RG-I pectic polysaccharides and hesperidin synergistically modulate gut microbiota: An in vitro study targeting the proportional relationship.

In this study, we investigated how different proportions blends of Rhamnogalacturonan-I pectic polysaccharides and hesperidin impact the gut microbiota and metabolites using an in vitro simulated digestion and fermentation model. The results indicated that both of them could modulate the gut microbiota and produce beneficial metabolites. However, their blends in particular proportions (such as 1:1) exhibited remarkable synergistic effects on modulating the intestinal microenvironment, surpassing the effects observed with individual components. Specifically, these blends could benefit the host by increasing short-chain fatty acids production (such as acetate), improving hesperidin bioavailability, producing more metabolites (such as hesperetin, phenolic acids), and promoting the growth of beneficial bacteria. This synergistic and additive effect was inseparable from the role of gut microbiota. Certain beneficial bacteria, such as Blautia, Faecalibacterium, and Prevotella, exhibited strong preferences for those blends, thereby contributing to host health through participating in carbohydrate and flavonoid metabolism.

Enhanced anti-inflammatory effect of fish myofibrillar protein by introducing pectin oligosaccharide and its molecular mechanisms.

This study investigated the efficacy of glycation with edible uronic acid-containing oligosaccharides via the Maillard reaction to enhance the anti-inflammatory effect of fish myofibrillar protein (Mf). Lyophilized Mf was reacted with pectin oligosaccharide (PO, half of the total protein weight) at 60 °C and 35 % relative humidity for up to 12 h to produce glycated Mf (Mf-PO). After pepsin and trypsin digestion, the anti-inflammatory effect was assessed by measuring the secretions of proinflammatory cytokines in LPS-stimulated RAW 264.7 macrophages, and the anti-inflammatory effect of Mf was enhanced by PO-glycation without marked lysine loss and browning. The effects on the expressions of genes related to the LPS-stimulated signaling pathway in macrophages were also examined. PO-glycation suppressed LPS-stimulated inflammation by suppressing expression of cd14 and enhancing suppressive effect of Mf on the TLR4-MyD88-dependent inflammatory signaling pathway. Therefore, as an edible reducing sugar, PO could be an effective bioindustrial material for developing anti-inflammatory Mf.

Functional pH-sensitive film based on pectin and whey protein for grape preservation and shrimp freshness monitoring.

A pH-sensitive film was prepared from pectin (P) and whey protein (W), incorporating anthocyanin-rich purple sweet potato extract (PPE) as the pH indicator. The effect of PPE content on the structure and properties of the films and the pH indicating function were determined and evaluated for shrimp freshness and grape preservation. The solubility (60.23 ± 7.36 %) and water vapor permeability (0.15 ± 0.04 × 10-11 g·cm/(cm2·s·Pa)) of the pectin/whey protein/PPE (PW-PPE) film with 500 mg/100 mL PPE were the lowest of the films tested and much lower than PW films without PPE. PW-PPE films were non-cytotoxic and had excellent biodegradability in soil. Grapes coated with PW-PPE film had reduced weight loss from water evaporation, and decay during storage was inhibited. The total color change (ΔE) of the PW-PPE films had a strong linear correlation with the pH of shrimps during storage. PW-PPE films have application potential to monitor the real-time freshness of meat and extend the shelf life of fruit.

Effect of excitation voltage in a magnetically induced electric field on the physicochemical, structural and functional properties of citrus pectin.

Treatment with a magnetic induced electric field (MIEF) under acidic conditions has proven to be an effective method for modifying pectin, enhancing its functional attributes. In this study, the effects of varying excitation voltages of MIEF under acidic conditions on the physicochemical, structural, and functional properties of citrus pectin (CP) were explored. The results demonstrated that compared to CP without MIEF treatment, MIEF-treated CP exhibited enhanced thermal stability, rheological behavior, emulsifying and gel-forming abilities, and antioxidant capacity. These improvements were attributed to higher degrees of esterification, reduced molecular weights, and increased levels of galacturonic acid and homogalacturonan in the structural backbone of the treated CP. Additionally, MIEF treatment under acidic conditions altered the surface morphology and crystalline structure of CP. Therefore, our findings suggest that applying moderate excitation voltages (150-200 V) during MIEF treatment can enhance the functional properties of CP, leading to the production of high-quality modified pectin.

