Carrageenan Research Articles

An Update on the Chemical Constituents and Biological Properties of Selected Species of an Underpinned Genus of Red Algae: Chondrus.

Macroalgae, particularly red seaweeds, have attracted significant attention due to their economic and health benefits. Chondrus, a red algae genus, despite its economic importance, seems to be undervalued. Among all its species, Chondrus crispus has been meticulously documented for its biological properties, and little is known about other species. No comprehensive review of the biological properties of this genus has been acknowledged. Thus, this review aimed to summarize the available information on the chemical constituents and biological properties of a few selected species, including Chondrus crispus, Chondrus ocellatus, Mazzaella canaliculata, and Chondrus armatus. We compiled and discovered that the genus is offering most of the important health-promoting benefits evidenced from in vitro and in vivo studies focused on antimicrobial, immunomodulation, neuroprotection, anti-atopic, anti-inflammatory, anti-viral, anti-diabetic, cytoprotective, antioxidant, anti-coagulation, nephroprotective, anti-tumor, and anti-venom activity, which speaks about the potential of this genus. Data on clinical studies are limited. Further, around 105 chemical constituents have been reported from Chondrus spp. Given its significance, further investigation is warranted, in the form of meticulously planned cell, animal, and clinical studies that concentrate on novel health-enhancing endeavors, in order to unveil the full potential of this genus. The review also outlines challenges and future directions.

Immunomodulation by xylan and carrageenan-type polysaccharides from red seaweeds: Anti-inflammatory, wound healing, cytoprotective, and anticoagulant activities

The immunomodulatory properties of the polysaccharides (carrageenan, xylan) from Chondrus crispus (CC), Ahnfeltiopsis devoniensis (AD), Sarcodiotheca gaudichaudii (SG) and Palmaria palmata (PP) algal species were studied. Using RAW264.7 macrophages, we investigated the proliferation and migration capacity of different extracts along with their immunomodulatory activities, including nitric oxide (NO) production, phagocytosis, and secretion of pro-inflammatory cytokines. Polysaccharides from C. crispus and S. gaudichaudii effectively mitigated inflammation and improved scratch-wound healing. Polysaccharide fractions extracted under cold conditions (25 °C), including CC-1A, SG-1A and SG-1B stimulated cell proliferation, while fractions extracted under hot conditions (95 °C), including CC-3A, CC-2B and A. devoniensis (AD-3A), inhibited cell proliferation after 48 h. Furthermore, RAW264.7 cells treated with the fractions CC-3A, AD-1A, and SG-2A significantly reduced LPS-stimulated NO secretion over 24 h. Phagocytosis was significantly improved by treatment with C. crispus (CC-2B, CC-3B) and A. devoniensis (AD-3A) fractions. RAW264.7 cells treated with the CC-2A and SG-1A fractions showed elevated TGF-β1 expression without affecting TNF-α expression at 24 h. Polysaccharide fractions of A. devoniensis (ι/κ hybrid carrageenan; AD-2A, AD-3A) showed the highest anti-coagulation activity. CC-2A and SG-1A fractions enhanced various bioactivities, suggesting they are candidates for skin-health applications. The carrageenan fractions (CC-3A: λ-, μ-carrageenan, SG-2A: ν-, ι-carrageenan) tested herein showed great potential for developing anti-inflammatory and upscaled skin-health applications.

Influence of consumption of the food additive carrageenan on the gut microbiota and the intestinal homeostasis of mice.

