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Biopolymer gels have considerable potential because of their ability to encapsulate, protect, and release bioactive components. In the present study, κ-carrageenan composited alginate gel beads were prepared and tested for use as potential delivery vehicles for the encapsulation and controlled release of capsanthin, an antioxidant ingredient contained in red pepper. By varying the weight ratio of κ-carrageenan, as well as the concentration or type of the crosslinking agent and outer organic phase, different sustained release characteristics of capsanthin from κ-carrageenan composited alginate gel beads were obtained. In the case of sustained release experiments using κ-carrageenan composited alginate gel beads, for a mass ratio of κ-carrageenan in the polymer (1wt%) of 50%, the sustained release ratio for a predetermined time was suppressed to about 80% of the maximum value for Ca2+ and about 40% for K+ at 120 min. When the KCl concentration of the crosslinking agent for gelation was increased, the start time of the sustained release was delayed. These were discussed on surface structure of the gel beads by scanning electron microscopy. Also, as the hydrophobicity of the outer organic phase increased, the beads shrank in volume, and the sustained release ratio decreased. These results indicate that the encapsulation of bioactive components using κ-carrageenan composited alginate polymer could provide an effective means for the controlled release of capsanthin.

The present investigation aims at development of extended release (ER) pellets using κ-carrageenan-montmorillonite (κ-Carr-MMT) polyelectrolyte complex (PEC) hydrogel. The PEC was used as binder an...

Background Mixtures of carrageenan and konjac gum are useful for specific applications in gel-based foods. Focusing on the changes of textural and structural properties, the effects of κ-carrageenan and konjac ratio and sucrose and Ca2+ concentrations on mixed gels were studied in this research. Furthermore, application of κ-carrageenan-konjac gum mixed gel to milk puddings was investigated. Results There was a better synergistic effect when the ratio of κ-carrageenan and konjac was 7:3. The mixed gel containing 10 g kg-1 κ-carrageenan-konjac gum was characterized by higher hardness, chewiness, adhesiveness and resilience and denser network structure. Besides, the addition of 5-10 wt% sucrose or 0.02 wt% Ca2+ could enhance the hardness, chewiness and adhesiveness of the mixed gel, as well as affording a denser network structure. For milk pudding, moderate hardness, chewiness and resilience could be obtained by adding 1.5 g kg-1 κ-carrageenan-konjac gum mixture. Conclusions This research provides useful information for the formation of κ-carrageenan-konjac gum gel and its application in milk pudding. © 2020 Society of Chemical Industry.

This study was conducted thanks to funding from theEmployment, Industry and Tourism Office of the Principality of Asturias (Spain) through project IDI/2018/000127

Carrageenans are widely utilized in many commercial applications such as the food and pharmaceutical industry, due to their excellent functional properties. In this study, a sensitive LC-MS/MS method was developed to determine κ-3, κ-5, and κ-7 carrageenan oligosaccharides simultaneously. Optimum MRM transitions for κ-3, κ-5, and κ-7 carrageenan oligosaccharides were (645.079→565.111, [M-H]−), (515.137→474.946, [M-2H]2−), and (471.484→445, [M-3H]3−), respectively. Chromatographic separation was performed on an Amide column coupled with a guard column operated at 60 °C under stepwise gradient elution. The linearity of the LC-MS/MS method for κ-3, κ-5, and κ-7 carrageenan oligosaccharides, evaluated over the concentration range of 0.10–20.0 µmol L−1, was excellent. The precisions of the method for κ-3, κ-5, and κ-7 carrageenan oligosaccharides were from 0.91% to 9.66%, and the inter-day precisions were from 0.92% to 10.5%. Validation of the LC-MS/MS method indicated that the method was precise and in line with the CFDA guidance. This method has been successfully applied to an in vitro absorption study.