Enhancing apple postharvest protection: Efficacy of pectin coatings containing Cryptococcus laurentii against Penicillium expansum.

The aim of this work is the application of pectin coatings containing Cryptococcus laurentii as a method of biocontrol of Penicillium expansum for postharvest protection of apples. For this purpose, the yeast was incorporated into a pectin matrix, and its viability and biocontrol activity in vitro and in vivo against P. expansum was evaluated over time. In addition, the influence of the sterilization process on coating thickness was studied. Results showed that pectin coating with C. laurentii enhanced mycelial growth inhibition in vitro studies, while no significant differences were observed in disease incidence and severity reduction in vivo studies. The sterilization process reduced the viscosity of the pectin solution, resulting in coating thicknesses ranging from 0.5 to 1 µm. As a general evaluation, in vitro and in vivo, biocontrol assays were useful in demonstrating better postharvest protection of the yeast at 7 °C concerning 25 °C.

Microencapsulation of Extracts of Strawberry (Fragaria vesca) By-Products by Spray-Drying Using Individual and Binary/Ternary Blends of Biopolymers.

Valorization of agricultural and food by-products (agri-food waste) and maximum utilization of this raw material constitute a highly relevant topic worldwide. Agri-food waste contains different types of phytochemical compounds such as polyphenols, that display a set of biological properties, including anti-inflammatory, chemo-preventive, and immune-stimulating effects. In this work, the microencapsulation of strawberry (Fragaria vesca) plant extract was made by spray-drying using individual biopolymers, as well as binary and ternary blends of pectin, alginate, and carrageenan. The microparticle morphologies depended on the formulation used, and they had an average size between 0.01 µm and 16.3 µm considering a volume size distribution. The encapsulation efficiency ranged between 81 and 100%. The kinetic models of Korsmeyer-Peppas (R2: 0.35-0.94) and Baker-Lonsdale (R2: 0.73-1.0) were fitted to the experimental release profiles. In general, the releases followed a "Fickian Diffusion" mechanism, with total release times varying between 100 and 350 (ternary blends) seconds. The microparticles containing only quercetin (one of the main polyphenols in the plant) showed higher antioxidant power compared to the extract and empty particles. Finally, the addition of the different types of microparticles to the gelatine (2.7 mPa.s) and to the aloe vera gel (640 mPa.s) provoked small changes in the viscosity of the final gelatine (2.3 and 3.3 mPa.s) and of the aloe vera gel (621-653 mPa.s). At a visual level, it is possible to conclude that in the gelatine matrix, there was a slight variation in color, while in the aloe vera gel, no changes were registered. In conclusion, these microparticles present promising characteristics for food, nutraceutical, and cosmetic applications.

Green Packaging Films with Antioxidant Activity Based on Pectin and Camellia sinensis Leaf Extract.

In the packaging materials sector, increasing globalization has created the need for increased efforts to develop consumer protection measures. Consequently, new packaging materials are being sought to replace petroleum-based materials in the future. For this reason, global awareness of the environmental problems associated with the use of synthetic and non-degradable packaging has increased the attention paid to bio-packaging based on natural and biodegradable polymers. The bio-packaging sector is developing innovations to address the sustainability issues facing the food packaging industry. Our research has shown that green matcha extract can be a promising source of antioxidants for the production of bioactive pectin films. This study further confirmed that green matcha extract can be a promising source of antioxidants for the production of bioactive pectin films. The antioxidant activity test showed high activity of films containing matcha extract. The antioxidant activity of films without matcha addition, P, PJ, PC, PJC, was negligible. The addition of matcha to the polymer matrix did not significantly affect the mechanical properties (TS, EB) of the films obtained. The addition of cellulose had the greatest effect on changing the mechanical properties. It caused a twofold increase in the mechanical properties of the obtained packaging films. The addition of matcha significantly improved the barrier properties (for PM films, the WVTR was 3.40 [g/m2d]; for PJM films the WVTR was 1.70 [g/m2d]). The green packaging films showed no toxic effects on the plants (Phacelia tanacetifolia, Salvia hispanica, Brassica napus) and invertebrates (Daphnia pulex, Chaoborus, Chironomus aprilinus) tested. The half-solubility time of the membranes in a solution mimicking gastric acid was also determined. The longest half-dissolution time of the films was about 2 min. Our research has therefore shown that the biodegradable and environmentally safe green packaging films with antioxidant activity that we have developed can be used as edible functional casings in the future, e.g., for sausages and other food products.

