Thermomechanically micronized sugar beet pulp: Dissociation mechanism, physicochemical characteristics, and emulsifying properties

Understanding the anti-browning mechanism and physicochemical properties in potato pulp during the magnetic field processing

To reduce the detrimental effects of enzymatic-browning on potato pulp quality, this study investigated the anti-browning potential of magnetic field at varying intensities. The magnetic field (4 mT) enhanced the structural integrity of potato pulp cells, with the highest hardness (119.37 g). Furthermore, the potato pulp subjected to a magnetic field treatment of 4 mT for 60 min at a temperature of 32 °C (PP-MF-4) shown an orderly macromolecular aggregation, increased viscoelastic properties of potato pulp. The PP-MF-4 demonstrated excellent anti-browning capability, as evidenced by the highest L⁎ value (59.18), reduced browning index, and lower accumulation of browning-products. Furthermore, the PP-MF-4 exhibited a significant reduction in oxidative damage, attributed to enhanced antioxidant activity and total phenolic content. Besides, the PP-MF-4 inhibited browning enzymes and improved the molecular structure orderliness. Consequently, magnetic field presents a viable approach for mitigating enzymatic-browning in potato pulp, offering a promising methods for preserving its quality.

Effect of ultrasonic pretreatment on the emulsion rheological properties and interface protein structure of epigallocatechin-3-gallate and rice bran protein complex

The effect of ultrasonic pretreatment on the emulsion rheological properties and the structural characteristics of interface-adsorbed protein (IAP) and interface-unabsorbed protein (IUP) of rice bran protein and epigallocatechin-3-gallate complex (RBP-EGCG) were studied. Compared to RBP-EGCG without ultrasonic pretreatment, appropriate ultrasonic pretreatment (ultrasonic power was 425 W) enhanced the IAP trypsin sensitivity (from 3.20 to 3.73), increased the IUP surface hydrophobicity (from 12.59 to 20.87), and decreased the ζ-potential (from -24.93 mV to -36.88 mV) and particle size (from 567.30 nm to 273.13 nm) of IUP, thereby increasing the viscosity and viscoelasticity of emulsion. Compared to appropriate ultrasonic pretreatment, high-power ultrasonic pretreatment (ultrasonic power was 500 W) attenuated the IAP trypsin sensitivity, and increased the ζ-potential and particle size of IUP, thereby decreasing the viscosity and viscoelasticity of emulsion. Overall, ultrasonic pretreatment changed the EGCG-RBP emulsion viscoelasticity by regulating spatial structural characteristics and flexibility of interface protein.

Natural protein-polysaccharide-phenol complex particles from rice bran as novel food-grade Pickering emulsion stabilizers

To develop novel food-grade Pickering emulsion stabilizers, insoluble rice bran protein-polysaccharide-phenol natural complex (IRBPPP) was prepared into Pickering emulsion stabilizers after different mechanical pretreatments (shear, high-pressure homogenization, ultrasonic, and combined mechanical pretreatment). With the increase in mechanical pretreatment types, the covalent binding of proteins and polysaccharides in IRBPPP gradually enhanced, the breakage efficiency of IRBPPP gradually increased (IRBPPP particle size decreased from 220.54 to 67.89 μm, the specific surface area of IRBPPP particle increased from 993.47 to 2033.86 cm-1/g), and the microstructure of IRBPPP gradually showed an orderly network structure, which enhanced the IRBPPP dispersion stability and the Pickering emulsion stability. Pickering emulsion stability was highly correlated (P < 0.01) with the breakage efficiency of IRBPPP particles. Overall, the combined mechanical pretreatment improved the stability of the IRBPPP-stabilized Pickering emulsion. The study added value to rice bran products and offered a new way to create stable food-grade Pickering emulsions for functional foods using natural protein-polysaccharide-phenol complex particles.

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.

