Polysaccharide Content Research Articles

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.

Enhancing frozen fish quality through polysaccharide-ice glazing: Insights from physical properties and preservation effects

Polysaccharide ice-glazing is a widely employed method for preserving frozen fish, with the choice of polysaccharide playing a crucial role in preservation effectiveness. This research investigates the impact of various polysaccharides, including neutral polysaccharides like konjac glucomannan (KGM) and pullulan (PUL), as well as ionic polysaccharides such as gellan gum (GG), κ-carrageenan (KC), carboxymethyl cellulose (CMC), and xanthan gum (XG), on the physical properties of ice. Additionally, we assess the influence of polysaccharide ice-glazing on the quality of frozen snakehead (Channa argus) fish fillets. Our study shows that the physical properties of polysaccharide-infused ice are affected by both polysaccharide type and concentration. Increasing the polysaccharide concentration led to a reduction in water activity within the supercooled polysaccharide solution. Additionally, the characteristics of ice formed by the polysaccharide solution, including ice crystal size, compressive strength, sublimation rate, and oxygen permeability, consistently decreased. In our comparative analysis, at equivalent polysaccharide concentrations, the PUL solution exhibited the lowest water activity. Notably, PUL-ice demonstrated superior performance, displaying the smallest ice crystal size, highest compressive strength, lowest ice sublimation rate, and the most effective oxygen permeability barrier. Following this in decreasing order of performance were the GG, KC, CMC, XG, and KGM samples. Moreover, when applied to glazing snakehead fish fillets, pullulan ice-glazing outperformed KGM ice-glazing in preserving fish quality, confirming the direct influence of polysaccharide-induced ice properties on fillet preservation outcomes. This study provides essential insights to guide informed decisions in the field of polysaccharide ice-glazing applications, aimed at enhancing the quality of frozen fish.

Study on fermentation preparation, physicochemical properties and biological activity of carboxymethylpachymaran with different degrees of substitution.

Carboxymethylpachymaran (CMP) is created by carboxymethylating pachyman (PM), which increases its water solubility and enhances a number of biological activities. Traditional polysaccharides modified by carboxymethylation employ strong chemical techniques. Carboxymethylcellulose (CMC) has been used previously for liquid fermentation to carboxymethyl modify bacterial polysaccharides. This theory can be applied to fungal polysaccharides because Poria cocos has the ability to naturally utilize cellulose. CMC with different degrees of substitution (DS) (0.7, 0.9 and 1.2) were added to P. cocos fermentation medium, and CMPs with different DS (0.38, 0.56 and 0.78, respectively) were prepared by liquid fermentation. The physical and chemical properties and biological activities of the CMPs were determined. Their structures were confirmed by Fourier transform infrared (FTIR) spectroscopy and monosaccharide composition. With the increase of DS, the viscosity and viscosity-average molecular weight of CMPs decreased, whereas polysaccharide content and water solubility increased, although the triple helix structure was not affected. The results of bioactivity assay showed that the higher the DS of CMPs, the higher the 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, and the stronger the bacterial inhibition ability. The present study has developed a method for producing CMPs by P. cocos liquid fermentation. The results of the study confirm that enhancing the DS of CMP could effectively enhance its potential biological activity. The findings provide safe and reliable raw materials for creating CMP-related foods and encourage CMP application in the functional food industry. © 2024 Society of Chemical Industry.

Effect of polysaccharide-protein interactions on the multi-scale structure of hybrid micellar casein-xanthan gum systems

