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1.
Crit Rev Food Sci Nutr ; : 1-17, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34309444

RESUMO

Meat and meat products are highly susceptible to the growth of micro-organism and foodborne pathogens that leads to severe economic loss and health hazards. High consumption and a considerable waste of meat and meat products result in the demand for safe and efficient preservation methods. Instead of synthetic additives, the use of natural preservative materials represents an interest. Essential oils (EOs), as the all-natural and green-label trend attributing to remarkable biological potency, have been adopted for controlling the safety and quality of meat products. Some EOs, such as thyme, cinnamon, rosemary, and garlic, showed a strong antimicrobial activity individually and in combination. To eliminate or reduce the organoleptic defects of EOs in practical application, EOs encapsulation in wall materials can improve the stability and antimicrobial ability of EOs in meat products. In this review, meat deteriorations, antimicrobial capacity (components, effectiveness, and interactions), and mechanisms of EOs are reviewed, as well as the demonstration of using encapsulation for masking intense aroma and conducting control release is presented. The use of EOs individually or in combination and encapsulated applications of EOs in meat and meat products are also discussed.

2.
Int J Biol Macromol ; 185: 535-542, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216656

RESUMO

Antimicrobial films based on polylactic acid (PLA) were developed by incorporating Thymus vulgaris essential oil (TV-EOs) with different concentrations of ethanolic extract of Mediterranean propolis (EEP) (5 wt% and 10 wt% based on PLA). The antimicrobial activities of EEP were performed by the agar disc diffusion method. The EEP exhibited high antimicrobial properties with inhibition zone diameter of 12.1 and 11.58 mm against Staphylococcus aureus and Penicillium sp., respectively. The addition of TV-EOs to films containing 5 and 10 wt% of EEP decrease the elastic modulus from 1292 MPa to 1084 MPa and 911.1 MPa to 794 MPa compared with films containing 5 and 10% of EEP alone, respectively. However, the elongation at break increased by 64% after the addition of TV-EOs to the film containing 10 wt% of EEP. Thermal stability of films improvement by the addition of TV-EOs and EEP. Antimicrobial activity of the films showed that films containing 10 wt% EEP inhibited the growth of Candida albicans and the combination of EEP and TV-EOs in the PLA matrix showed a synergistic effect against Escherichia coli. The developed PLA-based films with antimicrobial activity have a potential application in food packaging to increase the shelf life of packaged food.


Assuntos
Antibacterianos/farmacologia , Etanol/farmacologia , Óleos Voláteis/farmacologia , Poliésteres/química , Própole/química , Thymus (Planta)/química , Antibacterianos/química , Candida albicans/efeitos dos fármacos , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Etanol/química , Embalagem de Alimentos , Armazenamento de Alimentos , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Microb Pathog ; 158: 105047, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34129905

RESUMO

The interactions between various essential oils (EOs) were evaluated for the development of antimicrobial formulations. A full factorial design was applied for testing eight EOs (Mustard, Thyme, Garlic, Oregano, Chinese cinnamon, Cinnamon bark, Red bergamot, Winter savory) against nine bacteria (E.coli O157:H7 RM1239, E.coli O157:H7 RM 1931, E.coli O157:H7 RM 1933, E.coli O157:H7 RM 1934, E.coli O157:H7 380-94, Listeria monocytogenes LM 1045, Listeria innocua ATCC 51742, Salmonella Typhimurium SL 1344, Salmonella enterica Newport ATCC 6962) and two molds (Penicillium chrysogenum ATCC 10106, Aspergillus niger ATCC 1015). Results showed that combinations of Thyme + Oregano, Oregano + Cinnamon bark, Chinese cinnamon + Cinnamon bark have shown high interactions in Factorial design and validated to be mostly additive effects against tested bacteria. The combination of Mustard + Thyme, Mustard + Garlic, and Thyme + Garlic EOs showed high interactions and also all additive effects against tested molds. The corresponding results of Factorial design and checkerboard render the designation to demonstrate the highly efficient formulations and interactions rapidly among abundant mixtures.