Background: The high amounts of fat, sugar and calorie existing in dairy desserts can lead to increase the risk of health problems. Therefore, the development of functional and dietary forms of these products can help the consumer health. Objective: This study aims to investigate the effects of κ-carrageenan, modified starch and inulin addition on rheological and sensory properties of non-fat and non-added sugar dairy dessert. Methods: In order to determine the viscoelastic behavior of samples, oscillatory test was carried out and the values of storage modulus (G′), loss modulus (G″), loss angle tangent (tan δ) and complex viscosity (η*) were measured. TPA test was used for analysis of the desserts’ texture and textural parameters of samples containing different concentrations of carrageenan, starch and inulin were calculated. Results: All treatments showed a viscoelastic gel structure with the storage modulus higher than the loss modulus values. Increasing amounts of κ-carrageenan and modified starch caused an increase in G′ and G″ as well as η* and a decrease in tan δ. Also, firmness and cohesiveness were enhanced. The trained panelists gave the highest score to the treatment with 0.1% κ-carrageenan, 2.5% starch and 5.5% inulin (sucralose as constant = 0.25%) and this sample was the best treatment with desirable attributes for the production of non-fat and non-added sugar dairy dessert. Conclusion: It can be concluded that the concentration of κ-carrageenan and starch strongly influenced the rheological and textural properties of dairy desserts, whereas the inulin content had little effect on these attributes.

This research focused on the development of carrageenan based biodegradable films incorporated with olive leaves extract (OLE). OLE microbial inhibition and its total phenolics (TP) were evaluated. Carrageenan films were produced by casting technique and were characterized by thickness, water vapor permeability (WVP), color, mechanical properties, and infrared spectroscopy. In order to apply as lamb meat packaging, the antimicrobial effect of the films was investigated. Results showed that OLE inhibited E. coli growth and presented excellent TP (41.40 mgGAE/g). Thicknesses of the film with OLE (CAR‐OLE) were approximately 28% higher than film without OLE. Addition of OLE reduced the WVP by approximately 54%. CAR‐OLE was less resistant to breakage and more flexible showing darker color. FTIR showed interaction of carrageenan with OLE. Results revealed that CAR‐OLE promoted 167‐fold reduction in initial count of aerobic mesophiles indicating shelf‐life extension of lamb meat and promising use as antimicrobial food packaging., Active food packaging.

Providing enough water in farming has become a challenge in the Philippines due to insufficient irrigation and escalating drought conditions, thereby decreasing agricultural productivity. The impact of this problem can be lessened through efficient water usage: by reducing water wastage in runoff or evaporation and improving soil water retention. Hydrogels can be used for this purpose due to their water absorption capabilities. In this study, a novel, biodegradable agricultural hydrogel was developed from κ-carrageenan, sodium alginate and carboxymethyl cellulose, crosslinked with Ca2+ and K+ ions. Scanning electron microscopy analysis confirmed the successful crosslinking while swelling tests revealed them as superabsorbent hydrogels, with maximum absorption reaching 2000%. Soil amended with 2% (w/w) hydrogel showed reduced water-depletion rate and improved field capacity by a maximum of 17.6% and 17.4%, respectively. Fertilizer release test also showed the potential of these hydrogels as fertilizer carriers.

β-Carotene was encapsulated in microbeads formed by ionotropic gelation of multilayered emulsions containing sodium caseinate (Na-CAS) and κ-carrageenan at pH 7 and 3.5. The influence of κ-carrageenan concentration on the morphology of microbeads was studied, as well as the effect of pH on the encapsulation efficiency and rheological properties of microbead suspensions. Most of the microbeads showed monomodal size distribution with a mean particle diameter between 25.3 and 176.1 μm. Microbead morphology was influenced by the κ-carrageenan concentration, as microbeads tended to be larger and more spherical at higher κ-carrageenan concentrations. On the other hand, microbeads were slightly affected by pH, showing similar results for encapsulation efficiency and rheological properties of microbead suspensions in salt solution. The encapsulation efficiency was higher than 60% at both pH values. In addition, rheological measurements indicated that the incorporation of microbeads exerted a slight influence on the viscosity of aqueous solutions, mainly up to the 40% volume fraction. Therefore, these microbeads are promising systems for β-carotene vehiculation in food products without compromising their texture.

Polysaccharides have recently attracted increasing attention in the construction of hydrogel devices for biomedical applications. However, polysaccharide-based hydrogels are not suitable for most preclinical applications because of their limited mechanical properties and poor tunability. In this study, we employed a simple and eco-friendly approach to producing a macroporous polysaccharide hydrogel composed of salecan and κ-carrageenan without the use of toxic chemicals. We evaluated the physicochemical properties of the obtained salecan/κ-carrageenan hydrogel and found that its viscoelasticity, morphology, swelling, and thermal stability could be simply controlled by changing the polysaccharide dose in the pre-gel solution. The co-incubation of the fabricated hydrogel with mouse fibroblast cells demonstrated that the hydrogel can support cell adhesion, migration, and growth. Moreover, the hydrogel exhibited good biocompatibility in vivo. Overall, the findings provide a new strategy for the fabrication and optimization of polysaccharide-based hydrogel scaffolds for application in tissue engineering.

