RESUMEN Antecedentes: los β-glucanos (1-3: 1-4) son fibras solubles aplicadas a los alimentos debido a sus propiedades tecnológicas (capacidad de retención de agua, viscosidad, emulsificación y estabilización) y a sus efectos beneficiosos en la salud. Las propiedades funcionales de los β-glucanos pueden perderse durante los procesos de extracción y purificación. La alta viscosidad de los β-glucanos está relacionada con un alto peso molecular y con sus propiedades fisiológicas en el intestino. Por lo tanto, caracterizar la fibra después de su extracción y purificación es fundamental para comprender sus posibles aplicaciones en alimentos. Objetivos: caracterizar β-glucanos extraídos (EβG) y compararlos con tres marcas comerciales (CβG-A, CβG-B y CβG-C) para identificar su futura aplicación en alimentos y evaluar si la purificación enzimática afecta molecular y estructuralmente los β-glucanos. Métodos: se extrajeron β-glucanos de cebada (EβG), caracterizados por análisis químicos, comportamiento reológico y color, y se compararon con tres muestras comerciales. Posteriormente, el extracto (EβG) se purificó y se identificaron sus características estructurales y su peso molecular. Resultados: EβG contenía 64.38 ± 3.54% de β-glucanos, alta contaminación con almidón (12.70 ± 1.73%), alto contenido de calcio (8894 mg / kg), comportamiento pseudoplástico y color oscuro (L* = 52.77 ± 0.7). Todas las muestras comerciales mostraron una baja contaminación con almidón, color más claro y comportamiento newtoniano. Después de la purificación de EβG, la contaminación con almidón y proteína disminuyó (0.85 ± 0.46% y 5.50 ± 0.12%, respectivamente), aumentó el contenido de βG (69.45 ± 0.81%) y aumentó su luminosidad (L* = 92.60 ± 1.70). Los β-glucanos purificados (PβG) mostraron un peso molar de 690 ± 1,6 kDa y se identificaron en la estructura especies con grado de polimerización desde 3 (GP3) hasta 11 (GP11). Conclusiones: los EβG antes de la purificación presentaron alta viscosidad y contaminación. El proceso de purificación enzimática fue efectivo y permitió mantener una alta masa molar de la fibra y sus estructuras moleculares características (especies con GP3 y GP4). Las muestras comerciales CβG-A y CβG-B mostraron un bajo contenido de β-glucanos. Finalmente, la CβG-C presentó las mejores propiedades fisicoquímicas y reológicas para su posterior aplicación en alimentos.

ABSTRACT Background: β-glucans (1-3: 1-4) are soluble fibers applied to foods due to their technological properties (water binding capacity, viscosity, emulsification and stabilization) and their beneficial effects on health. The functional properties of β-glucans can be lost during the extraction and purification processes. The high viscosity of β-glucans is related to a high molecular weight and its physiological properties in the intestine. Therefore, to characterize the fiber after its extraction and purification is fundamental to understand its possible applications in foods. Objectives: characterize β-glucans extracted (EβG) and compare them with three commercial β-glucans (CβG-A, CβG-B and CβG-C) to identify its possible applications in foods and to evaluate if enzymatic purification affects molecular and structurally the β-glucans. Methods: barley β-glucans were extracted (EβG), characterized by chemical analyzes, rheological behavior, and color, and compared to three commercial β-glucans samples. Then, the extract was purified and its structural and molecular characteristics were calculated. Results: EβG contained 64.38 ± 3.54% of β-glucans, high starch contamination (12.70 ± 1.73%), high content of calcium (8894 mg/kg), pseudoplastic behavior, and dark color (L* = 52.77 ± 0.7). All commercial samples showed low starch contamination, lighter color, and Newtonian behavior. After purification starch and protein contamination decreased (0.85 ± 0.46% and 5.50 ± 0.12% respectively), increased the content of βG (69.45 ± 0.81%) and increased brightness (L* = 92.60 ± 1.70). Purified β-glucans (PβG) showed a molar weight of 690 ± 1.6 kDa and species with degree polymerization 3 (DP3) to 11 (DP11) were identified on the structure. Conclusions: EβG extracts before the purification presented a high viscosity and contamination. The enzymatic purification process was effective and allowed to maintain a high molar mass of PβG and its distinctive molecular structures (species with DP3 and DP4). The commercial samples CβG-A and CβG-B showed a low content of β-glucans. Finally, CβG-C presented the best physicochemical and rheological properties for its subsequent application in food.