Assuntos
Anti-Infecciosos , Listeria monocytogenes , Óleos Voláteis , Origanum , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Listeria , Óleos Voláteis/farmacologia
4.
J Food Sci ; 86(2): 420-425, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33438265

RESUMO

The edible coating has been used for covering fruits and vegetables, bringing surface protection, and extending product shelf-life. Due to the outstanding properties, nanomaterials have become a part of the packaging/coating new generation, demonstrating improvements in the barrier capacity of materials starting from construction products to the food industry. In the food industry, on the other hand, Agaricus bisporus mushrooms have a limited shelf-life from 1 to 3 days because of their high respiration rate and enzymatic browning. With the aim to reduce these two parameters and prevent rapid senescence, the objective of this study was to incorporate a natural source of nanomaterials (cellulose nanocrystals (CNCs) into a gellan gum-based coating and sprayed the surface of the mushrooms with the coating material. To evaluate the effect of CNCs, oxygen consumption, carbon dioxide production rate, and color change were recorded during the mushroom storage at 4 ± 1 °C. Results showed that all coatings were able to decrease total color change (ΔE) of mushrooms from 12 to 8 at day 10 when the coating was applied in all samples compared to control. In addition, significant differences were observed in the respiration rate when CNCs were added to the mushrooms. Oxygen consumption results exhibited a 44 mL O2 /kg · day production at day 5 with 20% CNCs compared to 269 mL O2 /kg · day observed in noncoated samples. This trend was similarly observed in the carbon dioxide production rate. PRACTICAL APPLICATION: With this research, it was remarkable to see the presence of CNCs in the coating solution reduced the respiration rate and increased the shelf-life of mushrooms. Similar applications can be industrially scaled-up to protect fruits and vegetables by CNCs-based coating or packaging materials. A variety of sustainable materials are available nowadays that serve as packaging matrix, and scientists are working on expanding the compatibility of these nanomaterials. In addition, it has been studied that CNCs enhance the degradation of polymers, an effort that many companies are making to reduce the environmental impact in their products.


Assuntos
Agaricus/metabolismo , Celulose , Embalagem de Alimentos/instrumentação , Nanopartículas , Polissacarídeos Bacterianos , Agaricus/química , Carboximetilcelulose Sódica , Cor , Excipientes , Armazenamento de Alimentos/métodos , Frutas , Oxigênio/metabolismo
5.
J Food Prot ; 83(12): 2134-2146, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32692357

RESUMO

ABSTRACT: The surface of iceberg lettuce (Lactuca sativa L.) is favorable to the survival of pathogens such as bacteria, parasites, and viruses such as norovirus. The present study was conducted to investigate the antiviral properties of treatment with cranberry juice (CJ), ozone (O3), and γ-radiation alone or in combination against feline calicivirus (FCV) F9 present on the surface of iceberg lettuce. The lettuce leaves were inoculated with virus suspensions at ∼6 log TCID50 (50% tissue culture infective dose)/mL and treated with CJ, O3, and γ-radiation alone and in combination during storage at 4°C. The D10-values of 1.21 kGy, 2.23% CJ, and 14.93 ppm of O3 were obtained when samples were treated with various radiation doses, CJ, and O3, respectively. Relative radiosensitization of FCV-F9 virus on lettuce was 1.20, 1.50, 1.09, and 1.00 after combined CJ treatments of 0.1, 0.25, 0.50, and 1.50%, respectively. Optimum treatments were 5 ppm for 7.5 min for O3, 0.25% CJ, and γ-radiation at 1.5 kGy when each treatment was used alone. The combination of the three treatments produced the highest reduction of 2.15 log TCID50/mL (from initial inoculation of ∼7 log TCID50/mL) during 10 days of storage at 4°C. Antibacterial properties of treatments and physicochemical quality of lettuce were investigated during 13 days of storage at 4°C. The treatment of lettuce with γ-radiation alone (1.5 kGy) reduced the total flora by 3 log CFU/g; however, the combination of CJ (0.25%) with irradiation (1.5 kGy) reduced it by ∼5 log CFU/g after 13 days of storage at 4°C. The texture and color of the lettuce treated with the combined treatments changed slightly during storage, and chlorophyll increased by 3.81 µg/mL after 10 days of storage at 4°C. Significant differences in taste and color were observed in lettuce without treatments after 5 days of storage, whereas no difference was observed after the 0.25% CJ or the combined treatments.