The safety of the carrageenan (CGN) consumption as a food additive is under debate, with negative effects being associated with the products of hydrolysis of CGN. Moreover, there is an increasing need to integrate gut microbiome analysis in the scientific risk assessment of food additives. The objective of this study was to test the effects of CGN consumption on the gut microbiota and the intestinal homeostasis of young male and female mice. Female and male ICR-CD1 mice (8 weeks old) orally received 540 mg kg-1 day-1 of CGN, representing the maximum-level exposure assessment scenario surveyed for children, over the course of two weeks. Fecal material and peritoneal immune cells were analyzed to determine changes in the fecal microbiota, based on the analysis of bacterial 16S rRNA gene amplicon sequences and short-chain fatty acid (SCFA) concentrations, and some immune functions and redox parameters of peritoneal leukocytes. Non-significant microbiota taxonomical changes associated with CGN intake were found in the mouse stools, resulting the housing time in an increase in bacterial groups belonging to the Bacteroidota phylum. The PICRUSt2 functional predictions showed an overall increase in functional clusters of orthologous genes (COGs) involved in carbohydrate transport and metabolism. A significant increase in the cytotoxicity of fecal supernatants was observed in CGN-fed mice, which correlated with worsening of immune functions and oxidative parameters. The altered immunity and oxidative stress observed in young mice after the consumption of CGN, along with the fecal cytotoxicity shown towards intestinal epithelial cells, may be associated with the gut microbiota's capacity to degrade CGN. The characterization of the gut microbiota's ability to hydrolyze CGN should be included in the risk assessment of this food additive.

Stengthening of Edible Film From Corn Starch and Iota Carrageenan with Butterfly Pea Flower Extraction (Clitoria ternate L) Addition

One of the most enormous waste is plastic. Most plastic waste can damage the environment on land and in the oceans. Food packaging plastic is switched from conventional to natural materials. The research goal is an analysis of biodegradable, edible film plastic materials. A combination of corn starch (CS) (4, 3.5, 3, 2.5, 2% w/v), iota-carrageenan (IC) (0, 0.5, 1, 1.5, 2% w/v), and butterfly pea flower extraction (BPE) (0, 4, 8% v/v) can be developed as edible biodegradable films. The method used in this research is bench casting. These edible films are characterized based on physico-mechanical properties, water properties, and biodegradation. The results of water vapor permeability as water properties in CS/IC3 samples was 19.449 g.mm/m2.h.kPa, and in the CS/IC/BPE 3-2 samples was 12.596 g.mm/m2.h.kPa. Based on the results, the tensile strength as physical-mechanical properties of the samples increased as the iota-carrageenan and BPE content occurred in the CS/IC5 sample with a value of 3.32 MPa and the CS/IC/BPE 5-2 sample with a value of 4.93 MPa. The CS/IC/BPE sample extensively reduced cherry tomato weight loss and increased the duration of storage of the studied tomatoes by 10 days. The research shows that the natural material CS/IC/BPE produces a good edible film for packaging.

A natural food-grade supramolecular self-assembly system for creation of hierarchically structured hydrogels.

We develop a novel hierarchically structured hydrogel by the supramolecular self-assembly of all-natural food-grade building blocks, glycyrrhizic acid (GA) and carrageenan (CG). The co-assembled GA-CG hydrogel system displays an unusual structural transition with the appearance from opacity to translucence and then to opacity, as a function of the concentration of metal ions. The unique GA-CG supramolecular hydrogel system can serve as solid, edible, and responsive active cargo delivery platforms for food and biomedical applications.

Biocompatible nanocomposite scaffolds based on carrageenan incorporating hydroxyapatite and hesperidin loaded nanoparticles for bone tissue regeneration

AbstractIn this study, injectable and osteoinductive carrageenan (CGN)‐based composite hydrogel integrated with 1% wt/vol hydroxyapatite (HA) and hesperidin (HPN) loaded poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate acid) nanoparticles (PHBV NPs) were developed as a scaffold for bone tissue engineering. Accordingly, HPN was encapsulated into PHBV NPs by the oil in water emulsion‐solvent evaporation technique and optimized using the fractional factorial design. Then, the effects of the amount of drug, polymer, surfactant concentration, sonication time, and the water/organic phase volume ratio on the characteristics of NPs, including particle size (PS), polydispersity index (PdI), zeta potential (ZP), drug loading (DL) % and encapsulation efficiency (EE) % were investigated. The crystalline state of HPN and the interaction between the drug and the polymer were also investigated using the x‐ray powder diffraction method and the Fourier transform infrared method, respectively. Further, CGN hydrogel was developed and loaded with optimized NPs and HA (HPN‐PHBV NPs‐CGN/HA hydrogel). The prepared hydrogel was then characterized for drug release, swelling and degradation behavior, mechanical properties, and injectability. In addition, the potential of the composite hydrogel as bone tissue scaffolds was assessed by the MTT assay, alkaline phosphatase (ALP) activity, and alizarin red S staining. The optimized formulation had the size of 353.5 nm, PdI of 0.43, EE% of 88.47%, DL% of 29.58% and the ZP of −17.4. HPN‐PHBV NPs‐CGN/HA hydrogel also showed sustained drug release, as compared to the HPN‐CGN/HA hydrogel. Further, the hydrogel containing HA showed improved mechanical properties, as compared with the HA free one. In addition, HPN‐PHBV NPs‐CGN/HA hydrogel significantly enhanced MG63 cell proliferation, ALP activity and matrix mineralization, as compared with other groups. Overall, the use of this hydrogel with enhanced osteogenic capacity could be considered as an effective approach for bone tissue engineering.