This study reports on the effect of pH and polysaccharide concentration (protein:polysaccharide ratios of 95:5, 85:15 and 75:25) on the interactions established between xanthan gum (XG) and micellar casein (MC), investigating the impact on the type of structures formed at the micro- and nanoscale. At pH ≥ 6, the micellar casein formed stable suspensions where micelles with diameters of ca. 130–150 nm showed a compact inner structure stabilised by colloidal calcium phosphate (CCP) nanoclusters, while at pH ≤ 3, a more loosely packed interconnected network structure, stabilised by protein-protein interactions, was noted. The addition of XG, even at low MC:XG ratios (95:5), resulted in increased stability of the system, preventing the formation of micelle aggregates at the microscale, and reducing the pH range at which casein precipitated close to the isoelectric point. For all the XG loadings, coacervates were formed at pH = 2–3 due to polysaccharide-protein electrostatic interactions, leading to separation into a solid gel-like phase composed of polysaccharide-protein fibrillar structures and a liquid phase rich in protein. At the nanoscale, XG was mostly coating the micelles and filling in the inner water channels when added at MC:XG ratios ≤85:15, while the higher polysaccharide content at the ratio 75:25 allowed to form an interconnected structure. Therefore, by adjusting pH and XG concentration, it is possible to improve casein stability, reduce agglomeration and manipulate the size of protein-polysaccharide complexes formed. This will be of great relevance for the development of novel food formulations with improved stability and modulated sensory and nutritional properties.

Quality and Process Optimization of Infrared Combined Hot Air Drying of Yam Slices Based on BP Neural Network and Gray Wolf Algorithm

In this paper, the effects on drying time (Y1), the color difference (Y2), unit energy consumption (Y3), polysaccharide content (Y4), rehydration ratio (Y5), and allantoin content (Y6) of yam slices were investigated under different drying temperatures (50–70 °C), slice thicknesses (2–10 mm), and radiation distances (80–160 mm). The optimal drying conditions were determined by applying the BP neural network wolf algorithm (GWO) model based on response surface methodology (RMS). All the above indices were significantly affected by drying conditions (p < 0.05). The drying rate and effective water diffusion coefficient of yam slices accelerated with increasing temperature and decreasing slice thickness and radiation distance. The selection of lower temperature and slice thickness helped reduce the energy consumption and color difference. The polysaccharide content increased and then decreased with drying temperature, slice thickness, and radiation distance, and it was highest at 60 °C, 6 mm, and 120 mm. At 60 °C, lower slice thickness and radiation distance favored the retention of allantoin content. Under the given constraints (minimization of drying time, unit energy consumption, color difference, and maximization of rehydration ratio, polysaccharide content, and allantoin content), BP-GWO was found to have higher coefficients of determination (R2 = 0.9919 to 0.9983) and lower RMSEs (reduced by 61.34% to 80.03%) than RMS. Multi-objective optimization of BP-GWO was carried out to obtain the optimal drying conditions, as follows: temperature 63.57 °C, slice thickness 4.27 mm, radiation distance 91.39 mm, corresponding to the optimal indices, as follows: Y1 = 133.71 min, Y2 = 7.26, Y3 = 8.54 kJ·h·kg−1, Y4 = 20.73 mg/g, Y5 = 2.84 kg/kg, and Y6 = 3.69 μg/g. In the experimental verification of the prediction results, the relative error between the actual and predicted values was less than 5%, proving the model’s reliability for other materials in the drying technology process research to provide a reference.

Effect of constant and variable temperature drying processes on drying characteristics, quality, and volatile profile of rose petals in infrared-assisted spouted bed drying.

The edible rose (Rosa Crimson Glory) petals were dried using infrared-assisted spouted bed drying technology. The effects of different drying temperature conditions (30, 35, 40, 45, and 50°C, as well as stepped heating drying [SHD] and stepped cooling drying) on the drying characteristics, physicochemical properties, antioxidant capacity, and changes in volatile flavor compounds of the rose petals were investigated. The results showed that the drying time was shortened with increasing drying temperature. Both variable temperature drying processes gave the shortest drying times. Optimal color retention of rose petals was achieved at a constant temperature of 40°C and SHD. Increased drying temperature resulted in higher water-soluble polysaccharide content in the dried rose petals, whereas lower temperatures facilitated anthocyanin preservation. The variable temperature drying processes favored the retention of water-soluble polysaccharides in rose petals, but not anthocyanins. Regarding antioxidant capacity, the samples dried at 40°C and those subjected to the two variable temperature drying processes performed better. This study also analyzed the differences in volatile flavor compounds of rose petals dried under different drying conditions. It was found that the majority of volatile flavor compounds in the rose petals dried by SHD exhibited higher content levels than the other drying conditions. Therefore, considering a thorough evaluation of all relevant factors, it was clear that utilizing the SHD process was the most efficient method for obtaining the best quality rose petals overall.

