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1.
Food Chem ; 400: 134032, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36055145

RESUMO

The formation mechanism of heat-induced egg yolk granules (EYGs)/sodium alginate (SA) emulsion gel was studied under pH 6.2 and 7.5. Particle size, water holding capacity, LF NMR, and protein solubility revealed that pH 7.5 increased the surface charge of EYGs and enhanced non-covalent interaction with SA, and hydrogen bonding dominated of the gel formation process. Microscopy and rheological analysis indicated that samples with 0.75% SA had the smallest particle size and highest G', with chain-like oil droplets. Excess SA (1%) led to depletion flocculation due to SA structural rearrangements around oil droplets caused by the increase in negatively charged, causing uneven network structure. The in vitro release property and storage stability of ß-carotene loaded in the EYGs/SA emulsion gel showed that SA increased storage stability and decreased bioaccessibility of ß-carotene with delayed digestion rate. These results provide a theoretical basis for the nutrient delivery system in gel foods.


Assuntos
Alginatos/química , Gema de Ovo/química , beta Caroteno/química , Emulsões/química , Géis/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Imageamento por Ressonância Magnética/métodos , Tamanho da Partícula , Proteínas/química , Reologia , Solubilidade , Água/química
2.
J Biomed Mater Res B Appl Biomater ; 111(1): 73-84, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35841326

RESUMO

Periodontal disease is a common disease in the oral field, and many researchers are studying periodontal disease and try to find some biological scaffold materials to make periodontal tissue regenerative. In this study, we attempted to construct a carbon nanotube/chitosan/sodium alginate (CNT/CS/AL) ternary composite hydrogel and then prepare porous scaffold by 3D printing technology. Subsequently, characterizing the materials and testing the mechanical properties of the scaffold. Additionally, its effect on the proliferation of human periodontal ligament cells (hPDLCs) and its antibacterial effect on Porphyromonas gingivalis were detected. We found that CNT/CS/AL porous composite scaffolds with uniform pores could be successfully prepared. Moreover, with increasing CNT concentration, the degradation rate and the swelling degree of scaffold showed a downward trend. The compressive strength test indicated the elastic modulus of composite scaffolds ranged from 18 to 80 kPa, and 1% CNT/CS/AL group had the highest quantitative value. Subsequently, cell experiments showed that the CNT/CS/AL scaffold had good biocompatibility and could promote the proliferation of hPDLCs. Among 0.1%-1% CNT/CS/AL groups, the biocompatibility of 0.5% CNT/CS/AL scaffold performed best. Meanwhile, in vitro antibacterial experiments showed that the CNT/CS/AL scaffold had a certain bacteriostatic effect on P. gingivalis. When the concentration of CNT was more than 0.5%, the antimicrobial activity of composite scaffold was significantly promoted, and about 30% bacteria were inactivated. In conclusion, this 3D-printed CNT/CS/AL composite scaffold, with good material properties, biocompatibility and bacteriostatic activity, may be used for periodontal tissue regeneration, providing a new avenue for the treatment of periodontal disease.


Assuntos
Quitosana , Nanotubos de Carbono , Doenças Periodontais , Humanos , Tecidos Suporte , Engenharia Tecidual , Alginatos , Impressão Tridimensional , Antibacterianos
3.
Carbohydr Polym ; 301(Pt B): 120362, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36446499

