Three materials(agar,konjac glucomannan(KGM)andκ-carrageenan)were used to prepare ternary systems,i.e.,sol-gels and their dried composites conditioned at varied relative humidity(RH)(33%,54%and 75%).Combined methods,...Three materials(agar,konjac glucomannan(KGM)andκ-carrageenan)were used to prepare ternary systems,i.e.,sol-gels and their dried composites conditioned at varied relative humidity(RH)(33%,54%and 75%).Combined methods,e.g.,scanning electron microscopy,small-angle X-ray scattering,infrared spectroscopy(IR)and X-ray diffraction(XRD),were used to disclose howκ-carrageenan addition tailors the features of agar/KGM/κ-carrageenan ternary system.As affirmed by IR and XRD,the ternary systems withκ-carrageenan below 25%(agar/KGM/carrageenan,50:25:25,m/m)displayed proper component interactions,which increased the sol-gel transition temperature and the hardness of obtained gels.For instance,the ternary composites could show hardness about 3 to 4 times higher than that for binary counterpart.These gels were dehydrated to acquire ternary composites.Compared to agar/KGM composite,the ternary composites showed fewer crystallites and nanoscale orders,and newly-formed nanoscale structures from chain assembly.Such multi-scale structures,for composites withκ-carrageenan below 25%,showed weaker changes with RH,as revealed by especially morphologic and crystalline features.Consequently,the ternary composites with lessκ-carrageenan(below 25%)exhibited stabilized elongation at break and hydrophilicity at different RHs.This hints to us that agar/KGM/κ-carrageenan composite systems can display series applications with improved features,e.g.,increased sol-gel transition point.展开更多
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 ...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℃ 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.展开更多
The performance and stability of perovskite solar cells(PSCs)is limited by detrimental defects,mostly distributed at the grain boundary(GB)of bulk perovskite film and interface,which induce serious carrier non-radiati...The performance and stability of perovskite solar cells(PSCs)is limited by detrimental defects,mostly distributed at the grain boundary(GB)of bulk perovskite film and interface,which induce serious carrier non-radiative recombination.Therefore,there is particularly urgent to realize simultaneous passivation of bulk defects and interfacial defects.In this work,a simple,low-cost and effective multifunctional modification strategy is developed by introducing theλ-Carrageenan(λ-C)as the interfacial layer of SnO_(2)/perovskite.The sulfate groups ofλ-C not only play a positive role in passivating the Sn4+from SnO_(2)film,resulting in high conductivity,but also effectively passivate the defects at the SnO_(2)/perovskite interface.Meanwhile,λ-C can effectively passivate the defects in the perovskite film due to the strong binding force between the high content of sulfate groups and PbI2.The synergistic effect ofλ-C simultaneously achieves interfacial defects and bulk defects passivation,better crystalline quality,suppressed charge recombination,released interfacial stress and more favorable interfacial energy level alignment.Based on the above efficient synergy,theλ-C-modified device achieves a high efficiency of 23.81%,which is~24.53%higher than the control device(19.12%).To our best knowledge,23.81%of power conversion efficiency(PCE)is the highest reported PCE value of PSCs employing green natural additives.Moreover,long-term and thermal stabilities are significantly improved after interface modification.Thus,this work provides an idea for developing multifunctional natural materials towards the attainment of the efficient and stable PSCs.展开更多
A rapid method of microwave assisted acid hydrolysis was established to prepare κ-carra-oligosaccharides. The optimal hydrolysis condition was determined by an orthogonal test. The degree of polymerization （DP） of ...A rapid method of microwave assisted acid hydrolysis was established to prepare κ-carra-oligosaccharides. The optimal hydrolysis condition was determined by an orthogonal test. The degree of polymerization （DP） of oligosaccharides was detected by high performance thin layer chromatography （HPTLC） and polyacrylamide gel electrophoresis （PAGE）. Considering the results of HPTLC and PAGE, the optimum condition of microwave assisted acid hydrolysis was determined. The concentration of κ-carrageenan was 5 mgmL-1; the reaction solution was adjusted to pH 3 with diluted hydrochloric acid; the solution was hydrolyzed under microwave irradiation at 100 ℃ for 15 min. Oligosaccharides were separated by a Superdex 30 column （2.6 cm × 90 em） using AKTA Purifier UPC100 and detected with an online refractive index detector. Each fraction was characterized by electrospray ioni- zation mass spectrometry （ESI-MS）. The data showed that odd-numbered κ-carra-oligosaccharides with DP ranging from 3 to 21 could be obtained with this method, and the structures of the oligosaccharides were consistent with those obtained by traditional mild acid hydrolysis. The new method was more convenient, efficient and environment-friendly than traditional mild acid hydrolysis. Our results provided a useful reference for the preparation of oligosaceharides from other polysaccharides.展开更多
