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The structure of ethanol precipitated fraction from 1 M KOH extracted flaxseed kernel polysaccharides (KPI-EPF) was studied for better understanding the molecular structures of flaxseed kernel cell wall polysaccharides. Based on methylation/GC–MS, NMR spectroscopy, and MALDI-TOF-MS analysis, the dominate sugar residues of KPI-EPF fraction comprised of (1,4,6)-linked-β- d -glucopyranose (24.1 mol%), terminal α- d -xylopyranose (16.2 mol%), (1,2)-α- d -linked-xylopyranose (10.7 mol%), (1,4)-β- d -linked-glucopyranose (10.7 mol%), and terminal β- d -galactopyranose (8.5 mol%). KPI-EPF was proposed as xyloglucans: The substitution rate of the backbone is 69.3%; R 1 could be T-α- d -Xylp-(1→, or none; R 2 could be T-α- d -Xylp-(1→, T-β- d -Galp-(1 → 2)-α- d -Xylp-(1→, or T-α- l -Araf-(1 → 2)-α- d -Xylp-(1→; R 3 could be T-α- d -Xylp-(1→, T-β- d -Galp-(1 → 2)-α- d -Xylp-(1→, T-α- l -Fucp-(1 → 2)-β- d -Galp-(1 → 2)-α- d -Xylp-(1→, or none. The Mw of KPI-EPF was calculated to be 1506 kDa by static light scattering (SLS). The structure-sensitive parameter (ρ) of KPI-EPF was calculated as 1.44, which confirmed the highly branched structure of extracted xyloglucans. This new findings on flaxseed kernel xyloglucans will be helpful for understanding its fermentation properties and potential applications. [ABSTRACT FROM AUTHOR]

In this study, the structural information (monosaccharide compositions, molecular weight parameters & FTIR analysis), chemical composition (moisture, protein, ash, carbohydrate & uronic acids), rheological properties, and surface activity of Lallemantia royleana seeds mucilage (BSG) were determined. The results showed BSG contains 8.51% (w.b.) moisture, 8.24% (d.b.) ash, 2.71% (d.b.) protein, 75.87% (d.b.) carbohydrate and 20.33% (d.b.) uronic acids. Monosaccharide analysis revealed the presence of arabinose (37.88%), galactose (33.54%), rhamnose (18.44%), xylose (6.02%) and glucose (4.11%) in the BSG polysaccharide. Although BSG had similar molecular weight (1.294 × 10 6 Da) compared to most seed gums, the intrinsic viscosity (23.06 dL/g) and gyration radius (104.84 nm) were higher. The BSG exhibited a strong shear-thinning behavior ( n < 0.29) over the shear rate range of 0.01 to 1000 s −1 . Flow behavior data was correlated with different time-independent models, which provided a good description of BSG rheological properties. Dynamic mechanical spectra demonstrated BSG is a typical of weak gel, which its rheological parameters were superior to those of many commercial gums. The FTIR spectra of the BSG polymer showed the presence of carboxyl groups, which may serve as binding sites for ions. BSG exhibited the ability to reduce the surface tension of water at concentrations lower than 0.75%. [ABSTRACT FROM AUTHOR]

The processing parameters for making a Maillard reaction product (SPPMP) from soy protein isolate (SPI) and soy soluble polysaccharide (SSPS) were studied against the yield of the product and its emulsification capacity in an oil-in-water emulsion. The optimized SPPMP was produced by dry-heating the SPI-SSPS mixture (SPP) at a ratio of 3:5, temperature of 60 °C and 75% relative humidity for 3 days. The formation of SPI-SSPS conjugates was confirmed by gel electrophoresis, FTIR spectroscopy and high performance size exclusion chromatography. The citral (10 wt%) oil-in-water emulsions stabilized by SPPMP exhibited superior physical stability than those stabilized by SPI or SPP during prolonged storage, after thermal treatment or under simulated gastrointestinal conditions. At pH 7.0, all the emulsions studied exhibited monomodal particle size distribution initially, however, only those stabilized by SPPMP remained monomodal distribution for up to 70 days during storage at 25 °C. The SPPMP-stabilized emulsion maintained its physical stability to the thermal treatment at 95 °C for 30 min or under simulated gastric conditions for 2 h; while the emulsions stabilized by SPI or SPP exhibited various degrees of instability. The release rate of citral from the emulsion droplets was found inversely related to the stability of emulsion. The emulsion droplets retained approximately 70% of citral after 2 h incubation in simulated gastric fluid, whereas, complete release of citral from the droplets occurred in 4 h in simulated intestinal fluid. These results indicate that SPPMP-stabilized emulsions have a good potential as a carrier system for intestinal delivery of hydrophobic compounds such as citral. [ABSTRACT FROM AUTHOR]

As part of a series of studies on the bioactivities and structures of polysaccharides from Dendrobium officinale , this study investigates the immunomodulatory activities of Dendrobium officinale and its two polysaccharide fractions (crude and purified, respectively) in cyclophosphamide induced mice. All three materials protected the body from immunosuppression in a dose-dependent manner. Biological activities related to immunomodulations investigated included stimulating the proliferation of splenocytes, balancing the ratio of spleen lymphocyte subsets and the secretion of serum cytokines, up-regulating the serum IgM, IgG and haemolysin formation, and accelerating the phagocytotic function of peritoneal macrophage. The degree of modulations were higher in purified Dendrobium officinale polysaccharide than crude polysaccharide, indicating that the purified polysaccharide was one of the key bioactive components in Dendrobium officinale , the main structure of which has been identified as O-acetyl-glucomannan (Dendronan) [ABSTRACT FROM AUTHOR]

Main objective of this study was to investigate the detailed structural information about O -acetylated sugar residues in Dendronan ® . A water solution (2%, w/w) of Dendronan ® was treated with endo-β-mannanase to produce oligosaccharides rich in O -acetylated sugar residues. The oligosaccharides were partly recovered by ethanol precipitation (70%, w/w). The recovered sample (designated Hydrolyzed Dendrobium officinale Polysaccharide, HDOP) had a yield of 24.7% based on the dry weight of Dendronan ® and was highly O -acetylated. A D 2 O solution of HDOP (6%, w/w) generated strong signals in 1 H, 13 C, 2D 1 H– 1 H COSY, 2D 1 H– 1 H TOCSY, 2D 1 H– 1 H NOESY, 2D 1 H– 13 C HMQC, and 2D 1 H– 13 C HMBC NMR spectra. Results of NMR analyses showed that the majority of O -acetylated mannoses were mono-substituted with acetyl groups at O-2 or O-3 position. There were small amounts of mannose residues with di- O -acetyl substitution at both O-2 and O-3 positions. Minor levels of mannoses with 6- O -acetyl, 2,6-di- O -acetyl, and 3,6-di- O -acetyl substitutions were also identified. Much information about sugar residue sequence was extracted from 2D 1 H– 13 C HMBC and 2D 1 H– 1 H NOESY spectra. 1 J C–H coupling constants of major sugar residues were obtained. Evidences for the existence of branches or O -acetylated glucoses in HDOP were not found. The major structure of Dendronan ® is shown as follows: [ABSTRACT FROM AUTHOR]