RESUMO

In this study, a novel effective bio adsorbent was produced and employed to remove congo red and methylene blue dyes from water matrices. First, Zn-Al layered double hydroxide (Zn-Al LDH) was manufactured in a hydrothermal process. Next, through in-situ nucleation and growing of crystalline NH2-modified Ti metal-organic framework (NH2-MIL-125(Ti) on Zn-Al sheets by solvothermal method, Zn-Al LDH@NH2-MIL-125(Ti) hybrid was produced. The prepared hybrid showed good adsorption capacity (qmax values: 294 mg/g and 158 mg/g) for congo red and methylene blue dyes in optimum condition (adsorbent amount = 5-7 mg, dye concentration = 100-150 mg/L, V = 10 mL, pH = no adjustment, and contact time = 2-5 h). Based on the isotherm and kinetic models, the Langmuir isotherm, as well as the pseudo-second-order model, were fit to the equilibrium data. In the next attempt, to improve the reusability of the powder and particle form of Zn-Al LDH@NH2-MIL-125(Ti) hybrid, as well as prevent of formation of secondary contamination in water, Na-alginate, as a cheap and effective substrate, was used. Novel architectures of robust, reusable, and efficient Ca-alginate/Zn-Al LDH@NH2-MIL-125(Ti) microgel beads were prepared and the performances of the microbeads were compared with pure LDH@NH2-MIL-125(Ti) hybrid.


Assuntos
Estruturas Metalorgânicas , Corantes , Alginatos , Vermelho Congo , Azul de Metileno , Ânions , Cátions , Água , Zinco
4.
Carbohydr Polym ; 301(Pt B): 120356, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36446513

RESUMO

Adsorbents with high adsorption capacity, sustainability, and reusability are desired in wastewater treatments. Herein, covalently crosslinked microporous cryogels with efficient removal of cationic dyes are fabricated by freezing radical copolymerization using methacrylated alginate (AlgMA) and sodium p-styrenesulfonate (NaSS). The chemical structure, morphology, and thermal stability of the AlgMA/PNaSS cryogels are characterized. Compared with the AlgMA/PNaSS hydrogels with the same chemical composition fabricated by thermal-initiated polymerization, the cryogels show higher adsorption of methylene blue. The AlgMA/PNaSS (with a mass ratio of 1:2) possesses the maximum adsorption capacity for MB with 2300 mg/g under alkaline condition. In addition, the adsorption process of AlgMA/PNaSS cryogels fits the pseudo-second order model and Freundlich model, respectively. The AlgMA/PNaSS cryogels also reveal selective adsorption capacity and reusability after regeneration, which own unchanged corrected adsorption capacity during five adsorption-desorption cycles. The AlgMA/PNaSS cryogels show great potential for use in wastewater treatments and intelligent separation.


Assuntos
Criogéis , Azul de Metileno , Sódio , Alginatos , Águas Residuárias , Íons , Poli A
5.
Methods Mol Biol ; 2598: 177-186, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36355292

RESUMO

Co-culturing is an essential method for unravelling the importance of cross talk and cellular interaction. This chapter describes the preparation of an indirect co-culture technique based on encapsulation of chondrocytes and mesenchymal stromal cells in polyurethane scaffolds and alginate beads, respectively. This way, both cell populations can communicate through paracrine effects in the absence of cell-cell contact. Due to the mechanical properties of polyurethane, this model can be employed in mechanobiology studies. The resulting engineered cultures can provide a more realistic environment, recreating the complex joints' microenvironment and physiology.


Assuntos
Cartilagem Articular , Células-Tronco Mesenquimais , Humanos , Condrócitos , Técnicas de Cocultura , Alginatos , Poliuretanos , Células Cultivadas , Engenharia Tecidual/métodos
6.
Chemosphere ; 311(Pt 1): 136932, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36283436

RESUMO

The engineering of a novel biocomposite based on Cerastoderma edule shells doped with copper and alginate (Ce-Cu@Alg) forming hydrogel beads was used for batch and dynamic adsorption thiabendazole (TBZ) pesticide from water. The prepared biosorbent was analyzed by various characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller analysis (BET), and energy dispersive spectroscopy (EDS), thermogravimetric and differential analysis (TGA-DTA). The results of the TBZ batch biosorption by Ce-Cu@Alg composite showed that the Langmuir model was the most adequate to describe the adsorption process, with a maximum adsorption capacity value of 21.98 mg/g. Moreover, the adsorption kinetics were adjusted by the pseudo-second-order model. The optimal conditions determined by the RSM approach coupled with the CCD design were 100 ppm of initial TBZ concentration, a Ce-Cu@Alg beads dose of 6 g/L and a contact time of 180 min for maximum removal of 83.42%. On the other hand, the TBZ sorption on a fixed bed of Ce-Cu@Alg beads was effective at high column height, low effluent flow and low solution concentration. The Thomas model was best fitted to the kinetic data. This study shows the possibility of using this new hybrid biocomposite in the industrial sector to treat large effluent volumes.