Supplementation with Citrus Low-Methoxy Pectin Reduces Levels of Inflammation and Anxiety in Healthy Volunteers: A Pilot Controlled Dietary Intervention Study.

Background/Objective: Although low-methoxy (LM) pectin (polysaccharides extracted from citrus peels) can reduce inflammation by binding to and inhibiting the TLR-2 pathway in animal models and in vitro studies, the anti-inflammatory effects of LM pectin in humans and mood have not been explored to date. The purpose of this study is to assess the role of dietary supplementation with LM pectin in healthy volunteers on inflammatory markers and on mood, specifically anxiety and depression. Methods: We carried out a 4-week dietary intervention with LM citrus pectin on healthy volunteers (N = 14, age 40 ± 16 y, BMI 24.7 ± 3.0 kg/m2, sex F 57%) comparing the effects of daily supplementation with 20 g of LM citrus pectin versus 10 g of maltodextrin as the control (N = 15 age 43.2 ± 11 y, BMI 25.18 ± 2.0 kg/m2, sex F 66%). The effects on mood and inflammation were also tested with LM pectin at 5 g, 10 g and 15 g (2 weeks each) in an independent cohort of n = 15 healthy volunteers (age 36 ± 21 y, BMI 23.5 ± 2.4 kg/m2, sex F 80%). We assessed serum levels of TNF-alpha (downstream from TLR-2 activation), IL-1 beta, IL-6, IL-10, INF-gamma, CRP, zonulin and TLR-2 concentration which were measured using ELISA in blood samples collected at both the baseline and follow-up visits. Validated measures of anxiety and depression were collected at baseline and follow-up. Results: Supplementation with 20 g of LM pectin resulted in decreases in the pro-inflammatory markers TNF-alpha, IL-1 beta, IL-6 and INF-gamma (all p < 0.05) and an increase in anti-inflammatory marker IL-10 (p = 0.01) at the end of the 4 weeks. No such effects were observed in the control group. In addition, a significant drop in anxiety scores (from 8.38 to 4.46, p < 0.006) was found with the 20 g/day intervention but not in the control arm. In the dose-response study, anti-inflammatory effects were seen only at 15 g for TNFα (p < 0.003) and a suggestive increase in IL-10 (p = 0.08), alongside a drop in TLR-2 (p < 0.027). No significant anti-inflammatory effects were observed at 5 g and 10 g doses of LM pectin supplementation. Significant dose-dependent drops in both anxiety and depression scores were found with 10 g (p < 0.001) and 15 g per day (p < 0.0002). Conclusions: The current study identifies anxiety-reducing and anti-inflammatory effects of supplementation with 15 g/day LM pectin in healthy humans. Further research is needed to elucidate the precise mechanism and to validate the efficient dose and minimum duration of supplementation.

Pectin methylesterase activity is required for RALF1 peptide signalling output.

The extracellular matrix plays an integrative role in cellular responses in plants, but its contribution to the signalling of extracellular ligands largely remains to be explored. Rapid alkalinisation factors (RALFs) are extracellular peptide hormones that play pivotal roles in various physiological processes. Here, we address a crucial connection between the de-methylesterification machinery of the cell wall component pectin and RALF1 activity. Pectin is a polysaccharide, contributing to the structural integrity of the cell wall. Our data illustrate that the pharmacological and genetic interference with pectin methyl esterases (PMEs) abolishes RALF1-induced root growth repression. Our data suggest that positively charged RALF1 peptides bind negatively charged, de-methylesterified pectin with high avidity. We illustrate that the RALF1 association with de-methylesterified pectin is required for its FERONIA-dependent perception, contributing to the control of the extracellular matrix and the regulation of plasma membrane dynamics. Notably, this mode of action is independent of the FER-dependent extracellular matrix sensing mechanism provided by FER interaction with the leucine-rich repeat extensin (LRX) proteins. We propose that the methylation status of pectin acts as a contextualizing signalling scaffold for RALF peptides, linking extracellular matrix dynamics to peptide hormone-mediated responses.

