Retention Capacity Research Articles

Host suitability for germination differs from that of later stages of development in a rare epiphytic orchid

We explore phorophyte suitability for germination and establishment of the epiphytic orchid, Psychilis kraenzlinii. We found that the orchid grows on a subset of the available tree species and shows preference for the endemic Machaonia portoricensis (Rubiaceae). The orchid preferred trees with smoother bark with high water holding capacity and low water retention capacity. Microclimatic conditions under which embryos began pre-germination stages mirrored that of the adult orchid, but germination did not, suggesting that suitable germination sites are not necessarily the best sites for later stages of development.

Mechanical and vegetative performance of ecological concrete with nutrient aggregates

Enhancing its performance and maximizing the utilization of solid waste are pressing matters that require attention to guarantee the sustainable development of ecological concrete. This study focuses on the development of a nutrient-rich aggregate ecological concrete that demonstrates favorable plant growth performance through the utilization of recycled engineering muck and agricultural waste straw biochar. First, a unsintered nutrient aggregate is formulated through the combination of engineering muck, agricultural waste straw biochar, compound fertilizer powder, and super absorbent polymer with magnesium phosphate cement (MPC) and a hydrophilic polyurethane solution (HPS). Subsequently, by employing the prepared unsintered nutrient aggregates to partially substitute natural aggregates, a novel ecological concrete containing nutrient aggregates is generated. The study examines the impact of the composition of nutrient aggregates and porosity on the mechanical properties, water retention capacity, fertilization performance, and ecological attributes of concrete. The findings indicated that a combination of 17.06% MPC and 5.38% HPS proved to be the most effective curing method for nutrient aggregates at a liquid-solid ratio of 0.34. The water retention, fertility, and ecological performance of ecological concrete with nutrient aggregates improve with higher nutrient aggregate content, albeit at the expense of reduced mechanical performance. Under equivalent nutrient aggregate content, low porosity ecological concrete demonstrates higher fertility performance compared to high porosity ecological concrete, whereas the water retention performance shows the opposite trend. Furthermore, the patterns observed in phosphorus leaching concentration and conductivity suggest that the ecological concrete with nutrient aggregates exhibits a self-release characteristic of nutrients. The study can offer technical assistance for the efficient utilization of solid waste, thus advancing the sustainable growth of the ecological concrete industry.

Challenges in Sustainable Agriculture—The Role of Organic Amendments

Soil degradation threatens global food security and environmental sustainability, necessitating effective soil management strategies. This review comprehensively examines the impact of organic soil amendments on soil quality and productivity across various soil types and climatic conditions. A review of significant research related to organic amendments was performed using encompassed data from online search engines for studies published up until 31 December 2023. Despite their heterogeneity and use of varying methodologies, the data were narratively synthesized, providing a comprehensive understanding of amendment-induced changes in the chemical and physical properties of soil and the effectiveness of restoration on soil degradation. Organic amendments, including compost, vermicompost, biochar, and pomace, are pivotal in enhancing soil quality by increasing soil organic matter content, fostering aggregate formation, and improving soil structure in the short term. They positively influence water retention capacity, pH levels, nutrient availability, and carbon sequestration. In several studies, amendment-induced changes were absent, indicating that the effects of amendments vary depending on soil texture, application rates, and cropping systems, which emphasizes the need for tailored, sustainable soil management practices. This study concludes that organic amendments are a promising option for structure improvement and organic matter accumulation. It further suggests that an approach that integrates various methods is essential in order to meet desirable soil quality and retain agricultural productivity and offers valuable insights and recommendations for policymakers, practitioners, and researchers. Organic amendments can improve soil ecosystem services and contribute to climate change adaptation. In the future, more attention should be directed to tillage management and soil amendment interaction, as well as their effectiveness over specific periods of time.

