Synthesis, structural characterization and in vitro digestion stability of a soluble soybean polysaccharide‑zinc chelate

The chelation reaction of soluble soybean polysaccharide (SSPS) with zinc was investigated. Using response surface methodology, the optimum parameters for SSPS-Zn synthesis were obtained: pH 5.3, SSPS-ZnCl2 mass ratio of 9.44:1, reaction temperature 50.44 °C, and reaction time 1.5 h, with the highest zinc content of 24.73 %. Compared with SSPS, SSPS-Zn increased in rhamnogalacturonan content and decreased in that of neutral monosaccharides (Fuc, Ara, Gal, Glu and Xyl). UV-vis spectra indicated that SSPS-Zn was lower than SSPS in protein content. FTIR spectra indicated that CO group of SSPS was bonded to Zn2+. X-ray diffraction spectra demonstrated that SSPS-Zn had higher crystallinity. Congo red reactions showed that SSPS possessed a triple-helix conformation while SSPS-Zn formed an irregular free-coiled conformation. EDX confirmed SSPS-Zn synthesis successfully. TGA curves exhibited that SSPS-Zn required higher temperature to undergo degradation. AFM revealed that SSPS-Zn was clustered while SSPS was filamentous. SEM micrographs showed the cracked fragments on the surface of SSPS-Zn. By in vitro simulation of gastrointestinal digestion, Zn2+ release reached 68.87 % after 2 h digestion. Consequently, the chelation of SSPS with zinc could change structure and provide a basis for research and application of novel zinc supplements.

Effects of physical method and enzymatic hydrolysis on the properties of soybean fiber-rich stabilizer for oil in water emulsions

BACKGROUND

Okara is a by-product from the soybean industry and an abundant resource of insoluble soybean fiber (ISF). ISF with various properties could be obtained by different extraction methods. It is an attractive option to utilize okara by taking advantage of ISF as an emulsifier or stabilizer.

RESULTS

Compared with the untreated ISF (ISFUT ), superfine grinding reduced the particle size and viscosity of ISF (ISFSG ). Steam explosion increased the water solubility from 17.5% to 51.7% but decreased the water holding capacity and swelling capacity of ISF (ISFSE ) from 15.0 and 14.0 g/g to 4.2 and 3.3 g/g, respectively. Emulsions prepared by ISFUT and ISFSG before or after enzymatic hydrolysis presented large oil droplets and were unstable. Although emulsions prepared by ISFSE after enzymatic hydrolysis (ISFSE-E ) showed flocculation, the volume-weighted average diameter (19.7 μm) were the smallest while the viscosity and viscoelastic modulus were the highest, and exhibited excellent physical stability during storage.

CONCLUSION

ISF obtained by physical and hydrolysis treatment displayed diverging physicochemical properties while ISF prepared by steam explosion-enzymatic hydrolysis presented the best potential to stabilize emulsions. The present study could provide novel information about the utilization of okara by the application of ISF as an emulsifier or stabilizer. © 2023 Society of Chemical Industry.

A review of extraction, purification, structural properties and biological activities of legumes polysaccharides

In recent years, polysaccharides derived from legumes polysaccharides have aroused worldwide interests. Phytochemical and pharmacological studies have studied the physicochemical properties (emulsification, stability and foaming) and demonstrated the biological activities (immune regulation, anti-oxidation, anti-tumor, hypoglycemic, hypolipidemic and intestinal flora regulation) of legumes polysaccharides. Besides, it is reported that the extraction methods will affect the structural features of polysaccharides, thus further changing their physicochemical properties and biological activities. This review appraised the available literatures described the extraction, purification, structural characterization, biological activity and functional properties of legumes polysaccharides in recent years. It can provide useful research underpinnings and updated information for the development and application of related polysaccharides in functional food and medicinal field.

Encapsulation of curcumin in soluble soybean polysaccharide-coated gliadin nanoparticles: interaction, stability, antioxidant capacity, and bioaccessibility

BACKGROUND

Gliadin nanoparticles are used as a delivery system for active substances because of their amphiphilicity and bioavailability. However, they are susceptible to destabilization by external agents. In this study, gliadin nanoparticles stabilized by soluble soybean polysaccharide (SSPS) were prepared by antisolvent precipitation. Formed stable complex nanoparticles were applied to protect and deliver curcumin (Cur).