Identification, charectrization and genetic transformation of lignin and pectin polysaccharides through CRISPR/Cas9 in Nicotiana tobacum.

CRISPR/Cas9 system has been successfully implemented in animals and plants is a second-generation genome editing tool. We are able to optimize a Cas9 system to edited Ntab06050 and Ntab0857410 genes in HD and K326 tobacco cultivars respectively. The gene Ntab06050 is related to lignin synthesis while the gene Ntab0857410 belongs to pectin synthesis by utilizing Agrobacterium-mediated leaf disc method. We have constructed total eight different constructs for the lignin related gene family CCoAMT, out of which three constructs have been selected from Ntab0184090, two constructs from Ntab0392460 while one construct from each Ntab0540120, Ntab0857410 and Ntab0135940 gene. To study the Cas9 system in pectin related genes, total five constructs have been utilized under Cas9 system and multiple target sites were selected by identifying PAM sequences. Out of which three constructs were targeted from NtabGAE1and NtabGAE6 homologous while two were targeted from NtabGAUT4 homologous. Where as, UDP-D-glucuronate 4-epimerase gene family is a Golgi localized, might have a role in the interconvertion of UDP-D-GlcA and UDP-D-GalA in pectin synthesis. We have succeeded in the mutation of pectin related NtabGAUT4 and lignin related NtabCCoAMT genes with 6.2% and 9.4% mutation frequency.

Transcriptome analysis reveals regulatory mechanism of postharvest softening in kiwiberry.

BACKGROUND: Kiwiberry is an emerging edible fruit with market potential owing to its advantages of small size, thin and hairless skin, and sweet taste. However, kiwiberry is highly susceptible to softening after harvest, which poses a challenge for storage and transport. To reveal the underlying cause of kiwiberry softening, it is essential to investigate the characteristics of postharvest fruit and the molecular mechanisms that affect changes in fruit firmness. RESULTS: Morphological observations and analysis of physical parameters showed that the skin of kiwiberry did not change markedly from the 1st to the 7th day after harvest, while the colour of the inner pericarp gradually turned yellow. By the 9th day of room temperature storage, the kiwiberries began to rot. The hardness decreased rapidly from the 1st to the 5th day postharvest, reaching the low level on the 5th day. The starch and pectin contents of kiwiberry showed a downward trend with increasing storage time. Transcriptome sequencing and weighted gene co-expression network analysis identified 29 key genes associated with the changes in the hardness of kiwiberry after harvest. Gene Ontology enrichment analysis indicated that these 29 genes are mainly involved in pectin metabolism, starch synthesis, starch decomposition, and starch metabolism. In addition, three transcription factors, AGL31, HAT14, and ALC, were identified to be strongly positively correlated with the 29 genes that affect the hardness changes of kiwiberry after harvest, and 28 of the 29 key genes were predicted to be regulated by HAT14. CONCLUSIONS: These results reveal the changes in morphological characteristics and physiological indicators during the postharvest ripening and softening of kiwiberry stored under room temperature conditions. Transcriptome analysis identified 29 key genes and three transcription factors that affect the firmness changes of postharvest kiwiberry. The results of this study thus provide insight into the transcriptional regulatory mechanism of kiwiberry softening during storage to improve the postharvest quality.

Characterization of pectinase-producing Saccharomyces cerevisiae UCDFST 09-448 and its effects on cull peach fermentations.