Superabsorbent quaternary ammonium guar gum hydrogel with controlled release of humic acid for soil improvement and plant growth

Growing plants in karst areas tends to be difficult due to the easy loss of water and soil. To enhance soil agglomeration, water retention, and soil fertility, this study developed a physically and chemically crosslinked hydrogel prepared from quaternary ammonium guar gum and humic acid. The results showed that non-covalent dynamic bonds between the two components delayed humic acid release into the soil, with a release rate of only 35 % after 240 h. The presence of four hydrophilic groups (quaternary ammonium, hydroxyl, carboxyl, and carbonyl) in the hydrogel more than doubled the soil's water retention capacity. The interaction between hydrogel and soil minerals (especially carbonate and silica) promoted hydrogel-soil and soil‑carbonate adhesion, and the adhesion strength between soil particles was enhanced by 650 %. Moreover, compared with direct fertilization, this degradable hydrogel not only increased the germination rate (100 %) and growth status of mung beans but also reduced the negative effects of excessive fertilization on plant roots. The study provides an eco-friendly, low-cost, and intelligent system for soil improvement in karst areas. It further proves the considerable application potential of hydrogels in agriculture.

Impacts of Land Use Conversion on Soil Erosion in the Urban Agglomeration on the Northern Slopes of the Tianshan Mountains

The serious problem of soil erosion not only has a profound impact on people’s lives but also results in a series of ecological and environmental challenges. To determine the impact of changes in land use type on soil erosion in the urban agglomeration on the northern slopes of the Tianshan Mountains, this study commences by employing the InVEST-SDR (integrated valuation of ecosystem services and tradeoffs–sediment delivery ratio) model to calculate soil erosion levels spanning from 2000 to 2020. Subsequently, it forecasts land use and land cover (LULC) conditions for the year 2030 under three scenarios: Q1 (natural development), Q2 (ecological protection), and Q3 (economic priority). This projection is accomplished through the integration of a coupled Markov chain and multi-objective planning model (MOP) alongside patch-generating land use simulation (PLUS) models. Ultimately, based on these outcomes, the study predicts soil erosion levels for the year 2030. There has been a consistent decline in soil erosion from 2000 to 2020 with high-intensity erosion concentrated in the Tianshan Mountain region. Grasslands, glaciers, and permafrost are identified as the most erosion-prone land types in the study area, with forests exhibiting the highest capacity for soil retention. Converting from grassland and barren land to forest within the same area results in a substantial reduction in soil erosion, specifically by 27.3% and 46.3%, respectively. Furthermore, the transformation from barren land to grassland also leads to a noteworthy 19% decrease in soil erosion. Over the past two decades, the study area has witnessed a significant decline in the area of grasslands, with a notable shift towards barren and impervious surfaces due to economic development and mining activities. The three predicted scenarios depict significant expansion towards barren land, grassland, and impervious area, respectively. Soil erosion decreases under different shared socio-economic pathway (SSP) scenarios relative to 2020. There is an increase in soil erosion in the Q1 scenario and in the Q3 scenario, whereas the amount of soil erosion in the Q2 scenario exhibits a continued decrease when only the effect of land change on soil erosion is considered. Persistently rapid economic development can exacerbate soil erosion problems, underscoring the need to find a balance between economic growth and ecological conservation. As economic expansion slows down, greater emphasis should be placed on environmental protection to maintain ecological stability.

Experimental Study of a Superabsorbent Polymer Hydrogel in an Alkali Environment and Its Effects on the Mechanical and Shrinkage Properties of Cement Mortars.

As internal curing self-healing agents in concrete repair, the basic properties of superabsorbent polymers (SAPs), such as water absorption and release properties, are generally affected by several factors, including temperature and humidity solution properties and SAP particle size, which regulate the curing effect and the durability of cementitious composites. This study aimed to investigate the water retention capacities of SAPs in an alkaline environment over extended periods by incorporating liquid sodium silicate (SS) into SAP-water mixtures and examining the influence of temperature. The influence of SAP particle size on mortar's water absorption capacity and mechanical behavior was investigated. Two mixing techniques for SAPs (dry and pre-wetting) were employed to assess the influence of SAP on cement mortars' slump, mechanical properties, and cracking resistance. Four types of SAPs (SAP-a, SAP-b, SAP-c, and SAP-d), based on the molecular chains and particle size, were mixed with SS to study their water absorption over 30 days. The results showed that SAPs exhibit rapid water absorption within the first 30 min, exceeding 85% before reaching a saturation point, and the chemical and temperature variations in the water significantly affected water absorption and desorption. The filtration results revealed that SAP-d exhibited the slowest water release rate, retaining water for considerably longer than the other three types of SAPs. The mechanical properties of SAP mortar were reduced due to the addition of an SAP and the improved cracking resistance of the cement mortars.