Citral is an important essential oil with antibacterial activities, but its use as an antibiotic alternative is limited due to its physical and chemical instability during processing and in biological systems such as the gastrointestinal tract of animals. This study aimed to investigate the capacity of a soy protein–polysaccharide Maillard reaction product (SPPMP) to stabilize citral in an oil-in-water emulsion system. The retention rates of citral in the emulsions during long time storage, upon heating and under simulated gastrointestinal conditions were determined. The results showed that SPPMP-stabilized emulsions demonstrated outstanding ability to stabilize citral under all challenge conditions as compared to emulsions stabilized by soy protein only, or by physical mixtures of soy protein and polysaccharide. Therefore, SPPMP-stabilized emulsions could potentially be used as protectors and carriers for targeted delivery of citral or other hydrophobic compounds to animal/human intestines. [ABSTRACT FROM AUTHOR]

Non-starch polysaccharides (GSP) from roots of American ginseng were extracted and purified. The physicochemical properties and detailed structure of GSP was systematically studied using high performance size-exclusion chromatography (HPSEC), Fourier transform infrared spectroscopy (FTIR), methylation analysis and 1D & 2D NMR spectroscopy. Weight average molecular weight (Mw) and intrinsic viscosity of GSP was 85.4 kDa and 0.41 dL/g, respectively. Monosaccharide composition analysis indicated that GSP consisted of rhamnose, arabinose, galactose, glucose and uronic acid with a weight ratio of 1:4:8:8:50. The dominate component in GSP was galacturonic acid (up to 70% in molar ratio) based on methylation analysis. FTIR demonstrated that GSP had pectin based structure and the degree of esterification (DE) was calculated to be 38%. Based on 1D & 2D NMR spectroscopy, the major sugar residue of GSP molecule was 4-α-D-Gal p A, other residues including 2-α-L-Rha p , 2,4-α-L-Rha p , α-L-Ara f , β-D-Gal p , 4-β-D-Gal p were also evidenced in GSP. As a pectin molecule, GSP contained mainly homogalacturonans structure, while a small portion of rhamnogalacturonan I character was also identified. [ABSTRACT FROM AUTHOR]

Highlights: [•] A pectic polysaccharide was purified from Mosla chinensis Maxim. cv. Jiangxiangru. [•] Structural characterization of MP-A40 was elucidated by methylation and 1D/2D NMR. [•] The backbone of MP-A40 was 1,4-linked α-d-GalpA and 1,4-linked α-d-GalpA6Me (32%). [•] MP-A40 could inhibit the growth of K562 cells. [•] MP-A40 increased production of NO from RAW264.7 in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the physico-chemical characteristics of sage seed gum (SSG) were determined in terms of chemical compositions (moisture, total protein, total ash, minerals, total carbohydrate, total uronic acids), rheological properties, and surface activity. Monosaccharide compositions, molecular weight parameters and FTIR analysis also provided further structural information on the polysaccharide gum. The SSG had, on average, 11.24% (w.b.) moisture, 9.20% (d.b.) ash, 2.08% (d.b.) protein, 69.01% (d.b.) carbohydrate and 30.2% uronic acids. Mineral content of SSG was comparable to commercial gums except for potassium content which was higher in SSG. The chromatographic and FTIR analyses revealed that the SSG polysaccharide is a galactomannan with a 1.78–1.93:1 mannose/galactose ratio and a weight average molecular weight of ∼4 × 105 Da. Although SSG exhibited lower molecular weight and radius of gyration compared to guar gum, the values of intrinsic viscosity were the same. Under steady and dynamic shear tests, SSG demonstrated a strong shear-thinning behavior and a typical of weak gel characteristic, respectively, which were more pronounced than most commercial gums. The FT-IR spectra of the SSG polymer showed the presence of carboxyl groups, which may serve as binding sites for ions. SSG exhibited the ability to reduce the surface tension of water at concentrations lower than 0.25%. The current study provides new information on sage seed gum, which will be invaluable for explaining its unique functional properties. [Copyright &y& Elsevier]

Abstract: Flaxseed (Linum usitatissimum L.) is rich in soluble and insoluble dietary fibres. Recent study in our research group discovered that the kernel of flaxseed contained about 20% (w/w) of dietary fibres, which has not been reported before. Scanning electron microscope (SEM) images revealed that flaxseed kernel dietary fibres (FKDF) are mostly in the supporting structure of the cell walls. To study the structure and physicochemical properties of FKDF, a modified sequential extraction and fractionation procedure was utilised, and five separate FKDF fractions were obtained as flaxseed kernel (FK) water-extracted polysaccharides (FK-WP), FK EDTA-extracted polysaccharides (FK-EP), FK Na2CO3-extracted polysaccharides (FK-NP), FK 1M KOH-extracted polysaccharides (FK-KPI), and FK 4M KOH-extracted polysaccharides (FK-KPII). FKDF fractions were all water-soluble. The average molecular weight of FK-WP was 486kDa, FK-EP 593kDa, FK-NP 704kDa, FK-KPI 770kDa, and FK-KPII 1660kDa. Monosaccharide compositions were different among FKDF fractions; alkaline solution extracted FKDF fractions had relatively higher percentage of arabinose, but relatively lower content of glucose compared with FK-WP and FK-EP. All FKDF fractions had the ability to lower the surface tension of water, among which FK-KPI exhibited the best surface activity. Rheological properties showed that FKDF fractions had low viscosity and 2% (w/v) FKDF water solution exhibited viscoelastic behaviour at 25°C. Those findings could benefit the related food industries for providing healthier and more value-added flaxseed products. [Copyright &y& Elsevier]

Highlights: [•] Theaflavins presents good affinity to bind to human α-Amylase. [•] Theaflavins interacted with side chain of Asp300 with hydrogen bonds and van der waals forces. [•] The galloylated theaflavin has higher binding affinity with α-Amylase than non-galloylated theaflavin. [Copyright &y& Elsevier]

Abstract: Soy whey protein isolate (SWPI)–fenugreek gum conjugates were prepared by Maillard type reactions in a controlled dry state condition (60 °C, 75% relative humidity for 3 days) to improve emulsification properties. SDS-PAGE electropherogram showed that conjugation formed high molecular weight products with the disappearance of 7S fraction, acidic subunits of the 11S fractions and protein band at molecular weight 21 and 24 kDa. However, the amount of protein at molecular weight 30 kDa remained unchanged. The protein solubility of SWPI–fenugreek gum conjugates improved as compared to SWPI and SWPI–fenugreek gum non-conjugated mixture especially at isoelectric point of protein when assessed in the pH range 3–8 at 22 °C. In comparison to SWPI, fenugreek gum and non-conjugated SWPI–fenugreek gum, SWPI–fenugreek gum conjugates had better emulsifying properties near the isoelectric pH of protein. Emulsification at near the isoelectric pH of protein was chosen as at this pH the proteins are prone to aggregate, which could destabilize the emulsion. Heating solutions of the conjugates prior to emulsification further improved their emulsification properties. The conjugates also showed a better emulsifying property at high salt concentration as compared to SWPI alone. [Copyright &y& Elsevier]

