Editorial

Editoria

Packaging evaluation to conditioning of minimally processed lettuce

The lettuce was packaged in five different plastic films in bags forms (LDPE-50, LDPE -60, LDPE -100, BOPP-LDPE and Conservax-trade mark), under active modified atmosphere of 5% O2 and 10% CO2. It was accompanied the atmosphere changes with the determination of the O2 and CO2 concentration inside the package during the storage. The shelf life was determined through sensorial evaluation whit Descriptive Quantitative Analyses using a nine points hedonic scale to visual quality and five points hedonic scale to taste, flavor, and texture. Permeability and thickness films characteristics were analyzed. In the films with lowers permeability rates (BOPP- LDPE and Conservax) it was favored quickly cellular tissues degeneration and lettuce quality loss. The films with higher permeability rates (LDPE -50 and LDPE -60)favored quickly CO2 reduction. In spite of this, all the modified atmosphere packaging obtained the best results allowing to lettuce keep the adequate consume characteristics until ten days under storage.A alface crespa minimamente processada foi acondicionada em cinco tipos de sacos plásticos confeccionados com diferentes filmes (PEBD-50, PEBD-60, PEBD-100, BOPP - PEBD e Conservax), sob atmosfera ativamente modificada com 5% de O2 e 10% de CO2. Monitorou-se a atmosfera durante o armazenamento por meio da determinação das concentrações de O2 e CO2 no interior das embalagens. A determinação da vida útil baseou-se na avaliação da qualidade sensorial realizada por meio de Análise Descritiva Quantitativa ADQ, aplicando-se escala hedônica de nove pontos para aparência e cinco pontos para sabor, aroma e textura. Determinaram-se as taxas de permeabilidade ao O2 e CO2 e a espessura dos filmes. Nos filmes com baixas taxas de permeabilidade (BOPP-PEBD e Conservax) ocorreu rápida degeneração dos tecidos celulares e perda da qualidade da alface. Os filmes com maiores taxas de permeabilidade (PEBD-50 e 60) propiciaram a rápida redução do CO2. Entretanto, todas as embalagens com atmosfera modificada proporcionaram os melhores resultados permitindo que a alface mantivesse características adequadas de consumo em até dez dias de armazenamento.82483

Microencapsulated ascorbic acid: Development, characterization, and release profile in simulated gastrointestinal fluids

The aim of this study was to produce ascorbic acid (AA) microcapsules by complex coacervation, characterize them, and evaluate the release profile in simulated gastrointestinal fluids. The microcapsules were made of gelatin and pectin at concentrations of 1.0, 2.0, and 3.0%. The coacervated microcapsules were assessed for morphology (by optical microscopy and scanning electron microscopy), water activity (Aw), hygroscopicity, solubility, encapsulation efficiency (EE), thermal behavior, and AA release profile. The AA microcapsules were characterized by low solubility, low hygroscopicity, high thermal stability, and low diameter (\u3c10 μm), with EE ranging from 23.7 to 94.3%. The release profile was faster in gastric fluid (pH 1.8) than in intestinal fluid (pH 6.8). The sample containing 2.0% of wall material and 50% (w/w) of the simple emulsion (core) had the highest EE and the best in vitro release profile, with release of only 68% of AA in 120 min in the gastric fluid. Practical applications Ascorbic acid (AA) is widely used in the food industry as an antioxidant, but practical use becomes limited due to its high instability. Microencapsulation was proposed as an alternative to increase the stability of this compound. Gelatin and pectin were used as wall materials in the production of ascorbic acid microcapsules by complex coacervation. Both solubility and hygroscopicity were low while the thermal stability of the active material improved with the microencapsulation process. Ascorbic acid release was more pronounced in gastric fluid (pH 1.8) and slower in intestinal fluid (pH 6.8). The results of this study demonstrate that the microcapsules produced represent a feasible method of increasing AA availability in food products, especially for those samples that presented high encapsulation efficiency

ASSESSMENT OF THE OSMO-CONVECTIVE DEHYDRATION ON THE QUALITY ATTRIBUTES AND CENTESIMAL COMPOSITION OF YACON (Smallanthus sonchifolius)