Bacterial cellulose (BC)/κ-carrageenan composite pellicles were prepared by in situ formation and subjected to post-formation alkali and neutralization treatments. κ-Carrageenan was incorporated into BC pellicles by in situ formation to form a gel by post-formation treatment with a solution containing K+. Structural analyses indicated that BC/κ-carrageenan pellicles had a double-stage structure, consisting dominantly of cellulose in the upper part and κ-carrageenan in the under part. BC/κ-carrageenan pellicles became weaker upon application of a tensile force and were harder compared with the BC pellicles. Vanillin was used to study the release of active agents from the pellicles. The fractional release of vanillin from BC/κ-carrageenan pellicles relative to the initial release (30–60 min) was greater than that from BC pellicles. These findings should aid basic research on BC/κ-carrageenan pellicles and help in determining their suitability for application in the biomedical and cosmetic industries.

The aim of this study is to offer a comprehensive view on drug release from hydrogel, from both an experimental and a theoretical point of view. Aiming to benefit cyclodextrins’ properties (not irritant; stable; able to modify the physical, chemical and biological properties of active compounds; accessible at low prices) and those of carrageenan polysaccharide (antitumor, immunomodulatory, antihyperlipidemic, anticoagulant, biocompatibility, biodegradability), original hydrogel films based on beta cyclodextrin and kappa carrageenan using epichlorohydrin as crosslinking agent were prepared and characterized from morphological and physical/chemical points of view. The results (morphology, the swelling degree, and the loading/release capacity) proved their potential as carriers for different types of drugs. Further, a new theoretical model, from a multifractal paradigm of motion, was proposed for the drug release from hydrogel films, starting from the fundaments of its evolution at a microscopic level, and aiming to obtain information on system evolution, at both the spatial and temporal scales, inapproachable by quantitative measurements.

The aim of this study is to offer a comprehensive view on drug release from hydrogel, from both an experimental and a theoretical point of view. Aiming to benefit cyclodextrins’ properties (not irritant; stable; able to modify the physical, chemical and biological properties of active compounds; accessible at low prices) and those of carrageenan polysaccharide (antitumor, immunomodulatory, antihyperlipidemic, anticoagulant, biocompatibility, biodegradability), original hydrogel films based on beta cyclodextrin and kappa carrageenan using epichlorohydrin as crosslinking agent were prepared and characterized from morphological and physical/chemical points of view. The results (morphology, the swelling degree, and the loading/release capacity) proved their potential as carriers for different types of drugs. Further, a new theoretical model, from a multifractal paradigm of motion, was proposed for the drug release from hydrogel films, starting from the fundaments of its evolution at a microscopic level, and aiming to obtain information on system evolution, at both the spatial and temporal scales, inapproachable by quantitative measurements.

The effects of dietary k-Carrageenan (k-CGN) at 10, 20, and 30 g kg−1 on growth rate, hemato-biochemical indices, innate-adaptive parameters and modification of pro- and/or anti-inflammatory cytokines and chemokines pathway in cobia, Rachycentron canadum against Lactococcus garvieae is reported. The weight gain (WG) increased substantially (P

The viscometric behaviour of κ-carrageenan in aqueous solutions and in the presence of monovalent salts was investigated at 25 °C. Coil, helix or double helix conformations were induced by cooling hot κ-carrageenan solutions under appropriate ionic conditions. A new viscometric approach was used for modeling the behaviour of κ-carrageenan solutions. The intrinsic viscosity, [η], is markedly changed by the presence of different monovalent salts (NaCl, NaI and CsI). In pure water, the intrinsic viscosity amounts to 48 dL·g−1. In 0.1 M NaCl solutions (single helix state) [η] is 6.2 dL·g−1, whereas in 0.1 M NaI (double helix conformation) it is approximately twice as large. In 0.1 M CsI (dissimilar cation and counter-ion) the intrinsic viscosity is three times larger, suggesting the formation of the associated κ-carrageenan helices. Stepwise association of κ-carrageenan helices was followed in presence of NaI/CsI mixtures of different compositions. The value of Smidsrod-Haug stiffness parameter (B) measured for κ-carrageenan in NaCl solutions is 4.47 × 10−2, higher than that of DNA (5.5 × 10−3), but lower than those reported for carboxymethyl cellulose (6.3 × 10−2), indicating that the chain conformation is moderately rigid.