Abstract: Soy whey protein isolate (SWPI)–fenugreek gum (hydrolyzed and unhydrolyzed) conjugates were prepared by Maillard-type reaction in a controlled dry state condition (60 °C, 75% relative humidity for 3 days) to improve emulsification properties. Fenugreek gum was partially hydrolyzed using 0.05 M HCl at 90 °C for 10 min (HD10), 30 min (HD30) and 50 min (HD50) to examine if molecular weight had an effect on the emulsifying properties. The formation of SWPI–fenugreek gum conjugates was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Measurements of particle size distribution and average particle size have shown that conjugation of SWPI–fenugreek gum at 60 °C for 3 days was enough to produce relatively small droplet sizes in oil-in-water (o/w) emulsions. A ratio of 1:3 and 1:5 of SWPI:fenugreek gum was more effective in stabilizing emulsion compared to 1:1 ratio. Unhydrolyzed fenugreek gum conjugates exhibited better emulsifying properties compared to partially hydrolyzed fenugreek gum conjugates. The order of the conjugates in lowering the particle size of emulsions was as follows: SWPI–unhydrolzed fenugreek gum > SWPI–HD10 > SWPI–HD30 > SWPI–HD50. [Copyright &y& Elsevier]

Abstract: The structure of acidic fraction gum (AFG) from flaxseed hulls was elucidated by methylation analysis and 1D/2D NMR spectroscopy. This acidic fraction was separated from water-soluble flaxseed gum using anion-exchange chromatography. AFG consisted of a rhamnogalacturonan-I (RG-I) backbone that features diglycosyl repeating units, →2)-α-l-Rhap-(1→4)-α-d-GalpA-(1→. Rhamnosyl residues (38.2%) were the most abundant neutral sugar component. It was present mainly as unbranched (16.5%) and branched (19.5%) →2)-α-l-Rhap-(1→ at O-3. Most of its branches were terminated by monosaccharides, α/β-d-Galp-(1→ (19.6%), α-l-Fucp-(1→ (4.5%) or β-d-Xylp-(1→ (3.1%). However, when this branching site was occasionally appended with →4)-α-d-GalpA-(1→ or →2)-α-l-Rhap-(1→, side chains may consist of rhamnogalacturonan-I (RG-I), homorhamnan (HR) or a mixture of both. AFG was highly branched as indicated by its high degree of branching (0.55). A possible structure of AFG was proposed: ▪ (HR, RG-I, and HG refer to homorhamnan, rhamnogalacturonan-I, and homogalacturonan, respectively. The locations of HR, RG-I, and HG are interchangeable; (m+n)/(n+i)≈1.5. The substitution rate of R1 is ∼54%. R1 is mostly monosaccharide (α/β-d-Galp-(1→, α-l-Fucp-(1→ or β-d-Xylp-(1→). R1 may also occasionally be a longer side chain with more than two residues beginning with →4)-α-GalpA-(1→ or →2)-α-l-Rhap-(1→, wherein the side-chain structure may be similar to part of the main chain.) [Copyright &y& Elsevier]

Abstract: The glycoprotein structure of gum ghatti was investigated. The covalent bonding between polysaccharides and proteins was firstly confirmed by high performance size exclusion chromatography (HPSEC) using refractive index (RI) and UV detectors. Partial acid hydrolysis and enzymatic degradation were also utilized. Several structural fragments such as AraHex2-HexA-HexNAc, Hex4HexNAc2, AraHex4HexNAc, Hex10HexNAc and Hex4HexNAc-Asn were identified from MALDI-TOF spectrum; using 1D and 2D NMR spectra, the linkage site of amino acids and polysaccharides was determined as N-linked (Hex)n-GlcNAc-Asn. Combined with the polysaccharide structure obtained before, a glycoprotein structure model was proposed. It was composed of 1,6-linked galactose backbone, which were attached by numerous of sugar side chains and peptide chains. [Copyright &y& Elsevier]

Abstract: An acidic polysaccharide (APS) was extracted from the boat-fruited sterculia seeds (Semen Sterculiae Lychnophorae). It consisted mainly of galacturonic acid (40.1%, w/w) along with rhamnose, arabinose, galactose, xylose and glucose as minor components, indicating a pectic polysaccharide which was confirmed by FT-IR spectra. The degree of esterification of APS determined by FT-IR method was 68%. The shear-thinning and viscoelastic behaviors of APS have been investigated by steady shear and small amplitude oscillatory experiments, respectively. Steady-shear rheological measurement in a range of shear rate (1–1000s−1) showed increase in pseudoplasticity (or non-Newtonian shear-thinning flow behavior) with the increase in APS concentration (1.0–10%, w/v). APS itself could not form a gel; however, thermal irreversible gels were obtained in the presence of sucrose at low pH (pH<3.5). The changes in storage modulus G′ and loss modulus G″ during heating and cooling cycles indicated that G′ was nearly reversible at temperature >30°C while G″ exhibited thermal hysteresis. [Copyright &y& Elsevier]

Abstract: Using 60% (w/v) ammonium sulfate precipitation, a heteropolysaccharide (designated 60S), with relatively low molecular weight (38.7kDa), was isolated from the seeds of Artemisia sphaerocephala Krasch. The structural properties of 60S were elucidated by partial acid hydrolysis, methylation analysis, 1D and 2D NMR spectroscopy, and MALDI-TOF-MS. The results of the partial acid hydrolysis and methylation analysis indicated that the main chain of 60S consisted of (1→4)-linked d-Manp and (1→4)-linked d-Glcp in a molar ratio of 1:1.3. Over half of the glucosyl residues in the main chain were branched at the O-6 position. The terminal sugar residues were mainly composed of T-Araf, T-Arap, T-Galp, T-GlcpA, and T-Glcp. Besides, 3-Araf and 2-Galp were also observed in comparable amounts. Based on all the aforementioned results and the data obtained by 1D and 2D NMR spectroscopy as well as MALDI-TOF-MS, a structure of 60S is proposed as follows: ▪ R could be one or some of -(3-α-Araf) n -(A), T-α-Galp (B), T-α-Glcp (C), T-Araf (H) or T-Arap. [Copyright &y& Elsevier]

Abstract: Molecular modelling was used to study the conformational properties of cereal β-glucans and compared with experimental results. Followed the steps of exploring global minima of β 1-4 and β 1-3 linked disaccharides and building up the repeating units, the consecutive cellotriosyl units, which are considered as reaction sites of β-glucan chains, were created and then characterized as a three fold helix with a pitch of 41.35 Å. Mostly importantly, the 3D molecular model of cereal β-glucans was created and the moderately extended sinuous chain conformation was first visualized. The conformational parameters of cereal β-glucans were calculated by RMMC simulation, which are in good agreement with experimental results. The calculated parameters also revealed that the chain stiffness of β-glucans increased with the tri/tetra ratio. [Copyright &y& Elsevier]