Design and Development of an Edible Coating for a Ready-to-Eat Fish Product.

The application of chitosan and alginate coatings for a ready-to-eat (RTE) baked fish product was studied. An experimental design was used to investigate the effect of coating a polysaccharide concentration and glycerol addition on the safety (microbial growth) and quality (water loss and lipid oxidation) of an RTE fish product under optimal and abused storage conditions. The results showed that a chitosan coating with 1% (w/v) chitosan in 1% (v/v) acetic acid and 15% (w/w chitosan) glycerol, or a 1% (w/v) alginate coating with no glycerol and no crosslinking, showed the best performance in controlling the tested safety and quality parameters. The desirability method was used to identify the shelf lives of chitosan, alginate, and double-coated RTE products. The chitosan-coated samples showed the best performance with a three-fold shelf-life extension compared to the uncoated products stored at 4 °C. Moreover, the tested coatings demonstrated their ability to provide protective functions under abused storage conditions. These results strongly suggest that edible coatings have significant potential in enhancing the shelf life and safety of ready-to-eat (RTE) fish products.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25–2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Ionic Strength Impacts the Physical Properties of Agarose Hydrogels.

Agarose is a natural polysaccharide known for its ability to form thermoreversible hydrogels. While the effects of curing temperature and polysaccharide concentration on mechanical properties have been discussed in the literature, the role of ionic strength has been less studied. In the present manuscript, we investigate the effects of supporting salt concentration and the role of cation (i.e. Na+ or Li+, neighbors in the Hofmeister series), on the setting and performance of agarose hydrogels. Compressive and rheological measurements show that the supporting salts reduce the immediate elastic response of agarose hydrogels, with Li+ showing a stronger effect than Na+ at high ionic strength, while they significantly increase the extent of linear stress-strain response (i.e., linear elasticity). The presence of increasing amounts of added supporting salt also leads to a reduction in hysteresis during mechanical deformation due to loading and unloading cycles, which is more pronounced with Li+ than with Na+. The combination of rheological measurements and NMR relaxometry shows a mesh size in agarose hydrogels in the order of 6-17 nm, with a thickness of the water layer bound to the biopolymer of about 3 nm. Of note, the different structuring of the water within the hydrogel network due to the different alkali seems to play a role for the final performance of the hydrogels.

A Comparison of Watermelon Flesh Texture across Different Ploidy Levels Using Histology and Cell Wall Measurements

Watermelon fruits of different ploidy levels exhibit significant variations in texture. This study aimed to investigate the primary factors that influence texture differences. To achieve this, we conducted an investigation into the differences in fruit texture development using homozygous autogamous diploid (2×) lines and their autotriploid (3×) and autotetraploid (4×) lines ‘Yixuan’. The study investigated fruit development, flesh texture profile analysis (TPA), flesh cell wall polysaccharide content, and flesh cell microstructure analysis in 2×, 3×, and 4× watermelon fruits. The study found that as watermelon fruits matured, several characteristics increased, including fruit weight, TSS (total soluble solids) content, rind hardness, flesh cell size, and cell wall polysaccharide contents such as crude fiber, cellulose, hemicellulose, lignin, and protopectin. In contrast, the flesh texture parameters and soluble pectin content of the flesh cell wall decreased over time. Significant differences in fruit flesh texture and flesh cell structure were observed among fruits of different ploidy levels at the 32 DAP. Specifically, the 2× fruits displayed considerably lower rind hardness, reduced flesh texture (Hardness, Fracturability, Chewiness, Gumminess), and cell density compared to the 3× and 4× fruits. Additionally, the 2× fruits had larger cell sizes than the 3× and 4× fruits. However, there were no significant differences observed in the flesh cell wall polysaccharide contents across various ploidy levels. These findings suggest that the variation in texture among watermelon fruits of different ploidy levels can be attributed to the size and arrangement of the flesh cells. This research provides a foundation for the further exploration of the intrinsic regulatory factors and molecular mechanisms contributing to texture variation in polyploid watermelon fruits.