Influence of Biochar Application Rate, Particle Size, and Pyrolysis Temperature on Hydrophysical Parameters of Sandy Soil

Sandy areas occupy a huge amount of land worldwide, but due to their characteristics, they are mostly low in fertility and low in organic matter. Sandy soils have coarse texture, high saturated hydraulic conductivity, low soil organic carbon, and poor aggregate stability and water retention capacity; therefore, it is necessary to add organic additives to them. The objective of this study was to assess the effect of particle size and application rate of biochar (BC) produced under different pyrolysis temperatures on the porosity P, available water content for plants AWC, saturated hydraulic conductivity Ks, and contact angle CA of sandy soil. The results show that an application of BC to sandy soil significantly increased AWC by 76–168%, CA by 252–489%, P by 6–11%, and significantly reduced Ks by 37–90%. Statistical analysis of the effect of three examined factors (BC application rate, particle size, and pyrolysis temperature) revealed that P, AWC, and Ks were affected by all three factors, while CA was affected only by BC application rate and particle size. The statistically significant interaction between the two factors was found for P (temperature × rate and size × rate), AWC (temperature × size), and Ks (size × rate). Statistically significant interaction among the three factors was not found for any hydrophysical parameter. The application of BC to amend sandy soils can be seen as a strategy to mitigate drought conditions and to reduce the amount of irrigation, saving water. Further investigations are needed with regard to the BC application under climate conditions with long hot and dry periods, which may promote soil water repellency.

Evaluating the Impact of Inulin Addition before Solar Drying on the Characteristics of Sour Cassava Starch as a Food Ingredient

AbstractSour cassava starch is obtained by spontaneous fermentation of the starch cake immediately after being extracted, followed by sun‐drying, where oxidation reactions take place that are essential for the enhanced baking expansion of this starch. The aim of this work is to evaluate the influence of adding a different polysaccharide to the starch cake before sun‐drying in the characteristics of the obtained product. Inulin is chosen for being a soluble prebiotic fiber that may improve the nutritional quality of the starch. Inulin modifies the oxidation of the fermented starch during sun‐drying, and forms a film around the granules that hinder their swelling and water retention capacity. The crystallinity of the inulin is increased by hydration and sun‐drying. Adding inulin to the fermented starch before sun‐drying reduces its expansion capacity, but in a lower rate than when inulin is added after sun‐drying. The fermented starch sun‐dried with inulin produces a baked snack with similar texture to that of the sour starch alone, and softer than that from the native starch.

Highly efficient recovery of vanadium from Abu Zeneima ferruginous siltstone, Southwestern Sinai, Egypt, by a novel polyimine‐based chelating ligand

AbstractTo extract V5+ ions from the ferruginous siltstone in the Abu Zeneima region of Southwestern Sinai, Egypt, a chelating polyimine ligand (PVAm‐Ben) was synthesized via a condensation reaction involving polyvinyl amine and α‐hydroxy ketone (Benzoin). The structure of PVAm‐Ben underwent comprehensive characterization employing various techniques, namely; FT‐IR, 1H‐NMR, 13C‐NMR, and GC/MS analyses. Experimental factors controlling such as pH, time, initial concentration, dosage, temperature, and stripping, were systematically optimized to enhance measurement accuracy. Under conditions of 25°C, 0.015 mol/L, and 30 minutes, PVAm‐Ben/C2H4Cl2 exhibited remarkable retention capacity at pH 3. Linear regression analysis results suggested the release of a mole of H+ during the extraction process. The stability constant (log β = 2.1882) of the PVAm‐Ben/V5+ complex was determined, yielding a value of 154.24. The stoichiometry mechanism between PVAm‐Ben and V5+ ions displayed a linear correlation (slope: 0.9922), signifying 1 mole of PVAm‐Ben reacting with 1 mole of vanadium. The pseudo‐second‐order kinetic model indicated an exothermic, spontaneous, and advantageous extraction process at low temperatures. Efficient stripping of PVAm‐Ben/C2H4Cl2 loaded with vanadium was achieved using 0.05 M NaOH with a 99% efficiency rate. Ultimately, enhanced variables were employed to yield a V2O5 concentrate with a vanadium content of 55% and a purity level of 98.21%.

