Optimization of polysaccharides extraction from watermelon rinds: Structure, functional and biological activities

Effect of structural changes of Rehmannia glutinosa polysaccharide before and after processing on anti-aging activity

Rehmannia glutinosa is often used to delay aging in traditional Chinese medicine (TCM). The processing methods utilized in TCM can enhance its anti-aging properties. Polysaccharides are the primary active constituents of R. glutinosa. Against this background, this study aims to investigate the alterations in polysaccharide structure before and after the processing of R. glutinosa, as well as the correlation between aging activity and polysaccharide structure. In this paper, Rehmanniae Radix polysaccharide (RGP50-2) and Rehmanniae Radix Praeparata(SDP50-2) were purified from R. glutinosa before and after processing. Structural analysis showed that compared with RGP50-2, the molecular weight of SDP50-2 (9.8-9.6 kDa) decreased, and the content of Ara (22.5 %-55.49 %) increased. NMR results show that the main chains of RGP50-2 and SDP50-2 are both →6)-β-Galp-(1→, →3,4,6)-α-Galp-(1→ and →2,3,5)-α-Araf-(1→, but the branching degree of SDP50-2 is lower. Pharmacological assessments showed that SDP50-2 had superior anti-aging activity over RGP50-2 by modulating the IIS signaling pathway. In conclusion, processing significantly alters the chemical structure of R. glutinosa polysaccharides, enhancing their anti-aging efficacy. Our research provides a theoretical framework and a reference for optimizing processing techniques and advancing development strategies for R. glutinosa polysaccharides.

Effects of selenylation on Chinese yam polysaccharides: Structure, antioxidant, and digestive properties

Natural polysaccharides have unsatisfactory properties in production and processing due to structural limitations. Recent studies have shown that chemical modifications can improve the physicochemical and functional properties of plant polysaccharides. Herein, the effect of selenylation on the structure, functional properties, and in vitro digestion characteristics of yam polysaccharide (YP) was investigated. Selenylated products with different selenium contents (YP-LSe and YP-HSe) were prepared by controlling the addition of sodium selenite, and all samples were identified as acidic polysaccharides. Selenylation induced alterations in the chemical composition of YP. FT-IR spectral analysis revealed that YP-LSe and YP-HSe exhibited characteristic vibrational absorption peaks associated with selenium-containing groups. Microstructure analysis showed that YP-LSe and YP-HSe presented stacked leaf-like structures with sphere attachments. Moreover, selenylation significantly enhanced the emulsion capacity, foaming capacity, and antioxidant capacity of YP. In the simulated digestion process, YP-LSe and YP-HSe exhibited greater resilience against the gastrointestinal environment than YP. This study provides a theoretical basis for the development and utilization of selenylation of YP in the field of functional foods.

Anticoagulant and angiotensin-converting enzyme inhibitory activities of a fucoidan from Sargassum horneri and its low molecular weight fragments prepared by acid degradation

A purified fucoidan SF (348 kDa) was isolated from Sargassum horneri. Six low molecular weight fragments SFs (75-8.1 kDa) were prepared by acid degradation from SF. Anticoagulant properties of SF and SFs were evaluated. SF and SFs with 75-17 kDa had better anticoagulant activities with the activated partial thromboplastin time (APTT) greater than 120 s at 200 μg/mL. The decrease in the molecular weight caused a decrease in anticoagulant activity, and a slight decrease almost resulted in loss of anticoagulant activity when below 17 kDa (APTT < 59 s). Angiotensin-converting-enzyme (ACE)-inhibitory activities were also detected. Only when the molecular weight dropped to a certain extent (8.1 kDa), the fucoidan showed ACE-inhibitory activity (IC50=2.16 mg/mL). Structure analysis indicated the main change of SFs was a reduction in molecular weight. Thus molecular weight is an essential factor affecting the bioactivities. Longer chains were essential to complete thrombin inhibition, whereas ACE-inhibitory activity required shorter ones.

Process optimization, structural characterization, and biological activity of Siraitia grosvenorii polysaccharides by ultrasonic aqueous two-phase extraction

In this research, ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was utilized to isolate polysaccharides from Siraitia grosvenorii (SGPs). Based on the results of model optimization experiments, the extraction parameters were determined. The total extraction rate of SGPs was 25.77 %, which was 1.39 times higher than that obtained through conventional hot water extraction (HWE). Various analyses indicated that all SGPs were acidic polysaccharides with similar molecular weights. However, there were slight variations in the monosaccharide composition, surface morphology, and infrared spectral characteristics. These structural features endowed SGPs with various antioxidant, hygroscopic, and moisturizing properties, which provided valuable data for the development of the cosmetic raw materials and also presented new ideas for the application of SGPs.

Anti-hyperuricemia effects of a polysaccharide-protein complex from Lentinula edodes mediated by gut-kidney axis

In order to investigate the effects of Lentinula edodes (L. edodes) on hyperuricemia, a polysaccharide-protein complex (LEPP) was prepared and characterized, and the activity was also systematically studied. LEPP was mainly composed of proteins (18.55 %) and polysaccharides (36.98 %) with three polysaccharide fractions (molecular weights were 8.98 × 106, 7.34 × 107 and 1.15 × 107 g/mol). The experiment results showed that 250-1000 mg/kg/day LEPP could decrease the serum uric acid (UA) level from 281.62 to 109.42-138.12 μmol/L (p < 0.001), and there were significant differences between high and low doses (p < 0.05). LEPP simultaneously improved renal function, relieved oxidative stress and inflammation in the kidney and regulated renal UA transporters (URAT1, GLUT9, OAT1 and ABCG2) of hyperuricemia rats. Furthermore, gut microbiota dysbiosis and intestinal barrier function disruption were modified by LEPP. Among them, LEPP could reverse the relative abundances of Parabacteroides, Lachnospiraceae, Colidextribacter, UCG-010, Monoglobus, Lactobacillus and Muribaculaceae, which were associated with regulating the UA level, renal function and the expression of renal UA transporters in hyperuricemia rats through correlation analysis. Conclusively, LEPP prevented the pathological process of hyperuricemia through regulating the gut-kidney axis, which provided its complementary role in existing anti-hyperuricemia treatment strategies.

Enhancing Physicochemical and Piezoelectric Properties of Eggshell Membrane Proteins by Ultrasonic-Assisted Enzymes for Food and Sensor Applications

This research sought to explore the impact of ultrasonic pretreatment on the physicochemical characteristics of proteins derived from eggshell membranes through enzymatic extraction. Response surface methodology (RSM) and Box-Behnken design were employed to identify the ideal conditions for the extraction process. The optimal parameters determined were enzyme usage at 4.2%, pH level at 2.4, a solid-to-solvent ratio of 1:20 g/mL, and an extraction time of 21.5 h. The eggshell membrane was pretreated by ultrasound before pepsin hydrolysis under optimized conditions. The findings indicated that the hydrolyzed products subjected to ultrasonic pretreatment exhibited enhanced solubility, surface hydrophobicity, water and oil retention, foaming characteristics, and emulsifying ability compared to the untreated hydrolyzed products. Furthermore, the piezoelectric properties of the protein with ultrasonic pretreatment were also significantly improved. Additionally, the protein-based piezoelectric device displayed excellent sensing performance and was successfully applied for human motion detection and precise identification of different pressure positions. These findings indicate that ultrasound has great potential to improve the physicochemical quality of eggshell membrane proteins, providing a theoretical basis and research approach for food protein modification and the preparation of green electronic devices.