A growing interest in development of milk desserts with good nutritional and rheological properties can be observed. A good and stability rheological as well as nutritional properties of such desserts can be provided by applying suitably composed gum mixtures. In this work, the effect of 0.1% κ-carrageenan addition on the rheological properties of based-milk desserts with different oat gum concentrations (0.1, 0.3 and 0.5%) was investigated. All milk desserts tested in presented study showed a time dependent and shear-thinning flow behavior. The mechanical spectra were characterized by storage module (G’) greater than loss module (G”), typical for viscoelastic materials such as gels and dispersions. The incorporation of 0.1% κ-carrageenan into milk dessert with different oat gum concentrations allows to obtain stronger gel structure compared to milk dessert with separate oat gum addition. It can be also observed that desserts systems with the 0.1% κ-carrageenan had more stable viscoelastic properties. Moreover, the use the κ-carrageenan addition caused an increase in consistency coefficient (K) and decreased in n-value for Ostwald de Waele rheological model. Combined addition of oat gum and carrageenan allows to obtain milk dessert with stronger texture. The hardness of milk desserts range from 0.32 to 0.49 N for desserts without κ-carrageenan addition and from 0.513 to 0.557 N for desserts with κ-carrageenan. The high synergistic effect of composed gum mixtures on rheological properties of milk dessert occurs at 0.1% oat gum and 0.1% κ-carrageenan concentration.

Natural biopolymers are biocompatible and biodegradable, and have been a focus on the research of biologically active carrier materials. In this manuscript, the nanoparticles of ovalbumin/κ-carrageenan (OVA-CRG) complex were fabricated to encapsulate and protect curcumin under moderate conditions, forming the ovalbumin/κ-carrageenan/curcumin (OVA-CRG-CUR) complex nanoparticles. The OVA-CRG complex nanoparticles show good curcumin entrapping performance, and the addition of curcumin does not affect the emulsifying stability (ES) and emulsifying activity (EA) of OVA-CRG complex nanoparticles. The maximum ES of OVA-CRG-CUR is reached at 36 h with the value of 84.6 min, and the maximum EA is reached at 48 h with the value of 74.2 m2/g. The encapsulated curcumin demonstrates high antioxidation activity, while its thermal and light stabilities of curcumin are both increased. The release behavior of curcumin is further studied in simulated gastric and intestinal fluids. The lower release rate of curcumin in simulated gastric fluid with the final value of 12.9% after 3 h indicates that the OVA-CRG complex nanoparticles are good carriers for improving the stability of curcumin in acidic environment, and are able to enhance the bioavailability of curcumin by a gradual release in intestine. Present researches elucidate that proteins-polysaccharides complex nanoparticles are feasible to solubilize and protect sensitive amphiphilic bioactive compounds and have extensive potential in food and medicinal applications.

Scaffolds for tissue engineering of specific sites such as cardiac, nerve, and bone tissues need a comprehensive design of three dimensional materials that covers all aspects of chemical composition and physical structures, required for regeneration of desired cells. Hydrogels, possessing highly hydrated and interconnected structures, are promising materials for tissue engineering applications. Improvement of an injectable hydrogel from biocompatible polysaccharides and poly‑N‑isopropyl acryl amide enriched with Au nanoparticles are the main goal of this study. Two main enhancements in this study are included mixture design of the components and addition of Au nanoparticles to access a homogeneous mixture that have potential application in tissue engineering. Chemical and physical properties of the injectable hydrogel are fully characterized. Addition of Au nanoparticles as a conductive component to enhance cell growth and attachment is investigated through MG-63 cell viability assay.