Fermentation of pectin-rich biomass by Saccharomyces cerevisiae can produce bioethanol as a fuel replacement to combat carbon dioxide emissions from the combustion of fossil fuels. Saccharomyces cerevisiae UCDFST 09-448 produces its own pectinase enzymes potentially eliminating the need for commercial pectinases during fermentation. This research assessed growth, pectinase activity, and fermentative activity of S. cerevisiae UCDFST 09-448 and compared its performance to an industrial yeast strain, S. cerevisiae XR122N. Saccharomyces cerevisiae UCDFST 09-448's growth was inhibited by osmotic stress (xylose concentrations above 1 M), ethanol concentrations greater than 5% v/v, and temperatures outside of 30°C-37°C. However, S. cerevisiae UCDFST 09-448 was able to consistently grow in an industrial pH range (3-6). It was able to metabolize glucose, sucrose, and fructose but was unable to metabolize arabinose, xylose, and galacturonic acid. The pectinase enzyme produced by S. cerevisiae UCDFST 09-448 was active under typical fermentation conditions (35°C-37°C, pH 5.0). Regardless of S. cerevisiae UCDFST 09-448's limitations when compared to S. cerevisiae XR122N in 15% w/v peach fermentations, S. cerevisiae UCDFST 09-448 was still able to achieve maximum ethanol yields in the absence of commercial pectinases (44.7 ± 3.1 g/L). Under the same conditions, S. cerevisiae XR122N produced 39.5 ± 3.1 g/L ethanol. While S. cerevisiae UCDFST 09-448 may not currently be optimized for industrial fermentations, it is a step toward a consolidated bioprocessing approach to fermentation of pectin-rich biomass. ONE-SENTENCE SUMMARY: Saccharomyces cerevisiae UCDFST 09-448 demonstrates the potential to ferment pectin-rich biomass as part of a consolidated bioprocess, but is sensitive to industrial stressors.

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.

Bioinspired hierarchical and dual-morphology humic-acid/pectin/chitosan composite aerogels for efficient removal of pollutants from wastewater.

How to solve the contradiction between the efficiency and adsorption rate of porous materials in adsorbing pollutants has always been one of the focus issues. In this study, the small landscape cypress trees structure like biomimetic of a hierarchical and dual morphology 3D porous HA-based aerogel was designed and synthesized to use humic acid (HA), pectin (PE) and chitosan (CTS) as raw materials, which it was formed by the disorderly overlapping of lamella composed of fiber networks in 3D space. Due to its special microstructure, it can be used like separation membrane, which allowing for rapid adsorption of pollutants in the water while the water flow passes through quick. In general, this work provides a new concept for owning fast adsorption rate and efficient adsorption of porous materials of preparation to use green method.

Novel pectin-carboxymethylcellulose-based double-layered mucin/chitosan microcomposites successfully protect the next-generation probiotic Akkermansia muciniphila through simulated gastrointestinal transit and alter microbial communities within colonic ex vivo bioreactors.

The rapid acceleration of microbiome research has identified many potential Next Generation Probiotics (NGPs). Conventional formulation processing methods are non-compatible, leading to reduced viability and unconfirmed incorporation into intestinal microbial communities; consequently, demand for more bespoke formulation strategies of such NGPs is apparent. In this study, Akkermansia muciniphila (A.muciniphila) as a candidate NGP was investigated for its growth and metabolism properties, based on which a novel microcomposite-based oral formulation was formed. Initially, a chitosan-based microcomposite was coated with mucin to establish a surface culture of A.muciniphila. This was followed by 'double encapsulation' with pectin (PEC) using a novel Entrapment Deposition by Prilling method to create core-shell double-encapsulated microcapsules. The formulation of A.muciniphila was verified to require no oxygen-restriction properties, and additionally, biopolymers were selected, including carboxymethylcellulose (CMC), that support and enhance its growth; consequently, a high viability (6 log CFU/g) of A.muciniphila microencapsulated in PEC-CMC double-encapsulates was obtained. Subsequently, the high stability of the PEC-CMC double-encapsulates was verified in simulated gastric fluid, successfully protecting and then releasing the A.muciniphila under intestinal conditions. Finally, employing a model of gastrointestinal transit and faecal-inoculated colonic bioreactors, significant alterations in microbial communities following administration and successful establishment of A.muciniphila were demonstrated.