Extraction Optimization and Bioactivity of Polysaccharides from Ganoderma leucocontextum Spores

Background: Oxidative stress is associated with the occurrence and progress of aging. Natural polysaccharides have attracted considerable attention in the field of antioxidants and anti-aging products due to their superior biological activity and low toxicity. Ganoderma leucocontextum is primarily found in the Tibetan plateau region and is classified as a subspecies of Ganoderma. Known as the famous white Ganoderma, it is a precious food and medicine that has potent biological activity, including antitumor, hypoglycemic, and immune regulation. Since available resources are limited, there are few studies on the spore of Ganoderma leucocontextum. Methods: In this work, a polysaccharide (named GLSP) was extracted from the spore of Ganoderma leucocontextum using a fast, simple, efficient, and environmentally friendly extraction process: the three-phase partitioning (TPP) method. Results: The extraction condition was optimized under the Box-Behnken design (BBD): ratio of the solute to the solvent, 1:21.126 (w/v); (NH4)2SO4 concentration, 30% (w/v); ratio of the slurry to tert-butanol, 1:1.945 (v/v); and shaking temperature, 54.136 °C. Furthermore, a polysaccharide termed GLSP-A1 was purified from GLSP by column chromatography. The basic physicochemical properties were analyzed by molecular weight, Fourier transform infrared spectroscopy, monosaccharide composition, and scanning electron microscopy. Conclusions: GLSP-A1 down-regulated the expression of the pro-inflammation cytokines interleukin-6 and interleukin-1β, indicating favorable in vitro anti-inflammatory properties. In vivo, the effect of GLSP-A1 on aging was examined using the Caenorhabditis model. The results showed that GLSP-A1 reduced reactive oxygen species levels and lipofuscin accumulation. In general, these findings improve our understanding of the chemical content and bioactivity of a polysaccharide from Ganoderma leucocontextum spore and highlight the possibility of GLSP-A1 being utilized in dietary supplements for its anti-aging properties.

Polysaccharides from sea buckthorn - Ultrasound-assisted enzymatic extraction, purification, structural characterization, and antioxidant activity analysis

This study employed a sophisticated approach consisting of ultrasound-assisted enzyme treatment to extract polysaccharides from sea buckthorn (SBP). The SBP extraction parameters were optimized, the following optimal parameters were identified: solid-liquid ratio of 1:32 g/mL, ultrasound duration of 26 min, ultrasound temperature of 52 °C, and composite enzyme concentration of 6000 U/100 mL, and the maximum extraction yield of SBP was 24.07 ± 0.15 %. The separation and purification of SBP resulted in the isolation of three fractions of polysaccharides (SBPR-1, SBPR-2, SBPR-3). The composition and structural characteristics of the SBPRs were identified. Furthermore, the SBPRs exhibited the characteristic absorption peaks of polysaccharides. Notably, the surface microstructures of the SBPRs showed significant variations. Moreover, all SBPRs demonstrated commendable thermal stability and in vitro antioxidant activity. This study serves as a reference for the development and application of natural antioxidants and provides a theoretical foundation for the environmentally friendly and effective extraction of SBP.

Utilizing ultrasound for the extraction of polysaccharides from the tuber of Typhonium giganteum Engl.: Extraction conditions, structural characterization and bioactivities

Polysaccharides from the dried tuber of Typhonium giganteum Engl. (TGEPs) were obtained by utilizing ultrasonic-assisted extraction (UAE) as the extraction method. The determination of optimal process parameters for the UAE of TGEPs (TGEP-U) was accomplished through the application of response surface methodology (RSM). The structural characteristics, antioxidant and hypoglycemic effects of TGEP-U and TGEPs obtained by hot water extraction (TGEP-H) were then compared. Consequently, the optimum extraction conditions predicted by RSM for TGEP-U were obtained as adding water at a ratio of 31 mL/g and extracted for 32 min under an ultrasound power of 440 W. In the verification experiment, the actual yield of TGEP-U was 7.32 ± 0.18 %. It was found that UAE could increase the yield and the total sugar content of TGEPs. Meanwhile, chemical composition analysis showed that both TGEP-U and TGEP-H were mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose, but the monosaccharide molar ratios were changed by UAE. Analysis of molecular weight (Mw) revealed the presence of three primary constituents within TGEP-U, and four main components in TGEP-H, and UAE reduced the average Mw of TGEPs. No obvious difference was found in the Fourier transform infrared spectroscopy analysis of TGEP-U and TGEP-H. The Congo red and Circular dichroism tests demonstrated that TGEP-U and TGEP-H had non-three helical structure. Scanning electron microscope observation further revealed that the aggregation of functional groups within TGEPs may be influenced by ultrasound, thereby affecting their powder morphology. TGEP-U has slightly poorer thermal stability than TGEP-H, which may be affected by ultrasonic cavitation effects. The results also indicated that TGEP-U had better antioxidant and hypoglycemic activity than TGEP-H. In summary, UAE is an effective method to extract and enhance the activity of TGEPs with enormous research value and potentials.

Structural Characterizations and Biological Evaluation of a Natural Polysaccharide from Branches of Camellia oleifera Abel

BACKGROUND

Camellia oleifera Abel (C. oleifera) is widely cultivated and serves as an important source of edible oil. Yet, during oil production, pruned branches generate significant waste and contribute to environmental pollution.

OBJECTIVES

In this work, we obtain a natural polysaccharide from the branches of C. oleifera and optimize its extraction using Box-Behnken design (BBD), which is a statistical method commonly used in response surface methodology. Additionally, we study its properties, such as monosaccharide composition, structural features, antioxidant, and anti-inflammatory abilities.

RESULTS

BBD was employed to optimize polysaccharide extraction (solid-liquid ratio = 1:40; 90 °C; 130 min) for a higher yield. After purification, the major monosaccharides of branches of C. oleifera's polysaccharide (CBP) were disclosed as glucose and galactose. Subsequent structural features of CBP were measured. The antioxidant and anti-inflammatory abilities were measured. The highly scavenging rates of the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals, with the chelating capacity of Fe2+, indicate potent antioxidant activity of CBP.

CONCLUSIONS

In general, CBP demonstrated significant anti-inflammatory activity with down-regulating the expression of IL-6 and IL-1β in the LPS-induced macrophage RAW264.7 model. This bioactive polysaccharide adds value to waste branches by offering a novel approach to waste recycling and the development of C. oleifera.

Characterization and Pickering emulsifying ability of Adinandra nitida leaf polysaccharides

Herein, Adinandra nitida leaf polysaccharides (ANPs) were isolated, identified, and used as a particle emulsifier to stabilize Pickering emulsions. ANP was identified as a polysaccharide with a weight-average molecular weight of 383.10 ± 8.57 kDa that was mainly composed of galacturonic acid (43.94 ± 3.63 mol%), arabinose (17.44 ± 1.06 mol%), glucose (8.53 ± 0.65 mol%), and rhamnose (4.88 ± 0.32 mol%). The main glycosidic linkages included t-Ara(f)-(1→, →4)-Gal(p)-(1→, and →4)-Gal(p)-UA-(1→, with molar percentage ratios of 8.97 %, 19.68 %, and 47.05 %, respectively. ANP possessed a reducing power and ABTS radical scavenging ability. ANP could also reduce the interfacial tension between medium-chain triglycerides (MCT) and water in a concentration-dependent manner, demonstrating its emulsifying role. When the addition amount (c) ≥ 3 %, ANP could stabilize the O/W-type MCT-based Pickering emulsion gel with an oil-phase volume fraction of 70 %, and c was proportional to mechanical parameters such as gel strength, macroscopic viscosity index, and elastic index.