Bifunctional low molecular weight polyacrylic acid as aqueous binder and coating agent enables high performance LiMn2O4 cathode for lithium-ion batteries

LiMn2O4 is considered to be a promising cathode material for lithium-ion batteries due to its decent energy density, low price and environmental benignity. However, the problems of Mn dissolution, migration and deposition during the cycle, seriously affect its lifespan, especially at high temperature. In this study, we developed a strategy by which we killed two birds with one stone. A low molecular weight polyacrylic acid (PAA) mixed with sodium carboxymethyl cellulose (CMC) is applied as binder and coating agent for cathode particles at the same time. The conventional and environmental unfriendly polyvinylidene difluoride (PVDF)-N-methylpyrrolidone (NMP) system is replaced by the cheap and green aqueous binder with improved adhesive effect. Furthermore, the binder-based surface coating layer not only alleviates the side reaction between the electrolyte and the cathode particles, but also chelates the dissolved Mn2+ by the large amount of carboxyl groups in PAA molecules and so prevents the following migration and deposition of Mn2+. In the button half-cell with low molecular weight PAA based binder, the capacity retention reaches 94.1 % after 1000 cycles at room temperature and 92.0 % after 200 cycles at 60 degrees centigrade. Meanwhile, 18650-type cylindrical cells were prepared with this binder, which shows a great high temperature storage performance. After the cell was held at 60 degrees centigrade for 25 days at full charged state, the internal resistance increased by only 1.25mΩ, the voltage decreased by only 0.1 V, the residual capacity retention and recovery capacity retention reaches 85.6 % and 92.2 %. This work shows the great potential of the aqueous binder in dealing with the problem of Mn dissolution during the cycling of manganese-based cathode materials for lithium-ion batteries.

Glyoxal crosslinking of electro-responsive alginate-based hydrogels: Effects on the properties

To improve the features of alginate-based hydrogels in physiological conditions, Ca2+-crosslinked semi-interpenetrated hydrogels formed by poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid and alginate (PEDOT/Alg) were subjected to a treatment with glyoxal to form a dual ionic/covalent network. The covalent network density was systematically varied by considering different glyoxalization times (tG). The content of Ca2+ was significantly higher for the untreated hydrogel than for the glyoxalized ones, while the properties of the hydrogels were found to largely depend on tG. The porosity and swelling capacity decreased with increasing tG, while the stiffness and electrical conductance retention capacity increased with tG. The potentiodynamic response of the hydrogels notably depended on the amount of conformational restraints introduced by the glyoxal, which is a very short crosslinker. Thus, the re-accommodation of the polymer chains during the cyclic potential scans became more difficult with increasing number of covalent crosslinks. This information was used to improve the performance of untreated PEDOT/Alg as electrochemical sensor of hydrogen peroxide by simply applying a tG of 5 min. Overall, the control of the properties of glyoxalized hydrogels through tG is very advantageous and can be used as an on-demand strategy to improve the performance of such materials depending on the application.

Turning Polysaccharides into Injectable and Rapid Self-Healing Antibacterial Hydrogels for Antibacterial Treatment and Bacterial-Infected Wound Healing.

Great efforts have been devoted to the development of novel and multifunctional wound dressing materials to meet the different needs of wound healing. Herein, we covalently grafted quaternary ammonium groups (QAGs) containing 12-carbon straight-chain alkanes to the dextran polymer skeleton. We then oxidized the resulting product into oxidized quaternized dextran (OQD). The obtained OQD polymer is rich in antibacterial QAGs and aldehyde groups. It can react with glycol chitosan (GC) via the Schiff-base reaction to form a multifunctional GC@OQD hydrogel with good self-healing behavior, hemostasis, injectability, inherent superior antibacterial activity, biocompatibility, and excellent promotion of healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds. The biosafe and nontoxic GC@OQD hydrogel with a three-dimensional porous network structure possesses an excellent swelling rate and water retention capacity. It can be used for hemostasis and treating irregular wounds. The designed GC@OQD hydrogel with inherent antibacterial activity possesses good antibacterial efficacy on both S. aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria), as well as MRSA bacteria, with antibacterial activity greater than 99%. It can be used for the treatment of wounds infected by MRSA and significantly promotes the healing of wounds. Thus, the multifunctional antibacterial GC@OQD hydrogel has the potential to be applied in clinical practice as a wound dressing.