This work has studied the application of the osmo-convective dehydration on yacon roots, regarding its composition and quality attributes. Slices of yacon were submitted to osmotic treatment with sucralose solution followed by convective dry. The experiments followed a complete 23 factorial design to assessthe effect of three variables of the process (temperature, stirring rate of the osmotic solution and drying temperature) over four quality attributes (moisture content, color, luminosity and soluble solid content). The application of the osmotic treatment before convective drying provided quality gains to the dried product, such as low browning and shrinkage rates, and reduction of the structural damages towards angular distortions and fissures, in comparison to the samples dried directly on the tray dryer. The effect of osmotic treatment over the centesimal composition of yacon have resulted on absorption of sucralose and water loss without a significance compromise of its nutritional attributes. The obtained product presented different contents of moisture, but similar levels of darkening and color alteration at diverse experimental conditions

Assessment of physicochemical characteristics, thermal stability and release profile of ascorbic acid microcapsules obtained by complex coacervation

The aim of this study was to determine the physicochemical characteristics, thermal stability and release profile of ascorbic acid (AA) microcapsules obtained by complex coacervation. Gelatin and gum arabic were used as wall materials in concentrations of 2.5, 5.0 and 7.5 g% (w/v). The coacervate microcapsules were freeze-dried and assessed for physicochemical characteristics, thermal behavior and stability during 60 days of storage. The release profile was evaluated at different pH values (1.1, 2.2, 5.4, 7.4, 9.6 and 12). The encapsulation efficiency ranged from 27.3 to 93.8%. The microcapsules of AA presented good characteristics for application in food matrices, such as average diameter below 12.4 μm, low solubility and low hygroscopicity. The AA had its thermal stability significantly improved by the encapsulation process, which extends its application in the food industry. The release of AA was slower at pH near neutrality, with release of 97, 96 and 99% of encapsulated AA at 240, 300 and 270 min at pH 5.4, 7.4 and 9.6, respectively. Different mathematical models were successfully fitted to the release kinetics: R2 \u3e 0.94, absolute deviations\u3c16% and RMS deviations\u3c0.09. A mathematical model for a two-step release was proposed, resulting in very high correlations with the experimental data observed: R2 \u3e 0.99, absolute deviations\u3c3.5% and RMS deviations around 0.02

Estudos de um compartimento cilíndrico em poliuretano para aplicação de pulso de campo elétrico em alimentos líquidosStudies of a compartment cylindrical in poliurethane for application of pulse electric fi eld in liquid foods

A câmara cilíndrica em poliuretano projetada para aplicações de Pulsos de Campo Elétrico (PCE) em alimentos líquidos foi estudada utilizando amostras de leite (50 ml) previamente contaminada com Escherichia coli ATCC 11229. O tratamento consistiu de aplicações de pulso do tipo duplo exponencial (1,2 - 50µs) de curta duração e alta tensão (kV) sobre o leite dentro da câmara de tratamento; esta composta de eletrodos de carbonos planos e paralelos, acoplada a um gerador de impulso e interligada a um medidor de corrente e tensão (osciloscópio), para produzir campo elétrico de alta intensidade (kV/cm). Verificou-se o projeto e a eficiência da câmara de tratamento para este processo. Para o estudo, variou-se o número de pulso e a tensão. O controle dos testes foi realizado por análises microbiológicas do leite antes e após o tratamento com PCE . Os testes realizados com a câmara de tratamento foram satisfatórios em relação à ausência de contaminação cruzada e ao seu projeto, pois gerou campos elétricos maiores que 20 kV/cm. Observou-se a ocorrência de dissipação da energia interna (detectada pelo osciloscópio) e conseqüente diminuição da intensidade do campo elétrico interno. Não foi possível obter uma redução microbiana esperada (2 a 4 ciclos logarítmicos), pois o intervalo e a duração do pulso juntamente com a dissipação da energia interna prejudicaram a eletroporação da membrana e conseqüentemente a inativação celular. Porém, ao variar o número de pulsos e a tensão, ocorreu a redução microbiana. Sugere-se trabalhar com pulsos de tipo square-wave (onda quadrada) de 1 hertz de freqüência e 2 µs de duração. Faz-se necessário realizar novos estudos para minimizar a dissipação do campo elétrico interno na câmara de tratamento para aumentar a redução microbiana e a eficiência do processo.Abstract Previously the cylindrical chamber in projected polyurethane for applications of Pulses of Electric Field (PEF) in liquid foods was studied using milk samples (50 ml) contaminated with Escherichia coli ATCC 11229. The treatment consisted of applications of pulses of exponential double type (1,2 – 50 µs) of short duration and high tension (kV) on milk, inside of chamber of treatment, this composed of plain and parallel carbon electrodes, connected to a linked generator of impulse and to a measurer of chain and tension (oscilloscope), to produce electric field of high intensity (kV/cm). It verified the project and the efficiency of the chamber of treatment for this process. For the study, one varied the number of pulses and the tension. The control of the tests was carried through by microbiological analyses of milk before and after the treatment with PEF. The tests carried through with the treatment chamber, had been satisfactory in relation the absence of crossed contamination and to its project, because it generated than electric fi elds 20 kV/cm. It was observed occurrence of waste of the internal energy (detected for the oscilloscope) and consequence reduction of the intensity of the internal electric field. It was not possible to get a waited microbial reduction (2 to 4 logarithmic cycles), therefore the interval and the duration of the together pulse with the waste of the internal energy had harmed the electroporation of the membrane consequently and the cellular inactivation. However, when varying the number of pulses and the tension occurred variation in the microbial reduction. Soon, how much larger the tension and the number of pulses wrist larger the microbial reduction. It suggests: to work with square-wave type of frequency 1 hertz and 2 µs of duration. Become necessary to carry though new studies to minimize the waste of internal electric fi eld in the treatment chamber to increase the microbial reduction and sufficiency of the process