Corrective role of endophytic exopolysaccharides from Clerodendrum infortunatum L. on arsenic-induced ovarian steroidogenic dysfunction and associated inflammatory responses

The present investigation aimed to evaluate the therapeutic potential of exopolysaccharides (EPSs) derived from endophytic fungi against arsenic [As(III)]-mediated metabolic and reproductive ailments. Two endophytic fungi, Diaporthe arengae (CleR1) and Fusarium proliferatum (CleR3), were isolated from Clerodendrum infortunatum (Cle), and used for the extraction of two types of EPSs. GC-MS analysis confirmed the presence of hydroxymethyl furfural (HMF) and α-d-glucopyranose in the EPS1 (CleR1) and EPS2 (CleR3), respectively. FTIR analysis revealed the potential As(III)-chelation properties of both EPSs. EPS1 and EPS2 significantly mitigated As(III)-induced oxidative stress and lipid peroxidation by restoring the activities of antioxidative enzymes. EPSs successfully corrected the gonadotropin imbalance and steroidogenic alterations. The downregulation of proinflammatory (NF-κB and TNF-α) and proapoptotic (BAX) mediators and the upregulation of antiapoptotic (Bcl-2) markers were also detected following the treatment with EPSs. Histomorphological restoration of reproductive and metabolic organs was also observed in both the EPS groups. Moreover, the As(III)-induced increase in the immunoreactivity of the androgen receptor (AR) was successfully reversed by these EPSs. Molecular docking predicted that HMF and α-d-glucopyranose of EPS1 and EPS2 interact with the active site of AR by limiting its activity. Hence, EPS could be effective for developing new therapeutic strategies for managing As(III) toxicity.

In vitro evaluation of the antitumor and antioxidant effects of purified and characterized polysaccharides from Ganoderma applanatum

BACKGROUND

In this study, the chemical properties of Ganoderma applanatum polysaccharides (GAP) were systematically investigated, followed by a comprehensive analysis of their antitumor and antioxidant capabilities.

METHODS

Ultrasonic circulation technology was employed for the extraction of GAP, facilitating the procurement of crude polysaccharides through the Sevag method, dialysis, and sequential alcohol precipitation. The chemical constituents of these polysaccharides were subsequently analyzed utilizing Fourier-transform infrared spectroscopy and gas chromatography-mass spectrometry. The antitumor and antioxidant properties of the polysaccharide components were assessed utilizing 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and free radical scavenging methods, respectively.

RESULTS

Gradient ethanol precipitation yielded three principal polysaccharide fractions: GAP-40, GAP-60 and GAP-80. Analysis revealed glucose as the predominant component in these fractions, with average molecular weights determined to be 77.75, 9.25 and 1.03 kDa, respectively. The antitumor activity of GAP-40, GAP-60 and GAP-80 against MCF-7 cells demonstrated both time and concentration dependence. Significantly, GAP-40, at a concentration of 1000 μg/mL over 48 h, presented a notable inhibition rate of 56.77%, outperforming GAP-60 and GAP-80. Furthermore, the antioxidant capacities of GAP-40, GAP-60 and GAP-80 were comparably significant to that of vitamin C, with detailed analysis revealing marked differences in antioxidant activity among the GAP variants. Specifically, GAP-40 exhibited superior efficacy in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radicals relative to GAP-60 and GAP-80. In contrast, GAP-80 was distinguished by its exceptional hydroxyl radical scavenging capacity, surpassing that of both GAP-40 and GAP-60.

CONCLUSION

These results substantiate the potential of GAPs as viable and effective antitumor agents, additionally suggesting their utility as functional foods endowed with antioxidant attributes.

Anti-inflammatory activity and underlying mechanism against sepsis-induced acute lung injury of a low-molecular-weight polysaccharide from the root of Stemona tuberosa Lour

The root of Stemona tuberosa Lour has been used to treat tuberculosis, scabies, and eczema. Polysaccharides are among its main bioactive ingredients. A low-molecular-weight (1819 Da) polysaccharide (SPS2-A) was obtained from the root of S. tuberosa Lour by optimizing three-phase partitioning, purified using an ion chromatography column, and its effects and mechanisms were investigated. Structural analysis revealed that SPS2-A contained arabinose, galactose (Gal), glucose (Glc), xylose, and mannose. The SPS2-A backbone structure comprised sugar residues →4)-α-D-Glcp-(1→, →4)-α-D-Galp-(1→, and →4,6)-β-D-Galp-(1→, while the side chain primarily comprised α-D-Glcp-(1 → connected to the O-6 position of the residue →4,6)-β-D-Galp-(1→. In vitro, SPS2-A downregulated the expression of interleukin-6 in lipopolysaccharide-induced RAW264.7 macrophages. In vivo, SPS2-A significantly downregulated the expression of myeloperoxidase, interleukin-6, interleukin-1β, and tumor necrosis factor-α in bronchoalveolar lavage fluid and lung tissue. Western blotting analysis indicated that SPS2-A reduced lung inflammation in mice with sepsis-induced acute lung injury by activating the nuclear factor κB pathway. These results suggest that SPS2-A is a potential anti-inflammatory candidate for the treatment of sepsis-induced acute lung injury.

Preparation of sulfated arabinogalactan-loaded hydrogel for wound healing in mouse burn model

Sulfation of polysaccharides can affect their biological activity by introducing sulfate groups. Skin burns occur regularly and have a great impact on normal survival. In this study, sulfated arabinogalactan (SAG) was prepared by sulfation, and polyvinyl alcohol (PVA) was used to prepare hydrogels for the treatment of scalded skin in mouse. The results show that the main chain of SAG consists of →3-β-D-Galactose (Gal)-(1, →3, 6)-β-D-Gal-(1 and →4)-β-d-Glucose (Glc)-(1. The chain is a neutral polysaccharide composed of T-β-L-Arabinose (Araf)-(1→, with a molecular weight of 17.9 kDa. At the same time, PVA + SAG hydrogel can promote the scald repair of mouse skin by promoting collagen deposition and angiogenesis, and regulating the TLR4/MyD88/NF-κB signaling pathway. Interestingly, the effect of SAG on promoting the repair of scald wounds is enhanced after AG is derivatized by sulfation. Therefore, the preparation of SAG by sulfation can promote scald repair, and has great application potential in the field of food and medicine.

Structural analysis and biological activity of cell wall polysaccharides and enzyme-extracted polysaccharides from pomelo (Citrus maxima (Burm.) Merr.)

Pomelo peel is a valuable source of pectin, but research on its cell wall polysaccharides is limited. This study compared the cell wall polysaccharides of pomelo peel, enzyme-extracted polysaccharides of pomelo peel, and enzyme-extracted polysaccharides of whole pomelo fruit. Cell wall polysaccharides, including water-soluble pectin (WSP), chelator-soluble pectin (CSP), sodium carbonate-soluble pectin (NSP), 1 mol/L KOH soluble hemicellulose (KSH-1), and 4 mol/L KOH soluble hemicellulose (KSH-2), were obtained by sequence-extraction method. Total polysaccharides from whole pomelo fruit (TP) and peel-polysaccharides from pomelo pericarps (PP) were obtained using enzyme-extraction method. The structural, thermal, rheological, antioxidant properties, and wound healing effect in vitro were described for each polysaccharide. WSP had a uniform molecular weight distribution and high uronic acid (UA) content, suitable for commercial pectin. NSP had the highest Rhamnose (Rha)/UA ratio and a rich side chain with highest viscosity and water retention. PP displayed the highest DPPH radical scavenging activity and reducing capacity at 0.1 to 2.0 mg/mL concentration range, with an IC50 of 1.05 mg/mL for DPPH free radicals. NSP also demonstrated the highest hydroxyl radical scavenging activity and promoted Human dermal keratinocyte proliferation and migration at 10 μg/mL, suggesting potential applications in daily chemical and pharmaceutical industries.