RESULTS

Gliadin/SSPS nanoparticles with the smallest particle size (196.66 nm, polydispersity index < 0.2) were fabricated when the mass ratio of gliadin to SSPS was 1:1 at pH 5.0. SSPS-stabilized gliadin nanoparticles had excellent stability at pH 3.0-8.0, 0.02-0.1 mol L-1 NaCl and at 90 °C heat. Gliadin/SSPS nanoparticles were used to encapsulate the Cur. The encapsulation efficiency of the Cur-loaded gliadin/SSPS nanoparticles was 84.59%. Fourier transform infrared spectroscopy and fluorescence spectrophotometry showed that the main forces were hydrogen bonds, electrostatic interactions and hydrophobic interactions between gliadin and SSPS. The X-ray diffraction patterns exhibited that the crystalline form of Cur converted to an amorphous substance. The retention rates of Cur-loaded gliadin/SSPS nanoparticles reached 79.03%, 73.43% and 87.92% after ultraviolet irradiation for 4 h, heating at 90 °C and storage at 25 °C for 15 days, respectively. Additionally, simulated digestion demonstrated that the bioavailability of gliadin/SSPS-Cur nanoparticles was four times higher than that of free Cur.

CONCLUSION

This study showed that SSPS improved the stability of gliadin nanoparticles. Gliadin/SSPS nanoparticles have the function of loading and delivering Cur. © 2022 Society of Chemical Industry.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

Optimization of dialdehyde soluble soybean polysaccharide: preparation by response surface methodology for cleaner leather tanning

Leather is widely used in daily necessities, such as shoes and bags. Traditional chrome tanning might produce leathers with excellent mechanical and thermal properties but gives rise to problems, such as environmental pollution. To find an ecological alternative for chrome-tanning agents, soluble soybean polysaccharide (SSPS) was oxidized by sodium periodate to yield dialdehyde soluble soybean polysaccharide (DPA). By the response surface methodology (RSM)-based optimization of the preparation process, DPA was obtained at the optimized condition at the mass ratio of 1 : 1.9, oxidation time of 0.53 h, and oxidation temperature of 20 °C, and the hydrothermal shrinkage temperature of the DPA-tanned leather reached 79 °C. The Fourier transform infrared (FT-IR) spectra and gel permeation chromatography (GPC) showed that the aldehyde group was successfully introduced, and the molecular weight was significantly reduced. The DPA-tanned leather has good collagen fiber dispersion and mechanical properties and thus is suggested to be a green tanning agent for leather making.

Leather is widely used in daily necessities, such as shoes and bags.

Green synthesis of silver nanoparticles using soluble soybean polysaccharide and their application in antibacterial coatings

In the present work, a facile and green synthesis approach for the production of monodispersed, small-sized (2.9 ± 0.7 nm) and stable silver nanoparticles (AgNPs) using soluble soybean polysaccharide (SSPS) was reported. SSPS was used as the reducing and stabilizing agent. The obtained SSPS-stabilized AgNPs (SA) were characterized by UV-vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. The antimicrobial activity of the SA colloidal dispersion (SACD) was evaluated based on the growth kinetics of bacteria E. coli and S. aureus. Afterwards, the colloidal dispersion was applied as a coating material to Kraft paper. The SACD-coated Kraft paper exhibited excellent antimicrobial activity against above bacteria strains and P. aeruginosa. The effects of SACD coating on surface wettability, barrier property and microstructure of the Kraft paper were also studied. The results suggested that the SSPS-stabilized AgNPs have great potential in antibacterial applications.

Prebiotic Potential and Anti-Inflammatory Activity of Soluble Polysaccharides Obtained from Soybean Residue

In the present study, we assessed the extraction of low molecular weight soluble polysaccharides (MESP) from soybean by-products using microwave-assisted enzymatic technology and proposed the chemical structure of MESP using Fourier transform-infrared spectroscopy, gas chromatography, and ¹H and ¹³C nuclear magnetic resonance spectrum analysis. The results suggested that MESP mainly comprised arabinose, rhamnose, and glucuronic acid with (1→4) glycosidic linkages in the backbone. Compared with inulin, MESP was found to selectively stimulate the growth of Lactobacillus probiotics. Moreover, the results of in vitro fermentation indicated that MESP significantly increased the concentrations of both acetate and butyrate (p < 0.05). MESP were treated on lipopolysaccharide (LPS)-stimulated RAW264.7 cells to determine the anti-inflammatory effect in vitro. It was observed that MESP inhibited nitric oxide, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 production. Furthermore, Western blotting results indicated that MESP significantly attenuated LPS-induced downregulation of phosphorylation levels of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in macrophages. The underlying mechanism might involve inhibition of the expression of pro-inflammatory cytokines, presumably via JAK2/STAT3 pathway. Collectively, the results of our study paved way for the production of MESP, which may be potentially used as nutraceutical ingredients for prebiotics and anti-inflammatory agents, from soybean residue.

