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1.
Opt Express ; 32(3): 4122-4136, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297620

RESUMO

Online monitoring technology plays a pivotal role in advancing the utilization of laser paint removal in aircraft maintenance and automation. Through the utilization of a high-frequency infrared pulse laser paint removal laser-induced breakdown spectroscopy (LIBS) online monitoring platform, this research conducted data collection encompassing 60 sets of LIBS spectra during the paint removal process. Classification and identification models were established employing principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). These models served as the foundation for creating criteria and rules for the online LIBS monitoring of the controlled paint removal process for aircraft skin. In this research, 12 selected characteristic spectral lines were used to construct the OPLS-DA model, with a predictive root mean square error (RMSEP) of 0.2873. Both full spectrum and feature spectral line data achieved a predictive accuracy of 94.4%. The selection of feature spectral lines maintains predictive performance while significantly reducing the amount of input data. Consequently, this research offers a methodological reference for further advancements in online monitoring technology for laser paint removal in aircraft skin.

2.
Appl Opt ; 62(10): 2569-2576, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37132805

RESUMO

Laser-induced breakdown spectroscopy (LIBS) is expected to be used for real-time monitoring and closed-loop control of laser-based layered controlled paint removal (LLCPR) from aircraft skin. However, the LIBS spectrum must be rapidly and accurately analyzed, and the monitoring criteria should be established based on machine learning algorithms. Hence, this study develops a self-built LIBS monitoring platform for the paint removal process utilizing a high-frequency (kilohertz-level) nanosecond infrared pulsed laser and collects the LIBS spectrum during the laser removal process of the top coating (TC), primer (PR), and aluminum substrate (AS). After subtracting the spectrum's continuous background and screening the key features, we construct a classification model of three types of spectra (TC, PR, and AS) based on a random forest algorithm, and the real-time monitoring criterion based on the classification model and multiple LIBS spectra was established and verified experimentally. The results show that the classification accuracy is 98.89%, the time-consuming classification is about 0.03 ms per spectrum, and the monitoring results of the paint removal process are consistent with the macroscopic observation and microscopic profile analysis results of the samples. Overall, this research provides core technical support for the real-time monitoring and closed-loop control of LLCPR from aircraft skin.

3.
Micromachines (Basel) ; 15(4)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38675257

RESUMO

The uCVD (microchemical vapor deposition) graphene growth system is an improved CVD system that is suitable for scientific research and experimental needs, and it is characterized by its rapid, convenient, compact, and low-cost features. The micro-hotplate based on an SOI wafer is the core component of this system. To meet the requirements of the uCVD system for the micro-hotplate, we propose a suspended multi-cantilever heating platform composed of a heating chip, cantilevers, and bracket. In this article, using heat transfer theory and thermoelectric simulation, we demonstrate that the silicon resistivity, current input cross-sectional size, and the convective heat transfer coefficient have a huge impact on the performance of the micro-heating platform. Therefore, in the proposed solution, we adopt a selective doping process to achieve a differentiated configuration of silicon resistivity in the cantilevers and heating chip, ensuring that the heating chip meets the requirements for graphene synthesis while allowing the cantilevers to withstand high currents without damage. Additionally, by adding brackets, the surfaces of the micro-hotplate have the same convective heat transfer environment, reducing the surface temperature difference, and improving the cooling rate. The simulation results indicate that the temperature on the micro-hotplate surface can reach 1050.8 °C, and the maximum temperature difference at different points on the surface is less than 2 °C, which effectively meets the requirements for the CVD growth of graphene using Cu as the catalyst.