A diet rich in low-fat dietary fiber helps to prevent chronic diseases. The use of whole wheat flour and fat substitute, adds nutritional value. Fat substitutes act by reducing the caloric level. The bran affects the rheological properties and the quality of the bread. Considering the challenge of adding nutritional value, maintaining the structure and stability of the crumb, our objective was to evaluate the physicochemical and rheological characteristics of whole wheat flour blends with fat substitute for future application in breads. The gluten values of the flour blends indicated that they were technologically acceptable for baking. The effect of the presence of the fat substitute was observed only in the alveography and in the color of the samples with higher level of substitute, because at a higher substitute level, the lower the results of the maximum tenacity of work.

Una dieta rica en fibras alimenticias con bajo contenido de grasas, ayuda a prevenir enfermedades cronicas. La utilizacion de harina de trigo integral y de substituto de grasa, agrega valor nutricional. Substitutos de grasa actuan reduciendo el nivel calorico. El salvado afecta las propiedades reologicas y la calidad del pan. Considerando el desafio de agregar valor nutricional, manteniendo la estructura y la estabilidad de la miga, nuestro objetivo fue evaluar las caracteristicas fisico-quimicas y reologicas de mezclas de harina de trigo integral con substituto de grasa para futura aplicacion en panes. Los valores de gluten de las mezclas de harinas indicaron que eran tecnologicamente aceptables para panificacion. El efecto de la presencia del substituto de grasa fue observado solamente en la alveografia y en el color de las muestras con mayor nivel de sustituto, pues a mayor nivel de substituto, menores fueron los resultados de la tenacidad maxima de trabajo.

Objective: To describe the initial steps in the development and validation of a new self-reported instrument designed to assess daily rhythms of mood symptoms, namely, the Mood Rhythm Instrument. Methods: A multidisciplinary group of experts took part in systematic meetings to plan the construction of the instrument. Clarity of items, their relevance to evaluation of mood states, and the consistency of findings in relation to the available evidence on the biological basis of mood disorders were investigated. The internal consistency of the questionnaire was evaluated through Cronbach’s alpha. Results: All of the items proposed in a first version were well rated in terms of clarity. The items more frequently rated as “rhythmic” were related to the somatic symptoms of mood. Their peaks in 24 hours were more frequent in the morning. The items associated with affective symptoms of mood were rated as less rhythmic, and their peak in 24 hours occurred more frequently in the afternoon and evening. Males and females behaved more similarly with respect to somatic than behavioral-affective items. The second version of the Mood Rhythm Instrument had a Cronbach’s alpha of 0.73. Conclusion: The proposed Mood Rhythm Instrument may be able to detect individual rhythms of cognitive and behavioral measures associated with mood states. Validation in larger samples and against objective measures of rhythms, such as actigraphy, is warranted.

RESUMO: O polvilho azedo é um amido naturalmente modificado, produzido por fermentação e seco ao sol, atingindo a propriedade de expansão. Produtos de panificação a partir do polvilho azedo podem ser preparados sem a adição de leveduras e são livres de glúten. O processo fermentativo tem sido exaustivamente estudado, mas as águas residuais com elevada acidez e ricas em compostos orgânicos derivados da degradação do amido, requerem futuros trabalhos. Neste estudo, a estrutura dos sólidos presentes nesse efluente foi estudada vislumbrando futuras aplicações para estes novos materiais. Os sólidos contidos na água residual foram secos em spray dryer com maltodextrina (MD), com equivalente de dextrose (DE) de 5 e 15. A estrutura das partículas foi observada por microscopia eletrônica de varredura. Uma estrutura regular com arranjo em rede foi observada para o material seco com MD DE 5, em características que diferem das estruturas do amido nativo e do amido fermentado, o que sugere uma nova e regular organização estrutural com futuras aplicações a serem determinadas.

ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the structure of solids present in this residue was studied, seeking to future applications for new materials. The solids of the wastewater were spray dried with maltodextrin (MD) with dextrose equivalent (DE) of 5 and 15 and the structure of the powder was evaluated by scanning electron microscopy. A regular structure with a network arrangement was observed for the dried material with MD of 5 DE, in contrast to the original and fermented starches structure, which suggests a regular organization of this new material, to be studied in future applications.