Assuntos
Anti-Infecciosos , Calicivirus Felino , Norovirus , Animais , Gatos , Alface , Tolerância a Radiação
6.
Microb Pathog ; 149: 104342, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32534179

RESUMO

Shiga toxin-producing Escherichia coli O157:H7, one of the most severe human foodborne pathogens, can withstand several stresses, including some levels of γ-irradiation. In this study, the response of E. coli O157:H7 to a sensitization irradiation dose of 0.4 kGy was assessed using RNA-seq transcriptomic at 10 (t10) and 60 (t60) min post-irradiation, combined with an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis at 60 min post-irradiation. Several functions were induced by the treatment, such as base excision repair and nucleotide excision repair pathways; sulfur and histidine metabolism, and virulence mechanisms. Additionally, the sulA gene, coding for the cell division repressor, together with other genes involved in SOS response and repair mechanism (including recA, recN, recJ, recQ, mutM and uvrB) were up-regulated at t60. As the early response to irradiation stress (t10), dnaK, groEL, ibpA, sulfur metabolism genes, as well as those related to oxidative stress were up-regulated, while histidine biosynthesis genes were down-regulated. Acid stress, heat shock, UV resistance and several virulence genes, especially stx2A/stx2b which code for the Shiga toxins characteristic of O157:H7, were upregulated at 60 min post-irradiation. The treatment was also found to increase the levels of CysN, MutM, DinG and DnaC in the cells, proteins involved respectively in sulfur metabolism, base excision repair, recombinational DNA repair and chromosome replication. Our results provide insights into the resistance response of E. coli O157:H7 to a non-lethal irradiation dose. Our findings indicate that E. coli O157:H7 can resist to γ-irradiation through important modifications in genes expression and proteins profiles.


Assuntos
Escherichia coli O157 , Proteínas de Escherichia coli , Reparo do DNA , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Humanos , Nucleotídeos , Proteômica
7.
Int J Biol Macromol ; 159: 859-869, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32445819

RESUMO

Carrageenan-based functional wound dressing materials were prepared through a one-pot green synthesis of silver nanoparticles (AgNPs) using lignin as a reducing and capping agent in the carrageenan matrix cross-linked with divalent cations such as CaCl2, CuCl2, and MgCl2. The wound healing efficacy of the hydrogel film was evaluated using Sprague-Dawley rats. Crosslinking with divalent cations improved the physical properties of carrageenan-based hydrogels containing AgNPs such as strength, flexibility, swelling ratio, and release rate of Ag ions depending on the type of crosslinking agent used. The carrageenan-based hydrogels were biocompatible against the mouse fibroblast cell line (L929 cell line). Carra/Lig/AgNPs/MgCl2 hydrogel significantly healed the wounds in Sprague-Dawley rats within two weeks, reducing the wound area to <3%, which was further confirmed by histological analysis with the epidermis and mature glands. Carrageenan-based multifunctional hydrogels have a high potential for wound dressing applications.