Comparative Analysis of Green and Brown Morphotypes of <em>Kappaphycus alvarezii Doty</em> (Doty): Morphology, Total Phenol Content, Antioxidant Activity and Antimicrobial Activity

Kappaphycus alvarezii Doty (Doty), commonly known as elkhorn sea moss, is a popular seaweed cultivated globally. It is a well-known source of carrageenan, which is a thickening agent used in food and other industries. Even though different morphotypes of K. alvarezii are reported globally, it has been cultivated and marketed as a single genotype. However, such information is important, especially to produce high-value products such as nutraceuticals. Therefore, this study aimed to evaluate differences in microscopic structure, antimicrobial and antioxidant properties, and total phenolic contents of green and brown morphotypes of K. alvarezii cultivated in Jaffna, Sri Lanka. Except for the colour, there was no significant difference in macroscopic parameters. There was no significant difference observed in cross-sections under the light microscope. Antimicrobial properties of ethanol, methanol and water extracts were evaluated by disc diffusion assay against, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Antioxidant properties and total phenolic contents were determined using 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Folin–Ciocalteau method, respectively. Interestingly, the antibacterial activity, antioxidant properties and total phenolic content of K. alvarezii depend on the morphotype. The green morphotype was rich in total phenolic compounds along with high antibacterial and antioxidant properties. Staphylococcus aureus was the most susceptible bacteria to antimicrobial agents of K. alvarezii and both ethanol and methanol extractions were efficient without significant differences between them in all the assays. The current data suggests better performance of the green morphotype of K. alvarezii as a natural source of antibacterial and antioxidant compounds.

Development and in vivo evaluation of 3D printed hydrogel patches for personalized cosmetic use based on skin type

Skincare products intend to enhance or restore skin to a healthy state. Despite the immense size of the cosmetics market and product availability, mass production still lags behind customers' demand for individualization and the use of natural ingredients. 3D printing technologies have revolutionized various industries including, more recently, the cosmetics market, providing personalized solutions based on individual's skin type and ingredient preferences. In this study, we have screened natural polymers to identify printable inks for the development of extrusion-based 3D printed hydrogel face patches. Iota carrageenan was selected as base material of the hydrogel inks and was co-formulated with sodium hyaluronate, glycerol, or Camellia sinensis leaf distillate to address the requirements of individual skin types.

Composite hydrogels formed from okara cellulose nanofibers and carrageenan: Fabrication and characterization

Currently, there is great interest in converting edible agro-waste, such as okara from soybean production, into value-added products. For this study, we focus on fabricating composite hydrogels from okara cellulose nanofibers (CNFs) and carrageenan (CA). We also examined the effects of TEMPO oxidation of the okara CNFs, as well as CA concentration, on the microstructure and physicochemical properties of the composite hydrogels. The water holding capacity, oil holding capacity, surface tension, gel strength, and viscoelasticity of the composite microgels increased with increasing CA concentration, and it was found that the highest values were obtained for TC-CA2 hydrogel: contact angle = 43.6° and surface tension = 45.12 mN/m, which was attributed to the formation of a more regular and dense three-dimensional gel network. All the CNF-CA microgels had highly anionic ζ-potential values (−38.8 to −50.1 mV), with the magnitude of the negative charge increasing with TEMPO oxidation and carrageenan concentration. These results suggest there would be strong electrostatic repulsion between the composite hydrogels. The composite microgels produced in our work may be useful functional materials for utilization within the food industry, thereby converting a waste product into a valuable commodity.