Abstract: The structure of a water soluble arabinogalactan isolated from gum ghatti (Gatifolia SD) was elucidated by methylation analysis and 2D NMR spectroscopy. The arabinogalactan fraction (F80) was obtained by a sequential ethanol precipitation of gum ghatti (Gatifolia SD). Methylation and GC–MS analysis indicated that F80 was a highly branched polysaccharide; the terminal sugar residues were about 40.8% of the total sugars. The majority of the terminal units were α-l-Araf, with small amounts of T-GlcpA, T-Arap, T-Rhap and T-Galp. About 14.2% of the total sugar residues were →6)-β-d-Galp-(1→ branched at 3rd and 4th positions. The linear portion of the arabinogalactan was composed of →4)-GlcpA(1→, →6)-Galp(1→ and →2)-l-Araf-(1→ linkages. Based on the results from methylation analysis, 1D (1H, 13C) and 2D (COSY, TOCSY, HMQC and HMBC) NMR spectroscopy, the structure of F80 was proposed as follows: Display Omitted R is one of the following groups: →3)-β-d-Galp-(1→, →5)-β-d-Araf-(1→, →2,3-Manp1→, T-α-l-Araf 1→, T-GlcpA1→ and T-l-Arap 1→. Galactose has the -β-D configuration, while the arabinose and rhamnose are in the α-l form. [Copyright &y& Elsevier]

Abstract: This paper describes the fractionation, chemical and physical characterization of processed gum Ghatti (Gatifolia SD), and identifies the source of its surface activity. Four fractions were separated using the gradual ethanol precipitation method. With the increase of alcohol concentration, the chemical composition of the fractions exhibited a pattern: arabinose content increased, but the galactose, protein and uronic acid contents decreased in the order of: F50 (50% ethanol precipitate), F65 (65% ethanol precipitate), F80 (80% ethanol precipitate) and FS (the supernatant after 80% ethanol precipitation). Rheologically gum ghatti and its fractions exhibited Newtonian flow behavior until gum concentrations reached to 20% (w/v), at which point gum ghatti showed some shear thinning. At the same shear rate and concentration, the apparent viscosities of these fractions decreased in the order: F50 > F65 > F80 > FS. When compared at same concentration, the FS fraction had the highest surface activity relative to the Gatifolia SD, the other fractions and even gum Arabic. Monosaccharide composition and preliminary structural analysis showed that the branching of the polymer increased in the order of F50, F65 and F80. The degree of branching levels, protein and uronic acid content could be responsible for the different solubility of the fractions in alcohol. However, the molecular structure of FS is significantly different from the other fractions. FT-IR spectroscopy revealed no esterified carboxyl group in gum ghatti. Detailed structural elucidation of each fraction will follow. [Copyright &y& Elsevier]

Abstract: The structure of a globular gum ghatti fraction (FS) with low surface tension was investigated using methylation–GC–MS, 1D (1H, 13C) and 2D (COSY, TOCSY, HMQC and HMBC) NMR spectra. FS was obtained from the supernatant after sequential ethanol precipitation of aqueous gum ghatti (Gatifolia SD) solutions after 80% (v/v) ethanol. FS is proposed to be a highly branched polysaccharide with small amount of acetyl substitution: Display Omitted R can be represented by the following groups: →2,3-Manp1→, →3,4-Glcp1→, →4-Galp1→, T-α-l-Araf 1→, T-GlcpA1→,T-Galp1→ and T-l-Arap 1→. Galactose has the -β-d configuration, while the arabinose and rhamnose are in α-l form. [Copyright &y& Elsevier]

Abstract: The extraction and fractionation methods as well as the physicochemical properties of Artemisia sphaerocephala Krasch polysaccharide (ASKP) were studied. ASKP was extracted from the outer layer of the seeds with high ratio of hot water to seeds (400:1, v/w). The yield of water-soluble ASKP was 13.6% (w/w). High performance size exclusion chromatography (HPSEC) results indicated that ASKP had two components with different molecular weights. The high molecular weight (Mw, 551.3KDa) fraction 60P was separated from the low molecular weight fraction 60S (Mw, 38.7KDa) by precipitation in 60% (w/v) ammonium sulfate salt solution. Steady flow rheological tests revealed that the apparent viscosity of 1.5% (w/v) ASKP decreased logarithmically with the increasing temperature. Small strain oscillation tests suggested that 4% (w/v) 60P solution was a typical viscous fluid. ASKP was composed of 66.9% (w/w) neutral sugar and 15.8% (w/w) uronic acid; 60P comprised of 55.4% (w/w) neutral sugar and 25.8% (w/w) uronic acid, while in 60S, the percentage of neutral sugar and uronic acid were 87.1% and 10.4%, respectively. Relative monosaccharide composition analysis showed that 60S was composed of 38.3% glucose, 28.1% mannose, 24.2% galactose and 9.4% arabinose, while the 60P fraction contained 80.5% xylose, 10.9% arabinose, 5.0% glucose, 2.3% galactose and 1.2% rhamnose. 60S exhibited the highest surface activity compared to ASKP, 60P, ASKPE (ASKP with protein removed) and 60PE (60P with protein removed) although no protein was detected in this fraction. [Copyright &y& Elsevier]

Abstract: The structure of a high molecular weight heteropolysaccharide (60P) isolated from Artemisia sphaerocephala Krasch was elucidated using methylation analysis and 2D NMR spectroscopy. 60P (Mw: 551kDa) was isolated from A. sphaerocephala Krasch (ASK) seeds, using hot water extraction and ammonium sulphate salt precipitation. Methylation and GC–MS analysis indicated that 60P was mainly composed of three types of sugar residues: 4-Xylp (27.8%), 2,4-Xylp (26.0%) and T-GlcpA (22.5%); small amount of 4-GalpA, 4-Glcp, T-Araf, T-Arap and 4, 6-GalpA were also detected with comparable molar ratio. Based on the results of monosaccharide composition, methylation analysis and NMR spectroscopy, a proposed structure is shown below: Display Omitted R represents one of the following groups: T-Araf, T-Arap, T-Araf →3-Araf (1→ and T-Arap →3-Araf (1→. [Copyright &y& Elsevier]

Abstract: Water unextractable polysaccharide from bran of a Chinese black-grained wheat variety was isolated with saturated barium hydroxide as extraction medium. The fraction composed mainly of arabinose (36.53%) and xylose (61.31%), indicating the presence of pure arabinoxylans. The arabinoxylan isolates exhibited the high average molecular weight (Mw) of 3.81×105 and an intermediate Ara/Xyl (A/X) ratio of 0.60. The fraction consisted of a β-d-(1→4)-linked xylan backbone, which was mono- or disubstituted with α-l-arabinofuranosyl (Araf) groups at position O-3, O-2 or at both O-2 and O-3 positions. The xylan backbone contained a relatively high amount of unsubstituted xylopyranosyl (Xylp) residues (57.71%) and low amount of disubstituted Xylp residues (6.22%). About 22.0% of Xylp residues were monosubstituted at O-3 position. α-l-Araf side groups were prevalently (1→3)-linked to β-d-Xylp residues as single units. Moreover, small quantities of 2-, and 5-linked α-l-Araf indicated the presence of short arabinan side chains. [Copyright &y& Elsevier]

