Página 1 dos resultados de 210 itens digitais encontrados em 0.002 segundos

Functional properties of sodium and calcium caseinate antimicrobial active films containing carvacrol

Arrieta, Marina P.; Peltzer, Mercedes A.; López, Juan; Garrigós, María del Carmen; Valente, Artur J. M.; Jiménez, Alfonso
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.72%
Active edible films were prepared by adding carvacrol into sodium caseinate (SC) and calcium caseinate (CC) matrices plasticized with two different glycerol concentrations (25 and 35 wt%) prepared by solvent casting. Functional characterisation of these bio-films was carried out by determination of some of their physico-chemical properties, such as colour, transparency, oxygen barrier, wettability, dye permeation properties and antibacterial effectiveness against Gram negative and Gram positive bacteria. All films exhibited good performance in terms of optical properties in the CIELab space showing high transparency. Carvacrol was able to reduce CC oxygen permeability and slightly increased the surface hydrophobicity. Dye diffusion experiments were performed to evaluate permeation properties. The diffusion of dye through films revealed that SC was more permeable than CC. The agar diffusion method was used for the evaluation of the films antimicrobial effectiveness against Escherichia coli and Staphylococcus aureus. Both SC and CC edible films with carvacrol showed inhibitory effects on both bacteria.

Development of edible films based on differently processed Atlantic halibut (Hippoglossus hippoglossus) skin gelatin

CARVALHO, R. A.; SOBRAL, P. J. A.; THOMAZINE, M.; HABITANTE, A. M. Q. B.; GIMENEZ, B.; GOMEZ-GUILLEN, M. C.; MONTERO, P.
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.7%
The gelatin prepared from the skins of the Atlantic halibut (Hippoglossus hippoglossus) was investigated for the development of edible films plasticized with 30g sorbitol/100g gelatin. Two types of dry gelatin preparations were obtained depending on whether an intermediate evaporation step at 60 degrees C in the drying procedure is included or not. The amino acid composition, molecular weight distribution (determined by SDS-polyacrylamide gel electrophoresis) and glass transition temperature (determined by differential scanning calorimetry) of the gelatins were determined and related to some physical properties of the resulting films. The gelatin extracted from the halibut skins showed a suitable filmogenic capacity, leading to transparent, weakly colored, water-soluble and highly extensible films. The intermediate evaporation step at 60 degrees C induced thermal protein degradation, causing the resulting films to be significantly less resistant and more extensible. No differences in water vapor permeability, viscoelasticity, glass transition or color properties were evidenced between the two gelatins tested. (C) 2007 Elsevier Ltd. All rights reserved.

Edible films from alginate-acerola puree reinforced with cellulose whiskers

Azeredo, Henriette M. C.; Miranda, Kelvi W. E.; Rosa, Morsyleide F.; Nascimento, Diego M.; de Moura, Marcia R.
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.7%
Fruit purees, combined or not with polysaccharides, have been used in some studies to elaborate edible films. The present study was conducted to evaluate tensile properties and water vapor barrier of alginate-acerola puree films plasticized with corn syrup, and to study the influence of cellulose whiskers from different origins (cotton fiber or coconut husk fiber, the latter submitted to one- or multi-stage bleaching) on the film properties. The whiskers improved the overall tensile properties (except by elongation) and the water vapor barrier of the films. The films with coconut whiskers, even those submitted only to a one-stage bleaching, presented similar properties to those of films with cotton whiskers, despite the low compatibility between the matrix and the remaining lignin in coconut whiskers. This was probably ascribed to a counterbalancing effect of the higher aspect ratios of the coconut whiskers. (C) 2011 Elsevier Ltd. All rights reserved.; CNPq; CNPq; Embrapa; Embrapa

Development of Novel Guava Puree Films Containing Chitosan Nanoparticles

Lorevice, Marcos V.; de Moura, Marcia R.; Aouada, Fauze A.; Mattoso, Luiz H. C.
Fonte: AMER SCIENTIFIC PUBLISHERS; VALENCIA Publicador: AMER SCIENTIFIC PUBLISHERS; VALENCIA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.81%
One of the overall goals of industries is to use packages that do not cause environmental problems at disposal time, but that have the same properties as the conventional ones. The goal of this study is to synthesize edible films based on hydroxypropyl methylcellulose (HPMC) with guava puree and chitosan (CS) nanoparticles. This was divided into two stages, the first is the synthesis of chitosan nanoparticles and the second is the production of the films. For the nanoparticles, average size and zeta potential measurements were performed. The characterizations of mechanical and thermal properties, solubility and water vapor permeability tests were conducted in the films. It was observed that when the nanoparticles were added to HPMC and guava puree films, they improved their mechanical and thermal properties, as well as decreased the films solubility and permeability. The potential application of the films prepared would be in edible films with flavor and odor to extend the shelf life of products.

