Combined membrane filtration and alcohol-precipitation of alkaline soluble polysaccharides from sugar beet pulp: Comparision of compositional, macromolecular, and emulsifying properties

Inhibition of dengue virus infection in vitro by fucoidan and polysaccharide extract from marine alga Sargassum spp

Dengue virus (DENV) infection poses a global health threat, leading to severe conditions with the potential for critical outcomes. Currently, there are no specific drugs available whereas the vaccine does not offer comprehensive protection across all DENV serotypes. Therefore, the development of potential anti-viral agents is necessary to reduce the severity risk and interrupt the transmission circuit. The search for effective antiviral agents against DENV has predominantly focused on natural resources, particularly those demonstrating diverse biological activities and high safety profiles. Cyanobacteria and algae including Leptolyngbya sp., Spirulina sp., Chlorella sp., and Sargassum spp., which are prevalent species in Thailand, have been reported for their diverse biological activities and high safety profile but not specifically for anti-DENV activity. In this study, the screening assay was performed to compare the anti-viral activity against DENV of crude polysaccharide and ethanolic extracts derived from 4 species of cyanobacteria and algae in Vero cells. Polysaccharide extracts from Sargassum spp. exhibited the most effective in inhibiting DENV-2 infection at co-infection conditions where the virus was exposed to the extract at the time of infection. Treatment of the extract significantly reduced the ability of DENV to bind to the host cells to 47.87 ± 3.88 % while treatment upon virus binding step had no anti-viral effect suggesting the underlaying mechanism of the extract on interfering virus binding step. Fucoidan, a key bioactive substance in Sargassum polysaccharide, showed to reduce DENV-2 infection to 26.59 ± 5.01 %, 20.46 ± 6.58 % in co-infection condition in Vero cells and A549 cell line, respectively. In accompanied with Sargassum polysaccharide, fucoidan disturbed the virus binding to the host cells. These findings warrant further development and exploration of the Sargassum-derived polysaccharide, fucoidan, as a promising candidate for combating DENV infections.

Influences of different ultrasonic treatment intensities on the molecular chain conformation and interfacial behavior of sugar beet pectin

In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil-water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.

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.

Thermomechanically micronized sugar beet pulp: Emulsification performance and the contribution of soluble elements and insoluble fibrous particles

In this work, thermomechanically micronized sugar beet pulp (MSBP), a micron-scaled plant-based byproduct comprised of soluble elements (∼40 wt%) and insoluble fibrous particles (IFPs, ∼60 wt%), was used as a sole stabilizer for oil-in-water emulsion fabrication. The influence of emulsification parameters on the emulsifying properties of MSBP was investigated, including emulsification techniques, MSBP concentration, and oil weight fraction. High-speed shearing (M1), ultrasonication (M2), and microfludization (M3) were used to fabricate oil-in-water emulsions (20% oil) with 0.60 wt% MSBP as stabilizer, in which the d_4,3 value was 68.3, 31.5, and 18.2 μm, respectively. Emulsions fabricated by M2 and M3 (higher energy input) were more stable than M1 (lower energy input) during long-term storage (30 days) as no significant increase of d_4,3. As compared to M1, the adsorption ratio of IFPs and protein was increased from ∼0.46 and ∼0.34 to ∼0.88 and ∼0.55 by M3. Fabricated by M3, the creaming behavior of emulsions was completely inhibited with 1.00 wt% MSBP (20% oil) and 40% oil (0.60 wt% MSBP), showing a flocculated state and could be disturbed by sodium dodecyl sulfate. The gel-like network formed by IFPs could be strengthened after storage as both viscosity and module were significantly increased. During emulsification, the co-stabilization effect of the soluble elements and IFPs enabled a compact and hybrid coverage onto the droplet surface, which acted as a physical barrier to endow the emulsion with robust steric repulsion. Altogether, these findings suggested the feasibility of using plant-based byproducts as oil-in-water emulsion stabilizers.

Valorizing protein-polysaccharide conjugates from sugar beet pulp as an emulsifier

Inspired by the emulsion stability of sugar beet pulp pectin, the hydrophobic protein fraction in sugar beet pulp (SBP) is expected to feature high interfacial activity. This work retrieved alkaline extracted protein-polysaccharide conjugates (AEC) from partially depectinized SBP by hot alkaline extraction. AEC was protein-rich (57.20 %), and the polysaccharide mainly comprised neutral sugar, which adopted a rhamnogalacturonan-I pectin-like structure. The hydrophobic polypeptide chains tangled as a dense 'core' with polysaccharide chains attached as a hydrated 'shell' (hydrodynamic radius of ~110 nm). AEC could significantly decrease the oil-water interfacial tension (11.58 mN/m), featuring superior emulsification performance than three control emulsifiers, especially the excellent emulsifying stability (10 % oil) as the emulsion droplet size of 0.438 and 0.479 μm for fresh and stored (60 °C, 5 d) emulsions, respectively. The relationship of molecular structure to emulsification was investigated by specific enzymic modification, suggesting the intact macromolecular structure was closely related to emulsifying activity and that the NS fraction contributed greatly to emulsifying stability. Moreover, AEC was highly efficient to stabilize gel-like high internal phase emulsions (oil fraction 0.80) with low concentration (0.2 %) and even high ionic strength (0-1000 mM). Altogether, valorizing AEC as an emulsifier is feasible for high-value utilization of SBP.