Protection against tuberculosis by a single intranasal administration of DNA-hsp65 vaccine complexed with cationic liposomes

<p>Abstract</p> <p>Background</p> <p>The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally.</p> <p>Results</p> <p>We developed a novel and non-toxic formulation of cationic liposomes, in which the DNA-hsp65 vaccine was entrapped (ENTR-hsp65) or complexed (COMP-hsp65), and used to immunize mice by intramuscular or intranasal routes. Although both liposome formulations induced a typical Th1 pattern of immune response, the intramuscular route of delivery did not reduce the number of bacilli. However, a single intranasal immunization with COMP-hsp65, carrying as few as 25 μg of plasmid DNA, leads to a remarkable reduction of the amount of bacilli in lungs. These effects were accompanied by increasing levels of IFN-γ and lung parenchyma preservation, results similar to those found in mice vaccinated intramuscularly four times with naked DNA-hsp65 (total of 400 μg).</p> <p>Conclusion</p> <p>Our objective was to overcome the significant obstacles currently facing DNA vaccine development. Our results in the mouse TB model showed that a single intranasal dose of COMP-hsp65 elicited a cellular immune response that was as strong as that induced by four intramuscular doses of naked-DNA. This formulation allowed a 16-fold reduction in the amount of DNA administered. Moreover, we demonstrated that this vaccine is safe, biocompatible, stable, and easily manufactured at a low cost. We believe that this strategy can be applied to human vaccines to TB in a single dose or in prime-boost protocols, leading to a tremendous impact on the control of this infectious disease.</p

Aula, repouso, aquecimento e desaquecimento vocal em professores de uma escola pública de ensino médio de Salvador - BA