Optimization of Desalination Efficiency and Exploratory Applications of TiO2 Active Site Electrode Enhanced by Activated Carbon and Tween 80 in Capacitive Deionization Technology.

Capacitive deionization (CDI) is an emerging desalination technology for seawater desalination. The development of high-desalination and long-life electrode materials is a research focus in the global water treatment field. In this experiment, Tween T80 was used as a surface activator, and a modified electrode was prepared by facilitating the deposition of TiO2 active sites onto the surface of activated carbon through a sol-gel/hydrothermal two-step synthesis strategy. The morphology and specific surface area of the composite material were analyzed through scanning electron microscopy, specific surface area measurements, and contact angle tests. The results indicated that the sol-gel/hydrothermal two-step synthesis strategy played a crucial role in the homogeneous combination and performance enhancement of the composite material. Under constant voltage mode, when the working voltage was 1.2 V, the desalination capacity of this composite material in a NaCl solution with an initial conductivity of 3000 μS·cm-1 reached 23.8 mg·g-1 (26% higher than materials prepared by conventional sol-gel methods). After 150 cycles, the capacity retention rate was 78%, and the retention capacity was significant (87%). Overall, the results demonstrate the potential of the sol-gel/hydrothermal two-step synthesis strategy in preparing high-performance CDI electrode materials. The modified electrode prepared using this method offers enhanced desalination capacity and durability, making it a promising candidate for seawater desalination and other water treatment applications.

Effects of combined fermentation and ultrasonic treatments on the structure and properties of Okara soluble dietary fiber

In this study, okara dietary fiber samples were prepared through a combination of solid-state fermentation using Aspergillus oryzae and ultrasonication. Subsequent infrared and UV–visible spectral analyses revealed that such treatment resulted in an increase in the oligosaccharide content of these samples through the enhanced cleavage of hydrogen bonds. Scanning electron microscopy and X-ray evaluation further confirmed the changes in the structural makeup of these okara SDF (soluble dietary fiber) samples relative to control samples. Following combination treatment, the soluble dietary fiber levels in these samples were three times higher than in control samples at 18.06 g/100 g. This treatment also led to a significant increase in the water holding, oil holding, and swelling capacities of the prepared fiber samples, whereas the capacity for water retention was slightly reduced. Ultrasonication alone failed to impact SDF oil holding capacity, nor did it impact cholesterol absorption at a pH of 2 used to simulate the stomach microenvironment. Together, these data thus offer a valuable reference for further work aimed at extracting soluble dietary fiber from okara.

A Comparative Biochemical Study of Mulberry (Morus spp.) Mini Clones Over Conventional Stem Cuttings

The mulberry (Morus spp.) plant holds significant value in the sericulture industry, as its foliage serves as a vital source of food for the mulberry silkworm (Bombyx mori L.). A research study was undertaken to figure out which mulberry variety V1 and MR2 propagated both by stem cuttings and apical cuttings was best performed locally. The investigation was based on biochemical composition including leaf moisture, moisture retention capacity, chlorophyll-a, chlorophyll-b, carotenoid, total chlorophyll, nitrogen, phosphorous, potassium, soluble protein, total carbohydrates, crude protein, total sugar content present in mulberry leaves. The nutritional status of different mulberry varieties is determined by its biochemical composition present. The findings showed that the mulberry mini-clones 60DAP-AC (V1) and 60DAP-AC (MR2) have registered enhanced nutritional parameters than 90DAP-SC (V1) and 90DAP-SC (MR2) and were therefore best suited for raising silkworms to obtain good cocoon parameters.

