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A comparative evaluation of integrity and colour preservation of sliced apples protected by chitosan and zein edible coatings. Repositório Alice
ASSIS, O. B. G. de; SCRAMIN, J. A.; CORREA, T. A.; BRITTO, D. de; FORATO, L. A..
bitstream/item/183316/1/A-comparative-evaluation-of-integrity-and-colour-preservation-of-sliced-apples-protected-by-chitosan-and-zein-edible-coatings..pdf
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Edible coatings; Minimally processed apples; Colorimetric analysis; Zein; Chitosan.
Ano: 2012 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/943494
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A comparative study on fungal laccases immobilized on chitosan BABT
Araújo,José Hilton Bernardino de; Uemura,Vinicius Oliveira; Moraes,Flavio Faria de; Barbosa,Aneli de Melo; Zanin,Gisella Maria.
The phenoloxidase enzyme laccase from the cultures of the Pleurotus ostreatus and Botryosphaeria sp. and a commercial laccase from Aspergillus sp. were immobilized on chitosan of pharmaceutical degree by adsorption followed by crosslinking. Different immobilization conditions in relation to the granulometry of support and amount of enzymatic laccase extract used were tested, aiming at reaching high enzymatic activity with the immobilized enzyme. Two different substrates, ABTS and DMP, were used for the determination of enzymatic activity. The highest enzymatic activity was obtained when 1.0mg/mL of the enzymatic laccase extract from Botryosphaeria sp. was used with 1.0g of support (200 mesh). These immobilized enzymes are to be applied to the improvement...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Laccases; Immobilization; Chitosan.
Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400001
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Amphotericin-B and vancomycin-loaded chitosan nanofiber for antifungal and antibacterial application BJPS
Karimi,Soroush; Moradipour,Pouran; Azandaryani,Abbas Hemati; Arkan,Elham.
In the present study, a mucoadhesive non-woven fiber mat (d= 116 nm) was fabricated by the electrospinning method using chitosan (80% Wt), polyethylene oxide (10% Wt), cysteine (4% Wt) and drugs (6% Wt), respectively. In addition, a comparative study was conducted to define effect of drugs and mucoadhesive agent on the nanofiber formation. FTIR, SEM, DSC and DMA were used to investigate the chemical and physical properties of the nanofibers. In vitro release of the drugs was assessed over a 48-hour period by the total immersion method. Release data were fitted to kinetic models, including the zero-order, first-order, Higuchi matrix, and Hixson-Crowell. Zone inhibition investigations were used to describe the inhibition content of vancomycin and amphotericin...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Mucoadhesive; Vancomycin; Amphotericin-B; Electrospinning; Aphthous; Chitosan.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100521
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Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan BABT
Ortega-Ortiz,Hortensia; Gutiérrez-Rodríguez,Baltazar; Cadenas-Pliego,Gregorio; Jimenez,Luis Ibarra.
The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Antibacterial activity; Chitosan; Complexes; Poly(acrylic acid); Polyelectrolytes.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000300016
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Antibacterial activity of chitosan biofilm for the conservation of fertile and table eggs Arq. Bras. Med. Vet. Zootec.
Prado,R.O.F.; Tellez,I.G.; García,M.L.J.; Aldaco,L.L.E.; García,C.A.C..
ABSTRACT The aim of this study was to develop a chitosan biofilm against Salmonella enteritidis, for the conservation of fertile and table eggs. Two experiments were performed. Experiment 1: 400 specific pathogen-free table eggs were divided in a completely randomized design into four treatments, five replicates and each replicate with 20 table eggs. Experimental groups were assigned to control and 1, 5 and 10% chitosan treatment. The eggs were immersed in the chitosan solution. They were then exposed to Salmonella enteritidis and stored for 1, 24, 96 and 168h at 4ºC. The eggs were then washed with 10mL of physiological saline solution. Experiment 2: 80 specific pathogen-free fertile eggs were tested, the assays were assigned to control and 1, 5 and 10%...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chitosan; Fertile eggs; Table eggs; Salmonella enteritidis.
Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352020000100208
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Antimicrobial activity of nisin in film and coating chitosan. Repositório Alice
BENEVIDES, S. D.; BORGES, M. de F.; SOUSA, C. R. V.; SILVA, S. M. F.; MARTINS, C. M.; CHAGAS, B. S.; BARROSO, M. K. A.; BASTOS, M. do S. R.; ROSENTHAL, A..
2015
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: Biopolímero; Propriedades antimicrobianas; Quitosana; Biopolímero; Propriedades antimicrobianas; Quitosana; Chitosan; Biopolymer.
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1036253
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Antimicrobial analysis of gels and films from chitosan and N,N,N-trimethyl chitosan. Repositório Alice
GOY, R. C.; BRITTO, D. de; ASSIS, O. B. G. de.
2010
Tipo: Capítulo em livro científico (ALICE) Palavras-chave: Films; Chitosan.
Ano: 2010 URL: http://www.alice.cnptia.embrapa.br/handle/doc/874623
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Biodegradability kraft paper coated with films emulsified chitosan and palmitic acid. Repositório Alice
REIS, A. B.; YOSHIDA, C. M. P.; VILELA, E. S. D.; NASCIMENTO, R. dos S.; MELO, I. S. de; FRANCO, T. T..
Abstract: The use of natural polymers is an alternative to polymers derived from petroleum that may reduce industrial waste and contribute to the environmental protection. Following the same reasoning, the biodegradability of paper packaging is already known for it being a product originated from cellulosic materials (cellulosic fibers). The aim of this work was to assess the process of degradation from the junction of two different materials; biopolymer and sheets of paper. This paper proposes the study of the biodegradability of chitosan film-coated Kraft paper sheets and emulsified chitosan film-coated Kraft paper sheets added with palmitic acid, both in comparison with uncoated Kraft paper sheets. The biodegradability study was conducted based on...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Biopolymer; Kraft paper; Microbial biomass carbon; Soil respiration; Biofilm formation; Enzymatic activity; Biodegradação; Papel; Biofilme; Biodegradation; Chitosan.
Ano: 2013 URL: http://www.alice.cnptia.embrapa.br/handle/doc/967553
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Changes in hyphal morphology due to chitosan treatment in some fungal species. Repositório Alice
OLIVEIRA JUNIOR, E. N.; MELO, I. S. de; FRANCO, T. T..
In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyl groups (FA 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth of Alternaria alternata (500 µg × mL-1), Botrytis cinerea (1,000 µg × mL-1), Penicillium expansum (1,000 µg × mL-1) and Rhizopus stolonifer (500 µg × mL-1). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs.
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Alternative control of fungi; Antifungal activity; Fungal morphology; Fungo; Doença fúngica; Chitosan; Antifungal agents; Plant pathogenic fungi.
Ano: 2012 URL: http://www.alice.cnptia.embrapa.br/handle/doc/941619
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Changes in hyphal morphology due to chitosan treatment in some fungal species BABT
Oliveira Junior,Enio Nazaré de; Melo,Itamar Soares de; Franco,Telma Teixeira.
In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyl groups (F A 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth of Alternaria alternata (500 µg × mL-1), Botrytis cinerea (1,000 µg × mL-1), Penicillium expansum (1,000 µg × mL-1) and Rhizopus stolonifer (500 µg × mL-1). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chitosan; Alternative control of fungi; Antifungal activity; Plant pathogenic fungi; Fungal morphology.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000500001
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Characterization of a Gelatin/Chitosan/Hyaluronan scaffold-polymer Electron. J. Biotechnol.
Enrione,Javier; Osorio,Fernando; López,Daniel; Weinstein-Oppenheimer,Caroline; Fuentes,Miguel A; Ceriani,Ricardo; Brown,Donald I; Albornoz,Fernando; Sánchez,Elizabeth; Villalobos,Patricio; Somoza,Rodrigo A; Young,Manuel E; Acevedo,Cristian A.