Operating performance of sequential batch system with calcium-modified basalt fiber bio-nest exposed to two typical perfluoroalkyl compounds (PFOA and PFBA)

The effects of per- and polyfluoroalkyl substances (PFASs) on the application of sequential batch system with basalt fiber as a biological carrier material have been rarely reported. This study explored the decontamination performance, extracellular polymeric substances (EPS) and microbial community structure of sequencing batch system with calcium-modified basalt fiber (Ca-MBF) bio-nest exposed to perfluorooctanoic acid (PFOA) and perfluorobutyric acid (PFBA). The results showed that 0.5 mg/L PFOA and PFBA both inhibited nitrification by 24.67 % and 19.47 %, while promoted denitrification by 16.54 % and 11.15 %, respectively. Overall, compared to PFBA, PFOA inhibited the removal of total nitrogen (TN) and total phosphorus (TP) by 11.27 % and 9.49 %, respectively. Further analysis of EPS showed that under PFOA exposure, the total EPS and polysaccharide (PS) content decreased by 34.57 % and 40.78 %, respectively. In addition, PFOA and PFBA exhibited a phenomenon of initially promoting by 89.21 % and 55.29 %, and subsequently inhibiting on protein (PN) content by 50.22 % and 51.37 %, respectively. Analyses of Illumina Miseq sequencing showed that PFOA and PFBA exposure for 50 days both inhibited the richness and diversity of microbial communities, and the inhibitory effect of PFOA was greater than that of PFBA. In addition, PFOA and PFBA respectively domesticated the resistant bacteria Meganema and Acinetobacter. These results may provide valuable information for ecological restoration and biodegradation of PFOA and PFBA.

Transcriptome Reveals Regulation of Quorum Sensing of Hafnia alvei H4 on the Coculture System of Hafnia alvei H4 and Pseudomonas fluorescens ATCC13525.

In the food industry, foodborne spoilage bacteria often live in mixed species and attach to each other, leading to changes in spoilage characteristics. Quorum sensing (QS) has been reported to be a regulating mechanism for food spoiling by certain kinds of bacteria. Here, the contents of biofilm, extracellular polysaccharides, and biogenic amines in the coculture system of Hafnia alvei H4 and Pseudomonas fluorescens ATCC13525 were significantly reduced when the QS element of H. alvei H4 was deleted, confirming that QS of H. alvei H4 is involved in the dual-species interactions. Then, transcriptomics was used to explore the regulatory mechanism at the mRNA molecular level. The deletion of the QS element decreased the transcript levels of genes related to chemotaxis, flagellar assembly, and the two-component system pathway of H. alvei H4 in the coculture system. Furthermore, a total of 732 DEGs of P. fluorescens ATCC13525 were regulated in the dual species, which were primarily concerned with biofilm formation, ATP-binding cassette transporters, and amino acid metabolism. Taken together, the absence of the QS element of H. alvei H4 weakened the mutual cooperation of the two bacteria in the coculture system, making it a good target for managing infection with H. alvei and P. fluorescens.