Effects of passion fruit peel (Passiflora edulis) pectin and red yeast (Sporodiobolus pararoseus) cells on growth, immunity, intestinal morphology, gene expression, and gut microbiota in Nile tilapia (Oreochromis niloticus).

This study explores the effects of dietary supplementation with passion fruit peel pectin (Passiflora edulis) and red yeast cell walls (Sporidiobolus pararoseus) on growth performance, immunity, intestinal morphology, gene expression, and gut microbiota of Nile tilapia (Oreochromis niloticus). Nile tilapia with an initial body weight of approximately 15 ± 0.06 g were fed four isonitrogenous (29.09-29.94%), isolipidic (3.01-4.28%), and isoenergetic (4119-4214 Cal/g) diets containing 0 g kg-1 pectin or red yeast cell walls (T1 - Control), 10 g kg-1 pectin (T2), 10 g kg-1 red yeast (T3), and a combination of 10 g kg-1 pectin and 10 g kg-1 red yeast (T4) for 8 weeks. Growth rates and immune responses were assessed at 4 and 8 weeks, while histology, relative immune and antioxidant gene expression, and gut microbiota analysis were conducted after 8 weeks of feeding. The results showed that the combined supplementation (T4) significantly enhanced growth performance metrics, including final weight, weight gain, specific growth rate, and feed conversion ratio, particularly by week 8, compared to T1, T2, and T3 (P < 0.05). Immunological assessments revealed increased lysozyme and peroxidase activities in both skin mucus and serum, with the T4 group showing the most pronounced improvements. Additionally, antioxidant and immune-related gene expression, including glutathione peroxidase (GPX), glutathione reductase (GSR), and interleukin-1 (IL1), were upregulated in the gut, while intestinal morphology exhibited improved villus height and width. Gut microbiota analysis indicated increased alpha and beta diversity, with a notable rise in beneficial phyla such as Actinobacteriota and Firmicutes in the supplemented groups. These findings suggest that the combined use of pectin and red yeast cell walls as prebiotics in aquaculture can enhance the health and growth of Nile tilapia, offering a promising alternative to traditional practices. Further research is needed to determine optimal dosages for maximizing these benefits.

Evaluation of protein-polysaccharide interactions through ζ-potential and particle size measurements to assess their functionality in wine.

Protein-polysaccharide-tannin interactions are important in every aspect of red wine production from physical stability to color, astringency, and body. For this model study, bovine serum albumin (BSA) was selected as the protein, while carboxymethyl cellulose (CMC), mannoproteins, and pectin were the model polysaccharides. Each protein-polysaccharide combination was analyzed for zeta (ζ) potential and particle size at neutral pH and within the wine-like solution. Mixtures were assessed regarding their protective, affinitive, and aggregative behaviors. Based on their individual ζ-potentials, pectin and mannoprotein were most stable at lower concentrations. At higher concentrations, they reduced the suspension's stability and increased the aggregate sizes. CMC consistently increased the stability of any solution under neutral pH conditions. However, with increasing concentrations, these large aggregates are expected to precipitate. Fruit pectin (FP) and BSA interactions seemed to be the main factors in the formation of visible precipitates at neutral pH. FP and the mannoprotein decreased stability enough to cause precipitation without haze formation. The mannoprotein decreased particle sizes, in both the suspension and precipitation, which may indicate greater selectivity toward proteins. FP also decreased the suspended particle sizes under wine conditions. These findings demonstrate the use of ζ-potential and particle size values to characterize macromolecular interactions in model systems and can also be used to indicate effective fining agents. PRACTICAL APPLICATION: This work demonstrates the capabilities of ζ-potential analysis paired with size particle measurements to predict and characterize the interactions between macromolecules in complex systems. The interactions between model wine macromolecules can be evaluated with this technology at a level that cannot be reached with any other analytical technique.

Fabrication of Anatomically Equivalent Pectin-Based Multifilament Nerve Conduits.