Assuntos
Cardiidae , Fungicidas Industriais , Poluentes Químicos da Água , Animais , Alginatos/química , Cobre/química , Hidrogéis/química , Fungicidas Industriais/análise , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Adsorção , Água/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Carbohydr Polym ; 301(Pt A): 120310, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36436871

RESUMO

The main goal was the development of a polysaccharide microcapsule for anticancer application based on guar gum and sodium alginate for the controlled release of hesperidin and betulinic acid by spray drying technique. The microcapsule showed an Encapsulation Efficiency of 98.15 ± 0.34 % for hesperidin and 99.76 ± 0.22 % for betulinic acid. In the release study, the Korsmeyer-Peppas mathematical model was identified as the most adequate to explain the observed release mechanism. In vivo tests were performed in zebrafish model, revealing that the microcapsules did not alter the locomotor activity and were not toxic within 96 h by oral administration, suggesting their biological safety. In vitro cytotoxic activity against HL-60 cells confirmed an IC50 value of 2.52 ± 0.23 µg mL-1 in 72 h. Additionally, a decrease in the cytotoxic activity of betulinic acid against L-929 (non-tumor) cells was evidenced. Therefore, the microcapsules synthesized in this work represent a promising formulation for anticancer applications.


Assuntos
Alginatos , Hesperidina , Animais , Cápsulas , Peixe-Zebra
8.
Carbohydr Polym ; 301(Pt A): 120294, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36436863

RESUMO

This work presents a novel polymer-based adsorbent, Sodium Dodecyl Sulphate modified alginate-pectin gel beads (APS221) prepared via controlled freeze drying & air drying, for the removal of copper ions from the aqueous solution. This work also critically discusses the role played by various components and their concentrations in the success of APS221. Addition of pectin to alginate resulted into approximately 150 % increase in the metal removal performance of the adsorbent while addition of SDS into alginate-pectin complex enhanced the performance by 14 % approximately, taking the maximum adsorption capacity of final complex APS221 to 111.11 mg/g. Our characterization studies revealed that the adsorption happened predominantly by complexation and ion-exchange mechanisms, and hence despite having a higher surface area, freeze-dried variant showed lesser adsorption capacity than air-dried variant as there was a loss of ion-exchange sites resulting from breakage of crosslinking bonds due to chain elongation. The adsorption process was found to follow Langmuir isotherm and pseudo-second order kinetics with a good fit of experimental data. Further, operating parameters have been optimized via RSM to, simultaneously, maximize the utilization of the adsorbent and minimize the cost of the process. Stability studies showed that APS221 beads could be used up to eight cycles.


Assuntos
Alginatos , Poluentes Químicos da Água , Alginatos/química , Cobre/química , Dodecilsulfato de Sódio , Pectinas , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Íons/química
9.
Carbohydr Polym ; 301(Pt A): 120307, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36436869

RESUMO

Recently, water-borne fluorescent inks have attracted extensive attention in anti-counterfeiting applications due to their convenient implementation and eco-friendliness. However, due to poor service durability, the latent authorization information from the inks is easily damaged, and even disappears when encountering water. Moreover, most of the existing fluorescent inks are monochromic, toxic, and allergic to skin, thus are unsuitable for their sustainability during real-life applications. Herein, this work presents environment-friendly, durable, and multicolor fluorescent anti-counterfeiting silicon nanoparticles (SiNPs)/sodium alginate (SA) inks. The multicolor SiNPs are synthesized by a one-pot method with defined morphologies and optical properties. Subsequently, SA is employed as the binder to prepare the fluorescent inks with optimized rheological properties. Practicability results show that the SiNPs/SA inks not only exhibit excellent printability, but also impart authentic information with superior covert performance. More notably, spraying solution of calcium dichloride can further improve fluorescent fastnesses of the SiNPs/SA inks by ionic crosslinking.