Comparison of Antioxidant effects of Polysaccharides of Mixed Microalgae Isolates Glagah Beach Yogyakarta and East Java, Indonesia

Indonesia is a country with a large marine and has a very high biodiversity of microalgae. Previous research has identified mixed microalgae from Glagah Beach, Yogyakarta, and several beaches in East Java. This study aims to extract polysaccharides and assessed the antioxidant activity of polysaccharides from those microalgae. Polysaccharides of Spirulina platensis, a mixed microalgae Glagah, and a mixed microalgae East Java were extracted by the alkaline method. The extraction rate and protein and carbohydrate content of polysaccharides of each of microalgae were calculated. The antioxidant activity of polysaccharides was observed in vitro using the DPPH assay method. The highest extraction rate was obtained from Glagah microalgae followed by S. platensis and East Java microalgae with values of 13.575%, 9.75%, and 2.375%, respectively. On the other hand, the carbohydrate content of the polysaccharides from Glagah microalgae was the lowest, followed by S. platensis and East Java microalgae, 1.2 mg/mL, 13.33 mg/mL, and 21.925 mg/mL, respectively. The protein content in polysaccharides from Glagah microalgae was the highest, followed by East Java microalgae and S. platensis the lowest, 2.23 mg/mL, 1.01 mg/mL, and 0.67 mg/mL, respectively. Based on the results of IC50 values, the antioxidant activity of mixed microalgae polysaccharides from Glagah and East Java was included in the active/moderate category, 125.21 µg/mL and 127.11 µg/mL, respectively, while the antioxidant activity of polysaccharide S. platensis was low, 171.82 µg/mL. In conclusion, Glagah and East Java Microalgae Polysaccharides have the opportunity to be promoted as health ingredients to overcome free radicals.

Impact of pretreatment with dielectric barrier discharge plasma on the drying characteristics and bioactive compounds of jackfruit slices.

Hot-air drying is a popular method for preserving the production of jackfruit, but heat treatment damages its nutritional qualities. Cold plasma is one of the pretreatment methods used to preserve quality attributes of fruits before drying. In the present work, we studied the effect of dielectric barrier discharge (DBD) plasma on the drying characteristics, microstructure, and bioactive compounds of jackfruit slices with different pretreatment times (15, 30, 45, and 60 s), followed by hot-air drying at 50, 60, and 70 °C. A homemade DBD device was operated via three neon transformers. Optical emission spectrophotometry revealed the emitted spectra of the reactive species in DBD plasma, including the N2 second positive system, N2 first negative system, nitrogen ion, and hydroxyl radical. The results showed that the DBD plasma promoted moisture transfer and enhanced the drying rate, related to the changes in the surface microstructure of samples damaged by DBD plasma. The modified Overhults model was recommended for describing the drying characteristics of jackfruit slices. The contents of ascorbic acid, total phenolics, total flavonoids, total polysaccharides, and antioxidant activity in pretreated jackfruit slices were improved by 9.64%, 42.59%, 25.77%, 27.00%, and 23.13%, respectively. However, the levels of color and carotenoids were reduced. Thus, the bioactive compounds in dried jackfruit slices can be improved using the DBD plasma technique as a potential pretreatment method for the drying process. © 2023 Society of Chemical Industry.

An inulin-type fructan CP-A from Codonopsis pilosula alleviates TNBS-induced ulcerative colitis based on serum-untargeted metabolomics.

Ulcerative colitis (UC) is an inflammatory disease with abdominal pain, diarrhea, and bloody stool as the main symptoms. Several studies have confirmed that polysaccharides are effective against UC. It is commonly accepted that the traditional benefits of Radix Codonopsis can be attributed to its polysaccharide contents, and inulin-type fructan CP-A is the main active monomer in the polysaccharide components. Herein, we established a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced UC rat model and lipopolysaccharide (LPS)-induced colonic epithelial cell model (NCM460) to investigate the effect of CP-A on UC. Untargeted metabolomics studies were conducted to identify differential metabolites using ultra-high performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS) and enrich metabolic pathways in rat serum. The in vivo assays demonstrated that CP-A reduces colonic macroscopic injury, disease activity index (DAI), histopathological score, interleukin (IL)-8, and tumor necrosis factor-α (TNF-α) levels, as well as the expression of intercellular adhesion molecules. On the other hand, CP-A increases IL-10 and transforming growth factor-β (TGF-β) levels. The in vitro experiments indicated that CP-A treatment could reduce nitric oxide (NO) and IL-1β after LPS stimulation. The metabolomics results suggested that CP-A therapy for UC may be related to the mammalian target of rapamycin (mTOR) signaling pathway. The in vitro and in vivo validation of the pathway showed similar results, indicating that CP-A alleviates UC by preventing the activation of mTOR/p70S6K signaling pathway. These findings offer a fresh approach to treating UC and a theoretical foundation for the future advancement of CP-A.NEW & NOTEWORTHY We report that an inulin-type fructan from Codonopsis pilosula CP-A exhibits a therapeutic effect on experimental colitis. Its mechanism may be to alleviate intestinal inflammation by preventing the activation of mammalian target of rapamycin (mTOR)/p70S6K signaling pathway. These findings offer a fresh approach to treating ulcerative colitis (UC) and a theoretical foundation for the future advancement of CP-A.