Watermelon Rind Dietary Fibers as Natural Source to Enhance Texture of Wheat Bread

The objective of this study was to explore how watermelon rinds (WMRs) and their derivatives, specifically water-soluble polysaccharides (WMRPs) and hemicellulose (WMRH), as sources of dietary fiber, could enhance the quality of wheat bread. The extraction process yielded 34.4% for WMRP and 8.22% for WMRH. WMR, WMRP, and WMRH exhibited promising functional characteristics and were incorporated separately into wheat flour with low bread-making quality (FLBM) at varying proportions (0.5%, 1%, and 1.5% (w/w)). The volume, texture, and crust and crumb color underwent evaluation and were compared to the control. The findings indicated that incorporating WMR notably enhanced the alveograph profile of the dough, demonstrating a more effective impact than the addition of WMRP and WMRH. Adding WMR, WMRP, and WMRH at a 1% concentration to low-quality wheat flour for bread making increased the deformation work values by 16%, 15%, and 13%, respectively, and raised the P/L ratios by 42%, 36%, and 38%, respectively. Additionally, the assessment of the bread highlighted a substantial enhancement in both volume and texture profile when WMR was added, in contrast to the control bread (made with FLBM). These findings underscore that incorporating 1% WMR into FLBM was the most effective means of improving bread quality based on the results of this study.

A Water Polysaccharide-Protein Complex from Grifola frondosa Inhibit the Growth of Subcutaneous but Not Peritoneal Colon Tumor under Fasting Condition

SCOPE

Grifola frondosa has been shown to induce immune modulatory, modulate autophagy, and apoptosis in cancer cells. However, little is known about its potential for managing tumor progression as an adjunct to nutrient restriction.

METHODS AND RESULTS

Water extract produces a G. frondosa polysaccharide-protein complex (G. frondosa PPC) of average molecular weight of 46.48 kDa, with glucose (54.8%) as the main constituent. Under serum-restricted conditions, G. frondosa PPC can significantly inhibit MC38 colorectal tumor cell migration in vitro. Under alternate-day fasting condition, G. frondosa PPC can only significantly inhibit the growth of subcutaneous (s.c.) tumor, but is feeble in halting its spread in the intraperitoneal (i.p.) cavity in tumor-bearing mice. Histopathological examination and Raman imaging show a significant increase in lipid content in the tumor microenvironment (TME) tissue of the s.c. tumor-bearing mice. G. frondosa PPC significantly increases C17:0 and C24:0 saturated fatty acids and significantly decreases C16:1 and C18:1 monounsaturated fatty acids in the TME of s.c. tumor-bearing mice compared with the i.p. cavity model.

CONCLUSION

G. frondosa PPC significantly inhibits tumor growth in s.c. tumor-bearing mice under intermittent fasting conditions by altering the fatty acid composition of the TME.

Characterizing date seed polysaccharides: A comprehensive study on extraction, biological activities, prebiotic potential, gut microbiota modulation, and rheology using microwave-assisted deep eutectic solvent

This study investigated the biological activities, prebiotic potentials, modulating gut microbiota, and rheological properties of polysaccharides derived from date seeds via microwave-assisted deep eutectic solvent systems. Averaged molecular weight (246.5 kDa) and a monosaccharide profile (galacturonic acid: glucose: mannose: fructose: galactose), classifying MPS as a heteropolysaccharide. MPS, at concentrations of 125-1000 µg/mL, demonstrates increasing free radical scavenging activities (DPPH, ABTS, MC, SOD, SORS, and LO), potent antioxidant potential (FRAP: 51.2-538.3 µg/mL; TAC: 28.3-683.4 µg/mL; RP: 18.5-171.2 µg/mL), and dose-dependent antimicrobial activity against common foodborne pathogens. Partially-purified MPS exhibits inhibition against α-glucosidase (79.6 %), α-amylase (85.1 %), and ACE (68.4 %), along with 80 % and 46 % inhibition against Caco-2 and MCF-7 cancer cells, respectively. Results indicate that MPS fosters the growth of beneficial fecal microbiota, including Proteobacteria, Firmicutes, and Actinobacteria, supporting microbes responsible for major SCFAs (acetic, propionic, and butyric acids) production, such as Ruminococcus and Blautia.

Functional properties, structural characteristics, and anti-complementary activities of two degraded polysaccharides from strawberry fruits

Two low-molecular-weight polysaccharides (DPSP50 and DPSP70) were obtained using hydrogen peroxide-vitamin C (H2O2-Vc) treatment at 50 °C and 70 °C, respectively. Both DPSP50 and DPSP70 comprised the same six monosaccharides in different ratios, and their molecular weights (Mws) were 640 kDa and 346 kDa, respectively. Functional properties analyses demonstrated that DPSP50 and DPSP70 each had an excellent water holding capacity, oil absorption capacity, and emulsion properties, as well as shear-thinning characteristics and viscoelastic properties. Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic assays confirmed the existence of α-, β-pyranose rings and the same six sugar residues in DPSP50 and DPSP70. The results of Congo red test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) demonstrated that DPSP50 and DPSP70 did not contain triple-helix conformations, but were amorphous aggregates with flake-like shape and rough surface. Additionally, both DPSP50 and DPSP70 showed strong anti-complementary activities through the classical pathway and the alternative pathway. The results support the potential utility of these degraded polysaccharides from strawberry fruits in functional foods and medicines.

Acetylation of the polysaccharide from Houttuynia cordata rhizome and their α-glucosidase inhibition mechanism

In this study, the polysaccharide (RHCP) extracted from Houttuynia cordata rhizome was acetylated through the acetic anhydride method. The physicochemical properties of RHCP and its acetylated derivatives (Ac-RHCP) were determined by infrared spectra, scanning electron microscopy, and Congo red test. Meanwhile, the α-glucosidase inhibition mechanism of RHCP and Ac-RHCP was analyzed by inhibition kinetics, and circular dichroism and fluorescence spectroscopy. Ac-RHCP resulted in a more porous surface structure and 1.83-fold higher solubility compared with RHCP. At a concentration of 6 mg/mL, the α-glucosidase inhibition rate of Ac-RHCP was 75.40%, while that of RHCP was 44.68%. RHCP and Ac-RHCP inhibited α-glucosidase in a mixed-type manner, reduced the endogenous fluorescence of α-glucosidase, affected the microenvironment of amino acid residues, and changed the conformation of α-glucosidase. The study indicates that Ac-RHCP exhibits a certain level of α-glucosidase inhibition, demonstrating its potential as a functional food for glycemic control.

Polysaccharides from fructus corni: Extraction, purification, structural features, and biological activities

Fructus Corni, derived from the dried fruit of Cornus officinalis Sieb. Et Zucc., is widely used as a food source and Chinese herb. Fructus Corni, as an indispensable ingredient in Liuwei Dihuang decoction, tonifies the liver and kidneys. As the main component of water decoctions, Fructus Corni polysaccharides demonstrate multifaceted effects, including hypoglycemic, hypolipidemic, antioxidant, anti-aging, sexual function regulation, and anti-epileptic, The ultrasound-assisted extraction method obtained the highest yields of Fructus Corni polysaccharides. However, it has notable shortcomings and lacks further innovation. The homogeneous polysaccharides obtained from Fructus Corni are mostly neutral polysaccharides with relatively limited structure, and the mechanism of their biological activity needs to be further elucidated. In addition, different extraction, isolation and purification methods may change the molecular weight, monosaccharide composition, and biological activity of polysaccharides. Therefore, this study systematically summarized the extraction, purification, structural features, and biological activities of Fructus Corni polysaccharides. This study aimed to provide support for the ongoing development and application of Fructus Corni polysaccharides.