Desenvolvimento de filme comestível à base de alginato incorporado do agente antimicrobiano óleo essencial de cravo: aplicação em alimento; Development of alginate-based edible film incorporated with clove essential oil as antimicrobial agent: application in food

Igarashi, Maria Crystina
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/08/2010 PT
Relevância na Pesquisa
56.7%
A utilização de embalagens biodegradáveis, tais como os filmes e coberturas comestíveis, apresenta-se como alternativa ao uso de recursos não-renováveis como material de embalagem. A incorporação de substâncias antimicrobianas em embalagens tem como objetivo minimizar o problema da contaminação microbiana em alimentos e, entre elas, os óleos essenciais (OE) têm recebido atenção especial por serem substâncias naturais e atenderem à preferência dos consumidores. Porém, a utilização de OE como um agente antimicrobiano natural é limitada por critérios organolépticos, sendo necessário determinar a concentração mínima necessária para inibir o desenvolvimento de microrganismos sem afetar sensorialmente as características do alimento. Assim, os objetivos desta pesquisa foram: desenvolver um filme comestível à base de alginato com incorporação de agentes antimicrobianos naturais e avaliar a adição de diferentes concentrações de cloreto de cálcio (CaCl2) como agente crosslinking na formulação do filme e na etapa complementar de formação do filme; caracterizar o filme frente às propriedades mecânicas e propriedades de barreira; determinar a concentração mínima inibitória (CIM) de óleos essenciais para Pseudomonas spp....

Development of Novel Guava Puree Films Containing Chitosan Nanoparticles

Lorevice, Marcos V.; Moura, Marcia R. de; Aouada, Fauze Ahmad; Mattoso, Luiz H. C.
Fonte: Amer Scientific Publishers Publicador: Amer Scientific Publishers
Tipo: Artigo de Revista Científica Formato: 2711-2717
ENG
Relevância na Pesquisa
56.73%
One of the overall goals of industries is to use packages that do not cause environmental problems at disposal time, but that have the same properties as the conventional ones. The goal of this study is to synthesize edible films based on hydroxypropyl methylcellulose (HPMC) with guava puree and chitosan (CS) nanoparticles. This was divided into two stages, the first is the synthesis of chitosan nanoparticles and the second is the production of the films. For the nanoparticles, average size and zeta potential measurements were performed. The characterizations of mechanical and thermal properties, solubility and water vapor permeability tests were conducted in the films. It was observed that when the nanoparticles were added to HPMC and guava puree films, they improved their mechanical and thermal properties, as well as decreased the films solubility and permeability. The potential application of the films prepared would be in edible films with flavor and odor to extend the shelf life of products.

Produção e caracterização de filmes compostos de metilcelulose, glucomanana, pectina, gelatina e lipidios; Production and characterization of composite films based on methilcellulose, glucomannan, pectin, gelatin and lipids

Hulda Noemi Chambi Mamani
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/02/2009 PT
Relevância na Pesquisa
56.78%
Uma alternativa interessante na produção de filmes comestíveis com propriedades mecânicas e de permeabilidade melhoradas é a mimetização de estruturas biológicas como a parede celular e a cutícula dos tecidos vegetais por conterem na sua composição polissacarídeos, proteínas e lipídios. O objetivo do presente trabalho foi produzir e caracterizar filmes compostos de glucomanana, pectina, metilcelulose, gelatina e lipídios. O trabalho foi desenvolvido em três etapas: (1) produção de filmes a partir dos polissacarídeos: glucomanana, pectina e metilcelulose, (2) produção de filmes à base de polissacarídeos e gelatina em diferentes proporções e pHs e (3) produção de filmes à base de misturas de polissacarídeos/gelatina e lipídios: cera de carnaúba, ácidos graxos esteárico e palmítico, estearoil-2-lactil-lactato de sódio (SSL) e éster de sacarose (ES). Nesta última etapa, os lipídios foram incorporados na forma de emulsão (contendo todos os lipídios) e na forma de dispersão (contendo SSL ou ES). Os filmes foram caracterizados quanto às suas propriedades mecânicas, permeabilidade ao vapor de água (PVA), morfologia, solubilidade, absorção de água, opacidade e estrutura (infravermelho e raios X). Na primeira etapa foram obtidos filmes com propriedades mecânicas melhoradas a partir da mistura metilceluloseglucomanana- pectina na proporção 1:4:1...