Assuntos
Bandagens , Carragenina/química , Lignina/química , Nanopartículas Metálicas/química , Prata/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Técnicas de Química Sintética , Reagentes para Ligações Cruzadas/química , Química Verde , Hidrogéis/química , Masculino , Fenômenos Mecânicos , Camundongos , Ratos , Solubilidade , Cicatrização
8.
Microb Pathog ; 144: 104178, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32240768

RESUMO

The antimicrobial activity of sulfur nanoparticles (SNPs) was compared with elemental sulfur and sulfur-containing salts (sodium thiosulfate and sodium metabisulfite) against bacteria (Escherichia coli, Staphylococcus aureus) and fungi (Aspergillus flavus, Candida albicans) using the paper disc, broth microdilution, and time-kill assay methods. The results of the paper disc and MIC tests showed stronger antimicrobial activity of SNPs compared to the elemental sulfur and sulfur-containing salts. SNPs showed more potent activity against bacteria than fungi. Among the test microorganisms, E. coli (Gram-negative) was the most susceptible to SNPs, followed by S. aureus (Gram-positive), C. albicans (yeast), and A. flavus (mold). Scanning electron micrographs of microorganisms treated with SNPs showed different cell disruption patterns depending on the type of microorganisms.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Enxofre/farmacologia , Quitosana/farmacologia , Testes de Sensibilidade Microbiana , Nanopartículas , Sulfitos/farmacologia , Tiossulfatos/farmacologia
9.
Microb Pathog ; 143: 104118, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32147410

RESUMO

Stored rice and rice products are prone to contamination by pathogenic fungi and bacteria such as Aspergillus niger, Bacillus cereus, and Paenibacillus amylolyticus. Treatment with antimicrobial essential oils (EOs) and irradiation are options to control spoilage organisms. Microbial samples with or without fumigation with an oregano/thyme EO mixture were irradiated at 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 kGy for calculation of a D10 value. The relative sensitivity was calculated as the ratio of D10 values for the irradiation plus oregano and thyme EO combination and irradiation alone treatments. In all cases, irradiation plus fumigation with the oregano and thyme EO mixture showed increased efficacy compared with irradiation alone. The relative sensitivity of γ-ray irradiation against A. niger was 1.22, 1.33, and 1.24 for radiation dose rates of 10.445, 4.558, and 0.085 kGy/h, respectively, however against B. cereus it was 1.28, 1.45, and 1.49, and against P. amylolyticus it was 1.35, 1.33, and 1.38, for respective γ-ray irradiation dose rates. The relative sensitivity of X-ray irradiation against A. niger, B. cereus, and P. amylolyticus was 1.63, 1.21, and 1.31, respectively, at the X-ray dose rate of 0.76 kGy/h. The results showed that the relative sensitivity of γ-ray irradiation was higher against the two bacteria than the fungus, whereas X-ray showed higher sensitivity against the fungus than the two bacteria. There was no consistent positive or negative relationship between dose rate and relative sensitivity. The results demonstrated the potential of an oregano and thyme EOs mixture as an antimicrobial agent and its efficacy to increase the radiosensitization of A. niger, B. cereus, and P. amylolyticus during γ-ray or X-ray irradiation treatments.


Assuntos
Irradiação de Alimentos/métodos , Conservação de Alimentos/métodos , Óleos Voláteis/uso terapêutico , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/efeitos da radiação , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/efeitos da radiação , Raios gama , Origanum , Oryza/microbiologia , Paenibacillus/efeitos dos fármacos , Paenibacillus/efeitos da radiação , Radiossensibilizantes/farmacologia , Radiometria , Thymus (Planta) , Raios X
10.
Carbohydr Polym ; 232: 115785, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952593

RESUMO

This work describes the development of membrane based on chitosan (CHI), cellulose nanocrystals (CNCs), and glycerol (GLY), and optimization of the formulation for immobilization of monoclonal anti-Shiga toxin 2B antibody (mAnti-stx2B-Ab) for E. coli O157:H7 detection. The effect of CHI deacetylation degree & viscosity, CNCs and GLY concentrations on Anti-stx2B-Ab immobilization efficiency was evaluated. Fractional factorial and Box-Behnken designs were applied to screen the effects of compounds interactions and optimize their concentrations for detection of Anti-stx2B-Ab. The results demonstrated that the use of 0.6 % (w/v) CNCs improved significantly the Anti-stx2B-Ab immobilization and the level of signal detection. The detection limit of Escherichia coli O157:H7 by developed optimized membrane is 1 log CFU/mL. The time needed for detection of E. coli O157:H7 was only 4 h of enrichment compared to 24 h with conventional methods. The developed immobilization support has potential for future pathogen detection in food and biomedical samples.