Optimization and evaluation of Atrina pectinata polysaccharides recovered by subcritical water extraction: A promising path to natural products

In this study, the recovery of Atrina pectinata posterior adductor polysaccharides (APP-PS) using subcritical water extraction (SWE) was optimized by response surface methodology (RSM) and the physicochemical and biological properties of the recovered APP-PS were evaluated. The optimal extraction conditions, which resulted in a maximum yield of 55.58 ± 1.12 %, were temperature, 152.08 °C; extraction time, 10 min; solid-liquid ratio, 30 g/600 mL. The obtained APP-PS was found to be 88.05 ± 0.17 % total sugar. Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) analyses confirmed the presence of the α-coordination of D-glucan in the polymer sample. The analysis of monosaccharide composition, along with thermogravimetric analysis, revealed the typical structure of the sample, composed of glucose alone. Total phenolic contents of APP-PS were measured as 5.47 ± 0.01 mg Gallic acid/g of dry sample and total flavonoids contents were determined to be 0.78 ± 0.06 mg Quercetin/g of dry sample. For biological activities, ABTS+, DPPH and FRAP antioxidant activities were measured to be 20.00 ± 0.71, 2.35 ± 0.05 and 4.02 ± 0.07 μg Trolox equivalent/100 g of dry sample, respectively. Additionally ACE inhibitory was confirmed to be 87.02 ± 0.47 %. These results showed that SWE is an effective method to recover biofunctional materials from marine organisms.

Sulfated polysaccharides from Caulerpa lentillifera: Optimizing the process of extraction, structural characteristics, antioxidant capabilities, and anti-glycation properties

The polysaccharides found in Caulerpa lentillifera (sea grape algae) are potentially an important bioactive resource. This study makes use of RSM (response surface methodology) to determine the optimal conditions for the extraction of valuable SGP (sea grape polysaccharides). The findings indicated that a water/raw material ratio of 10:1 mL/g, temperature of 90 °C, and extraction time of 45 min would maximize the yield, with experimentation achieving a yield of 21.576 %. After undergoing purification through DEAE-52 cellulose and Sephacryl S-100 column chromatography, three distinct fractions were obtained, namely SGP11, SGP21, and SGP31, each possessing average molecular weights of 38.24 kDa, 30.13 kDa, and 30.65 kDa, respectively. Following characterization, the fractions were shown to comprise glucose, galacturonic acid, xylose, and mannose, while the sulfate content was in the range of 12.2-21.8 %. Using Fourier transform infrared spectroscopy (FT-IR) it was possible to confirm with absolute certainty the sulfate polysaccharide attributes of SGP11, SGP21, and SGP31. NMR (nuclear magnetic resonance) findings made it clear that SGP11 exhibited α-glycosidic configurations, while the configurations of SGP21 and SGP31 were instead β-glycosidic. The in vitro antioxidant assays which were conducted revealed that each of the fractions was able to demonstrate detectable scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations. All fractions were also found to exhibit the capacity to scavenge NO radicals in a dose-dependent manner. SGP11, SGP21, and SGP31 were also able to display cellular antioxidant activity (CAA) against the human adenocarcinoma colon (Caco-2) cell line when oxidative damage was induced. The concentration levels were found to govern the extent of such activity. Moreover, purified SGP were found to exert strong inhibitory effects upon glycation, with the responses dependent upon dosage, thus confirming the potential for SGP to find a role as a natural resource for the production of polysaccharide-based antioxidant drugs, or products to promote improved health.

Consumer perception of whole watermelons

There are many varieties of watermelons, providing distinct external and internal sensory attributes. This study used an online survey (n = 700) and focus groups (n = 25) to investigate consumer perception of whole watermelons. Rind color, sound of the melon, size, and price were the most important attributes for consumers when selecting a whole watermelon. Freshness was the most important whole watermelon characteristic, and watermelon freshness/quality was driven by sweetness, crispness, and juiciness. Consumers preferred seedless watermelons that had a light rind with dark green stripes, red flesh, an oval/oblong shape, firm and crisp flesh, a weight of approximately 2.2-5.5 kg, and labeling that described them as fresh, juicy, and sweet. Two consumer clusters were identified from quantitative survey data and were also representative of focus group participants: value consumers and watermelon enthusiasts. Watermelon enthusiasts were differentiated by a higher value for claims including local, product of USA, sustainably farmed, and organic. Watermelon purchase is quality driven: consumers will pay more for guaranteed sweetness and crispness. PRACTICAL APPLICATION: The ideal watermelon for all consumers is one that is dark green with stripes, is medium sized and oblong in shape, has a minimal rind-to-flesh ratio, and boasts dark, vibrant red flesh that is sweet, crisp, and juicy. All consumers want a better guarantee on watermelon quality because it is hard to predict sensory quality when selecting a melon. This study demonstrated the intrinsic and external drivers of liking for fresh watermelons and summarized a consumer watermelon purchase and consumption journey map that can guide further research and development of watermelons and provide insights on how to increase watermelon sales.

Advances in modeling techniques for the production and purification of biomolecules: A comprehensive review

In response to the growing demand for therapeutic biomolecules, there is a need for continuous and cost-effective bio-separation techniques to enhance extraction yield and efficiency. Aqueous biphasic extractive fermentation has emerged as an integrated downstream processing technique, offering selective partitioning, high productivity, and preservation of biomolecule integrity. However, the dynamic nature of this technique requires a comprehensive understanding of the underlying separation mechanisms. Unfortunately, the analysis of parameters influencing this dynamic behavior can be challenging due to limited resources and time. To address this, mathematical modeling approaches can be employed to minimize the tedious trial-and-error experimentation process. This review article presents mathematical modeling approaches for both upstream and downstream processing techniques, focusing on the production of biomolecules which can be used in pharmaceutical industries in a cost-effective manner. By leveraging mathematical models, researchers can optimize the production and purification processes, leading to improved efficiency and processing cost reduction in biomolecule production.

Optimization and Physicochemical Characterization of Polysaccharide Purified from Sonneratia caseolaris Mangrove Leaves: a Potential Antioxidant and Antibiofilm Agent

The Box-Behnken design was applied to determine the optimal parameters of the extraction condition by using the response surface methodology (RSM) from the leaves of Sonneratia caseolaris L. The result indicates the best-optimized conditions used for the extraction of polysaccharides at 84.02 °C temperature, 3.12 h time, and 27.31 mL/g for the water-to-material ratio. The maximum experimental yield of 8.81 ± 0.09% was obtained which is in agreement with the predicted value of 8.79%. Thereafter, low molecular weight polysaccharide (SCLP) was separated after sequentially being purified through column chromatography with a relative molecular weight of 3.74 kDa. The physicochemical properties were evaluated by characterization techniques such as FT-IR spectra, NMR spectrum, and SEM analysis. RP-HPLC analysis confirmed that SCLP was a heteropolysaccharide, majorly comprising rhamnose (28.25%), and xylose (27.17%) residues, followed by mannose (18.90%), and galactose (17.17%), respectively. Thermal analysis (TGA-DSC) results showed that SCLP is a highly thermostable polymer with a degradation temperature of 361.63 °C. X-ray diffraction patterns and tertiary structure analyses indicate that SCLP had a semi-crystalline polymer having a triple-helical configuration. Moreover, SCLP displayed potential antibiofilm ability for all the tested pathogens while stronger activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. In addition, SCLP has potential in vitro antioxidant activity on DPPH, ABTS radical, superoxide, and Fe2+ chelating. These findings indicate that the polysaccharide has potentially been used in functional food, cosmetics, and pharmacological industries.