4.
Int J Biol Macromol ; 269(Pt 1): 131875, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38677701

RESUMO

The aim of this study was to develop novel konjac glucomannan (KGM)-based highly antibacterial active films, where five types of films were prepared and compared. The microstructure results showed that KGM-based films loaded with thyme essential oil (TEO) through bacterial cellulose nanofibers/Ag nanoparticles (BCNs/Ag nanoparticles) stabilized Pickering emulsions (Type V films) displayed the smoothest surface and the most evenly dispersed TEO droplets as compared with the other four types of films. Moreover, Type V films showed the highest contact angle value (86.28°), the best thermal stability and mechanical properties. Furthermore, Type V films presented the highest total phenol content (13.23 mg gallic acid equivalent/g film) and the best antioxidant activity (33.96 %) as well as the best sustained-release property, thus showing the best antibacterial activity, which was probably due to that BCNs/Ag nanoparticles and TEO displayed a synergistic effect to some extent. Consequently, Type V film-forming solutions were used as coatings for tangerines. The results showed that the tangerines treated with Type V coatings displayed excellent fresh-keeping properties. Therefore, the coatings, KGM-based film-forming solutions loaded with TEO through BCNs/Ag nanoparticles stabilized Pickering emulsions, have great potential for the preservation of fruits and vegetables.


Assuntos
Antibacterianos , Celulose , Emulsões , Mananas , Nanopartículas Metálicas , Nanofibras , Óleos Voláteis , Prata , Thymus (Planta) , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Nanofibras/química , Mananas/química , Celulose/química , Emulsões/química , Thymus (Planta)/química , Prata/química , Nanopartículas Metálicas/química , Antioxidantes/química , Antioxidantes/farmacologia , Testes de Sensibilidade Microbiana
5.
Int J Biol Macromol ; 259(Pt 2): 129392, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218289

RESUMO

The aim of this study was to compare the characterization of bacterial cellulose nanofibers/Ag nanoparticles (BCNs/Ag nanoparticles) obtained by three different pretreatment methods of BCNs (no pretreatment, sodium hydroxide activation pretreatment and TEMPO-mediated oxidation pretreatment), which were recoded as N-BCNs/Ag nanoparticles, A-BCNs/Ag nanoparticles and O-BCNs/Ag nanoparticles, respectively. The results of scanning electron microscopy and transmission electron microscopy showed the prepared Ag nanoparticles by three different pretreatment methods were spherical and dispersed on the surface of BCNs, while the Ag nanoparticles in O-BCNs/Ag nanoparticles displayed the smallest diameter with a value of 20.25 nm and showed the most uniform dispersion on the surface of BCNs. The ICP-MS result showed O-BCNs/Ag nanoparticles had the highest content of Ag nanoparticles with a value of 2.98 wt%, followed by A-BCNs/Ag nanoparticles (1.53 wt%) and N-BCNs/Ag nanoparticles (0.84 wt%). The cytotoxicity assessment showed that the prepared BCNs/Ag nanoparticles were relatively safe. Furthermore, the O-BCNs/Ag nanoparticles had the best antioxidant and antibacterial activities as compared with the other two types of BCNs/Ag nanoparticles, where O-BCNs/Ag nanoparticles destroyed the structure of bacterial cell membranes to lead the leakage of intracellular components. This study showed that O-BCNs/Ag nanoparticles as antibacterial agents have great potential in food packaging.


Assuntos
Nanopartículas Metálicas , Nanofibras , Nanofibras/química , Celulose/farmacologia , Celulose/química , Prata/farmacologia , Prata/química , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química
6.
Anal Methods ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946640

RESUMO

High-frequency pulse lasers, applied in the form of rapid scanning, act upon the surface of aircraft skin paint layers, thereby removing the paint layers, exhibiting characteristics of efficiency and eco-friendliness. Real-time monitoring of the paint removal effect and prevention of substrate damage necessitates the continuous monitoring of paint removal thickness. Combining Laser-Induced Breakdown Spectroscopy (LIBS) online monitoring technology enables laser-controlled paint removal under multiple effects coupling, meeting the requirements of airworthiness maintenance. This paper, based on a high-frequency nanosecond infrared pulse laser paint removal LIBS monitoring platform, conducts research on laser paint removal thickness LIBS online monitoring of aluminum alloy plates coated with dual-layer paint. Spectra corresponding to the removal thickness of each group are collected and, respectively, paint removal thickness monitoring models based on LIBS spectra are established using the standard curve method and Principal Component Analysis-Support Vector Regression (PCA-SVR) algorithm. When monitoring paint removal thickness using the standard curve method, the intensity of five Ti element characteristic spectral lines selected is correlated with the paint removal thickness, and segmented curve fitting according to the paint layer structure satisfies the segmented curve fitting of topcoat and topcoat + primer. Among them, the average coefficient of the curve fitting of the Ti II 589.088 nm characteristic spectral line is 0.89, and the root mean square error (RMSE) is 12.28 µm. Its performance is superior in the five standard curves; thus, its fitting equation is used as the criterion for paint removal thickness monitoring. To further improve monitoring accuracy, research on paint removal thickness monitoring models based on PCA-SVR is conducted. Compared to the traditional univariate standard curve method, the PCA-SVR model does not require segmented monitoring. After parameter optimization, the average fitting coefficient reaches 0.97, and the RMSE is 2.92 µm. The results indicate that the PCA-SVR-based paint removal thickness monitoring model has higher accuracy, thereby forming the basis for paint removal thickness monitoring. Through comparative research on paint removal thickness monitoring models, two types of paint removal thickness monitoring criteria are obtained, providing model solutions for high-precision monitoring and automation of aircraft skin laser paint removal thickness.