A new κ-carrageenase gene cgkS was cloned from marine bacterium Shewanella sp. Kz7 by using degenerate and site-finding PCR. The gene was comprised of an open reading frame of 1224bp, encoding 407 amino acid residues...A new κ-carrageenase gene cgkS was cloned from marine bacterium Shewanella sp. Kz7 by using degenerate and site-finding PCR. The gene was comprised of an open reading frame of 1224bp, encoding 407 amino acid residues, with a signal peptide of 24 residues. Based on the deduced amino acid sequence, the κ-carrageenase CgkS was classified into the Glycoside Hy- drolase family 16. The cgkS gene was expressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity with a specific activity of 716.8 U mg-1 and a yield of 69%. Recombinant CgkS was most active at 45 ℃ and pH 8.0. It was stable at pH 6.0-9.0 and below 30℃. The enzyme did not require NaCl for activity, although its activity was enhanced by NaCI. CgkS degraded κ-carrageenan in an endo-fashion releasing tetrasaccharides and disaccharides as main hydrolysis products.展开更多
The rising production of produced water from oilfields had been proven to bring detrimental environmental effects.In this study,an efficient,recyclable,and environmental-friendly reduced graphene oxide immobilizedκ-C...The rising production of produced water from oilfields had been proven to bring detrimental environmental effects.In this study,an efficient,recyclable,and environmental-friendly reduced graphene oxide immobilizedκ-Carrageenan hydrogel composite(κCaGO)was fabricated as an alternative sorbent for crude oil-in-water demulsification.Polyethyleneimine(PEI)was employed to form a stable hydrogel composite.The conditions for the immobilization of graphene oxide(GO)on PEI-modifiedκ-Carrageenan(κC)beads were optimized appropriately.An immobilization yield of 77%was attained at 2%PEI,2 h immobilization activation time,and pH 6.5.Moreover,the synthesizedκCaGO is capable of demulsification with an average demulsification efficiency of 70%.It was found that the demulsification efficiency increases with salinity andκCaGO dosage,and it deteriorates under alkaline condition.These phenomena can be attributed to the interfacial interactions betweenκCaGO and the emulsion.Furthermore,theκCaGO can be recycled to use for up to six cycles without significant leaching and degradation.As such,the synthesizedκCaGO could be further developed as a potential sorbent substitute for the separation of crude oil from produced water.展开更多
The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with ...The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.展开更多
The demand for plant protein is increasing significantly due to the shortage of protein resources.Walnut protein,the main by-product of preparing walnut oil,has limited application in the food industry due to its poor...The demand for plant protein is increasing significantly due to the shortage of protein resources.Walnut protein,the main by-product of preparing walnut oil,has limited application in the food industry due to its poor solubility.It was found that the soy protein isolate(SPI)concentration had significant effects on the gel properties of the walnut protein isolate(WNPI)-κ-Carrageenan(KC)composite system treated with 15 mmol/L NaCl.The results showed that the gel strength of the composite system increased first and then decreased with the increased concentration of SPI from 0 to 2.5%.The best rheological properties,texture properties,water holding capacity((92.03±1.05)%),swelling ratio((2.04±0.19)%),freeze-thaw stability and thermal stability(85.53°C)of the composite gel were found at an SPI concentration of 1%.In the meantime,the secondary structure of protein had the least α-helix content of 10.17% and the highest β-sheet content of 39.64%,the fluorescence intensity and free sulfhydryl content reached the highest value.1% SPI could also act as a filler for WNPI to enhance the intermolecular forces such as hydrophobic interaction between the two substances,thus forming a stable gel network structure.This study can provide technical support for improving the gel properties of walnut protein and producing new plant protein gel products.展开更多
ι-Carrageenan andβ-lactoglobulin(β-lg)stabilized oil-in-water(O/W)emulsions,which can be used for the oral administration of bioactive but environmentally sensitive ingredients,have been successfully prepared.The e...ι-Carrageenan andβ-lactoglobulin(β-lg)stabilized oil-in-water(O/W)emulsions,which can be used for the oral administration of bioactive but environmentally sensitive ingredients,have been successfully prepared.The effects of protein/polysaccharide ratios,total biopolymer concentration,environmental stress(thermal processing and sonication),and pH on the complex formation betweenι-carrageenan andβ-lactoglobulin have been investigated.We found thatβ-lactoglobulin andι-carrageenan stabilized emulsions can be formed at pH values of 6.0,4.0,and 3.4.However,the microstructures of emulsions stabilized byβ-lactoglobulin andι-carrageenan was identified by optical microscopy,and it indicated that the emulsion prepared at pH 6.0 flocculated more extensively,while its hydrodynamic radius was much bigger than those prepared at pH 4.0 and 3.4.Regarding rheological properties,the emulsion of pH 6.0 showed a more solid-like behavior but with a lower viscosity than those of pH 4.0 and 3.4.The optimum concentration ranges forβ-lg andι-carrageenan to form stable emulsions at pH 4.0 and 3.4 were 0.3 wt-%-0.6 wt-%and 0.4 wt-%-0.7 wt-%,respectively.展开更多