Assuntos
Anticorpos Monoclonais/imunologia , Celulose/química , Quitosana/química , Nanoestruturas/química , Toxina Shiga/imunologia , Anticorpos Monoclonais/química , Reações Antígeno-Anticorpo , Toxina Shiga/química
11.
Microb Pathog ; 141: 104008, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31991163

RESUMO

The checkerboard method was used to study the potential interactions between eight essential oils (Basil, Cinnamon, Eucalyptus, Mandarin, Oregano, Peppermint, Tea tree, and Thyme) when used as antibacterial agents against Bacillus cereus LSPQ 2872 and Paenibacillus amylolyticus ATCC 9995. The minimum inhibitory concentration (MIC) of each essential oil (EO) and the fractional inhibitory concentration (FIC) index for the binary combinations of essential oils (EOs) were determined. According to FIC index values, some of the compound binary combinations showed an additive effect; however, Thyme/Tea tree and Cinnamon/Thyme EOs exhibited a synergistic effect against P. amylolyticus and B. cereus, respectively. Cinnamon/Thyme EOs mixture exhibited no interactive effect against P. amylolyticus, but a synergistic effect against B. cereus. The combination of Oregano/Thyme EOs displayed the best antibacterial activity and showed a synergistic effect against B. cereus and P. amylolyticus bacteria. The Oregano/Thyme EOs mixture has potential application in food preservation to reduce the contamination of B. cereus and P. amylolyticus.


Assuntos
Bacillus cereus/efeitos dos fármacos , Paenibacillus/efeitos dos fármacos , Óleos Vegetais/farmacologia , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Cinnamomum zeylanicum/metabolismo , Sinergismo Farmacológico , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Testes de Sensibilidade Microbiana , Origanum/metabolismo , Thymus (Planta)/metabolismo
12.
Crit Rev Food Sci Nutr ; 60(3): 435-460, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31131614

RESUMO

Nanocellulose materials are derived from cellulose, the most abundant biopolymer on the earth. Nanocellulose have been extensively used in the field of food packaging materials, wastewater treatment, drug delivery, tissue engineering, hydrogels, aerogels, sensors, pharmaceuticals, and electronic sectors due to their unique chemical structure and excellent mechanical properties. On the other hand, metal and metal oxide nanoparticles (NP) such as Ag NP, ZnO NP, CuO NP, and Fe3O4 NP have a variety of functional properties such as UV-barrier, antimicrobial, and magnetic properties. Recently, nanocelluloses materials have been used as a green template for producing metal or metal oxide nanoparticles. As a result, multifunctional nanocellulose/metal or metal oxide hybrid nanomaterials with high antibacterial properties, ultraviolet barrier properties, and mechanical properties were prepared. This review emphasized recent information on the synthesis, properties, and potential applications of multifunctional nanocellulose-based hybrid nanomaterials with metal or metal oxides such as Ag NP, ZnO NP, CuO NP, and Fe3O4 NP. The nanocellulose-based hybrid nanomaterials have huge potential applications in the area of food packaging, biopharmaceuticals, biomedical, and cosmetics.