7.
Food Chem ; 402: 134262, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36126584

RESUMO

In this work, double-layered emulsions stabilized by bacterial cellulose nanofibers/soy protein isolate/chitosan complex were prepared using layer-by-layer self-assembly technology and used for the delivery of curcumin, and the physical and delivery properties of the prepared double-layered emulsions were investigated. The zeta-(ζ) potential of colloidal particles confirmed that the chitosan was adsorbed on surface of the single-layered emulsion droplets by attractive electrostatic interactions. Meanwhile, the physical properties showed that the double-layered emulsions displayed high pH-sensitivity and showed relatively higher stability under acid environment. Furthermore, the in vitro digestion result showed that the curcumin loaded by double-layered emulsions were more stable during simulated gastric digestion as compared with that loaded by single-layered emulsions. Especially, the bioaccessibility of curcumin delivered by the double-layered emulsions (77.4 ± 3.25%) was significantly higher than that of curcumin delivered by single-layered emulsions (32.8 ± 2.56%). Therefore, it can be concluded that the prepared double-layered emulsions showed a great potential application in the delivery of fat-soluble bioactive compounds.


Assuntos
Quitosana , Curcumina , Nanofibras , Emulsões/química , Curcumina/química , Celulose/química , Proteínas de Soja , Digestão , Bactérias/metabolismo , Concentração de Íons de Hidrogênio , Tamanho da Partícula
8.
J Food Sci ; 88(10): 4131-4145, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37642500

RESUMO

In this study, bacterial cellulose nanofibers (BCNs) (0%, 1%, 2%, and 3%) were used as nanofillers to prepare gelatin-based edible films, and their physical properties and fresh-keeping performance were investigated. The microstructure observation showed that the BCNs were well dispersed in the gelatin-based edible films and the surface roughness of the films increased with the increase of BCNs content. X-ray diffraction and thermogravimetric analysis showed that the crystallinity and thermal stability of the film were significantly increased with the increase of BCNs. Fourier-transform infrared spectroscopy analysis suggested that hydrogen bond interactions occurred between BCNs and gelatin polymers, leading to improved mechanical properties with the increase of BCNs content. Furthermore, the barrier performance was also improved with the increase of BCNs content, where gelatin-based edible films with 2% BCNs showed the best mechanical property. Meanwhile, the gelatin-based film-forming solutions (FFSs) containing different BCNs were coated on the fresh-cut apples and the corresponding fresh-keeping performance was investigated. The results showed that the fresh-keeping parameters of fresh-cut apples coated with FFSs containing BCNs were better as compared with those of pure gelatin FFSs. Moreover, the fresh-keeping parameters were improved with the increase of BCNs, especially the FFSs containing 2% BCNs that showed the best fresh-keeping parameters. Therefore, BCNs, used as nanofillers, are an excellent enhancer to improve the fresh-keeping performance of the gelatin-based edible coating, showing a promising potential application in the food preservation field.