The use of electric fields for edible coatings and films development and production : a review

Souza, B. W. S.; Cerqueira, M. A.; Teixeira, J. A.; Vicente, A. A.
Fonte: Springer Science ; Business Media, LLC Publicador: Springer Science ; Business Media, LLC
Tipo: Artigo de Revista Científica
Publicado em //2010 ENG
Relevância na Pesquisa
56.9%
Edible films and coatings can provide additional protection for food, while being a fully biodegradable, environmentally friendly packaging system. A diversity of raw materials used to produce edible coatings and films are extracted from marine and agricultural sources, including animals and plants. Electric fields processing holds advantage in producing safe, wholesome and nutritious food. Recently, the presence of a moderate electric field during the preparation of edible coatings and films was shown to influence their main properties, demonstrating its usefulness to tailor edible films and coatings for specific applications. This manuscript reviews the main aspects of the use of electric fields in the production of edible films and coatings, including the effect in their transport and mechanical properties, solubility and microstructure.; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil.; Fundação para a Ciência e a Tecnologia (FCT), Portugal.

Effect of whey protein purity and glycerol content upon physical properties of edible films manufactured therefrom

Ramos, Óscar L.; Reinas, Isabel; Silva, Sara I.; Fernandes, João C.; Cerqueira, M. A.; Pereira, Ricardo; Vicente, A. A.; Poças, M. Fátima; Pintado, Manuela E.; Malcata, F. Xavier
Fonte: Elsevier BV Publicador: Elsevier BV
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
66.7%
This manuscript describes the detailed characterization of edible films made from two different protein products e whey protein isolate (WPI) and whey protein concentrate (WPC), added with three levels of glycerol (Gly) e i.e. 40, 50 and 60%(w/w). The molecular structure, as well as barrier, tensile, thermal,surface and optical properties of said films were determined, in attempts to provide a better understanding of the effects of proteinaceous purity and Gly content of the feedstock. WPI films exhibited statistically lower (p < 0.05) moisture content (MC), film solubility (S), water activity, water vapor permeability (WVP), oxygen and carbon dioxide permeabilities (O2P and CO2P, respectively) and color change values, as well as statistically higher (p < 0.05) density, surface hydrophobicity, mechanical resistance, elasticity, extensibility and transparency values than their WPC counterparts, for the same content of Gly. These results are consistent with data from thermal and FTIR analyses. Furthermore,a significant increase (p < 0.05) was observed in MC, S, WVP, O2P, CO2P, weight loss and extensibility of both protein films when the Gly content increased; whereas a significant decrease (p < 0.05) was observed in thermal features...

Effect of glucose oxidase incorporation in chitosan edible films properties

Lopes, M. I.; Martins, Joana; Fonseca, L. P.; Vicente, A. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
56.82%
Demand for biodegradable and environmentally friendly packaging has draw attention into the development of biodegradable, polymer based edible packaging films. Edible films’ functionality can be enhanced by incorporating active substances such as biocatalysts. The main objective of this work was to evaluate the effect of GOx incorporation in the mechanical and barrier properties of chitosan edible films. Films were prepared by the casting method using 2% (w/v) chitosan with 25% (w/w) glycerol, containing 1.1% (v/v) of a glucose oxidase solution (0.02% (w/v)). Water vapor, oxygen and carbon dioxide permeabilities were evaluated and Fourier Transform InfraRed (FTIR) analysis was performed. The results of the mechanical tests showed that tensile strength and elongation-at-break values of chitosan films increased with the incorporation of glucose oxidase (from 9.6 to 10.6 MPa and from 65.5 to 71.6 %, respectively), however no significant (p<0.05) changes were observed. From permeability tests it was observed that the barrier properties of chitosan films were not affected by the enzyme incorporation. FTIR analysis showed a specific chemical interaction between functional groups of glucose oxidase and bioactive groups of chitosan. These results suggest that chitosan films with incorporated GOx could be used as active packaging as a strategy for extension of food’s shelf-life.