Real-time online monitoring technology for sweeping frequency ultrasound (SFU) assisted extraction of amur grape (Vitis amurensis) seed oil

Sweeping frequency ultrasound (SFU) was used to assist extraction of amur grape (Vitis amurensis) seed (AGS) oil. Extraction conditions and physicochemical properties were optimized and analyzed under different extraction methods. Meanwhile, frequency and time domains were online monitored during SFU assisted extraction of AGS oil. PVDF piezoelectric sensor was used in time domain, and the hydrophone in frequency domain, so as to obtain the time-voltage waveform, signal power, spectrum distribution and other visual models. Physical models of the spatial peak acoustic intensity, charge quantity and work done by electric field force under different ultrasonic conditions were derived. The mathematical model between the work done by electric field force and the spatial peak acoustic intensity under the working state of PVDF piezoelectric sensor was constructed. Results show that the content of AGS oil by SFU assisted extraction was higher than that by organic extraction. Furthermore, the optimal single-frequency was 40 kHz and dual-frequency was 28/33 kHz, and SFU extraction time of 30 min was suitable with higher oil yield of 16.70 % and 16.94 %, respectively. In addition, the selection and combination of SFU also affected the oil oxidation degree. The peak voltage, spatial peak acoustic intensity, signal power and work of electric field force at 28/33 kHz were all higher than those at 40 kHz.

Natural deep eutectic solvents for Ultrasonic-Assisted extraction of nutritious date Sugar: Molecular Screening, Experimental, and prediction

The aim of this study is to develop an environmentally friendly and effective method for the extraction of nutritious date sugar using natural deep eutectic solvents (NADES) and ultrasound-assisted extraction (USAE). The careful design of a suitable NADES-USAE system was systematically supported by COSMO-RS screening, response surface method (RSM) and artificial neural network (ANN). Initially, 26 natural hydrogen bond donors (HBDs) were carefully screened for sugar affinity using COSMO-RS. The best performing HBDs were then used for the synthesis of 5 NADES using choline chloride (ChCl) as HBA. Among the synthesized NADES, the mixture of ChCl, citric acid (CA) and water (1:1:1 with 20 wt% water) resulted in the highest sugar yield of 78.30 ± 3.91 g/100 g, which is superior to conventional solvents such as water (29.92 ± 1.50 g/100 g). Further enhancements using RSM and ANN led to an even higher sugar recovery of 87.81 ± 2.61 g/100 g, at conditions of 30 °C, 45 min, and a solvent to DFP ratio of 40 mL/g. The method NADES-USAE was then compared with conventional hot water extraction (CHWE) (61.36 ± 3.06) and showed 43.1% higher sugar yield. The developed process not only improves the recovery of the nutritious date sugar but also preserves the heat-sensitive bioactive compounds in dates, making it an attractive alternative to CHWE for industrial utilization. Overall, this study shows a promising approach for the extraction of nutritive sugars from dates using environmentally friendly solvents and advanced technology. It also highlights the potential of this approach for valorizing underutilized fruits and preserving their bioactive compounds.

Exploring Bioactive Compounds in Brown Seaweeds Using Subcritical Water: A Comprehensive Analysis

In this study, we characterized the bioactive properties of three important brown seaweed species, Sargassum thunbergii, Undaria pinnatifida, and Saccharina japonica, by subcritical water extraction (SWE), as these species are well known for their beneficial health effects. Their physiochemical properties, including potential antioxidant, antihypertensive, and α-glucosidase inhibitory activity, and the antibacterial activity of the hydroysates were also analyzed. The highest total phlorotannin, total sugar content, and reducing sugar content in the S. thunbergii hydrolysates were 38.82 ± 0.17 mg PGE/g, 116.66 ± 0.19 mg glucose/g dry sample, and 53.27 ± 1.57 mg glucose/g dry sample, respectively. The highest ABTS⁺ and DPPH antioxidant activities were obtained in the S. japonica hydrolysates (124.77 ± 2.47 and 46.35 ± 0.01 mg Trolox equivalent/g, respectively) and the highest FRAP activity was obtained in the S. thunbergii hydrolysates (34.47 ± 0.49 mg Trolox equivalent/g seaweed). In addition, the seaweed extracts showed antihypertensive (≤59.77 ± 0.14%) and α-glucosidase inhibitory activity (≤68.05 ± 1.15%), as well as activity against foodborne pathogens. The present findings provide evidence of the biological activity of brown seaweed extracts for potential application in the food, pharmaceutical, and cosmetic sectors.

Optimization of ultrasound-assisted aqueous two-phase extraction of polysaccharides from seabuckthorn fruits using response methodology, physicochemical characterization and bioactivities

BACKGROUND

Seabuckthorn fruits contains many active subtances, among them, the seabuckthorn polysaccharide is one of the main active ingredients, and exhibits diverse bioactivities. The extraction of polysaccharides from seabuckthorn fruits is the most important step for their wide applications. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) is a promising green method for extracting polysaccharides. Additionally, physicochemical characterization and antioxidant activities can evaluate the potential functions and applications in the food and medicine industries.

RESULTS

Based on the single-factor experiments, 20.70% (w/w) ammonium sulfate ((NH₄ )₂ SO₄ ) and 27.56% (w/w) ethanol were determined as the suitable composition for aqueous two-phase. The optimum conditions of UA-ATPE obtained by response surface methodology were as follows: ultrasonic power (390 W), extraction time (41 min), liquid-to-material ratio (72: 1 mL/g), and the total yield of the polysaccharides reached 34.14 ± 0.10%, The molecular weights of the purified upper-phase seabuckthorn polysaccharide (PUSP) and the purified lower-phase seabuckthorn polysaccharide (PLSP) were 65 525 and 26 776 Da, respectively. PUSP and PLSP contained the same six monosaccharides (galacturonic acid, rhamnose, xylose, mannose, glucose and galactose), but with different molar ratios. Furthermore, PUSP and PLSP displayed certain viscoelastic property, had no triple helical structure, possessed different thermal stability, surface morphology and conformation in aqueous solution. PUSP and PLSP displayed strong antioxidant properties by the assays of scavenging ability of ABTS⁺ ·, the protection of DNA damage and erythrocyte hemolysis.

CONCLUSION

UA-ATPE significantly increased the yield of seabuckthorn polysaccharides. PUSP and PLSP were different in many aspects, such as molar ratio, surface shape and antioxidant activities. Seabuckthornpolysaccharides possess great potential in medicine and functional foods. © 2022 Society of Chemical Industry.

Insights into the Oxidative Stress Alleviation Potential of Enzymatically Prepared Dendrobium officinale Polysaccharides

(1) Background: The extraction parameters can dramatically alter the extraction rate and biological activity of polysaccharides. (2) Methods: Here, an enzyme-assisted extraction (EAE) was employed to extract D. officinale polysaccharides (DOPs), and its optimal extraction conditions were established by single-factor and Box-Behnken design (BBD) experiments. Further, on the basis of in vitro antioxidant capacity, the paraquat (PQ)-induced oxidative stress of Caenorhabditis elegans (C. elegans) was chosen as a research model to explore the antioxidant activity of DOPs. (3) Results: The results showed that the extraction yield of DOPs reached 48.66% ± 1.04% under the optimal condition. In vitro experiments had shown that DOPs have considerable ABTS⁺ radical scavenging capacity (EC50 = 7.27 mg/mL), hydroxyl radical scavenging capacity (EC50 = 1.61 mg/mL), and metal chelating power (EC50 = 8.31 mg/mL). Furthermore, in vivo experiments indicated that DOPs (0.25 mg/mL) significantly prolonged the lifespan, increased antioxidant enzyme activity, and upregulated the expression of daf-16 (>5.6-fold), skn-1 (>5.2-fold), and sir-2.1 (>2.3-fold) of C. elegans. (4) Conclusions: DOPs can be efficiently extracted by EAE and are effective in the reduction of oxidative stress levels in C. elegans.