9.
Int J Biol Macromol ; 247: 125623, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37392915

RESUMO

Food-grade Pickering emulsion gels with different oil phase fractions stabilized by Bacterial cellulose nanofibers/Soy protein isolate complex colloidal particles were prepared by one-step method. The properties of Pickering emulsion gels with different oil phase fractions (5 %, 10 %, 20 %, 40 %, 60 %, 75 %, v/v) and their applications in ice cream were investigated in the present study. The microstructural results showed that Pickering emulsion gels with the low oil phase fractions (5 %-20 %) were an emulsion droplet-filled gel, where the oil droplets were embedded in the network structure of cross-linked polymer, while Pickering emulsion gels with higher oil phase fractions (40 %-75 %) were an emulsion droplet-aggregated gel, which formed a network structure by flocculated oil droplets. The rheology result showed that the low oil Pickering emulsion gels had the same excellent performance as the high oil Pickering emulsion gels. Furthermore, the low oil Pickering emulsion gels showed good environmental stability under harsh conditions. Consequently, Pickering emulsion gels with 5 % oil phase fraction were used as fat replacers in ice cream and ice cream with different fat replacement rates (30 %, 60 % and 90 %, w/w) was prepared in this work. The results showed the appearance and texture of the ice cream with low oil Pickering emulsion gels as fat replacers was similar to that of the ice cream with no fat replacers, and the melting rate of the ice cream with low oil Pickering emulsion gels as fat replacers showed the lowest value of 21.08 % during the 45 min of melting experiment, as the fat replacer rate in the ice cream reached to 90 %. Therefore, this study demonstrated that low oil Pickering emulsion gels were excellent fat replacers and had great potential application in low calorie food production.


Assuntos
Sorvetes , Nanofibras , Emulsões/química , Celulose/química , Proteínas de Soja , Géis/química , Bactérias
10.
Carbohydr Polym ; 304: 120497, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36641166

RESUMO

Recently, nanocellulose has gained growing interests in food science due to its many advantages including its broad resource of raw materials, renewability, interface stability, high surface area, mechanical strength, prebiotic characteristics, surface chemistry versatility and easy modification. Since then, this review summarized the sources, morphology, and structure characteristics of nanocellulose. Meanwhile, the mechanical, chemical, and combined treatment methods for the preparation of nanocellulose with desired properties were elaborated. Furthermore, the application of nanocellulose in Pickering emulsions, reinforced food packaging, functional food ingredient, food-grade hydrogels, and biosensors were emphasized. Finally, the safety, challenges, and future perspectives of nanocellulose were discussed. This work provided key developments and effective benefits of nanocellulose for future research opportunities in food.


Assuntos
Celulose , Nanoestruturas , Celulose/química , Nanoestruturas/química , Embalagem de Alimentos
11.
Int J Biol Macromol ; 226: 254-266, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36460250

RESUMO

In this work, the influence of soy protein isolated at different pH values (1-9) on the self-assembly behaviors of bacterial cellulose nanofibers/soy protein isolate (BCNs/SPI) colloidal particles via anti-solvent precipitation were investigated. The results showed that the formation of BCNs/SPI at pH values of 1-5 was mainly driven by electrostatic interaction, while the formation of those at pH values of 5-9 was driven by weak molecular interactions including hydrogen bonding and steric-hindrance effect. The FTIR demonstrated that the conformation of protein involved a transition from order to disorder at the level of secondary structure as pH values were away from the isoelectric point. The fluorescence spectroscopy and UV-vis adsorption spectroscopy indicated that hydrophobic region of SPI at pH value of 5 displayed more exposed as compared with that at pH values away from the isoelectric point. The changes in structure conformation of SPI induced by pH values led to the changes in properties of the BCNs/SPI colloidal particles including particle size, microstructure, crystallinity, hydrophily, thermal stability, and rheological properties. Furthermore, the structures of BCNs/SPI colloidal particles at different pH values significantly affected the stability of Pickering emulsion gels stabilized by the corresponding complex colloidal particles. This study provided a theoretical basis for the design of food-grade Pickering emulsion gels stabilized by BCNs/SPI complex colloidal particles.