A smart wound dressing based on carrageenan (κC), locust bean gum (LBG), and cranberry extract (CB) for monitoring bacterial wound infections was developed and characterized using UV-vis spectroscopy, FT-IR, and SEM. The mechanical, swelling, cytotoxic and pH sensor properties were also investigated. UV-vis spectra demonstrated that the obtained κC:LBG:CB hydrogel film exhibited a visible change of colors as it was immersed in PBS solution pH 5.0, 7.3 and 9.0. The spectra of FT-IR suggested that chemical interactions had occurred between κC and CB extract. The obtained κC:LBG:CB hydrogel film exhibited adequate mechanical properties and a swelling behavior dependent on pH. Cytotoxicity tests indicated that κC:LBG:CB hydrogel film had dose-dependent cytotoxicity against NIH 3T3 fibroblast cells. The in vitro studies using Staphylococcus aureus and Pseudomonas aeruginosa demonstrated that the color changes of the κC:LBG:CB hydrogel film could be observed by naked eyes, confirming the potential use of the obtained hydrogel film as a visual system for monitoring bacterial wound infections.

The main aim of the current study was to research the effect of the degree of konjac deacetylation on the rheological and textural properties of konjac glucomannan (KGM) and κ-carrageenan blends. A series of deacetylated konjac glucomannan (Da-KGM) with different degrees of deacetylation (0, 20.35%, 35.62%, 57.19%, and 74.01%) was prepared by a heterogeneous deacetylation method. The rheological and textural properties of mixed sols and gels of Da-KGM with different degrees of deacetylation and κ-carrageenan were determined. The results showed that the viscosities of mixed sols of Da-KGM and κ-carrageenan decreased with increasing degree of deacetylation. The partial removal of acetyl groups from konjac glucomannan could significantly improve the hardness and springiness of mixed gels of KGM and κ-carrageenan. Meanwhile, decreasing the acetyl content could decrease the syneresis of mixed gels. By regulating the deacetylation degree of konjac, gels with high gel strength could be prepared, which provides a new idea for the production of high-strength gelatin food.

PurposeThe main objective of this study is to explore the effects of the extracted mushroom polysaccharides in the form of polysaccharides-Alginate (Alg.)/kappa carrageenan (El-Aassar MR) microcapsules to activate natural killer cells (NK) against colon cancer. MethodsWater soluble polysaccharides were extracted from nine wild isolates of Egyptian Mushroom, and their safety patterns were checked on peripheral blood mononuclear cells (PBMC). The extracted Agaricus bisporus MH751906 polysaccharide was microcapsulated in Alg/κ-carrageenan microcapsules. The morphology and swelling behavior of Alg/κ-carrageenan microcapsules, Alg/κ-carrageenan*polysaccharide microcapsules was determined. Also, the in vitro release of Polysaccharide from Alg/κ-carrageenan*polysaccharide microcapsules was analyzed. The Effects of Alg/κ-carrageenan*polysaccharide microcapsules on activating NK cells against colon cancer was evaluated at both cellular and molecular levels. ResultsThe results showed that, the extracted polysaccharide from the isolate 8 (submitted to the Gen Bank as Agaricusbisporus MH751906) was the safest sample on PBMCs even at 5mg/ml. The microencapsulated polysaccharides in Alg/κ-carrageenan*polysaccharide formula showed better thermal stability at high temperature with higher hydrogel swelling rates in alkaline pH. Upon NK cells activation with microcapsules (ANK cells), a significant decrease in CD11b and CD16-CD56- and an increase in CD16+CD56+ NK cell populations were recorded. These activated NK cells showed 74.09% cytotoxic effects against CaCO-2cellswith an increase of cancer cell populations in the G0/G1 phase. Furthermore, the ANK cells-CaCo-2treated cells recorded down regulations both Bcl2 and TGF genes and up regulation of IkappaB-α expression.ConclusionA novel polysaccharides-alginate/κ-carrageenan microcapsules preparation to enhance NK cell cytotoxic effects against colon cancer cells and this inhibitory effect is associated with the regulatory effects of inflammatory pathway through the induction of IkappaB- alpha.