Justificativa: professores compõem uma categoria profissional que tem a voz como um dos cruciais instrumentos de trabalho. Fatores de risco os expõem a alterações vocais que podem prejudicar o exercício profissional. Dentre os aspectos considerados no cuidado com a voz, o aquecimento e o desaquecimento vocal possibilitam a preparação da voz para o uso em sala de aula. Objetivo: analisar os efeitos da aula, do repouso e de um procedimento de aquecimento e desaquecimento vocal na qualidade da voz e no grau de desconforto auto-referido. Métodos: Dezoito professores de uma escola pública estadual do município de Salvador-BA, selecionada por conveniência, compuseram a amostra deste estudo. Dividiram-se as amostras entre grupos experimental (n=8) e controle (n=10) e analisaram-se os efeitos da aula e repouso (grupo controle), aquecimento e desaquecimento vocal (grupo experimental), considerando-se a avaliação de juízes por meio da escala GRBASI e ressonância, análise acústica e grau de desconforto auto-referido. O material analisado foi submetido a tratamento estatístico, sendo considerado nível de significância de 5%. Resultados: A aula provocou elevação estatisticamente significante da freqüência fundamental e aumento do grau de desconforto auto-referido. Não houve diferença significante nas variáveis analisadas para o repouso vocal. O aquecimento vocal proporcionou redução do grau geral de alteração vocal e diminuição do desconforto, especialmente nos aspectos relacionados ao corpo. O desaquecimento vocal proporcionou diminuição da freqüência fundamental e redução do grau de desconforto, especialmente relacionado à voz. A comparação entre os grupos experimental e controle não demonstrou diferença estatisticamente significante em nenhuma variável analisada. Tanto o desaquecimento quanto o repouso vocal proporcionaram o retorno da voz ao ajuste coloquial...Justification: Voice is a main work tool for teachers and they are exposed to risk factors able to cause voice disorders. Vocal warm-up and cool-down procedures are used as preparation for the use of voice in classrooms. Goal: to analyze the effects of vocal warm-up and cool-down procedure, rest and lecture on voice quality, as well as on the degree of self-reported discomfort. Methods: the subjects of this research were 18 teachers of a state school in Salvador/BA, which were selected by convenience. They were divided in two groups, one experimental (n=8) and the control (n=10). Then they were subject to an analysis of the effects of lecture and rest (control group), vocal warmup and cool-down procedures (experimental group). The criteria for comparison between the voices were evaluation by judges, considering the GRBASI scale and resonance, analysis of acoustic parameters and the degree of self-related discomfort. The significance level for the statistical treatment was 5%. Results: lecture resulted in statistically relevant increase of the fundamental frequency and rising of self-related discomfort. Rest did not result on statistically significant difference on the variables. Vocal warm-up resulted on decreasing in degree of vocal alteration and discomfort, especially on body related aspects. Vocal cool-down resulted on decreasing the fundamental frequency and the degree of discomfort, especially on voice related aspects. Comparison between experimental and control groups did not show any statistical difference on the analyzed variables. Cool-down and rest showed equally positive on adjusting back to the colloquial voice. Conclusion: lecture has raised the vocal attrition, indicating the vocal loading to which teachers are exposed. The proposed procedure showed to be positive and able to be applied preventively. New studies, with a larger number of subjects, should take place, ...(Complete abstract click electronic address below

Qualidade sensorial da alface crespa minimamente processada embalada em diferentes filmes plásticos sob atmosfera modificada Packaging evaluation to conditioning of minimally processed lettuce

A alface crespa minimamente processada foi acondicionada em cinco tipos de sacos plásticos confeccionados com diferentes filmes (PEBD-50, PEBD-60, PEBD-100, BOPP - PEBD e Conservax), sob atmosfera ativamente modificada com 5% de O2 e 10% de CO2. Monitorou-se a atmosfera durante o armazenamento por meio da determinação das concentrações de O2 e CO2 no interior das embalagens. A determinação da vida útil baseou-se na avaliação da qualidade sensorial realizada por meio de Análise Descritiva Quantitativa ADQ, aplicando-se escala hedônica de nove pontos para aparência e cinco pontos para sabor, aroma e textura. Determinaram-se as taxas de permeabilidade ao O2 e CO2 e a espessura dos filmes. Nos filmes com baixas taxas de permeabilidade (BOPP-PEBD e Conservax) ocorreu rápida degeneração dos tecidos celulares e perda da qualidade da alface. Os filmes com maiores taxas de permeabilidade (PEBD-50 e 60) propiciaram a rápida redução do CO2. Entretanto, todas as embalagens com atmosfera modificada proporcionaram os melhores resultados permitindo que a alface mantivesse características adequadas de consumo em até dez dias de armazenamento.The lettuce was packaged in five different plastic films in bags forms (LDPE-50, LDPE -60, LDPE -100, BOPP-LDPE and Conservax-trade mark), under active modified atmosphere of 5% O2 and 10% CO2. It was accompanied the atmosphere changes with the determination of the O2 and CO2 concentration inside the package during the storage. The shelf life was determined through sensorial evaluation whit Descriptive Quantitative Analyses using a nine points hedonic scale to visual quality and five points hedonic scale to taste, flavor, and texture. Permeability and thickness films characteristics were analyzed. In the films with lowers permeability rates (BOPP- LDPE and Conservax) it was favored quickly cellular tissues degeneration and lettuce quality loss. The films with higher permeability rates (LDPE -50 and LDPE -60)favored quickly CO2 reduction. In spite of this, all the modified atmosphere packaging obtained the best results allowing to lettuce keep the adequate consume characteristics until ten days under storage