Assuntos
Nanopartículas , Silício , Tinta , Alginatos , Excipientes , Corantes , Água
10.
J Hazard Mater ; 441: 129965, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36122524

RESUMO

Oil spills frequently occur in the ocean, and adsorption is one of the effective ways to deal with oil spills. Compared with other adsorbent materials, biomass aerogel has superior selective adsorption capacity. CNF/SA aerogels with good mechanical properties (340 kPa at 90 % strain) and high adsorption capacity (88.91 g/g) were prepared by mixing cellulose nanofibers (CNF) with sodium alginate (SA) through bidirectional freeze-drying, ionic crosslinking, and surface modification to effectively solve the ocean oil spill problem. The bidirectional freeze-drying technology is a green and efficient technique for preparing layered microstructured composite aerogels. The prepared aerogels have a three-dimensional interpenetrating lamellar structure, low density (24.2 mg/cm3), high porosity (97.85 %), and high hydrophobicity (WCA = 144.5°), can be calibrated and used repeatedly. It has potential applications in water-oil separation and can be used as an absorbent for effectively treating oil spills in the ocean environment.


Assuntos
Incrustação Biológica , Nanofibras , Alginatos , Incrustação Biológica/prevenção & controle , Celulose/química , Géis/química , Interações Hidrofóbicas e Hidrofílicas , Nanofibras/química , Oceanos e Mares , Água/química
11.
J Hazard Mater ; 443(Pt B): 130247, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36345060

RESUMO

Long-term and extensive usage of thiamethoxam, the second-generation neonicotinoid insecticide, has caused a serious threat to non-target organisms and ecological security. Efficient immobilized microorganism techniques are a sustainable solution for bioremediation of thiamethoxam contamination. A Gram-negative aerobic bacterium Chryseobacterium sp H5 with high thiamethoxam-degrading efficiencies was isolated from activated sludge. Then we developed a novel polyvinyl alcohol (PVA)/sodium alginate (SA)/biochar bead with this functional microbe immobilization to enhance the biodegradation and removal of thiamethoxam. Results indicated that the total removal and biodegradation rate of thiamethoxam with PVA/SA/biochar (0.7 %) beads with Chryseobacterium sp H5 immobilization at 30 °C and pH of 7.0 within 7 d reached about 90.47 % and 68.03 %, respectively, much higher than that using PVA/SA immobilized microbes (75.06 %, 56.05 %) and free microbes (61.72 %). Moreover, the PVA/SA/biochar (0.7 %) immobilized microbes showed increased tolerance to extreme conditions. Biodegradation metabolites of thiamethoxam were identified and two intermediates were first reported. Based on the identified biodegradation intermediates, cleavage of C-N between the 2-chlorothiazole ring and oxadiazine, dichlorination, nitrate reduction and condensation reaction would be the major biodegradation routes of thiamethoxam. Results of this work suggested the novel PVA/SA/biochar beads with Chryseobacterium sp H5 immobilization would be helpful for the effective bioremediation of thiamethoxam contamination.


Assuntos
Chryseobacterium , Álcool de Polivinil , Biodegradação Ambiental , Álcool de Polivinil/química , Alginatos/química , Tiametoxam , Células Imobilizadas
12.
Environ Res ; 216(Pt 1): 114416, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181897