Ficus awkeotsang Makino pectin in acidic environments: Insights into pectin structure, gelation behavior, and gel properties

This study demonstrated the gelation capacity, gelation behavior, and mechanism of Ficus awkeotsang Makino pectin (JFSP) in acidic media (pH 3.4-4.5). JFSP exhibited an extraordinary ability to spontaneously form a gel at a low polymer concentration (0.3 %, w/v) within the pH range of 3.75-4.05 at room temperature, without the need to introduce exogenous metal ions or co-solutes. Analysis of zeta potential and carboxyl dissociation extent revealed the protonation of free carboxyl groups within JFSP under acidic conditions. Atomic force microscopy and small angle X-ray scattering elucidated the aggregation morphology and folding conformation of JFSP. At pH 3.8, the correlation length (ξ) of JFSP chains decreased to around 1.67 nm. Rheological experiments confirmed the formation of a stronger gel network at pH 3.8 and 4.0, with good thermal and freeze-thaw stability. Isothermal Titration Calorimetry (ITC), temperature sweeps, and gelation force analyses emphasized the pivotal role of hydrogen bonds in JFSP gels at pH 3.8 and 4.0. Further reducing the pH to 3.4-3.6 disrupted the dynamic equilibrium of gel-driving forces, leading to the formation of a flocculated gel network. These findings deepen our understanding of JFSP behavior in low-acid conditions, which may be useful for further food formulations at these conditions.

Development of sorghum arabinoxylan-soy protein isolate composite nanoparticles for delivery of curcumin: Effect of polysaccharide content on stability and in vitro digestibility

The purpose of this study was to fabricate composite nanoparticles using soy protein isolate (SPI) and sorghum bran arabinoxylan (AX) for the delivery of curcumin (Cur). The influences of AX concentrations on the physicochemical characteristic, stability and bioaccessibility of curcumin were investigated. The findings showed that the encapsulation efficiency of curcumin obviously increased upon incorporating AX in comparison to SPI-Cur particles. Hydrogen bonds and hydrophobic interactions were the primary driving forces for the formation of SPI-Cur-AX nanoparticles (SCA). SCA nanoparticles with 1.00 % AX exhibited a uniform size with orderly distribution, suggesting its remarkable physical stability due to the strengthened electrostatic repulsion. However, excessive AX led to aggregation of particles, a noticeable increase in size, and subsequently, a reduction in stability. Due to the heightened free radical scavenging capacity of sorghum AX, SCA nanoparticles exhibited superior antioxidant capabilities. Compared to free curcumin, encapsulation within composite particles significantly enhanced the retention rate and bioaccessibility of curcumin. This improvement was attributed to the potent emulsification ability of AX, which coordinated with bile salt to promote the transfer of curcumin into micelles. The research provides an effective strategy for developing food-grade delivery carriers aimed at enhancing dispersibility, stability and bioaccessibility of the fat-soluble bioactives.

Co-delivery of vitamin C and β-carotene in W/O/W emulsions stabilized by modified aggregated insoluble soybean protein hydrolysate-xanthan gum complexes

Environmentally friendly emulsifiers safe for human consumption are urgently needed to stabilize emulsions for applications in the food industry. In this study, we prepared complexes combining modified aggregated insoluble soybean protein hydrolysate (AISPH) mixed with xanthan gum (XG) (0.05-0.3 %, w/v), and further to construct water-in-oil-in-water (W/O/W) emulsions to deliver vitamin C and β-carotene. We observed a decrease in the AISPH α-helix and β-sheet content, surface hydrophobicity, and fluorescence intensity all decreased after binding. In contrast, the particle size and absolute ξ-potential significantly increased, indicating that molecular non-covalent interactions occurred in the solution. The emulsification property of AISPH was also improved by adding XG, and the AISPH-XG-stabilized emulsion showed improved stability, encapsulation efficiency, and rheological properties. Among them, AISPH-XG-0.25-stabilized emulsion exhibited a smaller particle size (8.41 ± 0.49 μm) and the highest encapsulation efficiency for vitamin C (90.03 ± 0.23 %) and β-carotene (70.56 ± 0.06 %). Additionally, simulated gastric digestion indicated that vitamin C and β-carotene bioavailability increased by 3.6 and 5.8 times, respectively. Finally, the emulsion exhibited good pH, ionic, and thermal stability. In general, AISPH-XG-stabilized W/O/W emulsions showed good stability and carrying capacity, providing a theoretical basis for improving their application.