Low-cost and eco-friendly PVA/carrageenan membrane to efficiently remove cationic dyes from water: Isotherms, kinetics, thermodynamics, and regeneration study

Methylene blue (MB), a common dye in the textile industry, has a multitude of detrimental consequences on humans and the environment. Accordingly, it is necessary to remove dyes from water to guarantee our health and sustainable ecosystem. In this study, we developed polyvinyl alcohol (PVA)-based hydrogel adsorbents with high adsorption capacity by adding three types of carrageenan (kappa, iota, and lambda) to remove MB from water. Thanks to the functional groups, the PVA/carrageenan membranes dramatically increased the removal efficiency (kappa, 98.8%; iota, 97.0%; lambda, 95.4%) compared to the pure PVA membrane (6.3%). Among the three types of PVA/carrageenan membranes, the PVA/kappa-carrageenan membrane exhibited the best adsorption capacity of 147.8 mg/g. This result implies that steric hindrance was considerably significant, given that kappa carrageenan has only one sulfate group in the repeating unit, whereas iota and lambda carrageenan composite PVA membranes possess two and three sulfate groups. Apart from the maximum adsorption capacity, this study addressed a variety of characteristics of PVA/carrageenan membranes such as the effects of initial MB concentration, kappa carrageenan weight percentage, contact time, adsorbent dosage, and temperature on the adsorption performance. In addition, the kinetic and thermodynamic studies were also carried out. Lastly, the reusability of the PVA/carrageenan membrane was verified by the 98% removal efficiency maintained after five adsorption-desorption cycles.

Optimization of an edible film formulation by incorporating carrageenan and red wine lees into fish gelatin film matrix

The study aimed to use response surface methodology (RSM) to create and understand a novel edible film made from fish gelatin (FG). This film includes wine lees (WL) and carrageenan (CAR). The concentrations of WL (0, 1, 2, and 3 %) and CAR (0, 1, and 3 %) were considered independent variables. The process variable combinations for the optimal response functions were 1.926 % WL and 3 % CAR, forming soft and rigid films with low tensile strength (TS) and high elongation at break (EAB%). Based on the evaluation of each response, FG film had the highest TS value, FG/CAR(3 %) film had the maximum EAB, and FG/WL (3 %)/CAR (3 %) film had the lowest vapor permeability (WVP) and the highest opacity (OP). The incorporation of WL considerably improved the functional properties of these films, enabling strong antioxidant activity and high phenolic content. Characterization of the films with analytical techniques: Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis demonstrated a considerable interaction between WL and FG, indicating a high level of compatibility between the two substances. Our data suggest that the formulation of edible films can be adjusted to fit the specific requirements of the design.

Research on printing performance of full potato powder: The relationship between rheological properties, microstructure, and printing performance

AbstractThis work evaluated the printing performance of mashed potatoes (MP), principally utilizing full potato powder as a raw material, with the aim of improving the printing quality and efficiency of MP. It investigated how different formulations affected the rheological traits, microstructure, and printing effectiveness of MP. Using a single‐factor controlled variable approach, the molding properties of MP were investigated in terms of the concentrations of full potato powder and the concentrations and ratio of the mixed colloid of carrageenan (CG) and xanthan gum (XG), respectively. Through the experiment, the relationship between the rheological properties, microstructure, and printing performance of MP was established, and its printing characteristics were evaluated in terms of the rheological parameters, microstructural characteristics, and extrusion molding effect of MP. The results showed that: the concentration of full powder significantly influences the printability of MP, and a specific concentration of full powder can make MP have better flow properties; CG–XG could enhance the viscoelasticity and surface quality of MP so that MP had good shear thinning characteristics and thixotropic properties, ensuring that the MP could immediately restore the viscoelasticity to maintain the stability of the structure of the parts after extruding; and the MP can be used to create composite materials. The 3D printing of potatoes was examined in this article based on the material's molding properties, offering a theoretical and technical foundation for the execution of MP high‐efficiency and high‐precision printing and is of significance in advancing the field of food 3D printing technology.Practical applicationsIn this study, the relationship between rheological properties, microstructure, and printing performance was established for the first time, and the structural characteristics of molding equipment were correlated with the properties of printable raw materials. This study also introduces a novel molding process. By incorporating the appropriate hydrophilic gel and potato starch and using full potato flour as the research object, the printable performance of mashed potatoes was enhanced. The molded food preserved the original nutrients and potato flavor to a large extent, which promoted the development of potato staple foods and was of significant importance for the study of the 3D printing capabilities of the paste food.