RESUMO

In this study, an adsorbent made of alginate (Alg) caged magnesium sulfide nanoparticles (MgS) microbeads were used to treat lead ions (Pb2+ ions). The MgS nanoparticles were synthesized at low temperatures, and Alg@MgS hydrogel microbeads were made by the ion exchange process of the composite materials. The newly fabricated Alg@MgS was characterized by XRD, SEM, and FT-IR. The adsorption conditions were optimized for the maximum removal of Pb2+ ions by adjusting several physicochemical parameters, including pH, initial concentration of lead ions, Alg/MgS dosage, reaction temperature, equilibration time, and the presence of co-ions. This is accomplished by removing the maximum amount of Pb2+ ions. Moreover, the adsorbent utilized more than six times with a substantial amount (not less than 60%) of Pb2+ ions was eliminated. Considering the ability of sodium alginate (SA) for excellent metal chelation and controlled nanosized pore structure, the adsorption equilibrium of Alg@MgS can be reached in 60 min, and the highest adsorption capacity for Pb2+ was 84.7 mg/g. The sorption mechanism was explored by employing several isotherms. It was found that the Freundlich model fits the adsorption process quite accurately. The pseudo-second-order model adequately described the adsorption kinetics.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Purificação da Água , Alginatos/química , Águas Residuárias , Magnésio , Microesferas , Chumbo , Poluentes Químicos da Água/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Adsorção , Cinética , Sulfetos , Concentração de Íons de Hidrogênio
13.
Sci Total Environ ; 857(Pt 1): 159392, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36240919

RESUMO

Kelp forests, among the most productive ecosystems on Earth, cover large areas of the South Atlantic coast. Sediment heterotrophic bacteria have a pivotal role in the degradation of kelp biomass, however, the response of sediment microbial communities to periodic kelp biomass inputs is mostly unknown. Here, we show that kelp biomass induced rapid changes in overlying water chemistry and shifts in sediment microbial communities, which differed in the experimental systems containing Macrocystis pyrifera (M) and Undaria pinnatifida (U) with sediments of the respective regions. We observed results compatible with the degradation of labile, high molecular weight compounds into smaller and more refractory compounds towards the end of the incubations. The capability of microbial communities to degrade alginate, the major component of kelp cell walls, significantly increased with respect to controls after kelp biomass addition (Absorbance at 235 nm 1.2 ± 0.3 and 1.0 ± 0.2 for M and U, respectively, controls <0.2, t = 4 days). Shifts in microbial community structure (based on 16S rRNA gene amplicon sequencing) were tightly related to the kelp treatment and, to a lesser extent, to the sediment provenance (Principal Coordinates Analysis, 80 % of variation explained in the first two axes). Dissolved oxygen, pH, salinity, alginolytic potential, Absorbance at 235 and 600 nm, total N, total C, and SUVA index correlated significantly with community structure. Differentially abundant populations between kelp-amended treatments and controls included members of the Flavobacteriia class (Algibacter and Polaribacter), and Gammaproteobacteria (Psychromonas and Marinomonas), among others. Metagenomes of M and U-amended sediments contained sequences from 18 of the 19 enzyme families related to alginate or fucoidan degradation. Specific taxonomic groups were associated with enzyme classes targeting different substrates, suggesting niche differentiation. This work expands our knowledge on the patterns of microbial assemblages from intertidal sediments in response to kelp biomass inputs.


Assuntos
Kelp , Macrocystis , Microbiota , Ecossistema , RNA Ribossômico 16S , Microbiota/fisiologia , Alginatos
14.
Gene ; 851: 146941, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36257469

RESUMO

Methotrexate (MTX), as a folate antagonist is used for breast cancer chemotherapy, but its application due to the adverse side effects was limited. In this study, MTX were encapsulated in magnetic alginate beads coated with glutaraldehyde to control its release in order to reduce the side effects and improve its stability. The complex was characterized by physicochemical studies. The encapsulation efficiency was 75 % and the complex showed acceptable controlled release behavior. The cell cytotoxicity assessed using methylthiazol tetrazolium (MTT) method showed that magnetic alginate beads-MTX, in lower dosage has higher anticancer effect compared to the free MTX. The real-time polymerase chain reaction (PCR) was used to evaluate apoptotic factors Bcl2 associated X gene (Bax), B-cell lymphoma 2 (Bcl-2), and neuroinflammatory marker tumor necrosis factor-alpha (TNF-α) genes expression level on the treated cells. The findings demonstrated the significant increase of expression of Bax and a significant decrease in the expressions of Bcl-2 and TNF-α in Michigan cancer foundation-7 (MCF-7) cells. These results indicated that the developed drug can overcome the side effects of MTX and offer a controlled drug release for a sustained period with the long-term treatment of breast cancer.