Abstract: The structure of a bioactive hydrophilic polysaccharide fraction from Cordyceps sinensis (CBHP) was studied using methylation analysis and 2D NMR spectroscopy. Monosaccharide composition analysis revealed that it consists mainly of glucose (95.19%) with trace amounts of mannose (0.91%) and galactose (0.61%). The results of methylation analysis indicated that α-1,4 linked Glcp is the main linkage type (65.7%), followed by t-Glcp (20.7%), 1,2,3,6-Glcp (4.1%), 1,2,4,6-Glcp (3.0%), 1,3,6-Glcp (2.0%), 1,4,6-Glcp (1.6%), and 1,2-Manp (1.9%) and 1,3-Galp (1.0%). Based on 1D and 2D NMR analysis, a preliminary structure is proposed: The backbone is composed of Glcp joined by 1→4 linkages and 1→3 linkages; the branching points are located at O-2 or O-6 of Glcp with α- terminal-d-Glcp as side chain. The trace amounts of 1,2-Manp and 1, 3-Galp linkages are probably located randomly in the side chains. A schematic structure is proposed as following: Display Omitted [Copyright &y& Elsevier]

Abstract: Cereal β-glucans form aggregates even in dilute aqueous solution. Their aggregation behaviours were studied by static and dynamic light scattering. It was shown that the aggregation of cereal β-glucans in aqueous solution was a very fast dynamic process and the equilibrium of molecular association and dissociation were reached quickly. The concentration dependence of the average apparent diameters of cereal β-glucans suggested that the cluster–cluster aggregation was dominant. The structural features of cereal β-glucans played an important role on their aggregation behaviours. As molecular weight increased, the degree of aggregation decreased due to the lower diffusion rate of large molecules. For the more rigid conformation (lower diffusion rate) of β-glucans with higher tri/tetra ratio, their degrees of aggregation were lower. These results suggested that the aggregation process was diffusion limited. [Copyright &y& Elsevier]

Abstract: It is more than 56 years since first used the term dietary fibre for the non-digestible constituents of plant cell walls and more than 30 years since adopted the term and suggested a definition for “dietary fibre”. Since this time there has been no accepted international regulatory definition until Codex adopted a final definition in its 2009 meeting. The sequence of these protracted discussions and consequential evolving views about dietary fibre regulatory definitions are here reviewed. The breakthrough came in the 2008 meeting of Codex when an FAO Expert Group forced the assembled countries to accept a quite different definition from the one which had been discussed and amended year after year for very many years without gaining full acceptance. The final 2009 definition represents a considerable modification from previous drafts and required compromises from FAO who did not press its proposal that dietary fibre should be defined only as intrinsic plant cell wall polysaccharides. The final outcome was heavily influenced by the EC who, frustrated at the lack of progress, had issued its own Directive on the subject (2008). The USA were still not in favour of the final decision but did not succeed in holding up the discussions again in the 2009 meeting of Codex which decided upon the following definition: Dietary fibre means carbohydrate polymers with ten or more monomeric units which are not hydrolysed by the endogenous enzymes in the small intestine of humans and belong to the following categories: [•] Edible carbohydrate polymers naturally occurring in the food as consumed, [•] carbohydrate polymers, which have been obtained from food raw material by physiological, enzymic or chemical means and which have been shown to have a physiological effect of benefit to health as demonstrated by generally accepted scientific evidence to competent authorities, [•] synthetic carbohydrate polymers which have been shown to have a physiological effect of benefit to health as demonstrated by generally accepted scientific evidence to competent authorities. Footnote 1: on lignin etc – this is pending adoption of Methods of Analysis and Sampling. Footnote 2: Decision on whether to include carbohydrates with monomeric units from 3 to 9 should be left to national authorities. The recommended methods of analysis to comply with this definition are also now in the finalisation stage. A review of the available and recommended methods has now been prepared by . These new developments place a more certain regulatory base to the commercial application for bioactive carbohydrate products. This paper describes the sequence and input of countries to the debate about the definition of dietary fibre and how eventually final agreement was achieved. [Copyright &y& Elsevier]

Abstract: The structure of the pectic polysaccharide (ASP3) isolated from roots of Angelica sinensis (Oliv.) Diels was investigated using partial acid hydrolysis, enzymic digestion combined with methylation analysis, and further supported by 1H and 13C NMR spectroscopy techniques. The results indicated that ASP3 contained a backbone of linear homogalacturonan fragments as “smooth regions” and rhamnogalacturonan fragments as “hairy regions” with repeating unit of [→4)-α-d-GalpA-(1→2)-α-l-Rhap-(1→]. A total of 58.8% rhamnopyranose residues in the backbone were substituted at O-4 position by the side chains. The side chains contained mainly β-1,6- and β-1,4-galactopyranan bearing 3,6- and 4,6-substituted β-d-galactopyranose residues as branched points and short α-1,5-arabinofuranan possessing 3,5-substituted α-l-arabinofuranose residues as branching points. In addition, β-1,6-galactopyranan side chains were highly branched with α-1,5-arabinofuranan carrying 3-O-substituents (1,3,6-Gal) and terminated by the α-arabinofuranose residues which form arabinogalactan. [Copyright &y& Elsevier]

Abstract: The strong gelling property of psyllium polysaccharides is closely related to its health benefits and applications, such as use as a binding agent in the landscape industry. However, information about gelling properties of psyllium polysaccharides is very limited. To explore the gel properties of psyllium, the alkaline extracted gel fraction (AEG) of psyllium polysaccharides was studied in this investigation. The rheological and low-temperature electron microscopy methods including cryo-scanning electron microscopy (Cryo-SEM) and freeze-substitution for transmission electron microscopy (TEM) were used to investigate Ca2+ influence on the gel properties of AEG. AEG formed a weak gel with a fibrous appearance. AEG did not have a sharp melting point and exhibited no thermal hysteresis during heating and cooling procedure. The origin of this gelling behaviour was due to the fibrillar gel structure of psyllium polysaccharide. It was found that Ca2+ had a significant influence on the gel properties and microstructure. Elastic modulus G′ of gel increased as Ca2+ concentration increased. Critical strain S at first increased and then decreased as Ca2+ concentration increased. AEG gel became more resistant to temperature change on addition of Ca2+. Psyllium gel changed to aggregated gel with added Ca2+. The strands of gel appeared thicker and the density of the junction zone increased with increasing Ca2+ concentration as revealed by SEM and TEM. The changing bulk gelling properties of psyllium polysaccharide by adding Ca2+ was attributed to the change in gel structure. [Copyright &y& Elsevier]