Co-Delivery System of Vitamin B12 and Vitamin E Using a Binary W/O/W Emulsion Based on Soybean Isolate Protein-Xanthan Gum/Carrageenan: Emulsification Properties, Rheological Properties, Structure, Stability, and Digestive Characteristics.

In this study, the soybean protein isolate (SPI)-xanthan gum (XG) or carrageenan (CA) W/O/W emulsions for the co-delivery of vitamin B12 and vitamin E were prepared. The effects of XG and CA concentrations on the physicochemical properties and digestive characteristics of the emulsions were also investigated. The addition of XG and CA improved the SPI aggregation and increased its electrostatic repulsion so that more SPI was adsorbed at the phase interface. The emulsifying activity index and emulsifying stability index increased to 24.09 (XG 0.4%) and 14.00 (CA 0.5%) and 151.08 (XG 0.4%) and 135.34 (CA 0.5%), respectively. The adsorbed protein content increased to 88.90% (XG 0.4%) and 88.23% (CA 0.5%), respectively. Moreover, the encapsulation efficiencies of vitamin B12 and vitamin E were increased to 86.72% (XG 0.4%) and 86.47 (CA 0.5%) and 86.31% (XG 0.4%) and 85.78% (CA 0.5%), respectively. The bioaccessibility of vitamin B12 and vitamin E increased to 73.53% (XG 0.4%) and 71.32% (CA 0.5%) and 68.86% (XG 0.4%) and 68.74% (CA 0.5%). The best properties of the emulsions were obtained at a 0.4% concentration of XG and 0.5% of CA. This study offers a novel system for delivering bioactive substances, which is favorable for the advancement of food with delivery capability in food processing.

Selective Sorption of Heavy Metals by Renewable Polysaccharides.

Renewable and biodegradable polysaccharides have attracted interest for their wide applicability, among them their use as sorbents for heavy metal ions. Their high sorption capacity is due mainly to the acidic groups that populate the polysaccharide backbone, for example, carboxylic groups in alginate and sulfate ester groups in the iota and lambda carrageenans. In this study, these three polysaccharides were employed, alone or in different mixtures, to recover different heavy metal ions from aqueous solutions. All three polysaccharides were capable of adsorbing Eu3+, Sm3+, Er3+, or UO22+ and their mixtures, findings that were also confirmed using XPS, TGA, and FTIR analyses. In addition, the highest sorption yields of all the metal ions were obtained using alginate, alone or in mixtures. While the alginate with carboxylic and hydroxyl groups adsorbed different ions with the same selectivity, carrageenans with sulfate ester and hydroxyl groups exhibited higher adsorption selectivity for lanthanides than for uranyl, indicating that the activity of the sulfate ester groups toward trivalent and smaller ions was higher.

Seaweed supplementation to organic dairy cows may reduce climate impact of manure in pasture soils during a laboratory incubation