Assuntos
Celulose , Nanofibras , Emulsões/química , Celulose/química , Proteínas de Soja/química , Géis/química , Tamanho da Partícula , Concentração de Íons de Hidrogênio
12.
Foods ; 12(20)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37893612

RESUMO

The aim of this study was to develop highly pH-sensitive bacterial cellulose nanofibers/gelatin-based intelligent films, where the intelligent films were loaded with different ratios (10:0, 0:10 2:8, 5:5 and 8:2, w/w) of curcumin:anthocyanin (Cur/ATH), and the characterization of intelligent films was investigated. The results showed that the microstructures of intelligent films were much rougher as the proportion of curcumin increased. FTIR results showed that anthocyanin and curcumin were fixed in gelatin matrix by hydrogen bonds. Moreover, XRD results showed that curcumin had a significant effect on the crystal structure of the films. Interestingly, films loaded with a Cur/ATH ratio of 5:5 had the best mechanical and antioxidant properties and a high pH-sensitivity property. Consequently, the bacterial cellulose nanofibers/gelatin-based intelligent films loaded with a Cur/ATH ratio of 5:5 were used for the packaging of fresh pork, displaying good fresh-keeping and freshness detection effects. Therefore, this study suggested that bacterial cellulose nanofibers/gelatin-based intelligent films have great potential in the fresh-keeping and freshness detection of meat.

13.
Front Neurosci ; 17: 1057908, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36960170

RESUMO

Introduction: Depression is a serious psychiatric disorder characterized by prolonged sadness, loss of interest or pleasure. The dominant alpha peak activity in resting-state EEG is suggested to be an intrinsic neural marker for diagnosis of mental disorders. Methods: To investigate an association between alpha peak activity and depression severity, the present study recorded resting-state EEG (EGI 128 channels, off-line average reference, source reconstruction by a distributed inverse method with the sLORETA normalization, parcellation of 68 Desikan-Killiany regions) from 155 patients with depression (42 males, mean age 35 years) and acquired patients' scores of Self-Rating Depression Scales. We measured both the alpha peak amplitude that is more related to synchronous neural discharging and the alpha peak frequency that is more associated with brain metabolism. Results: The results showed that over widely distributed brain regions, individual patients' alpha peak amplitudes were negatively correlated with their depressive scores, and individual patients' alpha peak frequencies were positively correlated with their depressive scores. Discussion: These results reveal that alpha peak amplitude and frequency are associated with self-rating depressive score in different manners, and the finding suggests the potential of alpha peak activity in resting-state EEG acting as an important neural factor in evaluation of depression severity in supplement to diagnosis.

14.
J Liposome Res ; 22(2): 120-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22313057

RESUMO

The aim of this study was to evaluate the pharmacokinetics and tissue distribution of the glycyrrhetinic acid (GA) liposome modified with galactosylated lipid (NOH-GA-LP), compared with GA conventional liposome (GA-LP) and GA solution in mice. The pharmacokinetics and biodistribution of liposomal and solution formulation of GA in mice were studied after intravenous administration. Plasma and tissues were treated using liquid-liquid extraction and determined using reversed-phase high-performance liquid chromatography. Results showed that the mean residence times of NOH-GA-LP (2.99-fold) and GA-LP (2.94-fold) were higher than that of the GA solution in plasma. NOH-GA-LP produced a drug concentration in the liver that was markedly higher than that in other tissues and was approximately 2.0- and 4.8-fold of that of GA-LP and GA solution, respectively. In conclusion, the NOH-GA-LP prepared in this study is a promising sustained-release and drug-targeting system for antitumor drugs.


Assuntos
Galactose/química , Ácido Glicirretínico/administração & dosagem , Ácido Glicirretínico/farmacocinética , Lipídeos/química , Lipossomos/química , Lipossomos/farmacocinética , Animais , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada , Galactose/administração & dosagem , Ácido Glicirretínico/química , Rim/metabolismo , Lipídeos/administração & dosagem , Lipossomos/administração & dosagem , Fígado/metabolismo , Pulmão/metabolismo , Camundongos , Miocárdio/metabolismo , Baço/metabolismo , Distribuição Tecidual
15.
J Liposome Res ; 21(3): 255-60, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21545336