Enhancing the Emulsification and Photostability Properties of Pectin from Different Sources Using Genipin Crosslinking Technique

Pectin is a potential polysaccharide-based emulsifier, but the stabilized emulsions suffer from insufficient emulsion stability. Therefore, modification is needed to enhance its emulsification performance to cater to practical applications. The genipin-crosslinking strategy was used in this work to modify pectin with different sources and extraction conditions. Chemical composition analysis, molecular weight (Mw), and radius of gyration (Rg) measurement revealed that sugar beet pectin (SBP) has a more compact and flexible conformation than commercial citrus pectin (CP) and apple pectin (AP), indicated by the significantly (p < 0.05) larger Mw/Rg of SBP (18.1−11.3 kg/mol/nm) than CP (8.3 kg/mol/nm) and AP (8.0 kg/mol/nm). Crosslinking modification significantly increased the Mw, radius of gyration, and viscosity. This significantly (p < 0.05) improved the emulsifying stability (a smaller increase in droplets size) by the contribution of both thicker adsorbed hydrated layers at the oil-water interface with a stronger steric-hindrance effect and larger viscosity effect to slow down droplet collision. The formation of a blue-black substance from crosslinking reaction was able to block the UV radiation, which significantly improved the photostability of β-carotene-loaded emulsions. Altogether, genipin-crosslinking is feasible to modify pectin of different sources to enhance the emulsion stability and for use as a vehicle for delivering bioactive compounds.

Development of Millettia speciosa champ polysaccharide conjugate stabilized oil-in-water emulsion for oral delivery of β-carotene: Protection effect and in vitro digestion fate

In this study, a natural antioxidant emulsifier, Millettia speciosa Champ polysaccharide conjugates (MSC-PC), was used for fabricating oil-in-water emulsion, and the influences of MSC-PC on β-carotene stability and bioaccessibility were studied. Results suggested that MSC-PC stabilized emulsion exhibited excellent resistance to a wide range of salt levels (0-500 mM of Na⁺), thermal treatments (50-90 °C) and pH values (3.0-11.0). MSC-PC also exhibited an outstanding inhibition capacity on lipid oxidation. Besides, MSC-PC stabilized emulsion had a better protective effect on β-carotene than other systems. Interestingly, in spite of similar lipolysis extent, β-carotene bioaccessibility in MSC-PC fabricated emulsion (14.75 %) was markedly higher than that in commercial Tween 80 fabricated emulsion (10.08 %), likely due to the steric-hindrance effect and antioxidant ability of MSC-PC, building interfacial layers that prevented β-carotene from degradation. This work supplied a deep insight into elucidating the mechanisms of emulsifying performance and β-carotene protection effect of MSC-PC fabricated emulsion.

Physicochemical properties of whey protein isolate and alkaline soluble polysaccharide from sugar beet pulp conjugates formed by Maillard reaction and genipin crosslinking reaction: A comparison study

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Emulsifying activity of ASP2 was obviously improved by graftingwith WPI.

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ASP2 self-crosslinking could be excuted by both maillard reaction and genipin crosslinking reaction.

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WPI linked with carbonyl group contributed more efficiency to emulsifying activity of PPC than linked with amino group of ASP2.

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Calcium bridge effect could not be efficiently inhibited by grafting ASP2 with WPI.

This study aim to investigate the effect of alkaline soluble polysaccharide from sugar beet pulp (ASP2) grafted with whey protein isolate (WPI) by two linking models (grafting on amino group or carbonyl group) on its emulsifying properties. Results demonstrated that the d_4,3 value of WPI, M−AW, M−AA, G-AW and G-AA stabilized emulsions was 0.18 μm, 0.28 μm, 0.72 μm, 0.56 μm and 0.83 μm, respectively, suggesting the higher emulsifying activity of the products prepared by Maillard reaction compared with the products obtained from genipin crosslinking reaction. After storage, the d_4,3 increment was 1.05 μm, 0.21 μm, 0.31 μm, 0.2 μm and 0.15 μm for WPI, M−AW, M−AA, G-AW and G-AA stabilized emulsions, respectively, indicating that the new generated polymers held stronger emulsifying stability compared with WPI. However, the aggregates emerged in high calcium emulsions system indicated that grafting with WPI could not efficiently reduce the sensitivity of ASP2 to calcium.

Effects of isolation conditions on structural and functional properties of the seed gum from Chinese quince (Chaenomeles sinensis)

Chinese quince seed gum (CQSG) extracted under water-, alkali- and acid- conditions at 25, 50, and 80 °C, were evaluated in terms of yield, monosaccharide composition, molecular distribution, thermal gravimetry, emulsifying stability, rheological properties, and free radical scavenging ability. The results showed that the yield of CQSG increased to 3.9% after water extraction at 80 °C. Alkali and acid treatments promoted the conversion of neutral sugars to the uronic acid branch. Regardless of the extraction temperature, the xylose chain was the main component (35%-40%); however, a reduction was observed as the extraction temperature increased to 80 °C. All CQSG solutions extracted under these isolation conditions exhibited non-Newtonian rheological behavior. Compared to water-extracted samples, the alkali-extracted samples showed the worst thermal stability, while the acid-treated samples showed the worst emulsifying stability. This study provides theoretical support for the potential application of CQSG polysaccharides in the food and pharmaceutical industries.