Assuntos
Neoplasias da Mama , Metotrexato , Humanos , Feminino , Liberação Controlada de Fármacos , Metotrexato/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Alginatos/uso terapêutico , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
15.
Environ Res ; 216(Pt 2): 114565, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36243052

RESUMO

Rotenone is a botanical pesticide and has long been used for control of insect pests and also as a natural piscicide for management of fish populations in many countries. Field application for pest control, however, often encounters the movement of rotenone into surface water due to spray drift or surface runoff after rainfall, which could potentially result in water pollution and unexpected death of fishes. To minimize its effect on freshwater and the problem of fish dying, one solution was to encapsulate rotenone in specific microspheres, limiting its release and reducing its toxicity since rotenone can be quickly degraded under sunlight. In this study, pH-responsive alginate-based microspheres were synthesized to encapsulating rotenone, which were designated as rotenone beads. The rotenone beads, along with alginate beads (devoid of rotenone) were characterized and evaluated for their responses to pH and effects on zebrafish. Results showed that the microspheres had high loading efficiency (4.41%, w/w) for rotenone, and rotenone beads well responded to solution pH levels. The cumulative release rates of rotenone from the beads were 27.91%, 42.72%, and 90.24% at pH 5.5, 7.0, and 9.0, respectively. Under acidic conditions, the rotenone release rate was lower due to hydrogen bonding. On the contrary, rotenone became more quickly released at the high pH due to intermolecular repulsion. The toxicity of rotenone beads to zebrafish and fish embryos at a pH of 5.5 was reduced by 2- and 4-fold than chemical rotenone. Since pH levels in most freshwater lakes, ponds, and streams vary from 6 to 8, rotenone release from the beads in such freshwater could be limited. Thus, the synthesized rotenone beads could be relatively safely used for pest control with limited effects on freshwater fishers.


Assuntos
Alginatos , Peixe-Zebra , Animais , Alginatos/química , Microesferas , Rotenona/toxicidade , Ácidos Hexurônicos/toxicidade , Ácidos Hexurônicos/química , Ácido Glucurônico/toxicidade , Ácido Glucurônico/química , Concentração de Íons de Hidrogênio
16.
Food Chem ; 404(Pt A): 134528, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36444010

RESUMO

To address consumer-level food waste, and pollution from commercial plastics, we developed intelligent films using sodium alginate (SA), pectin (PC), cellulose nanocrystals (CNCs), and anthocyanins extracted from red cabbage (RCA). We also investigated two methods of reinforcing these films - cross-linking (CL), and the addition of CNCs. Both together and separately, these methods improved SA/PC films' mechanical properties and thermal stability. The optimal SA/PC/CNCs/RCA/CL films exhibited pH-dependent color-response properties and high water resistance. These were then tested as colorimetric freshness indicators for shrimp samples, both through seepage and the monitoring of volatile compounds. The colors of the indicators changed from lilac to dark green to greenish-yellow after storage at 25 °C for 72 h, whereas at 4 °C, they changed much more slowly over the same time period. This demonstrated the excellent potential of such films to reduce food waste by providing real-time warnings of pH variation resulting from spoilage.


Assuntos
Nanopartículas , Eliminação de Resíduos , Pectinas , Celulose , Alginatos , Antocianinas , Alimentos Marinhos
17.
Food Chem ; 404(Pt A): 134556, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36444012

RESUMO

Whey protein (WP) is ubiquitously applied in food products, but its sensitivity to food processing conditions has limited its application. Herein, we chose propylene glycol alginate (PGA) to combine with WP to enhance its stability. The ideal ratio of WP/PGA for coacervation was 3:1, and the soluble complex and insoluble complex were formed at pH 5.2 (pHc) and pH 4.4 (pHφ1) at this ratio, respectively. The UV absorption spectra, fluorescence spectra, and XRD results revealed that the interaction between PGA and WP changed the tertiary conformation of WP. The FTIR and molecular docking results suggested electrostatic interactions, hydrogen bonding and hydrophobic interactions were all involved in the formation of WP-PGA complexes, and the thermal stability of WP was improved based on the DSC results. These findings supported PGA to keep dairy products stable and transparent at the isoelectric point and WP-PGA complexes could be applied in encapsulating bioactive substances.


