the chickpea genotype, and AQ from the CDC Leader chickpea produced the most stable food oil emulsions.

Emulsions Stabilized by Gum Arabic: How Diversity and Interfacial Networking Lead to Metastability

Gum arabic is a natural hydrocolloid composed of a diversity of amphiphilic species consisting of protein chains covalently linked to multiscale porous polysaccharides. Gum arabic is notably used as a food additive (E414) to provide metastability to oil-in-water emulsions, even after extensive dilution. Here, we investigate the mechanism underlying the emulsion stabilizing properties of gum arabic, using a combination of scattering and chromatographic analyses and the design of a harvesting method to collect adsorbed species. Increasing the interfacial packing of amphiphilic species leads to their irreversible interfacial aggregation, which is driven by hydrophobic interactions between protein chains. This aggregation is promoted by the size diversity of amphiphilic species, with smaller species first aggregating at intermediate interfacial packings, followed by larger species at higher packings. The resulting adsorbed layer can be considered as a shell composed of a two-dimensional protein network, irreversibly cross-linked through hydrophobic interactions, which is covalently linked to hyperbranched polysaccharide chains displaying severe conformational changes compared to their bulk structure. This shell is strongly anchored at the oil-water interface by the protein network and provides steric repulsions through the hydrated polysaccharides. Consequently, if such a shell is adequately formed during emulsification, emulsions stabilized by gum arabic may resist extensive mechanical stresses and display a long-term metastability even after drastic environmental changes. This paves the way toward more rational uses of gum arabic as an emulsion stabilizer in formulations and processes.

Is Gum Arabic a Good Emulsifier Due to CH...π Interactions? How Urea Effectively Destabilizes the Hydrophobic CH...π Interactions in the Proteins of Gum Arabic than Amides and GuHCl?

The photophysical studies of gum arabic (GA) in the presence of urea, 1,3-dimethylurea (DMU), tetramethylurea (TMU), guanidine hydrochloride (GuHCl), formamide (FA), acetamide (AA), and dimethyl formamide (DMF) were carried out by monitoring the emission, three-dimensional emission contour, and time-correlated fluorescence lifetime techniques. On addition of only 1 × 10-3 M urea, 75.0% of the fluorescence of GA is quenched, while the same occurs in GuHCl at 3.0 M. FA quenched 50% of the fluorescence of GA at 5.0 M. However, DMU, TMU, AA, and DMF resulted in a fluorescence enhancement. The unusual fluorescence trends reveal the existence of CH...π interactions in the proteins of GA. The experimental results and the structural aspects of proteins in GA led us to propose that the aggregation of polyproline helices in GA, through several CH...π interactions, would have a major role to play in the emulsification mechanism of GA.

Real-Time Intraoperative Assessment of Microcirculation in Living-Donor Small Bowel Transplant: A Case Report

Living-donor small bowel transplant has emerged as a modality to transplant patients with short bowel syndrome without prolonged wait time, albeit at the cost of technical challenges associated with vascular anastomosis due to the small size of vessels. Suboptimal perfusion in a transplanted bowel can lead to a devastating outcome, and clinical judgment alone is not completely reliable for assessment of bowel microcirculation. Here, we report a 55-year-old female patient who underwent flow cytometric cross-match-positive living-donor bowel transplant from her daughter. Initial suboptimal perfusion prompted a revision of the arterial anastomoses. Despite normal Doppler signals over the mesenteric vessels, the bowel had a variegated appearance. The microcirculation of the bowel wall was subsequently assessed in a real-time fashion by indocyanine green fluorescence angiography, which showed improved perfusion indices with time. Hence, this simple test helped us to avoid another unnecessary exploration and revision of the anastomoses. At present, the patient is thriving on an enteral diet. This case underpins the importance of real-time intraoperative assessment of bowel per-fusion and microcirculation in difficult cases. These assessments are needed to help surgeons identify tissues at risk for ischemia and necrosis, thereby allowing for maneuvers to improve intestinal viability.

Obtaining a novel mucilage from mutamba seeds exploring different high-intensity ultrasound process conditions

We evaluated the effect of ultrasonic power (200-600 W) and process time (1-7 min) on the recovery of a novel polysaccharide from mutamba (Guazuma ulmifolia Lam.) seeds applying high-intensity ultrasound. Ultrasound process conditions intensification gradually was removing the mucilage layer around the hydrated seeds. Then, the scanning electron micrographs showed that the mucilage was removed completely at the highest applied energy density (10,080 J/mL). Although the colour of mutamba seed mucilage (MSM) have been changed due to increase of energy density, it not affects its practical use because the MSM can be purified to remove impurities. The results obtained in this study demonstrated that the ultrasound process conditions intensification did not affect the primary structure of MSM according to ζ-potential, FTIR spectrum, and monosaccharide residues data. In conclusion, ultrasound process conditions intensification allows the full recovery of the MSM at a short process time (7 min) without altering its quality and the primary structure.