Phycocyanin/tannic acid complex nanoparticles as Pickering stabilizer with synergistic interfacial antioxidant properties

This study reported a type of phycocyanin (PC)-tannic acid (TA) complex nanoparticles (NPs) fabricated by simply mixing PC with TA at appropriate mass ratios. The assembly of PC-TA NPs was driven by secondary forces involving hydrophobic interactions and hydrogen bonding. PC-TA NPs promoted formations of Pickering emulsions with an oil volume fraction (φ) of 0.1-0.8. The interfacial antioxidant ability of PC-TA NPs was evaluated by comparing the contents of hydroperoxides, malonaldehyde, and hexanal due to lipid oxidation. The results showed that PC-TA NPs retarded lipid oxidation more efficiently than did PC, TA, tween 20, or tween 80, which suggested the synergistic antioxidant action of PC and TA. Besides, the PC-TA NPs stabilized high internal phase emulsion facilitated a higher retention of β-carotene under UV irradiation. Altogether, our findings demonstrate that the modification of PC by TA represents a strategy to fabricate PC-TA NPs with enhanced emulsification and antioxidant efficiency.

Pulsed electric field enhances glucose glycation and emulsifying properties of bovine serum albumin: Focus on polarization and ionization effects at a high reaction temperature

Previous studies demonstrated that the non-thermal effects of pulsed electric fields can promote protein glycation below 40 °C, but it does not always enhance the emulsifying properties of proteins, such as in the bovine serum albumin/glucose model. Therefore, the aim of this study was to investigate the impact of non-thermal effects on the glucose glycation and emulsification properties of bovine serum albumin at 90 °C. The results of circular dichroism, surface hydrophobicity, and molecular dynamics simulations showed that the polarization effect increased the degree of glycation of bovine serum albumin-glucose conjugates from 12.82 % to 21.10 % by unfolding protein molecule, while the emulsifying stability index was increased from 79.17 to 100.73 compared with the control. Furthermore, the results of principal component analysis and Pearson correlation analysis indicated that the ionization effect and the free radicals generated by pulsed electric fields significantly (p < 0.05) inhibited browning and reduced free sulfhydryl content. This study demonstrated that pulsed electric fields combined with heating can prepare glycated proteins with good emulsifying properties in a short period of time and at temperatures lower than conventional heating while reducing energy consumption. This processing strategy has potential applications in improving the emulsifying performance of highly stable proteins.

Pulse Protein Isolates as Competitive Food Ingredients: Origin, Composition, Functionalities, and the State-of-the-Art Manufacturing

The ever-increasing world population and environmental stress are leading to surging demand for nutrient-rich food products with cleaner labeling and improved sustainability. Plant proteins, accordingly, are gaining enormous popularity compared with counterpart animal proteins in the food industry. While conventional plant protein sources, such as wheat and soy, cause concerns about their allergenicity, peas, beans, chickpeas, lentils, and other pulses are becoming important staples owing to their agronomic and nutritional benefits. However, the utilization of pulse proteins is still limited due to unclear pulse protein characteristics and the challenges of characterizing them from extensively diverse varieties within pulse crops. To address these challenges, the origins and compositions of pulse crops were first introduced, while an overarching description of pulse protein physiochemical properties, e.g., interfacial properties, aggregation behavior, solubility, etc., are presented. For further enhanced functionalities, appropriate modifications (including chemical, physical, and enzymatic treatment) are necessary. Among them, non-covalent complexation and enzymatic strategies are especially preferable during the value-added processing of clean-label pulse proteins for specific focus. This comprehensive review aims to provide an in-depth understanding of the interrelationships between the composition, structure, functional characteristics, and advanced modification strategies of pulse proteins, which is a pillar of high-performance pulse protein in future food manufacturing.