Assuntos
Alginatos , Prostaglandinas A , Proteínas do Soro do Leite , Simulação de Acoplamento Molecular
18.
Food Chem ; 404(Pt B): 134705, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36444083

RESUMO

In the present study, highly efficient 5-Methyl-1,3,4-thiadiazole-2-thiol-modified silver nanoparticles (MTT-Ag NPs) were successfully synthesized and could be used for convenient and sensitive detection of Hg2+. MTT acts as a protective agent by forming Ag-S bonds with Ag NPs, meantime, MTT can also be captured Hg2+ through NN bonds. Furthermore, to improve the sustainability and stability of MTT-Ag NPs, sodium alginate (SA) was used as a substrate material for the formation of SA-MTT-Ag NPs films. As expected, SA-MTT-Ag NPs could be stored for more than 180 days at room temperature. When used SA-MTT-Ag NPs thin films as colourimetric sensors for detection of Hg2+ in lettuce, the low detection limit could be down to 0.22 µM (44 ppb) with wide linear range (0-1 µM and 1-150 µM) and good recovery (96.25 % - 98.75 %). Therefore, the method enables highly selective and efficient monitoring of Hg2+ in food samples.


Assuntos
Mercúrio , Nanopartículas Metálicas , Alface , Alginatos , Prata
19.
Food Chem ; 403: 134317, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182855

RESUMO

Ingesting large quantities of biogenic amines (BAs), which are released from spoiled foods, can have adverse side effects on the human body. Herein, we developed a colorimetric sensor using polydiacetylene (PDA)-based hydrogel beads that change color upon binding with BAs, thereby conveniently checking whether food is spoiled due to improper storage and distribution. The colorimetric sensor is fabricated by mixing PDA liposomes with an alginate solution. PDA undergoes a color change from blue to red when exposed to various external stimuli. In addition, alginate bestows the hydrogel with a three-dimensional porous structure, affording a large surface area. The PDA-based hydrogel beads can visually confirm the presence of BAs in solution or vapor form. Cadaverine and propylamine were rapidly detected with distinct color changes in the solution and vapor phases, respectively. The spoilage of pork meat at room temperature could be detected after two days as a 40.84% red chromatic shift.


Assuntos
Colorimetria , Hidrogéis , Humanos , Colorimetria/métodos , Aminas Biogênicas , Carne/análise , Alginatos
20.
Food Chem ; 403: 134425, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183475

RESUMO

Sodium alginate (SA), α1 â†’ 4 linked copolymer of ß-d-mannuronic acid (M) and α-L guluronic acid (G) forms two homopolymeric fractions (MM and GG) and a heteropolymeric fraction (MG). The main components of soybean protein isolate are ß-conglycinin (7S) and glycinin (11S). However, accurate structural analyses of the 7S/11S and MM/MG/GG complexes are lacking. The complexation mechanism, structure, and functional properties of the complexes of 7S/11S with SA blocks was investigated at pH 4. The number of intermolecular hydrogen bonds exceeded that of the intramolecular hydrogen bonds. Secondary and tertiary structures and molecular weights of the complexes were significantly different from those of 7S/11S. The crystalline structure transformed to an amorphous structure, and the complexes underwent fluorescence quenching. Complexes 11S-MM and 11S-MG exhibited good emulsifying properties of 37.88 % and 38.13 %, respectively; 7S-GG and 7S-MM exhibited excellent surface hydrophobicity and emulsifying properties; and 11S-MM, 11S-GG, and 11S-MG exhibited excellent thermal stability.


Assuntos
Globulinas , Proteínas de Soja , Proteínas de Soja/química , Alginatos , Globulinas/química , Proteínas de Armazenamento de Sementes/química , Antígenos de Plantas/química , Soja/química
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