RESUMO

In this study, NOH (NOH = N-octadecyl-4-[(D-galactopyranosyl)oxy]-2,3,5,6-tetrahydroxy hexanamide) was enzymatically synthesized as a targeting molecule and incorporated into liposomes to prepare a liposome surface modified with galactose. Glycyrrhetinic-acid-loaded liposome (GA-LP) and glycyrrhetinic-acid-loaded liposome surface modified with galactose (NOH-GA-LP) were prepared by the ethanol-injection method. NOH-GA-LP was characterized by morphology, particle size, zeta potential, encapsulation efficiency, release in vitro, and stability. The size of spherical particles was in the range of 179-211 nm. Spherical particles exhibit a positive electrical charge (38.7 mV) and possess high encapsulation efficiency (91.3%) and show sustained release (72% over 48 hours) in vitro. This novel approach for the liposome surface modified with galactose by enzymatic synthesis is expected to provide potential application as a drug carrier for active targeted delivery to hepatocytes.


Assuntos
Portadores de Fármacos/química , Galactose/química , Lipossomos/química , Amidas/química , Ácido Glicirretínico/química , Lipossomos/ultraestrutura , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
16.
Int J Biol Macromol ; 179: 377-387, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33652044

RESUMO

In order to understand the effects of emulsion particle sizes on the properties of novel konjac glucomannan (KGM)-based emulsion films, four types of Pickering emulsions with different oil phase (10%, 30%, 50% and 70%, v/v) were prepared by the same stabilizers (2% BCNs/SPI colloidal particles dispersions) and added into the film-forming solutions to keep the same final oil content (0.2%, w/v) in all KGM-based emulsion films. The results showed that the average particle sizes of the prepared Pickering emulsion increased with the increase of the oil phase in emulsion system. The microstructure analyses indicated that the KGM-based emulsion films became smoother as the emulsion particle sizes increased. Moreover, the contact angle values of KGM-based emulsion films slightly increased with the increase of the emulsion particle sizes, while the thermal stability of KGM-based films was not significantly affected by the particle sizes. Furthermore, the KGM-based emulsion films formed mainly through the hydrogen bond interactions as analyzed by FTIR. In addition, with the increase of the emulsion particle sizes, physical and mechanical properties of KGM-based emulsion films were significantly affected. Taken together, these results suggested that the particle sizes of Pickering emulsions had remarkable effects on the properties of KGM-based emulsion films.


Assuntos
Filmes Comestíveis , Emulsões/química , Mananas/química , Ligação de Hidrogênio , Tamanho da Partícula , Permeabilidade , Reologia , Temperatura , Resistência à Tração
17.
Front Nutr ; 8: 734620, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557512

RESUMO

In this study, the anti-solvent precipitation and a simple complex method were applied for the preparation of bacterial cellulose nanofiber/soy protein isolate (BCNs/SPI) colloidal particles. Fourier transform IR (FT-IR) showed that hydrogen bonds generated in BCNs/SPI colloidal particles via the anti-solvent precipitation were stronger than those generated in BCNs/SPI colloidal particles self-assembled by a simple complex method. Meanwhile, the crystallinity, thermal stability, and contact angle of BCNs/SPI colloidal particles via the anti-solvent precipitation show an improvement in comparison with those of BCNs/SPI colloidal particles via a simple complex method. BCNs/SPI colloidal particles via the anti-solvent precipitation showed enhanced gel viscoelasticity, which was confirmed by dynamic oscillatory measurements. Furthermore, high internal phase Pickering emulsions (HIPEs) were additionally stable due to their stabilization by BCNs/SPI colloidal particles via the anti-solvent precipitation. Since then, HIPEs stabilized by BCNs/SPI colloidal particles via the anti-solvent precipitation were used for the delivery of curcumin. The curcumin-loaded HIPEs showed a good encapsulation efficiency and high 2,2-diphenyl-1-picrylhydrazyl (DPPH) removal efficiency. Additionally, the bioaccessibility of curcumin was significantly increased to 30.54% after the encapsulation using the prepared HIPEs. Therefore, it can be concluded that the anti-solvent precipitation is an effective way to assemble the polysaccharide/protein complex particles for the stabilization of HIPEs, and the prepared stable HIPEs showed a potential application in the delivery of curcumin.