Stabilization of High Internal Phase Oil-in-Water Emulsions Using "Whole" Gracilaria lemaneiformis Slurry

In this study, a Gracilaria lemaneiformis slurry (GLS) was prepared using low-energy mechanical shearing. The resulting GLS, which was rich in polysaccharides, was utilized as an effective stabilizer for oil-in-water emulsions. The microstructures and stability of the resulting emulsions were controlled by adjusting the emulsion formulations, including Gracilaria lemaneiformis (GL) mass concentration and oil volume fraction (φ). The optimized GL mass concentration and φ conditions yielded high internal phase emulsions (HIPEs) with gel-like textures. Moreover, the presence of exogenous Ca2+ resulted in bridging structures in the emulsions, enhancing their viscoelasticity and forming a robust physical barrier against droplet coalescence. Our findings highlight the effectiveness of the GLS as an emulsifier for stabilizing HIPEs. Notably, this method relies solely on physical processes, aligning with the desirability of avoiding chemical additives, particularly in the food industry.

Spontaneous gelation behaviors and mechanism of Ficus awkeotsang Makino pectin

Ficus awkeotsang Makino (jelly fig) can produce edible gels by rubbing its seeds in water at room temperature in which pectin is considered as the main gelling component. However, the spontaneous gelation mechanism of Ficus awkeotsang Makino (jelly fig) pectin (JFSP) is still unclear. This study aimed to reveal the structure, physicochemical properties, and spontaneous gelation behaviors and mechanism of JFSP. JFSP was first obtained by water extraction and alcohol precipitation method, with a pectin yield of 13.25 ± 0.42 % (w/w), weight-average molar mass (Mw) of 111.26 kDa, and methoxylation degree (DM) of 26.8 %. Analysis of monosaccharide compositions showed that JFSP was composed of 87.8 % galactose acid, indicating a high percentage of galacturonic acid blocks. Measurement on the gelling capacity suggested that JFSP gels can be easily formed by simply dispersing the pectin in water at room temperature without adding any co-solutes or metal ions. Gelation force analysis indicated that hydrogen bonding, hydrophobic interactions, and electrostatic interactions were the main factors contributing to gel formation. At 1.0 % (w/v) of pectin concentration, JFSP gels exhibited relatively high gel hardness (72.75 ± 1.15 g) and good thermal and freeze-thawing stability. Overall, these findings highlight the potential application of JFSP as a promising commercial pectin resource.

Pulsed Electric Field-Assisted Enzymatic and Alcoholic-Alkaline Production of Porous Granular Cold-Water-Soluble Starch: A Carrier with Efficient Zeaxanthin-Loading Capacity

In this study, porous starch was modified using pulsed electric field (PEF) pretreatment and alcoholic-alkaline treatment to prepare porous granular cold-water-soluble starch (P-GCWSS). The soluble porous starch has high adsorption capability and high cold water solubility, allowing effective encapsulation of zeaxanthin and improving zeaxanthin's water solubility, stability, and bioavailability. The physical and chemical properties of GCWSS and complex were investigated using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The results showed that the cold water solubility of the pulsed electric field-treated porous granular cold-water-soluble starch (PEF-P-GCWSS) increased by 12.81% compared to granular cold-water-soluble starch (GCWSS). The pulsed electric field treatment also increased the oil absorption of PEF-P-GCWSS was improved by 15.32% compared to porous granular cold-water-soluble starch (P-GCWSS). PEF-P-GCWSS was effective in encapsulating zeaxanthin, which provided a good protection for zeaxanthin. The zeaxanthin-saturated solubility in water of PPG-Z was increased by 56.72% compared with free zeaxanthin. The zeaxanthin embedded in PEF-P-GCWSS was able to be released slowly during gastric digestion and released rapidly during intestinal digestion.

Natural Aldehyde-Chitosan Schiff Base: Fabrication, pH-Responsive Properties, and Vegetable Preservation

The aim of the present work was to fabricate Schiff base compounds between chitosan and aldehydes and use the resultant aldehyde-chitosan Schiff bases for broccoli preservation. Using an element analyzer, the degree of substitution was calculated as 68.27-94.65%. The aldehyde-chitosan Schiff bases showed acidic sensitivity to rapid hydrolysis for releasing aldehyde at a buffer solution of pH 4-6, in which more than 39% of the aldehydes were released within 10 h. The release of aldehydes endows the aldehyde-chitosan Schiff bases with a better antibacterial activity at pH 5 than at pH 7. In a simulated CO2 (5-15%) atmosphere with high humidity (92%), the hydrolysis of imine bonds (C=N) was triggered and continuously released aldehyde, even without direct contact with the aqueous phase. The application of aldehyde-chitosan Schiff bases significantly extended the shelf life of broccoli from 4 d to 5-7 d and decreased the weight loss of broccoli during storage. In summary, the fabrication of aldehyde-chitosan Schiff bases and the strategy of using pH-response imine bond (C=N) hydrolysis (thus releasing aldehyde to kill microorganisms) were feasible for use in developing EO-incorporated intelligent food packages for vegetable preservation.