Reuniting denuded nerve ends after a long segmental peripheral nerve defect is challenging due to delayed axonal regeneration and incomplete, nonspecific reinnervation, as conventional hollow nerve guides fail to ensure proper fascicular complementation and obstruct axonal guidance across the defects. This study focuses on fabricating multifilament conduits using a plant-derived anionic polysaccharide, pectin, where the abundant availability of carboxylate (COO-) functional groups in pectin facilitates instantaneous sol-gel transition upon interaction with divalent cations. Despite their advantages, pectin hydrogels encounter structural instability under physiological conditions. Hence, pectin is conjugated with light-sensitive methacrylate residues (49.8% methacrylation) to overcome these issues, enabling the fabrication of dual cross-linked multifilament nerve conduits through an ionic interaction-driven, template-free 3D wet writing process, followed by photo-cross-linking at 525 nm. The anatomical equivalence including peri-, epi-, and endoneurium structures of the customized multifilament conduits was confirmed through scanning electron micrographs and micro-CT analysis of rat and goat sciatic nerve tissues. Furthermore, the fabricated multifilament nerve conduits demonstrated cytocompatibility and promoted the expression of neuron-specific intermediate filament protein (NF-200) in PC12 cells and neurite outgrowth of 16.90 ± 1.82 µm on day 14. Micro-CT imaging of an anastomosed native goat sciatic nerve with an 8-filament conduit demonstrated precise fascicular complementation in an ex vivo interpositional goat model. This approach not only eliminates the need for a suture-intensive ligation process but also highlights the customizability of multifilament conduits to meet patient- and injury-specific needs.

Humidity-responsive pectin/AgNPs/ZnO composite films with high antimicrobial and UV-proof functions.

ZnO nanoparticles and Ag nanoparticles (AgNPs) tend to agglomerate when used individually, and high Ag+concentrations can cause cytotoxicity. To address these issues, we synthesized carboxymethyl cellulose (CMC)-based antimicrobial mimetic peptides (AMPMs) by introducing amphiphilic cations on the surface of CMC using a chemical grafting method. Bis-formaldehyde-formylated AMPMs were prepared through the directional oxidation of AMPMs with periodate and used as the reducing agent to synthesize AgNPs on the surface of pectin in situ for the preparation of a pectin/AgNPs/ZnO composite film. The physical and chemical properties of the films were characterized and analyzed by SEM (EDS), TEM, XRD, and UV spectroscopy. The results showed that the film's surface was smooth and flat, with small, well-stabilized AgNPs and uniformly dispersed ZnO. The film retained the original crystalline form of pectin, but exhibited altered crystallinity, indicating that the method employed was very mild. A systematic evaluation of the film's antimicrobial performance using the dynamic growth curve, inhibition zone, and colony counting methods showed that AgNPs and ZnO imparted excellent, long-lasting antimicrobial activity to the film (98 %). Additionally, the films exhibited good flexibility, excellent ultraviolet protection (99.9 %), biocompatibility, and biodegradability. Notably, the film was sensitive to humidity, as demonstrated by its humidity-responsive bionic application. This study provides a promising reference and strategy for advancing the development of multifunctional polysaccharide-based nanocomposites.

Citrus peel powder alters the rheological properties and 3D printing performance of potato starch gel.

Owing to the growing interest in sustainable resource utilization, the current study explores the potential replacement of pectin with citrus peel powder (CP) in starch-based 3D food printing ink formulations. The effect of different concentrations of pectin (1 %, 2 %, 3 %) and CP (1 %, 2 %, 3 %) on the printing fidelity, microstructure, rheological and textural properties of potato starch gel were investigated. The results showed that the 3D printing performance of CP-added inks was higher than that of pectin-added inks at all tested concentrations. The storage modulus of CP-added ink was higher than that of pectin-added ink proving higher printing fidelity of CP-added inks. Additionally, hardness, gumminess, springiness and chewiness of food ink increased with an increase in the concentration of CP while decreased with an increase in concentration of pectin. Interestingly, pectin and CP-added inks displayed similar in vitro digestibility, suggesting an insignificant effect of replacing pectin with CP on in vitro glucose release. Moreover, the antioxidant activity of CP-added ink was higher than pectin-added ink demonstrating the potential applications of CP-added ink in functional ink development. Therefore, this study claims for effective replacement of pectin with CP in starch-based 3D food printing ink formulations as a promising sustainable additive.