Preparation of allyl isothiocyanate nanoparticles, their anti-inflammatory activity towards RAW 264.7 macrophage cells and anti-proliferative effect on HT1376 bladder cancer cells

BACKGROUND

Allyl isothiocyanate (AITC), a volatile and water-insoluble compound present in several cruciferous vegetables, has been shown to possess several biological qualities such as anti-bacterial, anti-fungal, and anti-cancer activity. In this study, water-soluble allyl isothiocyanate nanoparticles (AITC-NPs) were prepared by oil dispersed in water (O/W) microemulsion and complex coacervation techniques and evaluated for their anti-inflammatory activity towards macrophage cell RAW 264.7 and anti-cancer effect on human bladder cancer cell HT1376.

RESULTS

The AITC-NPs with a particle size of 9.4 nm were stable during heating up to 110 °C or three freeze-thawing cycles. No significant cytotoxicity was shown on Caco-2 and intestine epithelial IEC-6 cells at AITC-NP doses ranging from 0.25 to 2 g L^-1 (8.75-70 mg L^-1 AITC). However, at 2 g L^-1 dosage, AITC-NPs could inhibit the growth of human bladder cancer cells HT1376 by 90%, while their low dosage at 0.25 g L^-1 could inhibit migration ability by 83.7, 71.3, 58.4 and 31.4% after 4, 8, 12, and 24 h of incubation, respectively. Compared to AITC and NPs, AITC-NPs showed a better inhibition on lipopolysaccharide (LPS)-induced TNF-α, IL-6, NO and iNOS production in RAW 264.7 macrophage cells.

CONCLUSION

The results demonstrate the potential of AITC-NPs as therapeutic agents for the treatment of bladder cancer and the enhancement of immune function. © 2018 Society of Chemical Industry.

Emulsions Stabilized by Gum Arabic: Composition and Packing within Interfacial Films

Gum arabic is a heterogeneous natural hydrocolloid commonly used in the agro-food industry to provide metastability to oil-in-water emulsions. Since aqueous solutions of gum arabic contain a complex mixture of protein/polysaccharide conjugates, the composition of interfacial films is expected to differ from the bulk composition. Here, we investigate the composition of interfacial films in oil/water emulsions stabilized by gum arabic at various concentrations, pH and salinity. Using both size exclusion and hydrophobic interaction chromatography separations, we show that the interface is enriched in protein-rich species displaying a broad range of sizes. These species are irreversibly adsorbed as monolayers at the oil/water interface. We observe that the surface coverage density, or packing, of the adsorbed species at oil/water interfaces drastically increases with both the increasing gum concentration and decreasing ionic repulsions, through increasing the ionic strength or decreasing the pH. Strikingly, these packing changes correspond to only minor composition changes in the adsorbed layer. We thus conclude that the key parameter modified in different formulations is the conformation of the adsorbed species rather than their composition distribution. These findings can be readily used to adjust the amount of gum arabic necessary to produce metastable emulsions.

Multicharacteristic Behavior of Tyrosine Present in the Microdomains of the Macromolecule Gum Arabic at Various pH Conditions

Gum arabic (GA), the dried exudates of Acacia seyal and Acacia senegal trees, being a biopolymer, has found many applications in the food, pharmaceutical, cosmetic, and lithography industries. GA, a water-soluble food hydrocolloid, is a complex and variable mixture of arabinogalactan oligosaccharides, polysaccharides, and glycoproteins. It has been a subject of great interest and a wide range of research has been done on the polysaccharide structural aspects and the emulsifying properties only. In the present study, fluorescence spectral technique is employed as an analytical tool to understand the photophysics of GA. The tyrosine microenvironment of GA was explored by studying the steady-state absorption, emission, fluorescence lifetime, and three-dimensional (3D) emission contour spectra of GA at various pH conditions in aqueous solution. The multiple emissive states are attributed to the presence of intrinsic fluorophore tyrosine in a heterogeneous microenvironment. The study portrays the multicharacteristic behavior of tyrosine in various pH conditions and in different microdomains. The exposure of the buried tyrosine to the heterogeneous aqueous phase was authenticated by 3D emission contour spectral studies. An interesting visualization of tyrosine involving in hydrogen-bonding network with another tyrosine moiety at neutral pH was ascertained. The coexistence of hydrophilic carbohydrate and hydrophobic protein in GA enables its emulsification and stabilization properties. Hence, any advancement toward understanding the protein microenvironment of GA is of great significance for chemists, as the molecular modeling and biosynthesis of the gum with desired end product are underway in many research institutes.

Tree gum-based renewable materials: Sustainable applications in nanotechnology, biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as 'green' bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal-hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.