Sustainable wastewater management in the brewing industry: Utilizing cellulose acetate membranes derived from brewers’ spent grain for enhanced treatment efficiency

Brewers’ spent grain (BSG), the primary by-product of the brewing industry, constitutes approximately 85.0% of the total by-products generated. BSG is known for its rich cellulose and non-cellulosic polysaccharide content, making it a valuable resource with significant potential for profitable recycling and reutilization. Given that the brewing sector is among the most substantial industrial consumers of water due to the water-intensive process of producing BSG, the effective management of wastewater in this industry is of paramount importance. This research focuses on investigating innovative wastewater management in the brewing sector. It employs the conversion of BSGs into a cellulose acetate membrane, thus enabling a physio-chemical treatment process utilizing the micro-filtration technique for wastewater treatment within the brewery industry. The results of this study demonstrate a substantial reduction in biochemical oxygen demand from the initial value of 16.65 mg/l (untreated) to 13.70 mg/l, 11.16 mg/l, 8.37 mg/l, 5.58 mg/l, and 3.14 mg/l after the first through fifth treatment cycles, respectively. Furthermore, the research indicates a high correlation with an R<sup>2 </sup>value of 0.999, affirming the viability and effectiveness of the treatment process. This is further substantiated by the results of chemical oxygen demand, total dissolved solids, total suspended solids, and hydrogen ion concentration analyses presented in this study. These findings not only validate the efficacy of utilizing BSG-derived cellulose acetate membranes but also emphasize the potential for revolutionizing wastewater treatment practices within the brewing industry. This research paves the way for sustainable, environmentally conscious strategies in industrial wastewater management, ensuring the optimal utilization of by-products while minimizing the environmental footprint of brewing operations.

Anti-Aging Effect of Hemerocallis citrina Baroni Polysaccharide-Rich Extract on Caenorhabditis elegans.

Plant polysaccharides are important for anti-aging research. Polysaccharides from Hemerocallis citrina Baroni (H. citrina) have been reported to have antioxidant activity; however, their anti-aging roles and mechanisms are not clear. In this study, we extracted polysaccharides from H. citrina by an ultrasonic-assisted water extraction-alcohol precipitation method and chemically determined the physicochemical properties such as extraction yield, content, and in vitro antioxidant properties of H. citrina polysaccharide-rich extract (HCPRE). Using Caenorhabditis elegans (C. elegans) as a model animal, the anti-aging effect of HCPRE was investigated, and the mechanism of action of HCPRE was explored by the in vivo antioxidant level assay of C. elegans and the related gene expression assay. The extraction yield of HCPRE was 11.26%, the total polysaccharide content was 77.96%, and the main monosaccharide components were glucose and galactose. In addition, HCPRE exhibited good antioxidant activity both in vitro and in vivo. Under normal thermal stress and oxidative stress conditions, being fed 1200 µg/mL of HCPRE significantly prolonged the life span of C. elegans by 32.65%, 17.71%, and 32.59%, respectively. Our study showed that HCPRE exerted an anti-aging effect on C. elegans, and its mechanism involves increasing the activities of catalase (CAT) and superoxide dismutase (SOD), reducing the level of reactive oxygen species (ROS) and regulating the expression of related genes.