Use of wheat bran arabinoxylans in chitosan-based films : effect on physicochemical properties

Costa, Maria J.; Cerqueira, M. A.; Ruiz, Héctor A.; Fougnies, Christian; Richel, Aurore; Vicente, A. A.; Teixeira, J. A.; Aguedo, Mário
Fonte: Elsevier BV Publicador: Elsevier BV
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
56.65%
The aim of this work was to evaluate physicochemical properties of chitosan-based films with different fractions of arabinoxylans (AXs). Five fractions composed by AXs or mixtures of AXs and arabino-xylo-oligosaccharides (AXOS) obtained through three different processes were added to chitosan-based films. These films were obtained by solvent casting and characterized in terms of water vapor permeability (WVP), opacity, thickness, moisture content and mechanical properties (i.e., tensile strength TS and elongation at break EB), being the chemical interactions evaluated by FTIR. Moisture content values ranged between 20 and 30% for all five studied films being the lowest value observed for chitosan films with the fraction F1 of AX/AXOS (21.1%). The films with incorporation of F3a, F3b and F4 AXs fraction were more opaque (>10%) than the other studied films. Regarding mechanical properties CH films presented EB and TS values of 31.26% and 8.25 MPa, respectively, both these values remain statistically equal with the incorporation of AX/AXOS except for films containing the fraction F1 and F2. For films with the F2 fraction were obtained higher values of EB (41.31%) while for CH films containing the F1 fraction the TS values (13.07 MPa) increased. In conclusion...

Whey protein isolate edible film: a carrier for probiotic bacteria

Odila Pereira, Joana; Gomes, Ana; Pintado, Manuela
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
56.87%
The use of edible films formulated with bioactive compounds in food products in order to convey new functionalities or extend shelf-life opens new possibilities as support for functional lactic acid bacteria. Thus, active coatings can be obtained by immobilization of the microorganisms in the film, which when in contact with food, will enable the release of microbial bioactive principles and/or after ingestion can directly exert functionality in the human body. Such action may include specific health benefits, such as modulation of the intestinal microbiota that may provide protection against gastrointestinal disorders. Probiotics, when delivered via food or supplement-like forms may contribute to such modulation if their survival and stability is assured until their reaching of the gastrointestinal tract. In this work the main objective was to study the stability of probiotic microorganisms, viz. Bifidobacterium animalis ssp. Lactis BB-12® and Lactobacillus casei 01, in edible films based on whey proteins for coating food products and improving their quality and safety. The selected probiotics at 109 CFU/g of film were incorporated in whey protein-based films to obtain stable edible films to be later applied in food products to provide them antimicrobial protection or make them carriers of viable probiotic bacteria. Films solutions were produced...

Edible coatings based on chitosan-beeswax emulsions

Marques, Sónia Cristina Pereira
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2012 ENG
Relevância na Pesquisa
56.83%
Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica; The use of edible biopolymer-based films and coatings is an environmentally friendly technology that offers substantial advantages for increase of shelf-life of many food products including fruits and vegetables. The development of this kind of films and coatings is a technological challenge for the industry and a very active research field worldwide. In this work biodegradable edible films of chitosan with different contents of beeswax were prepared and characterized. Their hygroscopic properties and water vapour permeability, as well as their CO2 and O2 permeability, mechanical, optical and superficial properties were determined. All the obtained films are transparent with a slightly yellowish colour. They are homogeneous and dense, despite the films with beeswax presented some cracks and depressions in their structure. The incorporation of beeswax increases the films hydrophobicity, higher contact angle values, but still prevails their hydrophilic nature. Regarding the mechanical properties, these films are flexible and elastic, but the increase of beeswax content increases their brittleness. The films showed decreased water vapour permeability as well as decreased hydrophilic properties...