Soluble soybean polysaccharide/nano zinc oxide antimicrobial nanocomposite films reinforced with microfibrillated cellulose

Nanocomposite films of soluble soybean polysaccharide (SSPS)/nano zinc oxide (nZnO) reinforced with microfibrillated cellulose (MFC) were developed by solvent casting method. The structure, optical, barrier, thermal, surface wettability, mechanical properties and antimicrobial activity of the SSPS/MFC, SSPS/nZnO and SSPS/nZnO/MFC nanocomposite films were evaluated. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra indicated interactions between SSPS and the nano-fillers. The nanocomposite films containing MFC showed improved tensile strength, stiffness, ultraviolet (UV) light barrier property, thermal stability and water resistance when compared with the neat SSPS film. The nZnO-incorporated nanocomposite films exhibited good antimicrobial activity against E. coli and B. subtlis. Overall, the MFC-reinforced SSPS/nZnO nanocomposite films possessed desirable characteristics to be considered as potential candidates for antimicrobial packaging and biomedical applications.

Enhancement of Versatile Extracellular Cellulolytic and Hemicellulolytic Enzyme Productions by Lactobacillus plantarum RI 11 Isolated from Malaysian Food Using Renewable Natural Polymers

Lactobacillus plantarum RI 11 was reported recently to be a potential lignocellulosic biomass degrader since it has the capability of producing versatile extracellular cellulolytic and hemicellulolytic enzymes. Thus, this study was conducted to evaluate further the effects of various renewable natural polymers on the growth and production of extracellular cellulolytic and hemicellulolytic enzymes by this novel isolate. Basal medium supplemented with molasses and yeast extract produced the highest cell biomass (log 10.51 CFU/mL) and extracellular endoglucanase (11.70 µg/min/mg), exoglucanase (9.99 µg/min/mg), β-glucosidase (10.43 nmol/min/mg), and mannanase (8.03 µg/min/mg), respectively. Subsequently, a statistical optimization approach was employed for the enhancement of cell biomass, and cellulolytic and hemicellulolytic enzyme productions. Basal medium that supplemented with glucose, molasses and soybean pulp (F5 medium) or with rice straw, yeast extract and soybean pulp (F6 medium) produced the highest cell population of log 11.76 CFU/mL, respectively. However, formulated F12 medium supplemented with glucose, molasses and palm kernel cake enhanced extracellular endoglucanase (4 folds), exoglucanase (2.6 folds) and mannanase (2.6 folds) specific activities significantly, indicating that the F12 medium could induce the highest production of extracellular cellulolytic and hemicellulolytic enzymes concomitantly. In conclusion, L. plantarum RI 11 is a promising and versatile bio-transformation agent for lignocellulolytic biomass.

Valorisation of By-Products from Soybean (Glycine max (L.) Merr.) Processing

In recent years, increased awareness of the health benefits associated with consuming soy-based foods, knowledge of milk-related allergies and a move towards more sustainable food production have led to an increase in the number of available soy-based products. The biggest producers in the world, the USA, South America and China, are from the Pacific region. This enormous production is accompanied by the accumulation of related by-products, in particular, a substance that is known as okara. Okara is a paste that is rich in fibre (50%), protein (25%), fat (10%), vitamins and trace elements. Its proper use would lead to economic advantages and a reduction in the potential for polluting the environment. Its high fibre content and low production costs mean that it could also be used as a dietary supplement to prevent diabetes, obesity and hyperlipidaemia. Chemical or enzymatic treatment, fermentation, extrusion, high pressure and micronisation can all increase the soluble fibre content, and thus improve nutritional quality and processing properties. However, the product also degrades rapidly due to its high moisture content (70-80%), which makes it difficult to handle and expensive to dry by conventional means. The aim of this paper is therefore to thoroughly study the existing literature on this subject in order to develop a general protocol for okara exploitation and valorisation. A cost/benefit analysis could drive the design of eco-friendly, sustainable protocols for the preparation of high-value nutritional products.