3D composite aerogels(CMC-CG)composed of carboxymethyl cellulose andκ-carrageenan were designed and fabricated using the one-pot synthesis technique.The optimized CMC-CG showed a good mechanical property and a high s...3D composite aerogels(CMC-CG)composed of carboxymethyl cellulose andκ-carrageenan were designed and fabricated using the one-pot synthesis technique.The optimized CMC-CG showed a good mechanical property and a high swelling ratio due to its superior textural properties with a proper chemically cross-linked interpenetrating network structure.CMC-CG was utilized for the removal of various fluoroquinolones(FQs)from water and exhibited high adsorption performance because of effective electrostatic attraction and hydrogen bonding interactions.Ciprofloxacin(CIP),a popular FQ,was used as the representative.The optimized CMC-CG had a theoretically maximal CIP uptake of approximately 1.271 mmol/g at the pH of 5.0.The adsorption capacity of CMC-CG was improved in the presence of some cations,Cu2+and Fe3+ions,at a low concentration through the bridging effect but was reduced at a high concentration.The investigation of adsorption mechanisms,based on the adsorption kinetics,isotherms and thermodynamic study,Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy analyses before and after adsorption,and changes in the adsorption performance of CMC-CG toward two molecular probes,further indicated that electrostatic attraction was the dominant interaction rather than hydrogen bonding in this adsorption.CMC-CG after saturated adsorption of CIP could be easily regenerated using a dilute NaCl aqueous solution and reused efficiently.Moreover,the disused aerogel could still be reused as a new adsorbent for effective adsorption of Cu2+ion.Overall,this study suggested the promising applications of this composite aerogel as an eco-friendly,cost-effective,and recyclable adsorbent for thie efficient removal of FQs from water.展开更多
Natural biopolymers have excellent biocompatibility and biodegradability;they can be used as biomedical materials for wound healing.In this work,the Silk Fibroin(SF)andκ-carrageenan(κ-Car)composite films containing ...Natural biopolymers have excellent biocompatibility and biodegradability;they can be used as biomedical materials for wound healing.In this work,the Silk Fibroin(SF)andκ-carrageenan(κ-Car)composite films containing Zinc-doped Bioactive Glass(ZBG)have been fabricated for wound closure applications.The as-fabricated SF-κ-Car/ZBG composite films have excellent stretchability and foldability,which facilitates them for application as wound dressing.They also exhibit excellent hydrophilicity and water-absorption capacity,which can effectively absorb wound exudate and keep the wound sites under moist state.In addition,the composite films have a good antibacterial effect against S.aureus and E.coli in vitro,which can reduce the risk of wound infection.Their excellent cell compatibility is confirmed by the CCK-8 assay.The strong vascular proliferation and wound regeneration are found in SF-κ-Car/ZBG composite films on a mouse skin wound model.The SF-κCar/ZBG composite films can inhibit the secretion of inflammatory factors,and stimulate the production of vascular factors and collagen fibers.The results derived from the performed investigations revealed that the SF-κ-Car/ZBG composite films are a promising candidate dressing for wound healing applications.展开更多
基金the National Natural Science Foundation of China(32172240)BL19U2 beamline of National Facility for Protein Science in Shanghai(NFPS)at Shanghai Synchrotron Radiation Facility,for their assistance during data collection。
文摘Three materials(agar,konjac glucomannan(KGM)andκ-carrageenan)were used to prepare ternary systems,i.e.,sol-gels and their dried composites conditioned at varied relative humidity(RH)(33%,54%and 75%).Combined methods,e.g.,scanning electron microscopy,small-angle X-ray scattering,infrared spectroscopy(IR)and X-ray diffraction(XRD),were used to disclose howκ-carrageenan addition tailors the features of agar/KGM/κ-carrageenan ternary system.As affirmed by IR and XRD,the ternary systems withκ-carrageenan below 25%(agar/KGM/carrageenan,50:25:25,m/m)displayed proper component interactions,which increased the sol-gel transition temperature and the hardness of obtained gels.For instance,the ternary composites could show hardness about 3 to 4 times higher than that for binary counterpart.These gels were dehydrated to acquire ternary composites.Compared to agar/KGM composite,the ternary composites showed fewer crystallites and nanoscale orders,and newly-formed nanoscale structures from chain assembly.Such multi-scale structures,for composites withκ-carrageenan below 25%,showed weaker changes with RH,as revealed by especially morphologic and crystalline features.Consequently,the ternary composites with lessκ-carrageenan(below 25%)exhibited stabilized elongation at break and hydrophilicity at different RHs.This hints to us that agar/KGM/κ-carrageenan composite systems can display series applications with improved features,e.g.,increased sol-gel transition point.