Assuntos
Celulose/química , Nanopartículas Metálicas/química , Metais/química , Óxidos/química , Humanos
13.
Int J Biol Macromol ; 146: 1009-1014, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31726140

RESUMO

The aim of this study was to develop a novel approach allowing simultaneous enrichment as well as specific and fast detection of Escherichia coli O157:H7 by indirect ELISA using optimized support membrane based on chitosan (CHI), cellulose nanocrystals (CNCs), and glycerol (GLY). Therefore, combining the step of the capture of the pathogen and enrichment steps for the microbial growth led to a high detection signal at a low inoculation level without cross-reaction with Pseudomonas and Salmonella strains. The detection was performed by varying incubation periods and different level of inoculations. The signal of detection in samples incubated with the chitosan-based support reinforced with CNCs and directly from E. coli O157:H7 bacterial culture was much higher as compared to CNCs-free support with cell-free supernatant samples. The CCG support reinforced with 0.6% CNCs improved the detection signal of E. coli O157:H7 by 25% compared to control. The whole bacterial culture showed a higher immobilization signal than unfiltered and cell-free supernatant. The spider web trap approach (SWTA) detect E. coli O157:H7 after only 4 h of enrichment compared to 24 h with conventional methods. The adjustment of this innovative SWTA could minimize the risks of cross-contamination and consequently, food product recalls by facilitating significantly the detection of foodborne pathogens in samples collected from food surface, tools and work surfaces in food processing industries.


Assuntos
Celulose/química , Quitosana/química , Escherichia coli O157/isolamento & purificação , Contaminação de Alimentos , Glicerol/química , Membranas Artificiais , Nanopartículas/química , Aranhas/anatomia & histologia , Animais , Escherichia coli O157/crescimento & desenvolvimento , Microbiologia de Alimentos , Temperatura
14.
Carbohydr Polym ; 224: 115191, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472875

RESUMO

κ-Carrageenan-based (Carr) functional wound healing hydrogel films were prepared by incorporating chitosan capped sulfur nanoparticles (SNP) and grapefruit seed extract (GSE). In vivo wound healing effect of the hydrogel films was tested using artificially wounded male Sprague-Dawley rats. The hydrogel film (Carr/GSE/SNP) showed higher mechanical strength, swelling ratio and ultraviolet barrier properties than the carrageenan film, but the water vapor permeability and water solubility were decreased. The hydrogel film showed antibacterial activity strong enough to destroy Staphylococcus epidermis and Escherichia coli within 3 h of incubation and showed high biocompatibility against mouse fibroblast (L929 cell lines). The hydrogel film (Carr/GSE/SNP3%) showed excellent wound healing effect (1.3% wound area after 2 weeks) compared to the control group (31% wound area after 2 weeks) through in vivo wound healing test. Histological examination showed the complete appearance of the healed epidermis. The Carr/GSE/SNP hydrogel films are most likely to be used for the treatment of full-thickness wounds.


Assuntos
Carragenina/química , Citrus paradisi/química , Hidrogéis/química , Hidrogéis/farmacologia , Extratos Vegetais/química , Enxofre/química , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Fenômenos Mecânicos , Camundongos , Nanopartículas/química , Permeabilidade , Ratos , Ratos Sprague-Dawley , Sementes/química , Solubilidade , Staphylococcus epidermidis/efeitos dos fármacos , Vapor
15.
Mater Sci Eng C Mater Biol Appl ; 105: 110068, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546417

RESUMO

Eco-friendly antimicrobial nanoparticles were prepared by adsorbing metal ions to keratin nanoparticles (KNP) isolated from the chicken feather. The mean size of KNP determined by STEM and DLS was 47 ±â€¯15 nm and 80.7 ±â€¯8.3 nm, respectively. The KNP-Ag complex exhibited a larger negative surface charge (-28.2 ±â€¯4.2 mV) than the KNP-Cu (-2.7 ±â€¯0.9 mV) and KNP-Zn (-5.7 ±â€¯1.3 mV) complexes. The FTIR results showed that the interaction of KNP and metal ions was different depending on the type of metal ion. EDX and XPS results revealed the presence of metal ions in KNP-metal ion complexes. Metal ion adsorption and desorption kinetics results showed that the silver binding to KNP was the highest among the metal ions tested, while the release rate was the slowest. The adsorption of cationic metal ions promoted the adhesion of KNP to bacterial cell and enhanced the killing effect for both Gram-positive and Gram-negative bacteria. Metal ion depletion test result revealed that the bactericidal activity of the KNP-metal ion complex was time-dependent due to the desorption of metal ions from the KNP core. The antimicrobial activity of the KNP-metal ion complex was dependent on the type of metal ions. The nanoparticle complex prepared by adsorbing antimicrobial metal ions on biodegradable core materials is likely to be used for the development of eco-friendly antimicrobial nanomaterials.