Abstract: A small-scale (100g) wet-milling process was used to isolate starch from commercial wheat bran at a recovery of 90%. Chemical analysis revealed that wheat bran starch contained a lower amount of protein contamination (0.15%) and damaged starch (0.15% and 1%, respectively) than commercial wheat starch (0.35% and 1.5%, respectively). Wheat bran starch contained 45% small granules compared to 15% in commercial wheat starch. Wheat bran starch also exhibited higher amylose content, higher crystallinity, and swelling power compared to commercial wheat starch. The pasting and thermo analysis revealed that wheat bran starch exhibited lower pasting peak and final viscosities, lower onset and peak gelatinization temperatures, and a lower retrogradation rate compared to those of commercial wheat starch. A positive correlation was observed between small-granule content and starch crystallinity, enthalpy, and swelling power. The enzyme digestibility experiment found that the digestibility of wheat bran starch was similar to that of commercial wheat starch, however, the resistant starch content in wheat bran starch (9.5%) was significantly higher than that in commercial wheat starch (4.3%). The unique thermo and physicochemical properties demonstrated by wheat bran starch may lead to broader applications of this novel material. [Copyright &y& Elsevier]

Abstract: Psyllium gum has been used in the landscape industry as an environmental friendly natural binder. This research is focused on the basic chemical and some physical properties of psyllium gum. Psyllium husk was extracted with hot water (80°C), and with 0.5M NaOH, 1.2M NaOH and 2.0M NaOH solutions (at room temperature), respectively, to produce a series of psyllium gum fractions labeled as water extractable (WE), 0.5M alkali extractable (AES0.5), 1.2M alkali extractable (AES1.2), and 2.0M alkali extractable (AES2.0). The alkaline extracted solutions were neutralized, during which, a gel-like precipitate was observed in the 0.5M NaOH extracted solution, which was then separated by centrifugation to give a soluble fraction (AES0.5) and a gel fraction (AEG0.5). The yields of fractions WE, AES0.5 and AEG0.5 were 18.6%, 8.7%, and 61.4%, respectively, based on the dry weight of husk. The combined yields from the 1.2 and 2.0M NaOH extracted fractions were less than 1.5%. Monosaccharide analysis revealed that WE, AES and AEG contained mainly xylose and arabinose. Substantial amounts (∼15%) of uronic acids were found in the WE and AES0.5 fractions compared to AEG0.5, which only contains neutral sugars. Methylation analysis proved that WE and AEG0.5 basically contain 1→4) and 1→3) linked β-d-xylopyranosyl residues in the main chain. The side chains are primarily composed of terminal arabinose and xylose connected to the main chain by O-3 and/ or O-2 linkage. In contrast, the backbone chain of AES0.5 fraction was mainly composed of 1→4 linked β-d-xylopyranosyl residues and the side chains only contained arabinosyl residues where were linked only through the O-3 position of the 1→4 linked β-d-xylopyranosyl residues. Further study was carried out to evaluate the particle size of the molecules in solutions by dynamic light scattering (DLS). It was found that these fractions were very soluble in 1M NaOH solutions, and the fraction AES0.5 and AEG0.5 were stable in such alkaline conditions, but slight degradation occurred for WE with time. Fraction WE also dissolved well in water, however, aggregation formed over storage. The apparent hydrodynamic diameters (d h) determined by DSL were over 100nm for all three fractions. Theses gums are of high molecular weight and can be expected to be good viscosity enhancers. The current study provided new structural information on psyllium gum, which will be helpful for explaining its unique functional properties. [Copyright &y& Elsevier]

Abstract: Response surface methodology (RSM) was applied to optimize the extraction of crude polysaccharides from boat-fruited sterculia seeds. A central composite design was used for experimental design and analysis of the results to obtain the optimal extraction conditions. Extraction temperature, pH, extraction time and water to seed ratio were found to have a significant influence on the yield and purity of the extracted crude polysaccharides, while the three other factors except the water to seed ratio also significantly affected the relative viscosity. Based on the RSM analysis, optimum conditions were: temperature 60–65°C, time 2.3–3.1h, pH at 7.0 and water to seed ratio at 75:1. Under the optimized conditions, the experimental values were in close agreement with values predicted by the model. The crude polysaccharides prepared under optimum conditions contained 58.2% total carbohydrates (including uronic acids), 20% proteins, 9% moisture and 4.5% ash. The crude polysaccharides consisted of glucose (22.6%), rhamnose (10.0%), arabinose (7.9%), galactose (5.0%), xylose (0.8%) and galacturonic acid (11.8%). [Copyright &y& Elsevier]

Crude water-soluble polysaccharides (SP) isolated from boat-fruited sterculia seeds by hot water extraction and ethanol precipitation were fractionated into a neutral polysaccharide (NSP) and an acidic one (ASP) by anion-exchange chromatography. The molecular weight, intrinsic viscosity and radius of gyration of NSP and ASP were determined by high performance size exclusion chromatography (HPSEC). NSP was rich in glucose (85.86%), with small amounts of galactose, arabinose and xylose. Whereas ASP consisted mainly of galacturonic acid (40.13%) along with rhamnose, arabinose, galactose, and small amounts of xylose and glucose, indicating a pectin-like polysaccharide which was confirmed by FT-IR spectra. Bioactivity of NSP and ASP was tested using ear edema induced by dimethylbenzene and cotton pellet-induced granuloma tissue in murine models. The results showed ASP possessed a potent dose-dependent anti-inflammatory activity. The results from the current study provided a scientific basis for the traditional use of this plant as a medical remedy for its anti-inflammation effects. [Copyright &y& Elsevier]

Abstract: The series of control Acacia senegal gums and the samples which had been matured to produce the Acacia (sen) SUPERGUM™ samples (FR-2877, FR-2878, FR-2879) described in Part 1–3 of this Series were examined by NMR, FT-IR spectroscopy. No chemical difference in any of the samples could be detected by 13C NMR or 2D NMR (COSY) spectroscopy. The 1H NMR and FT-IR spectra confirming these observations, however, showed that at the highest level of maturation to average molecular weights in excess of 2.5×106, some changes could be observed, which probably is due to dehydration of the carboxyl group (–COOH) of the uronic acid. The selection of matured gums for commercial use ensures that no observable changes in structure are evident in these gums. [Copyright &y& Elsevier]

Abstract: A high purity wheat β-d-glucan (91.58%) was obtained from white wheat bran after alkali extraction and multi-precipitation with ammonium sulphate compared to previous reported purity of only 70%. The molecular weight (M w) of the purified wheat β-d-glucan was 487,000g/mol with a broad M w distribution (polydispersity is M w/M n =1.65). By applying an ammonium sulphate gradient precipitation method, the purified wheat β-d-glucan was fractionated into six fractions with M w ranged from 43,000 to 758,000g/mol and much narrower M w distribution (polydispersity is M w/M n=1.03 to 1.26). Structural analysis revealed that there were no significant differences between the six fractions and between the fractions and the original sample. This set of sample was used to investigate the effect of M w on physical properties of wheat β-d-glucan. Dynamic rheometry and scanning calorimetric studies revealed that the gelation rate and the melting enthalpy (ΔH) of wheat β-d-glucan increased with the decrease of molecular weight indicating smaller wheat β-d-glucan molecules (must be above a minimum M w) is easier to form junction zones and establish stronger three-dimensional network due to their high mobility and structural regularity (high ratio of tri/tetra). In contrast, the melting temperature of wheat β-d-glucan gels increased with the increase of molecular weight, suggesting a more extended structural network was formed for high M w wheat β-d-glucans. [Copyright &y& Elsevier]