Extraction optimization, purification and characterization of polysaccharides from the seed coat of black soybean

In this study, the extraction of water-soluble polysaccharides from the seed coat of black soybean (BSCP) was investigated and optimized. A response surface methodology based on a Box-Behnken design (BBD) was used to optimize the extraction conditions as follows: extraction temperature, 100°C; ratio of water to material, 22.3 mL/g; and extraction time, 133.2 min. Under these conditions, the experimental yield of polysaccharides was 10.56%, which was consistent with the predictive yield. A novel galactomannan, BSCP-1, with a molecular weight of 7.55 × 105 Da determined by high-performance gel permeation chromatography, was isolated from the black soybean seed coat. Through gas chromatography-mass spectrometry analysis, BSCP-1 was identified as a galactomannan consisting of galactose, mannose and rhamnose in a molar ratio of 6.01:3.56:1.00. Cytotoxicity against the human gastric carcinoma cancer cell line was also determined.

Protective Effects of Degraded Soybean Polysaccharides on Renal Epithelial Cells Exposed to Oxidative Damage

This study aimed to investigate the protective effects of degraded soybean polysaccharides (DSP) on oxidatively damaged African green monkey kidney epithelial (Vero) cells. Low DSP concentration (10 μg/mL) elicited an evident protective effect on H₂O₂-induced cell injury (0.3 mmol/L). The cell viabilities of the H₂O₂-treated group and the DSP-protected group were 57.3 and 93.1%, respectively. The cell viability decreased to 88.3% when the dosage was increased to 100 μg/mL. DSP protected Vero cells from H₂O₂-mediated oxidative damage by enhancing cellular superoxide dismutase activity and total antioxidant capacity and by decreasing malonaldehyde content and lactate dehydrogenase release. The H₂O₂-treated cells stimulated the aggregation of calcium oxalate monohydrate crystals. DSP could also reduce the crystal size, decrease the attached crystal content, and prevent the cell aggregation by alleviating oxidative injury and lipid peroxidation, enhancing antioxidant capacity, and decreasing hyaluronan expression on cellular surfaces. The internalization ability of the injured cells was improved after these cells were exposed to DSP solution. The regulation ability of DSP-repaired cells on calcium oxalate dihydrate formation, crystal attachment, aggregation, and internalization was lower than that of normal cells but was higher than that of the injured cells. DSP may be a potential green drug to prevent calcium oxalate (CaOx) stone formation because DSP could protect cells from oxidative damage and inhibit CaOx crystal formation.

Physicochemical Characterization of a Polysaccharide Fraction from Platycladus orientalis (L.) Franco and Its Macrophage Immunomodulatory and Anti-Hepatitis B Virus Activities

A polysaccharide fraction, here called POP1, was purified from the leaves of Platycladus orientalis (L.) Franco by water extraction and alcohol precipitation. Physicochemical characterization indicated that POP1 had a relative molecular weight of 8.10 × 10(3) Da and consisted of rhamnose (5.74%), arabinose (12.58%), mannose (10.97%), glucose (64.96%), and galactose (6.55%). The main linkage types of POP1 consisted of (1→5)-linked α-l-Ara, (1→3)-linked α-l-Man, (1→6)-linked β-l-Rha, (1→4)-linked α-d-Glc, (1→6)-linked α-d-Glc, (1→6)-linked β-d-Gal, (1→3,6)-linked β-d-Gal, and termination with α-l-Man and α-d-Glc residues based on periodate oxidation, Smith degradation, methylation, and NMR analysis. POP1 exhibited excellent immunostimulating activity by enhancing macrophage NO, TNF-α, IL-6, and IL-12 secretion and activating related mRNA expression. Besides, POP1 showed significant anti-HBV activity through inhibiting the expression of HBsAg (IC50 = 1.33 ± 0.12 mg/mL) and HBeAg (IC50 = 1.67 ± 0.13 mg/mL) and interfering with the HBV DNA replication (IC50 = 0.80 ± 0.03 mg/mL). The present study suggested that POP1 could be used as immunoregulatory agent in functional foods for the prevention of HBV infection.