Evaluation of the potential use of the by‐products of Passiflora maliformis L. and Passiflora edulis Sims from the Southern Colombian Massif as dietary fibre and prebiotic activity

SummaryWithin tropical fruits, the Passifloraceae family is distinguished; Colombia is recognised as the most diverse country in this family. In this study, we aimed to evaluate the potential use of by‐products (shell‐seeds + pulp) of Passiflora maliformis L. and Passiflora edulis Sims as dietary fibre and prebiotic activity, through tests of water, oil and swelling retention capacity and dietary fibre, its potential application was evident in products that require hydration, viscosity development and freshness conservation. Toxicity test, extracts can be classified as ‘safe’ when ingested, as cell viability is equal to or greater than 90%. Probiotic potential is evident for a growth of Latilactobacillus sakei BAP110‐FSC111 ranging from 15% to 100%, Lactiplantibacillus plantarum CECT220 ranging from 10% to 75%, acid digestibility test, hydrolysis percentage varied from 20% to 100%, values according to the by‐product, extract and study species. Highlighting its use as a source of prebiotics, because it increases the proliferation of probiotics from the Lactobacillus family.

Synthesis of geopolymer powder and beads based on red clay waste for the adsorption of methyl orange dye from aqueous solutions: Characterization, application of response surface methodology, and cost analysis

The current research focuses on the valorization of red clay waste (RCW) to develop alumino-silicate geopolymer binders (GPP) and geopolymer spheres obtained from GPP powder modified with sodium alginate (Alg/GPP). GPP and Alg/GPP were applied in the environmental field for the retention of methyl orange (MO) from an aqueous solution. The raw material and the synthesized geopolymers were characterized by various physico-chemical methods. The results of XRF, XRD, and FTIR confirmed the successful synthesis of GPP and Alg/GPP, while the SEM/EDX findings revealed the homogeneous surface of the adsorbents. A significant specific surface area was detected for GPP (73.56 m2/g) and Alg/GPP (91.24 m2/g) with a high cation exchange capacity around 122 meq/100g for GPP and 185 meq/100g for Alg/GPP. The removal process was performed using the response surface methodology according to the Box-Behnken design, optimizing the retention efficiency of MO by different factors, including temperature, initial concentration, solution pH, and contact time. The obtained data was treated through the analysis of variance (ANOVA) and fitted by a quadratic polynomial model based on multiple regression analysis. In an acidic medium at 45 °C, the optimal conditions for MO retention were estimated to be 120 mg/L of MO concentration in 55 min using GPP and 180 mg/L of MO concentration in 20 min using Alg/GPP. The pseudo-second-order kinetics were more appropriate for describing the MO removal onto GPP and Alg/GPP adsorbents. The Langmuir model identified a high retention capacity of MO around 94.78 mg/g via GPP and 224.85 mg/g via Alg/GPP. The thermodynamic data confirmed that the elimination of MO dye onto GPP and Alg/GPP adsorbents was endothermic, favorable, and spontaneous. This study provided insights into the valorization of composite materials based on solid waste in dye retention, which can potentially be employed in wastewater treatment.

Synthesis and characterization of novel D‐mannitol based hydrogel: Swelling and adsorption behavior of heavy metal ion studies

AbstractA highly efficient hydrogel derived from D‐Mannitol xanthate has been successfully synthesized using a free‐radical solution copolymerization technique. An equimolar mixture of acrylonitrile (AN) and acrylic acid (AA) has been reacted with D‐Mannitol xanthate (DMX) under inert atmosphere. Three distinct grades of D‐Mannitol xanthate‐based hydrogels viz. DMXHGs‐1, DMXHGs‐2, and DMXHGs‐3, were prepared. Extensive analyses were conducted on the hydrogels using various methods such as UV, FT‐IR, SEM, XRD, GPC, TGA and ΔpHPZC. The maximum swelling ratio of DMXHGs‐3 was found to be 52122%, 50434% and 48576% for 24 h with water retention ratio of 80.98%, 78.64% and 79.22% for 30 h in distilled, tap and gray water respectively. These findings indicate the DMXHGs‐3 hydrogel has remarkable swelling and water retention capacity. Comprehensive investigations were carried out to evaluate the hydrogel's remarkable adsorption capacity to act as an adsorbent for effectively removing hazardous metal ions. The highest removal percentages of 95.5% and 94.4% and maximum adsorption capacities of 523.56 mg g−1 and 462.96 mg g−1 were observed with DMXHGs‐3 hydrogel for Cu2+ and Co2+ ions, respectively. Metal ion removal experiments were conducted by varying several parameters including dosage, pH, temperature, concentration, and time. The quantification of Cu2+ and Co2+ was accomplished using UV–visible spectroscopy. Present studies demonstrate the suitability of D‐mannitol xanthate‐based hydrogels for the efficient removal of toxic metal ions from wastewater.