BACKGROUND Konjac glucomannan (KGM) showed a synergistic interaction with κ-carrageenan (CAR), which led to the formation of a promising compound hydrocolloid gel in the food field (such as jelly). Nevertheless, the mixed gels formed by adding KGM to CAR still displayed defects in gel strength and syneresis, and would hardly meet the quality requirements of some gel foods. However, deacetylated KGM and maltodextrin (MD) have always been used in gel foods and affect their viscosity and rheological properties. RESULTS In our paper, different amounts of MD were first used to alter the textural properties, and the results showed that both tensile strength and elongation exhibited first an increasing and then a decreasing trend with the increasing MD proportion and achieved a maximum at a final maltodextrin proportion of 4 g kg-1 in the KGM/CAR/MD system. Based on the above results, we further explored the effects of deacetylation degree of KGM on the gel properties of mixed gel system. The results revealed that, compared to the native KGM, the partial deacetylated KGM was capable of significantly improving the tensile strength and elongation of KGM/CAR mixed gel. CONCLUSION Our study found that the appropriate addition of MD (0.4%) and DKGM were able to alter the tensile properties of KGM/CAR mixed gel, with potential to meet the needs of consumers and further design innovative tensile gel products in the soft gel industry. © 2021 Society of Chemical Industry.

In the last two decades, the utilization of magnetic nanospheres in intelligent polymeric structures have received increased attention of researchers in numerous biomedical applications. Here, hybrid nanostructured triple-responsive magnetic nanospheres (κ-Car-g-P(AA/DMA)@Fe3O4) containing inorganic iron oxide core (Fe3O4) and organic graft copolymeric shell based on κ-carrageenan (κ-Car) and poly(acrylic acid/dimethylaminoethyl methacrylate) (P(AA/DMA)) were synthesized by microwave induced co-precipitation technique. The structure, size, surface morphology, magnetic property and stability of synthesized κ-Car-g-P(AA/DMA)@Fe3O4 magnetic nanospheres were characterized using FTIR, UV, XRD, TEM, Zeta-sizer, and VSM. κ-Car-g-P(AA/DMA)@Fe3O4 nanospheres were loaded with 5-Fluorouracil (5-FU) as an antineoplastic drug, and their 5-FU release behavior was explored in diverse graft yields, pH values, temperatures and in the existence of an alternating magnetic field. The κ-Car-g-P(AA/DMA)@Fe3O4 nanospheres demonstrated pH-, thermo-, and magnetic field-responsive 5-FU release with good biocompatibility and excellent anticancer activity. In addition, 5-FU release under 50 mT magnetic field reached to 100% within 4 h. This work exhibits that hybrid nanospheres have a triple stimuli-responsive influence, which is of principal importance for the future design and application of multi-functional responsive platforms to develop externally stimulated release of active agents and their healthcare capability. 2018/055 The authors are thankful to the Scientific Research Projects Coordination Unit of Kırıkkale University [Project number: 2018/055 , 2018] for their financial support. The authors are thankful to the Scientific Research Projects Coordination Unit of Kırıkkale University [Project number: 2018/055, 2018] for their financial support. 2-s2.0-85117113370

This work aimed to design montmorillonite-incorporated pH-responsive and magnetic κ-carrageenan/chitosan hydrogels via a completely green route for controlled release of sunitinib anticancer drug. This was accomplished by ionic cross-linking of two biopolymers, κ-carrageenan and chitosan, in the presence of magnetic montmorillonite (mMMt) nanoplatelets. Interestingly, it was observed that the amount of mMMt affected not only the microstructure of hydrogels, but also the drug loading efficiency of nanocomposite hydrogels was noticeably increased by introducing mMMt (from 69 to 96%). The in vitro sunitinib release experiments showed that a low content of loaded sunitinib was released from all hydrogels in the buffered solution with pH 7.4. In contrast, a relatively sustained release with a high content of drug release was observed in the acidic solution of pH 5.5. During 48 h, the hydrogels nanocomposite containing a high content of mMMt showed cumulative release of 64.0 and 8.6% at pH 5.5 and 7.4, respectively. During two days, while the cumulative release of sunitinib was obtained 84.3% for the magnetic-free hydrogel, the magnetic ones showed 74.4 and 64% with the low and high contents of magnetic MMt, respectively. The developed κ-carrageenan/chitosan hydrogels with a high capacity of drug loading and subsequent pH-sensitive drug release can be considered in prolonged cancer therapy with reduced side effects.