Abstract: Three soy protein isolates were prepared from two commercial defatted soybean flours (SG and ADM) and flour indigenously prepared from soybeans grown in Ontario (ON). Denaturation degree and protein composition of three isolates as measured by DSC and SDS–PAGE were not different significantly, but remarkable differences in ANS surface hydrophobicity and turbidity were noticed. Heat induced gelling properties of these soy protein isolates were examined by small deformation oscillatory rheological test. The critical gelling concentrations of the two isolates from commercial soy flours (SG and ADM) in distilled water were 90 mg/ml, much lower than 110 mg/ml for ON. The effect of type and concentration of salts on the gelling properties of the three protein isolates were also examined. In 1 mol/L NaCl solution, ADM had the higher gel strength than SG. It was found that the increase in gel strength of ON by addition of NaSCN was much greater than that in NaCl solution. N-Ethylmaleimide (NEM) was observed to increased the gel strength for all soy protein isolates examined despite its sulfhydryl groups blocking function. It is suggested that a non-heat aggregation of protein which led to turbidity development was responsible for the inferior gelling property of ON while the different gelling behavior between SG and ADM could be attributed to their difference in ANS surface hydrophobicity. [Copyright &y& Elsevier]

Abstract: Pectins extracted from Krueo Ma Noy (Cissampelos pareira) leaves mainly consisted of galacturonic acid with trace amount of neutral sugars. The dominant structure of Krueo Ma Noy pectin was established as a 1,4-linked α-d-galacturonan by a combination of carboxyl reduction and methylation analysis, and confirmed by FT-IR spectroscopy. The degree of esterification of Krueo Ma Noy pectins was 41.7 and 33.7% for crude and dialyzed pectins, respectively. Krueo Ma Noy pectin has an average molecular weight of 55kDa, radius of gyration of 15.2nm and intrinsic viscosity of 2.3dl/g. Krueo Ma Noy pectin exhibited gelling properties in aqueous solutions at 0.5% (w/v) at 5°C. Gels were formed at concentrations of 1.0% (w/v) and above even at room temperature. The gel strength, melting point, and melting enthalpy of Krueo Ma Noy pectin increased with polysaccharide concentration. [Copyright &y& Elsevier]

Gelling properties of soy protein–gum mixtures were determined by small deformation oscillation measurement and the experimental data were analyzed with blending laws of polymers. Gel strength of soy protein–carrageenan mixture was found to follow either upper or lower bounds depending on the concentration of the constituents, suggesting the occurring of phase shift. G′ of soy protein–xanthan mixed gel always followed the upper bound, indicating that soy protein was the continuous phase regardless variations of the gum concentration. Combination of soy protein with propylene glycol alginate (PGA) produced a mixed gel with high gel strength and stayed above the upper bound at all gum concentrations examined. Covalent bonds between PGA and soy protein was suggested to contribute to the rigidity. Storage modulus of the mixture of soy protein–locust bean gum (LBG) was below the lower bound at low gum concentrations due to the limited demixing process of LBG. G′ values of the mixture of soy protein and LBG–xanthan followed the lower bound but approached upper bound on reducing protein concentration, suggesting that the presence of soy protein might inhibit LBG–xanthan mixture from forming continuous networks. [Copyright &y& Elsevier]

Highland barley is an excellent source of dietary fiber and therefore this grain is receiving more and more popularity. The aim of this study was to improve the shelf life of highland barley by inactivating lipolytic enzyme using superheated steam (SS) with proper tempering and effects of SS processing on storage properties were compared. Results indicated that barley was stabilized by SS processing (160 °C) holding for 6 min with 6 h of tempering time could effectively reduce 38.85% lipase activity and 100% peroxides (POD) activity. Low-field nuclear magnetic resonance results showed tempering for 6 h provided proper water distribution of kernels meeting enzyme. Under the optimal conditions, highland barley maintained low free fatty acid (FFA) level and peroxide value (PV) after 8 weeks of storage and the storage quality in the form of flour has been improved more significantly than the kernels, lowing FFA levels of kernels by 15.00% and flour by 37.55%, respectively (P < 0.05). The changes of FFA composition was slowed down by SS processing after storage. Furthermore, color values and water hydration properties were altered by SS processing during the storage. In conclusions, these data highlighted the importance of SS processing, especially with proper tempering, and provided valuable information for the industry to improve the storage qualities of highland barley. • Tempering prior to SS processing was highly effective to optimize the enzyme inactivation. • Tempering time of 6 h induced much water binding to enzyme, beneficial to inactivation. • SS improved lipid stability of barely during storage in forms of both kernel and flour. [ABSTRACT FROM AUTHOR]

• Diet rosemary extract (RE) alleviated high-fat induced oxidative damage in vivo and in vitro. • Diet RE enhanced the antioxidant enzyme activity, gene and protein expression level. • The protective effect of diet RE was achieved by regulating Nrf2 pathway. Rosemary extract (RE), a useful component isolated from Rosmarinus officinalis L. , was recently reported to protect cells against the harmful effects of ROS. However, the underlying mechanisms of this action remained unknown. We investigated the defensive effect of RE on the oxidative stress injury resulted from high fat diet in hamsters and oleic acid (OA) in HepG2 cells respectively, and its underlying mechanisms. Treatment with RE alleviated liver steatosis and reduced plasma and liver content of TG and TC, as well as plasma content of AST and ALT. RE apparently increased the activity of SOD, GSH-Px, CAT and decreased MDA content. RE notably increased CuZn-SOD, Mn-SOD, CAT, GSH-Px, GCLC, GCLM and Nrf2 mRNA and protein expression level. Nrf2 shRNA knockdown in HepG2 cells increased OA-induced ROS generation, and effectively altered OA-induced cytotoxicity, suggesting that Nrf2 is a crucial mediator against high-fat induced oxidative damage. [ABSTRACT FROM AUTHOR]