Structure and properties of acidic polysaccharides isolated from Massa Medicata Fermentata: Neuroprotective and antioxidant activity

Massa Medicata Fermentata (MMF) is a fermented food with therapeutic effects. Previous studies suggested that after stir-frying, the uronic acid content in MMF crude polysaccharides increases, and the pH value decreases, which is caused by the change in acidic polysaccharides. However, the detailed physicochemical properties and structure-activity correlation of the acidic polysaccharides in MMF have not been fully explored. In this study, two acidic polysaccharides (SMMFAP and CMMFAP) were isolated from the MMF and its stir-fried product, respectively. Their structural characteristics and bioactivities were comparatively studied, and the structure-activity correlation was examined. Our findings revealed that the SMMFAP had a higher average Mw and higher Gal and Man content than the CMMFAP. Both the SMMFAP and CMMFAP were mainly composed of Xyl, Man, and Gal residues, whereas the CMMFAP had fewer linkage types. Additionally, the CMMFAP exhibited stronger neuroprotective activity than the SMMFAP owing to its higher content of 1,6-linked-Galp, while the SMMFAP exhibited better antioxidant activity, which might be related to its higher average Mw. Our findings suggest that acidic polysaccharides may be the active substances that cause differences in effectiveness between the sheng and chao MMF. Furthermore, the research qualified the SMMFAP and CMMFAP with different potential applications.

Determination of prebiotic properties of rice bran extract.

This research investigated and compared the prebiotic properties of a rice bran extract obtained through commercial xylanase extraction in comparison with water extraction. Prebiotic properties were evaluated by probiotic growth stimulation (Lacticaseibacillus casei and Lactiplantibacillus plantarum) and gastrointestinal pathogen inhibition (Bacillus cereus and Escherichia coli). The rice bran extract obtained with xylanase (RB1) displayed significantly higher total polysaccharide and total reducing sugar contents than those obtained with water (RB2; p<0.05). After extraction for 30 min, RB1 exhibited the highest total polysaccharide and total reducing sugar contents. HPLC (high performance liquid chromatography) analysis revealed that RB1 primarily contained xylose, while RB2 contained less glucose and lacked other sugar derivatives. RB1 proved effective in stimulating the growth of L. casei and L. plantarum, surpassing even inulin (a commercial prebiotic). Furthermore, it demonstrated a high potential for inhibiting the growth of pathogenic B. cereus and E. coli, comparable to inulin. In contrast, RB2 exhibited lower inhibitory capacity against B. cereus and E. coli.

In vitro gastrointestinal digestion and fecal fermentation of Pleurotus eryngii proteins extracted using different methods: insights for the utilization of edible mushroom-based proteins as novel nutritional and functional components.

Pleurotus eryngii (P. eryngii) protein is considered a high-quality protein because it is rich in essential amino acids and displays multiple significant functional characterizations that vary with its fabrication processes. We aimed to investigate the differences in P. eryngii protein extracted via alkaline extraction and acid precipitation (AA), cellulase complex alkaline extraction and acid precipitation (CAA), ultrasound-assisted alkaline extraction and acid precipitation (UAA), and salt dissolution (S) in terms of gastrointestinal digestion and fecal fermentation consequences. Protein hydrolysis and structural analysis were performed after in vitro gastrointestinal digestion, and it was found that AA showed the highest hydrolysis degree, whereas CAA showed the lowest. The results of fluorescence chromatography and infrared chromatography indicated that the reasons for the digestion difference might be the unfolding degrees of the protein tertiary structure and polysaccharide content, which is the major component of crude proteins and can prevent protein hydrolysis. Metagenomic analysis suggested that compared with other groups, AA had excellent biological functions, including regulating obesity and insulin-related microbiota. This study could provide a new theoretical basis for the P. eryngii protein as a novel type of nutritional and functional component and contributes to the development of a diversified emerging food protein supply system.