Calculation of viscoelastic properties of edible films: application of three models

CHANDRA,Prabir K.; SOBRAL,Paulo J. do A.
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2000 EN
Relevância na Pesquisa
66.75%
The viscoelastic properties of edible films can provide information at the structural level of the biopolymers used. The objective of this work was to test three simple models of linear viscoelastic theory (Maxwell, Generalized Maxwell with two units in parallel, and Burgers) using the results of stress relaxation tests in edible films of myofibrillar proteins of Nile Tilapia. The films were elaborated according to a casting technique and pre-conditioned at 58% relative humidity and 22ºC for 4 days. The testing sample (15mm x 118mm) was submitted to tests of stress relaxation in an equipment of physical measurements, TA.XT2i. The deformation, imposed to the sample, was 1%, guaranteeing the permanency in the domain of the linear viscoelasticity. The models were fitted to experimental data (stress x time) by nonlinear regression. The Generalized Maxwell model with two units in parallel and the Burgers model represented the relaxation curves of stress satisfactorily. The viscoelastic properties varied in a way that they were less dependent on the thickness of the films.

Mechanical and permeability properties of milk protein films

Folegatti,Marília I.S.; Antunes,Aloísio José; Marcondes,Jorge A.
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1998 EN
Relevância na Pesquisa
56.75%
Edible films present a potential alternative for replacing plastic films used for packaging in food industry. One of the major advantages is the environmental appeal of this technology, which produces no packaging waste. Some films made with other edible materials have found commercial applications, and many more are being developed using a myriad of food based components. This paper focuses on some important characteristics of films produced with sodium and calcium caseinates. The effects of caseinate type and concentration, plasticizer concentration and pH were studied. Major parameters investigated were solubility, tensile properties, water vapour and oxygen permeabilities. Caseinate films showed high solubility at pH range 6.0-8.0 and complete insolubility at pH 3.0 and 4.0. Calcium caseinate films had a higher tensile strength and a lower % elongation at break than sodium caseinate films. There was not significant difference in water vapour and oxygen permeabilities between sodium and calcium caseinate films.

Effects of interactions between the constituents of chitosan-edible films on their physical properties

Cerqueira, M. A.; Teixeira, J. A.; Vicente, A. A.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
66.66%
The main objective of this work was to evaluate the effect of chitosan and plasticizer concentrations and oil presence on the physical and mechanical properties of edible films. The effect of the film constituents and their in-between interactions were studied through the evaluation of permeability, opacity and mechanical properties. The effects of the studied variables (concentrations of chitosan, plasticizer and oil) were analysed according to a 2 3 factorial design. Pareto charts were used to identify the most significant factors in the studied properties (water vapour, oxygen and carbon dioxide permeability; opacity; tensile strength; elongation at break and Young's modulus). When addressing the influence of the interactions between the films' constituents on the properties above, results show that chitosan and plasticizer concentrations are the most significant factors affecting most of the studied properties, while oil incorporation has shown to be of a great importance in the particular case of transport properties (gas permeability), essentially due to its hydrophobicity. Water vapour permeability values (ranging from 1. 62 × 10 -11 to 4. 24 × 10 -11 g m -1 s -1 Pa -1) were half of those reported for cellophane films. Also the mechanical properties (tensile strength values from 0. 43 to 13. 72 MPa and elongation-at-break values from 58. 62% to 166. 70%) were in the range of those reported for LDPE and HDPE. Based on these results...

Edible films and coatings for cheese; Filmes e revestimentos comestíveis para queijos

Orosa, Maria Inês Franco
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
ENG
Relevância na Pesquisa
66.82%
Over the last years there has been an increasing interest to replace synthetic materials by biodegradable ones, due to the ecological problems. Edible and biodegradable films can be produced using polysaccharides, lipids, proteins and composites, and act as a package without damaging the environment. By choosing a suitable coating composition it is possible to preserve several desired properties of a certain food product. Important properties should be considered, such as mechanical, functional and barrier properties. The main goal of this study was to evaluate edible films and coatings from plant proteins (pea, soy), with incorporated natural antimicrobial and antioxidant agents, to potentially protect cheese from physico-chemical and microbial deterioration and to preserve the organoleptic characteristics, especially of sliced cheeses. The work performed focused mainly on the preparation and characterization of pea protein films, with added chitooligosaccharides (COs) (0.5%, 1% and 2%) and two types of essential oils at 1%, bay and thyme oils. Films with 0.5% of COs showed the highest values of Young’s modulus, tensile strength and elongation. Regarding the barrier properties, the film with 1% of COs showed the lower permeability value. Addition of small amounts of COs may be advantageous to improve the mechanical properties of the PPI films...