18.
Int J Biol Macromol ; 149: 178-186, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31982531

RESUMO

The present research aimed to study the nanofibers from bacterial cellulose (BC) by HCl hydrolysis and explore its new potential application in fresh-cut apples. Bacterial cellulose nanofibers (BCNs) showed low and more homogeneity particle size, as well as higher zeta potential and transparency in comparison with BC, which was confirmed by morphological analysis. Physical properties analysis showed that BCNs was more excellent semi-crystalline polymer with higher thermal stability as compared with BC. Rheological results displayed that BCNs suspensions presented a shear thinning behaviour with higher apparent viscosity, storage (G') and loss (G'') moduli at the same concentration in comparison with BC. Furthermore, BCNs suspensions were more stable than BC suspensions under storage condition of 4 °C. Additionally, 2% (wt%) of BCNs suspensions were coated on fresh-cut apples. Results showed that the samples coated with BCNs suspension displayed more excellent properties of keeping fresh-cut apples as compared with that coated with BC suspensions, including delaying weight loss, improving firmness and soluble solids content, reducing browning index and titratable acidity. Therefore, the low cost and high biocompatibility of BCNs can be used as new coatings for fresh-cut apples and have great potential to coat fresh-cut fruits and vegetables in food industry.


Assuntos
Acetobacteraceae/química , Celulose/química , Conservação de Alimentos , Frutas , Malus , Nanofibras/química
19.
Food Funct ; 11(5): 4591-4604, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32432239

RESUMO

The potential effects of Komagataeibacter hansenii CGMCC 3917 cells on alcohol-induced liver injury and their probable mechanisms were investigated. Male Kunming mice were orally administered with alcohol (10 mL per kg BW) alone or in combination with administration of K. hansenii CGMCC 3917 cells at 2 × 108 and 2 × 106 CFUs for 10 weeks. Administration of strain CGMCC 3917 cells, especially high dose administration, decreased the liver weights, fat gain, and fatty-acid metabolism-related enzyme SCD-1, ACC and FAS expressions and endotoxin release, which were elevated by alcohol treatment. Furthermore, the total contents of long chain fatty acids of the liver and serum in alcohol-treated mice supplemented with a high dose of strain CGMCC 3917 cells were decreased to 5.44 ± 0.19 µg mL-1 and 3.66 ± 0.15 µg mL-1 from 6.65 ± 0.31 µg mL-1 and 4.52 ± 0.21 µg mL-1, respectively. Conversely, the SCFAs decreased by ethanol treatment, particularly the acetic acid, propionic acid and butyric acid, were obviously enhanced in the faeces, colon and cecum of the mice supplemented with strain CGMCC 3917 cells. Moreover, strain CGMCC 3917 cells could regulate gut microbiome by significantly decreasing the abundance of Actinobacteria, Proteobacteria and Firmicutes, and dramatically increasing the abundance of Bacteroidetes in alcohol-treated mice. These findings suggest that K. hansenii CGMCC 3917 cells alleviate alcohol-induced liver damage via regulating fatty acid metabolism and intestinal microbiota diversity in mice.


Assuntos
Acetobacteraceae , Microbioma Gastrointestinal , Hepatopatias Alcoólicas/prevenção & controle , Animais , Modelos Animais de Doenças , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos , Fitoterapia
20.
Int J Biol Macromol ; 158: 1007-1019, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32387361

RESUMO

Bacterial cellulose, a pure exocellular polysaccharide produced by microorganisms, has many excellent properties as compared with plant-derived cellulose, including high water holding capability, high surface area, rheological properties, biocompatibility. Due to its suspending, thickening, water holding, stabilizing, bulking and fluid properties, BC has been demonstrated as a promising low calorie bulking ingredient for the development of novel rich functional foods of different forms such as powder gelatinous or shred foams, which facilitate its application in food industry. In this review, the recent reports on the biosynthesis, structure and general application of bacterial cellulose in food industry have been summarized and discussed. The main application of bacterial cellulose in current food industry includes raw food materials, additive ingredients, packing materials, delivery system, enzyme and cell immobilizers. In addition, we also propose the potential challenges and explore the solution of expanding the application of BC in various fields.

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