Laccase-Induced Gelation of Sugar Beet Pectin-Curcumin Nanocomplexes Enhanced by Genipin Crosslinking

Research on the use of polysaccharides as hydrophobic bioactive carriers instead of proteins is still scarce. Sugar beet pectin (SBP) contains a small amount of protein and is a potential carrier for loading curcumin. In this work, SBP encapsulation, genipin crosslinking, and laccase-induced gelation were used to develop novel jelly food and improve the stability of curcumin without the incorporation of oil. By mixing the SBP solution (40 mg/mL) with curcumin powder (25 mg/mL SBP solution), an SBP-curcumin complex (SBP-Cur) was fabricated with a loading amount of 32 mg/g SBP, and the solubility of curcumin improved 116,000-fold. Fluorescence spectroscopy revealed that hydrophobic interactions drove the complexation of curcumin and SBP. Crosslinked by genipin (10 mM), SBP-Cur showed a dark blue color, and the gel strength of laccase-catalyzed gels was enhanced. Heating and UV radiation tests suggested that the genipin crosslinking and gelation strategies substantially improved the stability of curcumin. Because of the unique UV-blocking capacity of blue pigment, crosslinked samples retained 20% more curcumin than control samples. With the enhanced stability of curcumin, the crosslinked SBP-curcumin complexes could be a functional food ingredient used in functional drinks, baked food, and jelly food.

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.

The microstructure and thermal properties of pulsed electric field pretreated oxidized starch

The structure and thermal properties of pulsed electric field (PEF) assisted sodium hypochlorite oxidized starch were investigated. The carboxyl content of the oxidized starch was increased by 25 % when compared with the traditional oxidation method. Dents and cracks were evident on the surface of the PEF-pretreated starch. Compared with native starch, the peak gelatinization temperature (T_p) of PEF-assisted oxidized starch (POS) was reduced by 10.3 °C, while that of the oxidized starch without PEF treatment (NOS) was only reduced by 7.4 °C. In addition, PEF treatment further reduces the viscosity and improve the thermal stability of the starch slurry. Therefore, PEF treatment combined with hypochlorite oxidation is an effective method to prepare oxidized starch. PEF showed great potential in expanding starch modification, to promote a wider application of oxidized starch in the paper, the textile and the food industry.

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.

Encapsulation Efficiency and Functional Stability of Cinnamon Essential Oil in Modified β-cyclodextrins: In Vitro and In Silico Evidence

Essential oils (EOs) have good natural antioxidant and antimicrobial properties; however, their volatility, intense aroma, poor aqueous solubility, and chemical instability limit their applications in the food industry. The encapsulation of EOs in β-cyclodextrins (β-CDs) is a widely accepted strategy for enhancing EO applications. The complexation of cinnamon essential oil (CEO) with five types of β-CDs, containing different substituent groups (β-CD with primary hydroxyl, Mal-β-CD with maltosyl, CM-β-CD with carboxymethyl, HP-β-CD with hydroxypropyl, and DM-β-CD with methyl), inclusion process behaviors, volatile components, and antioxidant and antibacterial activities of the solid complexes were studied. The CEOs complexed with Mal-β-CD, CM-β-CD, and β-CD were less soluble than those complexed with DM-β-CD and HP-β-CD. Molecular docking confirmed the insertion of the cinnamaldehyde benzene ring into various β-CD cavities via hydrophobic interactions and hydrogen bonds. GC-MS analysis revealed that HP-β-CD had the greatest adaptability to cinnamaldehyde. The CEO encapsulated in β-, Mal-β-, and CM-β-CD showed lower solubility but better control-release characteristics than those encapsulated in DM- and HP-β-CD, thereby increasing their antioxidant and antibacterial activities. This study demonstrated that β-, Mal-β-, and CM-β-CD were suitable alternatives for the encapsulation of CEO to preserve its antioxidant and antibacterial activities for long-time use.