Structural characterization, α-glucosidase inhibitory activity and antioxidant activity of neutral polysaccharide from apricot (Armeniaca Sibirica L. Lam) kernels

Screening for α-glucosidase inhibitors and antioxidants from natural sources that could reduce postprandial glucose in diabetic patients and reduce oxidative stress had attracted considerable interest. In this study, a neutral polysaccharide (AP-1) with a triple helix structure was isolated and purified from the residue of apricot (Armeniaca sibirica L. Lam.) kernels by using DEAE-52 and Sephadex G-100 columns. The molecular weight of AP-1 was 23.408 kDa and consisted mainly of glucose with trace amounts of arabinose, galactose, and mannose, which had molar percentages of 98.48, 0.63, 0.62 and 0.27 %, respectively. The main chain of AP-1 was composed of →4)-α-D-Glcp-(1 → interlinked, and α-D-Glcp-(1 → was attached as a branched chain at the O-6 position of →4,6)-α-D-Glcp-(1→. In addition, AP-1 exhibited stronger α-glucosidase inhibition and free radical scavenging ability compared to crude polysaccharides. Therefore, AP-1 could be used as a potential natural hypoglycemic agent and antioxidant in the treatment of diabetes mellitus.

Development of active packaging with chitosan, guar gum and watermelon rind extract: Characterization, application and performance improvement mechanism

The objective of this study was to make a film matrix containing chitosan (CS) and guar gum (GG), and to improve the physicochemical properties of the film using watermelon rind extract (WRE) as a cross-linker and active substance for the preservation of fresh-cut bananas. The results of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy showed that the WRE and CG matrix formed intermolecular hydrogen bond interactions, which made the structure of the resulting films more compact. With increasing amounts of WRE, the mechanical properties of the films were significantly increased, but the permeability of water vapor and oxygen was significantly decreased (p < 0.05). Notably, when the amount of extract reached 4 wt%, the DPPH radical scavenging activity of the composite film significantly increased to 83.24 %, and the antibacterial activity also reached its highest value. Fresh-cut bananas were stored at room temperature with polyethylene film, CG and CG-WRE. The CG with 4 wt% WRE effectively inhibited the changes in appearance, firmness, weight, color and total soluble solids content of fresh-cut bananas during storage. Therefore, CG-WRE as a novel active food packaging material, has good physicochemical properties and great potential to extend the shelf life of foods.

Comparison of chemical property and in vitro digestion behavior of polysaccharides from Auricularia polytricha mycelium and fruit body

The antioxidant activity of Auricularia polytricha is associated tightly with its polysaccharide concentration, molar mass and architecture. This study aims to explore the differences in structural and physicochemical traits and oxidation resistances between the polysaccharides from fruit body (ABPs) and mycelial (IAPs) of Auricularia polytricha. The results showed that ABPs and IAPs were constituted by glucose, glucuronic acid, galactose and mannose. However, the molecular weight distribution of IAPs (3.22 × 10⁴ Da (52.73%) and 1.95 × 10⁶ Da (24.71%)) was wider than that of ABPs (5.4 × 10⁶ Da (95.77%)). The shear-thinning performance and viscoelastic behavior of both IAPs and ABPs are representative. IAPs are scattered in sheets, with folds and holes, and have a triple helix structure. ABPs are compact in structure and clear in texture. The main functional groups and thermal stability of both polysaccharides were similar. Concerning the in-vitro oxidation resistance, both of the studied polysaccharides exhibited the potent potential to scavenge hydroxyl radicals (IC₅₀ = 3.37 ± 0.32 and 6.56 ± 0.54 mg/mL, respectively) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (IC₅₀ = 0.89 ± 0.22 and 1.48 ± 0.63 mg/mL, respectively), as well as the moderate reduction power. In addition, IAPs and ABPs were both completely undigested in simulated contexts of saliva, small intestine and stomach, and the two polysaccharide types maintained high DPPH and hydroxyl radical scavenging activities. DDPH scavenging rate during digestion was positively correlated with uronic acid content. To conclude, this study suggests the potential of IAPs as an equivalent alternative to ABPs.

Structural Characterization, Antioxidant and Antitumor Activities of the Two Novel Exopolysaccharides Produced by Debaryomyces hansenii DH-1

Exopolysaccharides produced by edible microorganisms exhibit excellent constructive physicochemical and significant biological activity, which provide advantages for the food or pharmaceutical industries. Two novel exopolysaccharides produced by Debaryomyces hansenii DH-1 were characterized, named S1 and S2, respectively. S1, with a molecular weight of 34.594 kDa, primarily consisted of mannose and glucose in a molar ratio of 12.19:1.00, which contained a backbone fragment of α-D-Manp-(1→4)-α-D-Manp-(1→2)-α-D-Glcp-(1→3)-α-D-Manp-(1→3)-β-D-Glcp-(1→4)-β-D-Manp-(1→. S2, with a molecular weight of 24.657 kDa, was mainly composed of mannose and galactose in a molar ratio of 4.00:1.00, which had a backbone fragment of α-D-Manp-(1→6)-β-D-Manp-(1→2)-α-D-Manp-(1→4)-α-D-Galp-(1→3)-β-D-Manp-(1→6)-α-D-Manp-(1→. Both S1 and S2 exhibited good thermal stability and potent hydroxyl radical scavenging activity, with ~98%. Moreover, S1 possessed an additional strong iron-reducing capacity. In vitro antitumor assays showed that S1 and S2 significantly inhibited the proliferation of Hela, HepG2, and PC-9 cancer cells. Moreover, PC-9 was more sensitive to S1 compared with S2. The above results indicate that S1 and S2 have great potential to be utilized as natural antioxidants and candidates for cancer treatment in the food and pharmaceutical industries.

Simultaneously enhanced stability and biological activities of chlorogenic acid by covalent grafting with soluble oat β-glucan

Chlorogenic acid (CA) has a wide range of biological activities but the chemical structure is extremely unstable. In this study, CA was grafted onto a soluble oat β-glucan (OβGH) to improve the stability. Although the crystallinity and thermal stability of CA-OβGH conjugates reduced, the storage stability of CA significantly improved. The DPPH and ABTS scavenging ability of CA-OβGH IV (graft ratio 285.3 mg CA/g) were higher than 90 %, which is closed to activities of equivalent concentration of Vc (93.42 %) and CA (90.81 %). The antibacterial abilities of CA-OβGH conjugates are improved compared to the equivalent content of CA and potassium sorbate. Particularly, the inhibition rate of CA-OβGH for gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) are significantly higher than that of gram-negative bacteria (Escherichia coli). The results demonstrated that covalent grafted CA with soluble polysaccharide is an effective strategy to enhance its stability and biological activities.

A review on shellfish polysaccharides: Extraction, characterization and amelioration of metabolic syndrome

Shellfish are diverse, widely distributed organisms that are a rich source of biological resources. Polysaccharides are an important components in shellfish, hence a great deal of attention has been directed at isolation and characterization of shellfish polysaccharides because of their numerous health benefits. Differences in shellfish species, habits, and environment result in the diversity of the structure and composition of polysaccharides. Thus, shellfish polysaccharides possess special biological activities. Studies have shown that shellfish polysaccharides exert biological activities, including antioxidant, antitumor, immune-regulation, hypolipidemic, antihypertensive, and antihyperglycemic effects, and are widely used in cosmetics, health products, and medicine. This review spotlights the extraction and purification methods of shellfish polysaccharides and analyses their structures, biological activities and conformational relationships; discusses the regulatory mechanism of shellfish polysaccharides on hyperlipidemia, hypertension, and hyperglycemia caused by lipid metabolism disorders; and summarizes its alleviation of lipid metabolism-related diseases. This review provides a reference for the in-depth development and utilization of shellfish polysaccharides as a functional food to regulate lipid metabolism-related diseases. To achieve high value utilization of marine shellfish resources while actively promoting the development of marine biological industry and health industry.