Gelatin, chitosan and hyaluronic acid are natural components used to prepare polymeric scaffold in tissue engineering. The physical properties of these materials confer an appropriate microenvironment for cells, which can be used as a regeneration system for skin and cartilage. In this work, we prepared and characterized a Gelatin/Chitosan/Hyaluronan lyophilized-polymer. Physical properties of lyophilized-polymer changed slightly with moisture, but when polymer was totally hydrated the elasticity changed significantly. Thermophysical characterisation indicated that temperatures higher than 30ºC could modify irreversibly the polymeric matrix probably due to protein denaturation. Besides, we used the polymer as scaffold to prepare a biosynthetic-skin,...
Tipo: Journal article Palavras-chave: Chitosan; Fibrin; Gelatin; Hyaluronic acid; Scaffold.
Ano: 2010 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500020
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Characterization of the interactions between chitosan/whey protein at different conditions Ciênc. Tecnol. Aliment.
YE,Lizhu; CHEN,Huibin.
Abstract This research investigated the interaction between chitosan and whey protein molecules in terms of pH and heating. The FTIR, rheological analysis, turbidity, and zeta potential measurements were used to assess this interaction. At pH 4.0, addition of low amount chitosan with chitosan/whey protein isolate (C/WPI) ratio of 1:5 effectively prevented the denaturation of whey proteins after heating, whereas high amount of chitosan (C/WPI,1:2) led to depletion flocculation. The combination of chitosan and whey proteins was electrostatic attracting at pH 5.5 and 6.0. At low chitosan addition, the complexes formed at pH 5.5 showed higher viscosity and the complexes formed at pH 6.0 showed a shear-thinning behaviour. At high chitosan addition, the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Chitosan; Whey protein; Molecule; Interaction; PH.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612019000100163
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Chemically modified cellulose nanocrystals as polyanion for preparation of polyelectrolyte complex. Repositório Alice
VASCONCELOS, N. F.; FEITOSA, J. P. A.; ANDRADE, F. K.; MIRANDA, M. A. R.; SASAKI, J. M.; MORAIS, J. P. S.; SILVA, L. M. A. e; CANUTO, K. M.; ROSA, M. de F..
Bacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Carboxymethylation; Polyelectrolytic complexes; Hydrolysis; Nanocrystals; Chitosan.
Ano: 2019 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1118682
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Chitosan and poly(Methyl methacrylate-co-butyl methacrylate) bioclends: a compatibility study. Repositório Alice
SOUZA, N. L. G. D.; BRANDAO, H. de M.; OLIVEIRA, L. G. C. DE.
2014
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Chitosan; Compatibilidade; Interação supramolecular.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1013463
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Coating with chitosan film of sea bream (Sparus aurata) fillets: determining shelf life in refrigerator conditions Ciênc. Tecnol. Aliment.
İZCİ,Levent; EKİCİ,Furkan; GÜNLÜ,Ali.
Abstract In the investigate, we objectived to assess the effect of coating with chitosan film on the shelf life. To this end, skinless sea bream fillets were separated as control group (C), vacuum packed (VP) and coated with chitosan film and vacuum packed (CF+VP). Samples of each group were periodically analyzed for microbiological [Total mesophilic aerobic count (TMAc) and Total psychrophilic aerobic count (TPAc)] and physicochemical [pH, Total volatile basic nitrogen (TVB-N), Thiobarbituric acid (TBA) and Trimethylamine nitrogen (TMA-N)] in storage time. It was determined that CF+VP had the highest shelf life among the sample groups. The findings of the study showed that covering sea bream fillets with chitosan film and vacuum packaging significantly...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sea bream; Chitosan; Film coating; Shelf life.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612018000100054
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Desenvolvimento de nanobiocompósitos superparamagnéticos para aplicação em dispositivos eletrônicos. Repositório Alice
MENEZES, F. L. de.
O progresso da eletrônica nos últimos anos tem aumentado a necessidade de materiais leves, flexíveis, de alta razão eficiência/volume e biodegradáveis. Polímeros naturais podem ser usados para esse intuito. Significantes contribuições à miniaturização e performance desses materiais são reportadas na literatura quando um preenchimento de fases magneto-dielétricas é disperso nessas matrizes. Esse trabalho apresenta diferentes compósitos obtidos com a dispersão de nanopartículas superparamagnéticas (NPMs) em três biomacromoléculas: quitosana, colágeno e celulose. Suas propriedades térmicas, morfológicas, estruturais, dielétricas e magnéticas, bem como a elaboração de um substrato para antenas microfita, foram avaliados. NPMs de Fe3O4 foram sintetizadas e...