Acute salinity stress happens unnoticed in shrimp ponds and there is a need to protect the animals by providing dietary functional ingredients that will elicit resistance to this stress. k-Carrageenan, a sulfated polysaccharide from red seaweed, is reported to trigger innate immunity in vitro and in vivo in shrimps. The present study aims to evaluate its potential as growth-promoter and its immune-enhancement effects against salinity stress. Three separate experiments were done: (a) an attractability test; (b) a 30-day feeding trial to determine optimal inclusion of k-carrageenan, and (3) acute salinity stress test. Results of the attractability tests showed that all the experimental diets did not differ in their attractability to the shrimps. In the feeding trial, 5 groups of post larval shrimp were fed with 5 experimental diets containing various inclusion levels of k-carrageenan, namely, 0.0, 0.15, 0.30, 0.45, and 0.60 g kg-1. Results showed that the final average body weight (FABW), weight gain (WG), and specific growth rate (SGR) and feed conversion efficiency (FCE) values of shrimps in the 0.15 and 0.3 g kg-1 were significantly higher than that of the control group; the values of those in 0.45 and 0.60 g kg-1 groups were not significantly different from those of the control group. Protein efficiency ratio (PER) values, in contrast, were not significantly different from each group. Optimal inclusion level in the diet of k-carrageenan was 0.29 g kg-1. In the acute salinity stress test, 5 groups of shrimps were fed with the same 5 experimental diets as those in the feeding experiment for 2 weeks, transferred them from 21 ppt salinity media to 4 ppt. Results showed that the control group exhibited significantly highest mortality rate while in the 0.6 g kg-1 group the lowest; each group were significantly different from each other. Mortality rate decreased with increased dietary k-carrageenan level in a linear fashion. In conclusion, the study demonstrated that the the diets containing dietary k-carrageenan was equally as attractive as the basal/control diet and that k-carrageenan showed both growth-promoting and immune-stimulating effects against acute salinity stress in the black tiger shrimp P. monodon post larvae.

Anti-washout calcium phosphate cement (CPC) was prepared by dissolving water-soluble konjac glucomannan (KGM) and κ-carrageenan (KC) blend in the cement liquid. The anti-washout property, setting time, compressive strength and in vitro cytocompatibility of the CPC modified with KGM/KC blend were evaluated. The results indicated that the CPC pastes modified with KGM/KC blend exhibited excellent anti-washout property. The addition of KGM/KC blend shortened the setting time and increased the injectability of CPC. Although the introduction of KGM/KC blend reduced the compressive strength of CPC, the compressive strength still surpassed that of human cancellous bone. The optimal KGM/KC mass ratio was 2:8, with which the modified cement exhibited the most efficient washout resistance and the highest compressive strength. The introduction of KGM/KC blend obviously promoted the proliferation of mouse bone marrow mesenchymal stem cells. This anti-washout CPC modified by KGM/KC blend with excellent in vitro cytocompatibility will have good prospects for application in bone defect repair.

It is highly desired yet challenging to develop hydrogels with a combination of excellent mechanical properties and good stability for potential applications. Here we report κ-carrageenan/polyacryl...

Fiber intake improves gut health and prevents non-communicable diseases. The current study investigates the substitution of carrageenan in white bread and evaluates its effect on the physiochemical and structural characteristics of bread. The 100% wheat flour was used as control and the test sample contained 4% carrageenan. The physio-chemical analysis showed that carrageenan-substitution improved the hydration properties of the flour (WHC—1.33 g/g; SC—3.50 ml/g). Carrageen substituted bread had reduced the loaf volume. The fiber content in carrageenan-substituted bread was noticeably higher (9.4 g%) than control (3.5 g%). Crude lipid (4.6 g%) and protein (7.0 g%) content improved with carrageenan-substitution. The mineral contents (Na, K, Mg, Ca, Fe, and Zn) were increased in carrageenan-breads. The texture profile analysis showed a decreased hardness (H1—92.3 N, H2—62.5 N) and improved springiness (5.3 mm) in carrageenan-bread.