Cryoprotective effect of epigallocatechin gallate replacing sucrose on Hypophythalmichthys molitrix surimi during frozen storage.

The present study aimed to investigate the cryoprotective effect of epigallocatechin gallate (EGCG) replacing sucrose on surimi during frozen storage. Substitution or partial substitution of 0.1% EGCG for sucrose (1.5%) was added to surimi, and the surimi samples without and with commercial cryoprotectants (4% sucrose and 4% sorbitol) were used as the control group. The results obtained suggest that, with the increase in frozen storage time, the structural performance of surimi protein gradually weakened (e.g. the decrease in the surface hydrophobicity, the increase in the total sulfhydryl and solubility, and the protein myosin heavy chain bands became shallow) and surimi gel quality gradually deteriorated (e.g. the decrease in water-holding capacity, gel strength and all texture profile attributes). However, compared with the other three group surimi samples during the frozen period, the surimi proteins with partial replacement of sucrose by EGCG had a higher total sulfhydryl group content and solubility of proteins, as well as lower surface hydrophobicity of protein, suggesting that the addition of EGCG as a partial substitute for sucrose can enhance the antifreeze ability of surimi. Meanwhile, the surimi gel with the partial replacement of sucrose by EGCG had a higher water retention capacity, gel strength and texture attributes (e.g. hardness, springiness, cohesiveness, chewiness, and resilience), indicating that the addition of EGCG as a partial substitute for sucrose can inhibit the deterioration of surimi gel quality. Overall, EGCG partially replacing sucrose can play an alternative cryoprotectant with a lower sweetness to prevent the quality of surimi from deteriorating. © 2024 Society of Chemical Industry.

Towards a zero-waste sustainable biorefinery of Codium sp. seaweed: From bioactives application to soil enhancement materials

In the pursuit of sustainability and circularity, this study aimed to develop a multi-purpose biorefinery pipeline using extracts from the green seaweed Codium sp. and transforming its post-extracted biomass into biochars, emphasizing holistic resource utilization. Five extracts from Codium sp. were evaluated, testing their antioxidant potential, cytotoxicity, photoprotective effects, anti-inflammatory activity, and inhibitory capabilities against enzymes hyaluronidase, collagenase, and elastase.The ethyl acetate extract showed the highest values in the ORAC assay, indicating antioxidant activity. However, no relevant antioxidant activity was observed in the FRAP and DPPH assays for the other extracts. The hydroethanolic extract exhibited the best anti-enzymatic capacity, inhibiting elastase by 88% at 200 μg/mL. It also demonstrated a photoprotective effect and reduced ROS production (30%) induced by UVB exposure. The hydroethanolic and ethanol extracts significantly reduced the concentration of the tumour necrosis factor-alpha (TNF-α) in response to LPS stimulation, indicating anti-inflammatory activity.The hydroethanolic post-extracted biomass was converted into biochars using conventional slow pyrolysis, hydrothermal carbonization (HTC), and acid-mediated carbonization (AMC). The biochars contained 56–75% C and 22–30% O and the one synthesized by HTC had the highest textural development. The biochar obtained by AMC showed better performance in improving soil water retention capacity, suggesting that acid surface chemistry plays a more significant role than porosity.The Codium sp. extracts and biochars produced from the post-extracted biomass have demonstrated potential as a source of valuable bioactive compounds and biomaterials for a circular economy framework and biorefinery pipeline with wide-ranging applications.