Transformation of Inferior Tomato into Preservative: Fermentation by Multi-Bacteriocin Producing Lactobacillus paracasei WX322

Loss and waste of postharvest vegetables are the main challenges facing the world’s vegetable supply. In this study, an innovative method of value-added transformation was provided: production of bacteriocin from vegetable waste, and then its application to preservation of vegetables. Antibacterial activity to soft rot pathogen Pectobacterium cartovorum (Pcb BZA12) indicated that tomato performed best in the nutrition supply for bacteriocin production among 12 tested vegetables. Moreover, the antibacterial activity was from Lactobacillus paracasei WX322, not components of vegetables. During a fermentation period of 10 days in tomato juice, L. paracasei WX322 grew well and antibacterial activity reached the maximum on the tenth day. Thermostability and proteinase sensitivity of the bacteriocin from tomato juice were the same with that from Man-Rogosa-Sharpe broth. Scanning electron microscope images indicated that the bacteriocin from tomato juice caused great damage to Pcb BZA12. At the same time, the bacteriocin from tomato juice significantly reduced the rotten rate of Chinese cabbage from 100% ± 0% to 20% ± 8.16% on the third day during storage. The rotten rate decrease of cucumber, tomato, and green bean was 100% ± 0% to 0% ± 0%, 70% ± 14.14% to 13.33% ± 9.43%, and 76.67% ± 4.71% to 26.67% ± 4.71%, respectively. Bacteriocin treatment did not reduce the rotten rate of balsam pear, but alleviated its symptoms.

Dietary pectic substances enhance gut health by its polycomponent: A review

Pectic substances, one of the cell wall polysaccharides, exist widespread in vegetables and fruits. A surge of recent research has revealed that pectic substances can inhibit gut inflammation and relieve inflammatory bowel disease symptoms. However, physiological functions of pectins are strongly structure dependent. Pectic substances are essentially heteropolysaccharides composed of homogalacturonan and rhamnogalacturonan backbones substituted by various neutral sugar sidechains. Subtle changes in the architecture of pectic substances may remarkably influence the nutritional function of gut microbiota and the host homeostasis of immune system. In this context, developing a structure-function understanding of how pectic substances have an impact on an inflammatory bowel is of primary importance for diet therapy and new drugs. Therefore, the present review has summarized the polycomponent nature of pectic substances, the activities of different pectic polymers, the effects of molecular characteristics and the underlying mechanisms of pectic substances. The immunomodulated property of pectic substances depends on not only the chemical composition but also the physical structure characteristics, such as molecular weight (M_w ) and chain conformation. The potential mechanisms by which pectic substances exert their protective effects are mainly reversing the disordered gut microbiota, regulating immune cells, enhancing barrier function, and inhibiting pathogen adhesion. The manipulation of pectic substances on gut health is sophisticated, and the link between structural specificity of pectins and selective regulation needs further exploration.

Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure-activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug-target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

Preparation, characterization, antioxidant and antiglycation activities of selenized polysaccharides from blackcurrant

An ultrasound-assisted enzymatic method was used to extract the polysaccharides from blackcurrant fruits (BP), and then a nitric acid-sodium selenite method was employed to prepare twelve kinds of selenized blackcurrant polysaccharides (SBPs). Among them, SBP-1, SBP-2 and SBP-3 with different selenium contents of 250 ± 11, 312 ± 15 and 643 ± 24 μg g⁻¹, displayed relatively higher 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) scavenging activities than the others. After treating with a Sepharose-6B chromatography column, the purified blackcurrant polysaccharide (PBP) and three selenized polysaccharides (PSBP-1, PSBP-2, PSBP-3) with high purity were obtained. Compared with PBP, PSBPs possessed a larger absolute value of zeta potential (ZP) and smaller particle size, indicating the positive influence of selenized modification on physical stability of polysaccharides. Ultraviolet (UV), Fourier transform infrared (FT-IR) and circular dichroism (CD) spectra confirmed that selenium had been introduced onto the polysaccharide structure. X-ray diffraction (XRD) and I₂–KI reaction results indicated that selenized modification did not cause an obvious change in crystal form and branch structure of blackcurrant polysaccharides. In addition, PSBPs were superior to PBP in antioxidant and antiglycation capacities, and the bioactivities of PSBPs were significantly improved in positive correlation with selenium content. This study suggested that PSBPs may be a potential selenium source and serve as functional food and medicine.

An ultrasound-assisted enzymatic method was used to extract the polysaccharides from blackcurrant fruits (BP), and then a nitric acid-sodium selenite method was employed to prepare twelve kinds of selenized blackcurrant polysaccharides (SBPs).