In this study, carbon nanotube-based adsorbents, oxidized multi-walled carbon nanotube (OMWCNT) with non-magnetic property and OMWCNT-Fe3O4 and OMWCNT-κ-carrageenan-Fe3O4 nanocomposites with magnetic property, having different structural and surface properties were prepared and their adsorptive properties for the removal of toxic diquat dibromide (DQ) herbicide from water by adsorption were determined in detail. For each adsorption system, the effects of initial DQ concentration, contact time and temperature on the adsorption processes were determined. Equilibrium time was found to be 300 min for DQ solutions. OMWCNT showed faster adsorption and higher maximum adsorption capacity value than magnetic adsorbents. With increasing initial herbicide concentration from 5.43 mg.L−1 to 16.3 mg.L−1, the values of initial sorption rate exhibited a decrease from 29.1 mg.g−1.min−1 to 4.28 mg.g−1.min−1 for OMWCNT-DQ system, from 1.21 mg.g−1.min−1 to 0.823 mg.g−1.min−1 for OMWCNT-Fe3O4-DQ system and from 0.674 mg.g−1.min−1 to 0.612 mg.g−1.min−1 OMWCNT-κ-carrageenan-Fe3O4 system. Maximum adsorption capacity value of OMWCNT was approximately 2.8-fold higher than magnetic OMWCNT-Fe3O4 and 5.4-fold higher than magnetic OMWCNT-κ-carrageenan-Fe3O4 at 25 °C. Adsorption kinetic and isotherm data obtained for all adsorption systems were well-fitted by pseudo second-order and Langmuir models, respectively. Thermodynamic parameters indicated that the adsorption of DQ onto carbon nanotube-based adsorbents was spontaneous and endothermic process. Furthermore, OMWCNT having the highest herbicide adsorption capacity could be regenerated and reused at least five times. This study showed that carbon nanotube-based adsorbents with magnetic and non-magnetic property were of high adsorption performance for the removal of DQ from water and could be promising adsorbent materials for the efficient removal of herbicides from wastewaters.

The inflammatory effects of carrageenan (CGN), a ubiquitous food additive, remains controversial. Gut microbiota and intestinal homeostasis may be a breakthrough in resolving this controversy. Here we show that, κ-CGN did not cause significant inflammatory symptoms, but it did cause reduced bacteria-derived short-chain fatty acids (SCFAs) and decreased thickness of the mucus layer by altering microbiota composition. Administration of the pathogenic bacterium Citrobacter rodentium, further aggravated the inflammation and mucosal damage in the presence of κ-CGN. Mucus layer degradation and altered SCFA levels could be reproduced by fecal transplantation from κ-CGN-fed mice, but not from germ-free κ-CGN-fed mice. These symptoms could be partially repaired by administering probiotics. Our results suggest that κ-CGN may not be directly inflammatory, but it creates an environment that favors inflammation by perturbation of gut microbiota composition and then facilitates expansion of pathogens, and this effect may be partially reversed by the introduction of probiotics.

Fish gelatin (FG) and κ-carrageenan (KC) were mixed to simulate the physicochemical properties of porcine gelatin (PG). The effects of the mixing ratio between FG and KC on the interaction, structure, and rheological properties of FG were investigated. The maximum associative interaction occurred at the critical mixing ratio of KC:FG (w/w) at 4:96, where the median particle size (D50) of the FG-KC coacervates was 1168 ± 175 nm, and the zeta potential was −3.8 ± 0.8 mV. Interestingly, the rheological properties of the mixed gel (KC:FG at 4:96) matched those of PG, including the melting temperature (Tm), gelling temperature (Tg), dynamic consistency factor (Kf), and instantaneous compliance (J0). The relationship between structure and physicochemical properties was proposed as a schematic model. The associative interaction between FG and KC was critical for FG's modification and could be applied to improve FG's rheological properties towards PG.

The influence of cyclodextrins (CDs) on the rheological and structural properties of κ-carrageenan (κ-CA) gel was investigated. Gelling temperature (Tg) of κ-CA was improved by CDs present in the system. Variation of the Herschel-Bulkley model parameters indicates that the addition of CDs increases plasticity of the κ-CA sol. Scanning electronic micrographs show that networks of κ-CA become flat and firm after CDs were added. κ-CA gel containing methyl-β-CD shows the most uniform and fine network structure. Moreover, a proposed model of CDs in κ-CA phase was provided. The influence of CDs on κ-CA gelation was mainly through (i) the exclusion of CDs from κ-CA in the sol state, (ii) the regular rearrangement of κ-CA random coils influenced by CDs in the sol state, (iii) the binding of CDs to the κ-CA surface by hydrogen bonds in the gel.