AbstractIntroductionEnteric methane (CH4) emissions are one of the largest components of the anthropogenic CH4 budget, and with accelerating climatic changes, there are calls to reduce anthropogenic greenhouse gas emissions. Certain seaweeds fed as supplements can reduce enteric CH4 emissions from ruminant animals by as much as 80%; however, these studies have yet to analyze downstream impacts that may arise from the deposit of affected manures on pastures or agricultural fields.Materials and MethodsHere we conducted a 28‐day soil and manure incubation utilizing manures collected from dairy cows in a seaweed feeding trial to analyze the impacts of manure on greenhouse gas fluxes and nutrient cycling. Cows were fed different diets with a control group (no seaweed supplementation), and a 3% and 6% by dry‐weight seaweed (Chondrus crispus) supplementation. Three soil moisture treatments were also tested, with a field moist capacity [67% gravimetric water content (GWC)], a drier group (50% GWC), and a saturated treatment (84% GWC).ResultsWe found that manure from seaweed‐fed cows reduced emissions of carbon dioxide and had similar emissions of methane and nitrous oxide to the control. Higher moisture levels increased CH4 emissions and nitrous oxide emissions with CH4 emissions trending higher in seaweed supplements trending higher in. Inorganic nitrogen turnover varied more based on moisture levels than seaweed supplements, as did the magnitude of methane and nitrous oxide emissions. Total carbon and nitrogen mostly decreased except in the 3% seaweed supplementation, which increased carbon and nitrogen with a drop in C:N in the 50% GWC group.ConclusionSeaweed supplements may partially reduce climate impacts of manures from cows fed seaweed supplements or at least not cause harm or impact manure quality. Given feeds may reduce enteric CH4 emissions, they may be a part of a successful strategy to reduce climate impacts of cattle.

Preparation and characterization of ι-carrageenan nanocomposite hydrogels with dual anti-HPV and anti-bacterial activities

Sexually transmitted diseases (STDs) are usually caused by co-infections of bacteria and viruses. However, there is a lack of products that possess both antibacterial and antiviral activities without using chemical drugs. Here, we developed a carrageenan silver nanoparticle composite hydrogel (IC-AgNPs-Gel) based on the antiviral activity of iota carrageenan (IC) and the antibacterial effect of silver nanoparticles (AgNPs) to prevent STDs. IC-AgNPs-Gel showed excellent biocompatibility, hemostasis, antibacterial and antiviral effects. IC-AgNPs-Gel not only effectively prevented S. aureus, E. coli, P. aeruginosa, and C. albicans without using antibiotics, but also significantly inhibited human papilloma virus (HPV)-16 and HPV-6 without using chemotherapy drugs. Moreover, IC-AgNPs-Gel showed the effects of accelerating infected wound healing and reducing inflammation in a rat wound model infected with S. aureus. Therefore, the multifunctional hydrogel shows great potential application prospect in preventing STDs.

Constructing a biodegradable carrageenan based food packaging film according to the synergistic strategies between peppermint essential oil and thymol

The research and development trend of food packaging is changing from synthetic polymers to eco-friendly materials such as polysaccharides and other hydrocolloids, aiming to solve the problem of pollution from plastic wastes. In this work, a biodegradable food packaging noted KC/PT film was constructed using konjac glucomannan (KGM)/carrageenan (CAR) composite as the matrix and peppermint essential oil (PO)/thymol (THY) with synergistic effect as the reinforcements. The KC/PT film showed great mechanical properties, UV-blocking activity, increased water contact angle and reduced water vapor permeability. Due to the synergistic effect between PO and THY, the KC/PT film showed excellent antioxidant performance and antibacterial behavior against Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 19115 and Staphylococcus aureus ATCC 6538. The antibacterial mechanism was further illustrated. The prepared KC/PT film, as a unique packaging film, not only successfully extended the shelf life of strawberry to 16 days at 4 °C, but also well expressed its environmental friendliness that it could nearly degrade after 47 days in natural soil conditions. Most importantly, the film exhibited good stability in terms of mechanical properties, antioxidant activity and antibacterial performances after 4 months storage. Therefore, the film the KC/PT film has great potentials in the field of food packaging area.

Combination of carrageenan with sodium alginate, gum arabic, and locust bean gum: Effects on rheological properties and quiescent stabilities of partially crystalline emulsions