基金supported by the Shandong Provincial Natural Science Foundation,China (No. ZR2019BC025)Open Research Fund Program of Shandong Provincial Key Laboratory of Glycoscience&Glycotechnology (Ocean University of China)the Fundamental Research Funds for the Central Universities (Nos. 201912008,201964019)。
文摘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℃ 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.
基金supported by the National Nature Science Foundation of China(12204193,U21A2068,12104178,61935009,11974142,12174151)the Science and Technology Development Program of Jilin Province(20200401059GX,20220101008JC)。
文摘The performance and stability of perovskite solar cells(PSCs)is limited by detrimental defects,mostly distributed at the grain boundary(GB)of bulk perovskite film and interface,which induce serious carrier non-radiative recombination.Therefore,there is particularly urgent to realize simultaneous passivation of bulk defects and interfacial defects.In this work,a simple,low-cost and effective multifunctional modification strategy is developed by introducing theλ-Carrageenan(λ-C)as the interfacial layer of SnO_(2)/perovskite.The sulfate groups ofλ-C not only play a positive role in passivating the Sn4+from SnO_(2)film,resulting in high conductivity,but also effectively passivate the defects at the SnO_(2)/perovskite interface.Meanwhile,λ-C can effectively passivate the defects in the perovskite film due to the strong binding force between the high content of sulfate groups and PbI2.The synergistic effect ofλ-C simultaneously achieves interfacial defects and bulk defects passivation,better crystalline quality,suppressed charge recombination,released interfacial stress and more favorable interfacial energy level alignment.Based on the above efficient synergy,theλ-C-modified device achieves a high efficiency of 23.81%,which is~24.53%higher than the control device(19.12%).To our best knowledge,23.81%of power conversion efficiency(PCE)is the highest reported PCE value of PSCs employing green natural additives.Moreover,long-term and thermal stabilities are significantly improved after interface modification.Thus,this work provides an idea for developing multifunctional natural materials towards the attainment of the efficient and stable PSCs.
基金supported by the Special Fund for Marine Scientific Research in the Public Interest (201005024)NSFC-Shandong Joint Fund for Marine Science Research Centers (U1406402)+1 种基金Qingdao Science & Technology Project (11-2-2-1-hy)National Science & Technology Support Program of China (2013BAB 01B02)
文摘A rapid method of microwave assisted acid hydrolysis was established to prepare κ-carra-oligosaccharides. The optimal hydrolysis condition was determined by an orthogonal test. The degree of polymerization （DP） of oligosaccharides was detected by high performance thin layer chromatography （HPTLC） and polyacrylamide gel electrophoresis （PAGE）. Considering the results of HPTLC and PAGE, the optimum condition of microwave assisted acid hydrolysis was determined. The concentration of κ-carrageenan was 5 mgmL-1; the reaction solution was adjusted to pH 3 with diluted hydrochloric acid; the solution was hydrolyzed under microwave irradiation at 100 ℃ for 15 min. Oligosaccharides were separated by a Superdex 30 column （2.6 cm × 90 em） using AKTA Purifier UPC100 and detected with an online refractive index detector. Each fraction was characterized by electrospray ioni- zation mass spectrometry （ESI-MS）. The data showed that odd-numbered κ-carra-oligosaccharides with DP ranging from 3 to 21 could be obtained with this method, and the structures of the oligosaccharides were consistent with those obtained by traditional mild acid hydrolysis. The new method was more convenient, efficient and environment-friendly than traditional mild acid hydrolysis. Our results provided a useful reference for the preparation of oligosaceharides from other polysaccharides.