Yellow mustard gum (YMG), a clean-label hydrocolloid with commercial potential, has been found to synergistically interact with κ-carrageenan to form a stronger gel. The primary gelation mechanism has been proposed but needs a thorough investigation and understanding from multiple techniques. In addition to the rheological methods of dynamic oscillation, this study used transient mechanical tests (stress relaxation), differential scanning calorimetry (DSC) and cryogenic scanning electron microscopy (cryo-SEM) to evaluate gel characteristics, thermal properties and microstructure of YMG-κ-carrageenan binary gels. The stress relaxation spectrum showed that the interactions between the two types of gums were mainly polymer associations. The DSC cooling and heating scans revealed that YMG did not disturb the coil-to-helix transition of κ-carrageenan but affected its helix aggregation during gel setting. The microstructure of the binary gel network captured by cryo-SEM showed a denser and more compact gel structure with smaller pores in comparison with the κ-carrageenan gel structure. All these results supported a refined gelation mechanism proposed in this study. This thorough investigation of the synergistic gelation between YMG and κ-carrageenan not only supports applications of the binary mixtures as texturizers, gelling aids and thickeners but also expands the application of YMG to promote its eventual commercialization. Co-gel network formed by yellow mustard gum with κ-carrageenan. [Display omitted] • Yellow mustard gum (YMG) can synergistically interact with κ-carrageenan (C). • The synergism of YMG and C occurs at a blending ratio of 3–7. • YMG does not disturb the coil-to-helix transition of C. • YMG affects the helical aggregation of C during gel setting. • YMG-C shows a denser and more compact gel structure compared to C. [ABSTRACT FROM AUTHOR]

Glucomannans (GMs) from abundant natural resources have excellent processing properties and plentiful bioactivities. In current study, functional properties of GMs with different structural characteristics, including KGM from konjac, DOP from dendrobium, AGP 40 , ASP-4N, ASP-6N, & ASP-8N from aloe were determined. Results suggested that molecular weights (M w) of GMs were positively correlated with their water absorption capacity, fat absorption capacity, and viscosity, while ratio of mannose/glucose showed negative effect. Higher degree of acetylation (DA) mainly corresponded to higher values of solubility and ζ -potential. Then, effects of the six GMs on general health status, serum biochemicals, and intestinal SCFAs production in mice were evaluated in vivo. Analysis of general health status and levels of serum biochemicals revealed that mice with consecutive supplementation of GMs for 14 days performed normally compared with those in control group. Interestingly, the productions of SCFAs (mainly acetate and butyrate) in the cecal and colonic contents were significantly promoted. Generally, higher concentrations of SCFAs were produced when mice were treated with GMs having higher M w , ratio of glucose, and DA. The current investigation suggested that both functional and intestinal fermentation property of GMs were jointly determined by the monosaccharide composition, molecular weight, and degree of acetylation. • Functional properties of GMs with different structures were compared. • The M w positively influenced viscosity and water absorption capacity of GMs. • Degree of acetylation (DA) mainly affected zeta potential and solubility of GMs. • Effects of GMs on serum biochemical and intestinal SCFAs production were evaluated. • The M w , DA, and M/G ratio were all related to production of intestinal SCFAs. [ABSTRACT FROM AUTHOR]

Glucomannans (GMs) are a group of hydrophilic polysaccharides, which have been produced from different parts of natural plants. Studies on plant-derived GMs contribute to wide applications of GMs or GMs-added products that have desirable quality and health characteristics. Among those popular GMs, konjac glucomannan (KGM) and acemannan are the most famous ones that have been widely reviewed from various points in recent years. However, there is a lack of a comprehensive review to introduce the sources, extraction and purification methods, structural features, and other aspects of GMs from common natural plants such as Aloe, Dendrobium, Bletilla, and so on. This review firstly presents the extraction and purification technologies of GMs from different plant sources, aiming at optimizing more effective production methods with specific treatments for special plant origins. After that, structural features, biological properties, as well as structure-function relationship are summarized. GMs have been widely isolated from different sectors (leaf, stem, and roots) of many plant resources. A general extraction and purification procedure together with several suggestions is put forward to prepare GMs. Although the β-(1 → 4)-linked main chain has been confirmed, detailed structural characteristics of GMs such as side chain and functional group related properties need further studies. Molecular weights, monosaccharide composition, and acetyl group of GMs are key factors that have been identified to affect plentiful biological properties such as immunomodulatory, anti-tumor, anti-diabetic activities. However, the inherent action mechanisms remain unclear. Several research interests in the future are recommended. Image 1 • Sources, methods for extraction and isolation of glucomannans are outlined. • Chemical features of glucomannans are discussed. • Glucomannans have assorted potential, but remains underdeveloped. • Structure–activity relationships of glucomannans are discussed. [ABSTRACT FROM AUTHOR]

In the present study, the effects of pentosanase (Pn) and glucose oxidase (GOX) on the properties of whole wheat steamed buns dough were investigated, including the composition, rheology, and microstructure, to reveal the effects and mechanisms of action of these two enzymes in whole wheat steamed buns making. Compared with the Control, the dough exhibited a higher content of water extractable arabinoxylan and a stronger solubility in protein in the presence of Pn. Additionally, Pn-treated dough showed high extensibility, with the gluten matrix more open and the starch granules more visible. On the other hand, the addition of GOX decreased the number of free sulfhydryls and increased the content of glutenin macropolymer (GMP), indicating the formation of disulfide bonds. Reducing SDS-PAGE of albumin and globulin suggested the generation of large protein aggregates and the conjugation of protein-polysaccharide by non-disulfide covalent bonds. The GOX-treated dough was significantly strengthened, which generated a more continuous and highly dense gluten network. Although the effects of Pn and GOX on the dough were considerably different, they both significantly changed the rheology and microstructure of the dough, due to the solubilization of water un-extractable arabinoxylan and the increase of GMP and the formation of protein-polysaccharide conjugates. These effects observed for steamed buns could be extended to other fermented flour products. [ABSTRACT FROM AUTHOR]

A water-soluble polysaccharide, named NCSP-50, was obtained from natural Cordyceps sinensis by hot water extraction and ethanol fractionation precipitation. It was eluted as a single symmetrical peak and had an average molecular weight of 9.76 × 10 5 Da. The structure was determined by monosaccharide composition, methylation analysis, 1D/2D NMR spectroscopy, and enzymatic hydrolysis and characterization of the oligosaccharides by MALDI-TOF mass spectrometry. The repeating unit of this polysaccharide was proposed as follows: Image 2 This glucan showed potent immunostimulatory activity on the basis of its significant abilities to promote macrophage proliferation, enhance NO production, as well as and cytokines (IL-1β and TNF-α) secretion. [ABSTRACT FROM AUTHOR]

The fine structure in terms of backbone and branch chain features of a bioactive polysaccharide from Ganoderma atrum (PSG-1) was re-elucidated systematically using high performance anion-exchange chromatography (HPAEC), methylation and GLC–MS analysis, and 1D & 2D NMR spectroscopy. Monosaccharide composition analysis revealed that PSG-1-F 0.2 fraction mainly consisted of glucose (73.8%) and glucuronic acid (15.3%), with small amount of mannose (5.7%) and galactose (5.2%). Based on methylation, multistep partial acid hydrolysis and NMR study, were proposed to substitute at the O -6 position of β-(1 → 3)-glucan. The small amount of mannose and galactose residues were considered to be from the other fraction in PSG which was very difficult to be separated from PSG-1-F 0.2 . This revised structure as an acidic β-(1 → 3, 1 → 6)-glucan is considered to be more accurate than the previous proposal of PSG-1. [ABSTRACT FROM AUTHOR]