INFLUENCE OF THE USE OF EDIBLE FILMS IN MINIMALLY PROCESSED ORANGE ‘PÊRA’; INFLUÊNCIA DO USO DE PELÍCULAS COMESTÍVEIS EM LARANJA ‘PÊRA’ MINIMAMENTE PROCESSADA

Leme, Ana Carolina; Groppo, Vanessa Daniel; Romero, Alessandra de Cássia; Spoto, Marta Helena Fillet; Jacomino, Ângelo Pedro
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 30/07/2007 POR
Relevância na Pesquisa
66.7%
The objective of this work was to evaluate the effect of edible films in the preservation of orange ‘Pêra’, minimally processed (MP), kept under refrigeration at 5ºC ± 1ºC during 7 days, by physical, physical-chemical and physiological analyses. The control, the cassava fecula (3%) and the sodium alginato (1%) and CaCl2 (1%) were tested. The use of edible films wasn’t effective to reduce the minimally processed orange ‘Pêra’ respiratory rate and the physical and physico-chemical features of the fruits preservation. The use of cassava fecula and sodium alginato kept the colors, the ascorbic acid value and the pH of minimally processed oranges, however during the storage period it was observed a decrease of the titratable acidity and an increase of the total soluble solids (TSS). The MP orange with cassava fecula showed higher hardness than the ones treated with sodium alginate through the storage period.  ; O objetivo deste trabalho foi avaliar o efeito de películas comestíveis na conservação de laranja ‘Pêra’ minimamente processada, mantida sob refrigeração a 5ºC ± 1ºC durante 7 dias, mediante análises físicas...

Optical, microstructural, functional and nanomechanical properties of Aloe vera gel/gellan gum edible films

Alvarado-González,J.S.; Chanona-Pérez,J.J.; Welti-Chanes,J. S.; Calderón-Domínguez,G.; Arzate-Vázquez,I.; Pacheco-Alcalá,S. U.; Garibay-Febles,V.; Gutiérrez-López,G. F.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 EN
Relevância na Pesquisa
66.75%
Edible films of Aloe vera gel (Al), gellan gum (Ge) and their blend (AlGe) were prepared by the casting method and dried in a conventional oven. Optical, microstructural, functional and nanomechanical properties were evaluated. The films elaborated had adequate optical properties to be used in foods; AlGe showed higher values of transpareney (6.5), total color difference (5.4) and extinction coefficient (0.052) than the Al and Ge; however, intermedíate gloss (34.4) and refractive index (1.53) values were obtained for AlGe, maybe promoted by chemical interactions between Aloe vera and gellan gum. Microscopy and image analysis techniques were used to evaluate the microstructure of pure and blend films; the interactions due to the crosslinked among the polysaccharides of the blend were elucidated by atomic force microscopy. Water sorption capacity (-0.42 %/min) and water vapor permeability (21.3 g-mm/d-m²-kPa) of AlGe were enhanced as compared to Al and Ge; besides the hardness (2.3 MPa) and elastic modulus (0.1 GPa) of the blend at nanometric level was reinforced with the gellan gum addition. The present research could be helpful to understand the blending effect on the property-structure-functionality relationships of edible films with potential use in food industry.

Comparative study of the mechanical properties of edible films made from single and blended hydrophilic biopolymer matrices

Villagómez-Zavala,D. L.; Gómez-Corona,C.; San Martín Martínez,E.; Pérez-Orozco,J.P.; Vernon-Carter,E.J.; Pedroza-Islas,R.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 EN
Relevância na Pesquisa
66.68%
Sodium alginate, κ-carrageenan, mesquite gum and/or whey protein concentrate were used alone or blended for obtaining edible films, using sorbitol as plasticizer. Film mechanical properties were determined with a TA-XT2 texture analyzer. Films with greater breaking factor, tensile strength, tensile strength at break, and tensile energy at break were obtained when sodium alginate was used alone. Low Young's modulus values were obtained with blends of sodium alginate and κ-carrageenan (with the latter predominating in the blend) and mesquite gum-whey protein concentrate (with the former predominating in the blend). The latter blend exhibited highest elongation. Films containing pure sodium alginate or κ-carrageenan or blended with the other gums (with sodium alginate predominating) could be classified as hard, strong and resistant. Films where mesquite gum or whey protein concentrates were on their or where their blend predominated over that of sodium alginate and/or κ-carragenan were mostly soft and weak.