基金supported by the Key Technologies Research and Development Program of China(2013BA B01B02)National Science Foundation of China(310707 12)+1 种基金Special Fund for Marine Scientific Research in the Public Interest(201005024 and 201105027)National Hightech R&D Program of China(2011AA09070304)
文摘A new κ-carrageenase gene cgkS was cloned from marine bacterium Shewanella sp. Kz7 by using degenerate and site-finding PCR. The gene was comprised of an open reading frame of 1224bp, encoding 407 amino acid residues, with a signal peptide of 24 residues. Based on the deduced amino acid sequence, the κ-carrageenase CgkS was classified into the Glycoside Hy- drolase family 16. The cgkS gene was expressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity with a specific activity of 716.8 U mg-1 and a yield of 69%. Recombinant CgkS was most active at 45 ℃ and pH 8.0. It was stable at pH 6.0-9.0 and below 30℃. The enzyme did not require NaCl for activity, although its activity was enhanced by NaCI. CgkS degraded κ-carrageenan in an endo-fashion releasing tetrasaccharides and disaccharides as main hydrolysis products.
基金The authors would like to acknowledge for the financial supports given by Fundamental Research Grant Scheme (FRGS/1/2019/TK02/CURTIN/03/2) from Ministry of Higher Education (MOHE),Malaysia.
文摘The rising production of produced water from oilfields had been proven to bring detrimental environmental effects.In this study,an efficient,recyclable,and environmental-friendly reduced graphene oxide immobilizedκ-Carrageenan hydrogel composite(κCaGO)was fabricated as an alternative sorbent for crude oil-in-water demulsification.Polyethyleneimine(PEI)was employed to form a stable hydrogel composite.The conditions for the immobilization of graphene oxide(GO)on PEI-modifiedκ-Carrageenan(κC)beads were optimized appropriately.An immobilization yield of 77%was attained at 2%PEI,2 h immobilization activation time,and pH 6.5.Moreover,the synthesizedκCaGO is capable of demulsification with an average demulsification efficiency of 70%.It was found that the demulsification efficiency increases with salinity andκCaGO dosage,and it deteriorates under alkaline condition.These phenomena can be attributed to the interfacial interactions betweenκCaGO and the emulsion.Furthermore,theκCaGO can be recycled to use for up to six cycles without significant leaching and degradation.As such,the synthesizedκCaGO could be further developed as a potential sorbent substitute for the separation of crude oil from produced water.
基金The authors would like to acknowledge the support from the National Natural Science Foundation of China(Project number 20299035,20035010,20275039)Pilot of Knowledge Innovation Program of the Chinese Academy of Science(KSCX 2-3-02-02)on the above work.
文摘The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.
基金funded by the Research and Application of Key Technology of Xinjiang Walnut Oil Refining Deep Processing(2022A02004-4)the National Key R&D Program of China(2018YFD0400302)+2 种基金the Special Fund for Anhui Agriculture Research System(AHCYJSTX-NCPJG)-15the Cooperative Projects of Hefei University of Technology-Wuhan Xudong Food Co.,Ltd.(W2020JSKF0457,W2021JSKF0356)the 7^(th) Young Elite Scientist Sponsorship Program by CAST(2021QNRC001).
文摘The demand for plant protein is increasing significantly due to the shortage of protein resources.Walnut protein,the main by-product of preparing walnut oil,has limited application in the food industry due to its poor solubility.It was found that the soy protein isolate(SPI)concentration had significant effects on the gel properties of the walnut protein isolate(WNPI)-κ-Carrageenan(KC)composite system treated with 15 mmol/L NaCl.The results showed that the gel strength of the composite system increased first and then decreased with the increased concentration of SPI from 0 to 2.5%.The best rheological properties,texture properties,water holding capacity((92.03±1.05)%),swelling ratio((2.04±0.19)%),freeze-thaw stability and thermal stability(85.53°C)of the composite gel were found at an SPI concentration of 1%.In the meantime,the secondary structure of protein had the least α-helix content of 10.17% and the highest β-sheet content of 39.64%,the fluorescence intensity and free sulfhydryl content reached the highest value.1% SPI could also act as a filler for WNPI to enhance the intermolecular forces such as hydrophobic interaction between the two substances,thus forming a stable gel network structure.This study can provide technical support for improving the gel properties of walnut protein and producing new plant protein gel products.