Assuntos
Antibacterianos , Escherichia coli/crescimento & desenvolvimento , Queratinas , Listeria monocytogenes/crescimento & desenvolvimento , Metais Pesados , Nanopartículas/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Galinhas , Íons/química , Íons/farmacologia , Queratinas/química , Queratinas/farmacologia , Metais Pesados/química , Metais Pesados/farmacologia
16.
J Microbiol Methods ; 165: 105692, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31437555

RESUMO

Biological synthesis of nanomaterials has been increasingly gaining popularity due to its eco-friendly nature and cost-effectiveness. This study aimed to synthesize silver nanoparticles (AgNPs) using Senna alata bark extract as reducing and capping agents, and to evaluate their antimicrobial activities. AgNPs was characterized using UV-vis spectrophotometry, transmission electron microscopy, and Fourier transform infrared spectroscopy (FTIR). The formation of AgNPs was monitored by recording the surface plasmon resonance peak observed at 425 nm. High-resolution TEM images elucidated the formation of spherical AgNPs with an average diameter of 10-30 nm. Energy dispersive spectroscopy (EDS) revealed the presence of silver. The functional groups of biomolecules present in the extract and their interaction with AgNPs were identified through FTIR analysis. Biosynthesized AgNPs displayed antimicrobial activity against different microorganisms, including Gram-positive and Gram-negative bacteria as well as fungi, as indicated by the diameter of inhibition zones between 11.37 and 14.87 mm. Minimum inhibitory concentration of AgNPs for the tested microorganisms was in the range from 31.25 to 125 µg/mL. Potassium leakage is a primary indicator of membrane damage which is a significant mode of action of AgNPs against the tested microorganisms. The amount of potassium ions leaked from the microbial cells after 4 h contact time ranged between 0.97 and 3.05 ppm. Morphological changes were observed in all AgNPs-treated microorganisms. The green synthesized AgNPs with high antimicrobial activity has potential to be used in food packaging and biomedical research areas.


Assuntos
Candida albicans/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Nanopartículas Metálicas/química , Extrato de Senna/farmacologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Casca de Planta/metabolismo , Senosídeos/metabolismo , Prata/química
17.
Mater Sci Eng C Mater Biol Appl ; 93: 289-298, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30274061

RESUMO

Zinc oxide nanoparticles (ZnO NPs) were synthesized using zinc chloride and NaOH and they were incorporated to prepare PLA/ZnO NPs composite films. The SEM images showed that the ZnO NPs were cubical in shape with size ranged from 50 to 100 nm, and the PLA/ZnO NPs composite films were smooth and compact. The composite films exhibited strong UV-light barrier property with a slight decrease in the transparency. The thickness, tensile strength, and water vapor barrier property of the films increased significantly after incorporation of ZnO NPs. The TS of PLA films increased by 37.5%, but the WVP decreased by 30.5% from 3.11 × 10-11 to 2.16 × 10-11 g m/m2·Pa·s when 0.5 wt% of ZnO NPs was incorporated. The composite films exhibited potent antibacterial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes. The developed films were applied to the packaging of a minced fish paste and showed strong antibacterial function. The prepared composite films could be used as antibacterial and UV-light barrier films for food packaging and biomedical applications.