The antihyperglycemic effect of pulsed electric field-extracted polysaccharide of Kaempferia elegans officinale on streptozotocin induced diabetic mice

Kaempferia elegans polysaccharide (KEP) was extracted using a high-voltage pulsed electric field-assisted hot water method. Its physicochemical properties, in vitro activity and hypoglycemic effect was investigated. Experiments were undertaken with diabetic mice models and the potential mechanism of KEP to improve blood glucose levels was unveiled through measurements of relevant indicators in the serum and liver of the mice. Results showed that KEP is mainly composed of glucose, rhamnose, arabinose, and galactose. It has certain DPPH and ABTS free radical scavenging ability and good α-glucosidase inhibitory ability, indicating that KEP has the potential to improve blood glucose levels in diabetes patients. The experimental results of KEP treatment on mice showed that KEP could control the continuous increase of fasting blood glucose levels. The potential mechanisms behind this blood glucose level control composes of (1) increasing the glucokinase and C peptide levels and decreasing Glucose-6-phosphatase content for improving key enzyme activity in the glucose metabolism pathway. This promotes the consumption of blood glucose during glycolysis, thereby inhibiting the production of endogenous glucose in gluconeogenesis pathway; (2) reducing triglyceride, total cholesterol, low density lipoprotein cholesterol, and increasing high density lipoprotein cholesterol content, for regulating blood lipid indicators to normal levels; and (3) by improving the activities of catalase, glutathione peroxidase, and antioxidant enzymes superoxide dismutase for further improving the antioxidant defense system in the body to reduce blood glucose.

Succinylated whey protein isolate-chitosan core-shell composite particles as a novel carrier: Self-assembly mechanism and stability studies

Single protein [whey protein isolate (WPI) or succinylated whey protein isolate (SWPI)] and composite particles of proteins with chitosan (CS) were tested for their ability to encapsulate and protect curcumin (CUR). Combining protein and CS resulted in changes in zeta-potential and surface hydrophobicity, particularly in the SWPI-H (high degree of succinylation, 90 %) and CS composite particle (H-CS). Furthermore, the secondary and tertiary structures were dramatically altered using Fourier transform infrared (FTIR), circular dichroism (CD), and X-ray diffraction (XRD). Scanning electron microscopy (SEM) and atomic force microscope (AFM) analyses revealed that H-CS exhibited a soft core-rigid shell morphology due to electrostatic interactions, hydrophobic interactions, and H-bond interactions. Fluorescence quenching results demonstrated that H-CS had a higher binding constant (K, 1.69 ×104 M-1) and encapsulation effectiveness (EE, 88.3 %) of CUR. Because of increased binding sites and steric hindrance, CUR was stabilized more effectively in H-CS in photostability and thermostability tests,. These results show that SWPI-CS composite particles can be utilized to build a protection system for water-insoluble nutritional supplements.

Influence of glycosyl composition on the immunological activity of pectin and pectin-derived oligosaccharide

Factors causing differences in immune activities between pectin and pectin-derived oligosaccharides have not been fully studied. In this article, four samples with different molecular weights and monosaccharide compositions, including polygalacturonic acid (poly-GA) and its oligosaccharide (oligo-GA), navel orange peel pectin (NP) and its oligosaccharide (oligo-NP), were used to compare their immunomodulatory properties on RAW264.7 cells. All samples had nontoxic effect on cells, oligo-GA and oligo-NP could increase the production of nitric oxide and cytokines to a much higher level than poly-GA and NP. The findings revealed that reducing the molecular weight and preserving the branched regions of pectin-derived samples could improve their immune-enhancing effects on macrophages. Interestingly, the addition of TAK-242 (TLR4 inhibitor) also demonstrated that the tested pectin oligosaccharides could stimulate the activation of macrophages through TLR4 signaling pathway. These results confirmed the potential value of pectin oligosaccharides, and provided theoretical support for their application in the pharmaceutical industry.

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.