基金supported by the United States Department of Agriculture National Research Initiative(#2009-35603-05071).
文摘ι-Carrageenan andβ-lactoglobulin(β-lg)stabilized oil-in-water(O/W)emulsions,which can be used for the oral administration of bioactive but environmentally sensitive ingredients,have been successfully prepared.The effects of protein/polysaccharide ratios,total biopolymer concentration,environmental stress(thermal processing and sonication),and pH on the complex formation betweenι-carrageenan andβ-lactoglobulin have been investigated.We found thatβ-lactoglobulin andι-carrageenan stabilized emulsions can be formed at pH values of 6.0,4.0,and 3.4.However,the microstructures of emulsions stabilized byβ-lactoglobulin andι-carrageenan was identified by optical microscopy,and it indicated that the emulsion prepared at pH 6.0 flocculated more extensively,while its hydrodynamic radius was much bigger than those prepared at pH 4.0 and 3.4.Regarding rheological properties,the emulsion of pH 6.0 showed a more solid-like behavior but with a lower viscosity than those of pH 4.0 and 3.4.The optimum concentration ranges forβ-lg andι-carrageenan to form stable emulsions at pH 4.0 and 3.4 were 0.3 wt-%-0.6 wt-%and 0.4 wt-%-0.7 wt-%,respectively.
基金supported by the National Natural Science Foundation of China(Nos.42061144014 and 51978325).
文摘3D composite aerogels(CMC-CG)composed of carboxymethyl cellulose andκ-carrageenan were designed and fabricated using the one-pot synthesis technique.The optimized CMC-CG showed a good mechanical property and a high swelling ratio due to its superior textural properties with a proper chemically cross-linked interpenetrating network structure.CMC-CG was utilized for the removal of various fluoroquinolones(FQs)from water and exhibited high adsorption performance because of effective electrostatic attraction and hydrogen bonding interactions.Ciprofloxacin(CIP),a popular FQ,was used as the representative.The optimized CMC-CG had a theoretically maximal CIP uptake of approximately 1.271 mmol/g at the pH of 5.0.The adsorption capacity of CMC-CG was improved in the presence of some cations,Cu2+and Fe3+ions,at a low concentration through the bridging effect but was reduced at a high concentration.The investigation of adsorption mechanisms,based on the adsorption kinetics,isotherms and thermodynamic study,Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy analyses before and after adsorption,and changes in the adsorption performance of CMC-CG toward two molecular probes,further indicated that electrostatic attraction was the dominant interaction rather than hydrogen bonding in this adsorption.CMC-CG after saturated adsorption of CIP could be easily regenerated using a dilute NaCl aqueous solution and reused efficiently.Moreover,the disused aerogel could still be reused as a new adsorbent for effective adsorption of Cu2+ion.Overall,this study suggested the promising applications of this composite aerogel as an eco-friendly,cost-effective,and recyclable adsorbent for thie efficient removal of FQs from water.
基金supported by the Zhejiang Provincial Natural Science Foundation(LBY20H110001,LY18E030006)National Natural Science Foundation of China(51873194,51373155).
文摘Natural biopolymers have excellent biocompatibility and biodegradability;they can be used as biomedical materials for wound healing.In this work,the Silk Fibroin(SF)andκ-carrageenan(κ-Car)composite films containing Zinc-doped Bioactive Glass(ZBG)have been fabricated for wound closure applications.The as-fabricated SF-κ-Car/ZBG composite films have excellent stretchability and foldability,which facilitates them for application as wound dressing.They also exhibit excellent hydrophilicity and water-absorption capacity,which can effectively absorb wound exudate and keep the wound sites under moist state.In addition,the composite films have a good antibacterial effect against S.aureus and E.coli in vitro,which can reduce the risk of wound infection.Their excellent cell compatibility is confirmed by the CCK-8 assay.The strong vascular proliferation and wound regeneration are found in SF-κ-Car/ZBG composite films on a mouse skin wound model.The SF-κCar/ZBG composite films can inhibit the secretion of inflammatory factors,and stimulate the production of vascular factors and collagen fibers.The results derived from the performed investigations revealed that the SF-κ-Car/ZBG composite films are a promising candidate dressing for wound healing applications.