Assuntos
Antibacterianos/química , Escherichia coli/crescimento & desenvolvimento , Listeria monocytogenes/crescimento & desenvolvimento , Membranas Artificiais , Nanocompostos/química , Raios Ultravioleta , Água , Óxido de Zinco/química
18.
Int J Biol Macromol ; 120(Pt A): 846-852, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30189274

RESUMO

Antimicrobial poly(lactide) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend films incorporated with grapefruit seed extract (GSE) were prepared using a solvent casting method. Effect of GSE on the morphological, water vapor barrier, thermostability, color, optical, and antimicrobial properties of PLA/PBAT composite films was investigated. The composite films showed a yellowish tint after incorporation of GSE and exhibited a high UV-light barrier property. Incorporation of GSE increased the flexibility and tensile strength of the composite films. Films incorporated with 7 wt% of GSE exhibited potent antibacterial activity against Listeria monocytogenes, but they showed only bacteriostatic activity against Escherichia coli. The PLA/PBAT-GSE composite film with UV-light barrier and antibacterial properties has a high potential for an active food packaging application.


Assuntos
Antibacterianos/química , Citrus paradisi/química , Embalagem de Alimentos , Extratos Vegetais/química , Antibacterianos/síntese química , Escherichia coli , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/patogenicidade , Extratos Vegetais/síntese química , Poliésteres/química , Sementes/química , Resistência à Tração , Difração de Raios X
19.
Mater Sci Eng C Mater Biol Appl ; 92: 508-517, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184776

RESUMO

Sulfur nanoparticles (SNPs) were prepared using sodium thiosulfate and hydrochloric acid, and the UV-visible spectrum showed the formation of nanoparticulate sulfur. The SNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The antibacterial activity and the cytotoxic effects of the SNPs on the human lung carcinoma (A549), mouse colon carcinoma (CT26), Caco-2, and human fibroblast (CCD-986sk) cells were tested. In addition, the inhibitory effect of the SNPs on the cancer cell migration was evaluated. The SNPs capped with chitosan (SNP2) exhibited strong antibacterial activity against Escherichia coli and Staphylococcus aureus. SNP2 also effectively inhibited the proliferation and migration of cancer cells with minimal toxic effect on normal cells. SNP2 therefore has potential for medical applications, including those used as antibacterial and chemotherapeutic agents.


Assuntos
Antibacterianos , Citotoxinas , Escherichia coli/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Enxofre , Células A549 , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Células CACO-2 , Quitosana/química , Quitosana/farmacologia , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Humanos , Enxofre/química , Enxofre/farmacologia
20.
Int J Biol Macromol ; 118(Pt B): 1824-1832, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30017990

RESUMO

Functionalized halloysite nanotubes were prepared by surface activation of halloysite (Hal) with sodium hydroxide and deposition of zinc oxide nanoparticles (ZnONP). The surface charge of Hal was changed from 0.18 ±â€¯0.6 mV to -35.2 ±â€¯2.8 mV after alkali treatment. The functionalized Hal (AT-Hal/ZnONP) was incorporated into alginate biopolymer as a reinforcing filler with different concentration of AT-Hal/ZnONP (1, 3, 5, and 7 wt% of alginate). Alginate films with AT-Hal/ZnONP exhibited a significant increase in the mechanical, water vapor barrier, and UV light barrier properties. The thermal stability of composite films has not changed after AT-Hal/ZnONP incorporation. The AT-Hal/ZnONP incorporated alginate films demonstrated strong antibacterial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes. The nanocomposite film with 7 wt% of AT-Hal/ZnONP exhibited complete sterilization of E. coli and L. monocytogenes after 3 and 9 h of treatment, respectively.


Assuntos
Alginatos/química , Álcalis/química , Argila/química , Nanocompostos/química , Nanotubos/química , Óxido de Zinco/química , Alginatos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Fenômenos Químicos , Bactérias Gram-Negativas/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Mecânicos , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Nanotubos/ultraestrutura , Permeabilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
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