Tipo: Tese/dissertação (ALICE) Palavras-chave: Antenas de microfita; Celulose; Colágeno; Chitosan; Cellulose; Collagen; Magnetite.
Ano: 2018 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1103405
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Design Polysaccharides of Marine Origin: Chemical Modifications to Reach Advanced Versatile Compounds ArchiMer
Chopin, Nathalie; Guillory, Xavier; Weiss, Pierre; Le Bideau, Jean; Colliec-jouault, Sylvia.
Polysaccharides are among the most abundant macromolecules on Earth. These polymers are easily obtained from various marine resources such as algae, microorganisms and crustacean shells. The structure of these natural carbohydrates is innovative and quite complex. Marine biopolymers represent key scaffolds toward large challenging fields, such as biomedical applications (glycosaminoglycans, regenerative medicine and drug delivery) and tailored biomaterials. Chemical modifications can be applied to modify their final properties in a specific purpose. New functional glycans are achievable and represent a real potential with their intrinsic biocompatibility and biodegradability. Hydroxyl groups are ubiquitous in polysaccharides structure and involved in most...
Tipo: Text Palavras-chave: Alginates; Carrageenans; Chemical modification; Chitin; Chitosan; Grafting; Marine polysaccharide; Polymer.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00199/31027/29902.pdf
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Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC) films plasticized with sorbitol Ciênc. Tecnol. Aliment.
Rotta,Jefferson; Minatti,Edson; Barreto,Pedro Luiz Manique.
In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC) films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v) in water and chitosan (2% w/v) in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w) to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100) of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The results obtained indicate that the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Films; Chitosan; Hydroxypropylmethylcellulose; Physico-chemical properties.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000200026
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DNA-lipid systems: A physical chemistry study BJMBR
Dias,R.; Antunes,F.; Miguel,M.; Lindman,S.; Lindman,B..
It is well known that the interaction of polyelectrolytes with oppositely charged surfactants leads to an associative phase separation; however, the phase behavior of DNA and oppositely charged surfactants is more strongly associative than observed in other systems. A precipitate is formed with very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. Techniques like phase diagram determinations, fluorescence microscopy, and ellipsometry were used to study these systems. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: DNA; Cationic surfactants; Catanionic mixtures; Chitosan; Phase behavior; Polyelectrolyte-oppositely charged surfactant systems.
Ano: 2002 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000500002
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Efecto de quitina y quitosano sobre huevos y juveniles de nemátodos formadores de nódulos radiculares, Nacobbus aberrans y Meloidogyne incognita bajo condiciones de in vitro e in vivo Colegio de Postgraduados
Sánchez Portillo, Juan Fernando.
El nematodo agallador Meloidogyne incognita Kofoid y White, 1919, Chitwood, 1949, distribuido en 23 de los 32 estados del país y Nacobbus aberrans Thorne 1935, Thorne and Allen, 1944, distribuido en 10 de 32 estados de la República Mexicana, su combate para ambas especies, casi siempre se hace aplicando diferentes agroquímicos, los cuales algunos ya tienen problemas de registro. Se necesita evaluar nuevos productos que sean otra alternativa a su manejo y mas amigables al ambiente. En el presente trabajo se evaluó el efecto de quitina-quitosano con diferentes grados de desacetilación, biopolímeros naturales que poseen propiedades nematicidas y utilizados como reguladores de la población de estos fitonematodos; los estudios se hicieron in vitro, sobre la...
Palavras-chave: Biopolímero natural; Meloidogyne incognita; Nacobbus aberrans; Desacetilación; Control; Quitina; Quitosano; Chitin; Chitinase; Natural biopolymer; Chitosan; Deacetylation; Fitopatología; Maestría.
Ano: 2010 URL: http://hdl.handle.net/10521/55
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