Active Thermoplastic Starch Film with Watermelon Rind Extract for Future Biodegradable Food Packaging

Petrochemical plastic wastes generate serious environmental problems because they are resistant to natural decomposition. The aim of this study was to develop a biodegradable active thermoplastic film composed of polyvinyl alcohol (PVA), corn starch (ST), glycerol, and the active compounds from watermelon rind extract (WMRE), or PVA/ST/WMRE, using the casting technique. The film was examined for its mechanical, antioxidant, and functional properties against selected foodborne pathogens. The results showed that the addition of 10% v/v of watermelon rind extract to the film formulation significantly increased the tensile strength from 19.44 ± 0.84 MPa to 33.67 ± 4.38 MPa and slightly increased the percent elongation at break (% EAB) from 35.04 ± 0.96% to 35.16 ± 1.08%. The antioxidant property of PVA/ST/WMRE film was analyzed based on the DPPH scavenging activity assay, which significantly increased from 29.21 ± 0.24% to 63.37 ± 4.27%. The minimum inhibitory concentration (MIC) of watermelon rind extract was analyzed for the growth inhibition of Bacillus cereus ATCC 11778, Escherichia coli ATCC 8739, and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311, with 10% (v/v) found as an optimal concentration against B. cereus. Wrapping fresh-cut purple cabbage with PVA/ST/WMRE film significantly reduced the microbial load after 3 days of storage, in comparison to commercial packaging (PET) and thermoplastic control film. Consumer testing of the packaging film indicated that user acceptance of the product was favorable. Therefore, we suggest that this newly developed film can be used as a biodegradable food packaging item that will lead to enhanced food safety, food quality, prolonged shelf life, and consumer acceptance for further food applications.

Hybrid techniques of pre and assisted processing modify structural, physicochemical and functional characteristics of okra pectin: Controlled-temperature ultrasonic-assisted extraction from preparative dry powders and its field monitoring

Diversiform okra dry powders were prepared and controlled-temperature ultrasonic-assisted extraction (CTUAE) was then utilized to obtain okra pectin (OP) from the preparative powders. During processing of hybrid techniques, 6 types of dry powders were prepared through different drying technologies (hot air drying, HD; freeze-drying, FD) and meshes (60, 80, 120 meshes) at first. Next, the extraction yield, physicochemical and function characteristics, and molecular structure of OP were analyzed with or without CTUAE technique. Meanwhile, the time-frequency domains of acoustic fields during extraction process of OP were monitored to analyze the effects of ultrasonic fields. Results showed that OP main chains with less cracking by FD than that by HD; the yield, GalA, esterification degree (DE), M_w and viscosity of OP increased, but its particle size decreased. Water holding capacity (WHC) and oil holding capacity (OHC) of OP by HD were more prominent. Secondly, HD OP had dendritic rigid chains, while FD OP had flexible chains with multiple branches. For HD OP, as meshes of okra dry powders decreased, GalA, viscosity and emulsification ability decreased; while gel strength and thermal stability increased. For FD OP, the reduction of meshes improved thermal stability. Above all, CTUAE technique increased the yield and GalA, and decreased DE, M_w and particle size of OP. In terms of functional characteristics, the technique also improved gel strength, resilience and viscoelasticity, enhanced emulsifying stability, WHC and thermal stability, and reduced viscosity. Finally, the correlation between functional and structural characteristics of OP was quantified, and some suggestions were made for its application in food areas.

Onion and garlic polysaccharides: A review on extraction, characterization, bioactivity, and modifications

Allium cepa (onion) and Allium sativum (garlic) are important members of the Amaryllidaceae (Alliaceae) family and are being used both as food and medicine for centuries in different parts of the world. Polysaccharides have been extracted from different parts of onion and garlic such as bulb, straw and cell wall. The current literature portrays several studies on the extraction of polysaccharides from onion and garlic, their modification and determination of their structural (molecular weight, monosaccharide unit and their arrangement, type and position of glycosidic bond or linkage, degree of polymerization, chain conformation) and functional properties (emulsifying property, moisture retention, hygroscopicity, thermal stability, foaming ability, fat-binding capacity). In this line, this review, summarizes the various extraction techniques used for polysaccharides from onion and garlic, involving methods like solvent extraction method. Furthermore, the antioxidant, antitumor, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, and antidiabetic properties of onion and garlic polysaccharides as reported in in vivo and in vitro studies is also critically assessed in this review. Different studies have proved onion and garlic polysaccharides as potential antioxidant and immunomodulatory agent. Studies have implemented to improve the functionality of onion and garlic polysaccharides through various modification approaches. Further studies are warranted for utilizing onion and garlic polysaccharides in the food, nutraceutical, pharmaceutical and cosmetic industries.

A cold-water polysaccharide-protein complex from Grifola frondosa exhibited antiproliferative activity via mitochondrial apoptotic and Fas/FasL pathways in HepG2 cells

Grifola frondosa (G. frondosa) is widely known for its anti-tumor potential, which has been demonstrated by numerous scientific researches. In this study, two water soluble polysaccharide-protein complexes were extracted from G. frondosa at 4 °C (GFG-4) and 100 °C (GFG-100) and purified. Compared with GFG-100, GFG-4 had a higher protein content and molecular weight. The main monosaccharides of GFG-4 and GFG-100 were rhamnose, glucose, and galactose, with an approximate ratio of 3.00: 1.00: 0.86 and 2.85: 1.00: 0.94, respectively. The Fourier transform infrared spectra indicated that the two polysaccharide-protein complexes displayed characteristic functional groups of polysaccharides and proteins, and mainly contain pyranose ring with α-glycosidic linkage. Atomic force microscope images showed that both GFG-4 and GFG-100 exhibited straight chains, and GFG-4 possessed a relatively abundant fraction of branched chains. Intriguingly, GFG-4 showed a stronger antiproliferative activity against HepG2 cells than GFG-100. The mechanisms were further investigated by quantitative real-time PCR and western blot, it found that GFG-4 inhibited the proliferation of HepG2 cells mainly through the intrinsic activation of mitochondrial pathway and the Fas/FasL-mediated Caspase-8/-3 pathway. Conclusively, G. frondosa cold-water extracted polysaccharide-protein complexes could be used as a functional food for preventing or treating hepatocellular carcinoma.

Subcritical Water Hydrolysis of Comb Pen Shell (Atrina pectinata) Edible Parts to Produce High-Value Amino Acid Products

Artina pectinata (Comb pen shell, CPS) is a high-protein source that contains a variety of essential amino acids. Subcritical water hydrolysis (SWH) was used to recover amino acids from the posterior adductor muscle (PAM), anterior adductor muscle (ADM), and mantle. The temperatures ranged from 120 °C to 200 °C, and the pressure and time of hydrolysis were 3 MPa and 30 min, respectively. Further characterization of the hydrolysates was performed to ascertain amino acid profiles and biofunctional properties. The hydrolysates contained more free amino acids than the untreated samples. Antioxidant activity of treated samples increased as SW temperatures increased. At 200 °C, those inhibiting ACE had a maximum antihypertensive activity of 200 °C in 1% PAM, ADM, and mantle with 85.85 ± 0.67, 84.55 ± 0.18, and 82.15 ± 0.85%, respectively, compared to 97.57 ± 0.67% in 1% standard captopril. Perhaps the most significant finding was the predominance of taurine in the three parts following SW treatment at 120 °C. The hydrolysates may be of considerable interest for use in food or energy drinks. SWH demonstrates efficacy in recovering amino acids, particularly taurine, from edible parts of A. pectinata.