In the present study, carrageenan (CG) was combined with sodium alginate (SA), gum arabic (GA), and locust bean gum (LBG) to obtain four gum combinations (CG, CG + SA, CG + GA, and CG + LBG). The effects of different combinations on rheological properties and quiescent stabilities of PCEs were systematically investigated through characterization of fresh emulsion related parameters (rheological properties, forces between proteins, zeta potentials, surface tensions, interfacial adsorption properties, and multiple light scattering) and storage related parameters (visual appearance, creaming index, viscosities, particle sizes, and microscopic morphology). Rheological results indicated that CG PCEs had the highest apparent viscosities of 7.77–41.91 Pa·s at 0.01 s−1, followed by CG + SA PCEs (2.35–30.62 Pa·s), CG + GA PCEs (2.37–21.16 Pa·s), and CG + LBG PCEs (2.06–19.93 Pa·s). At low thickener concentration (0.02 %), CG PCE exhibited weak gel structure due to higher G′ than G″ at all frequencies, while CG + SA, CG + GA, and CG + LBG PCEs had entangled network due to intersection between G′ and G″. After three months of storage, CG + SA PCEs showed the lowest creaming index values (11.47–17.75 %), which were significantly lower than CG PCEs (15.35–20.85 %), CG + GA PCEs (15.97–24.42 %), and CG + LBG PCEs (17.13–21.71 %). Meanwhile, all the samples except for 0.02 % CG + SA PCE completely lost fluidity, and their viscosities were above 14,000 mPa·s. It was further found that CG stabilized emulsions showed severe droplet flocculation induced by hydrophobic interactions among adsorbed proteins. Combination of CG with SA, GA, and LBG, especially CG + SA, formed strong network structure and reduced contribution of hydrophobic interactions, which effectively inhibited flocculation of fat droplets, thereby improving rheological properties and storage stabilities of PCEs.

Seaweed polysaccharides on seed germination of Brassica napus L.

Seaweed polysaccharides, when compared to synthetic commercial fertilizers, have been proven to achieve excellent results in plant growth parameters. When applied to the soil directly or sprayed on the foliage, seaweed poly- and oligosaccharides can improve seed germination and plant vigor, increase the uptake of soil nutrients, and protect plants against several abiotic and biotic stresses, by stimulating a plant to produce secondary metabolites and manage its defense pathways. In this study, three different polysaccharides (alginate, agar and carrageenan) were extracted from one brown seaweed, Saccorhiza polyschides, and two red seaweeds, Gracilaria gracilis and Chondrus crispus, respectively, with aim to analyse their impact on Brassica napus L. seed germination. The polysaccharides' chemical structure, mineral profile and other physicochemical properties were assessed. Carrageenan exhibited the best results in seedling growth and germination percentage when compared to alginate and agar. The carrageenan extracted from the tetrasporophyte, non-fructified thalli and female gametophyte of Chondrus crispus exhibited 94.67, 92 and 98.67 % seed germination, respectively. Carrageenan's bioactivities appear to be related with their sulphation level, plus the pH and the conductivity of its solution. The optimum concentration for germination of each polysaccharides' solution was assigned to propose further experiments in turnip greens.

Graphene oxide@Fe3O4-decorated iota-carrageenan composite for ultra-fast and highly efficient adsorption of lead (II) from water

The aggravated problem of lead pollution, especially in aquatic environments, necessitates the development of eminent adsorbents that could radically solve this environmental problem. Hence, a new composite was constructed based on iota carrageenan (i.Carr), graphene oxide (GO) and magnetite (Fe3O4) for removing noxious Pb2+ ions. The GO@Fe3O4-i.Carr composite was characterized by VSM, SEM, XPS, XRD, FTIR and Zeta potential. The removal of Pb2+ ions attained a quick equilibrium of almost 30 min with a removal efficiency reaching 93.68 %. The removal of Pb2+ was boosted significantly, in the order of GO@Fe3O4-i.Carr(1:1) > GO@Fe3O4-i.Carr(1:3) > GO@Fe3O4-i.Carr(3:1). Moreover, acquired experimental data fitted the pseudo 2nd order kinetic model and Freundlich isotherm model with a maximal monolayer adsorption capacity reached 440.05 mg/g. Notably, after five adsorption runs, the composite maintained its removal efficiency exceeding 74 %. The assumed adsorption mechanisms of Pb2+ onto GO@Fe3O4-i.Carr were complexation, precipitation, Lewis acid-base, and electrostatic attraction forces. Overall, the GO@Fe3O4-i.Carr composite elucidated the auspicious adsorbent criteria, comprising fast adsorption with high performance, ease-separation and tolerable recyclability, advising its feasible use to decontaminate water bodies from hazardous heavy metals.