The cellular structure of healthy food products, with added dietary fiber and low in calories, is an important factor that contributes to the assessment of quality, which can be quantified by image analysis of visual texture. This study seeks to compare image analysis techniques (binarization using Otsu’s method and the default ImageJ algorithm, a variation of the iterative intermeans method) for quantification of differences in the crumb structure of breads made with different percentages of whole-wheat flour and fat replacer, and discuss the behavior of the parameters number of cells, mean cell area, cell density, and circularity using response surface methodology. Comparative analysis of the results achieved with the Otsu and default ImageJ algorithms showed a significant difference between the studied parameters. The Otsu method demonstrated the crumb structure of the analyzed breads more reliably than the default ImageJ algorithm, and is thus the most suitable in terms of structural representation of the crumb texture.

A composição química da farinha de trigo e a presença de fibras afeta as características dos pães. Uma forma de contribuir com a prevenção de doenças crônicas não transmissíveis é através de alimentação saudável, incluindo grãos integrais na dieta alimentar e reduzindo as calorias de determinado alimento, substituindo a gordura. Assim, este trabalho tem como objetivo determinar a composição centesimal das amostras de farinha de trigo integral, refinada e as misturas entre elas; bem como os parâmetros farinográficos (absorção de água, tempo de desenvolvimento e estabilidade) das mesmas. Além disso, verificar volume específico, perfil de textura do miolo e análise de imagem de pães elaborados com 60% de farinha de trigo integral e com 3% de gordura ou com substituto de gordura. Os dados foram submetidos à análise de variância. À medida que aumenta o percentual de farinha integral, os teores de proteína, cinzas e fibra insolúvel alcançam valores significativamente maiores e a absorção de água fica maior na farinografia, bem como o tempo de desenvolvimento e a estabilidade. O amido modificado enzimaticamente utilizado na elaboração de pão com 60% de farinha de trigo integral funcionou como um efetivo substituto de gordura. O pão integral elaborado com substituto de gordura apresentou volume específico significativamente igual ao pão integral elaborado com gordura, porém com diferenças em relação a parâmetros do perfil de textura, maior firmeza e menor elasticidade além de maior densidade celular do que o pão elaborado com gordura.

Bread characteristics are dependent upon the chemical composition and fiber content of the wheat flour used. A healthy diet can help prevent chronic diseases, where whole grains and fewer calories from fat are components of a healthy diet. The aims of this study were to determine the centesimal composition of wheat flour samples (whole, refined, and flour blends) along with their farinographic parameters (water absorption, development time and stability) and also to verify the specific volume, crumb texture profile and digital imaging of bread loaves made with 60% whole wheat flour and 3% fat or fat replacer. Increasing the whole wheat flour percentage in the blends also increased levels of protein, ash and insoluble fiber. All the farinographic parameters were also increased. Enzymatically modified starch was found to be an effective fat replacer in whole wheat loaves. The loaves made using fat replacer had the same specific volume and higher cell density as those made with fat, but exhibited different texture profile parameters such as higher hardness value and lower springiness value.

Na produção de pães integrais de trigo no Brasil, são utilizadas mesclas de farinha integral (FI) com farinha refinada (FR), as quais diferem em sua composição. Assim, o objetivo deste estudo foi investigar as propriedades de pasta de mesclas de FI com FR. Foram analisadas amostras com 100% de FI, 100% de FR (controles) e mesclas de FI com FR nas proporções de 20, 40, 60 e 80%, em equipamento RVA (Rapid Visco Analyzer). A temperatura de pasta das amostras foi semelhante. A viscosidade máxima diminuiu proporcionalmente com o aumento de FI na mescla. Maiores valores de quebra e de viscosidade mínima à temperatura constante foram encontrados em farinhas com pico de viscosidade elevado. Os valores de viscosidade final e de tendência à retrogradação diminuíram à medida que aumentou o teor de FI na mescla. As propriedades de pasta das mesclas de FI com FR devem ser vistas de forma conjunta, pois afetam a produção de pão e o armazenamento. Os resultados mostraram também que o RVA pode ser usado para ajudar a formular mesclas de FI/FR com certas propriedades de pasta.

In whole wheat bread production in Brazil blends of whole flour (WF) with refined flour (RF) are used, which differ in their composition. Thus, the objective of this study was to investigate the pasting properties of WF with RF blends. Samples with 100% of WF, 100% of RF (controls) and blends of WF with RF in the proportions of 20, 40, 60 and 80% were analyzed, in a RVA (Rapid Visco Analyzer) equipment. The samples pasting temperatures were similar. The peak viscosity decreased proportionally with the increase of WF in blends. Higher values of breakdown and holding strength were found in flour with high viscosity peak. Final viscosity and setback values decreased as the content of WF in blends increased. The pasting properties of WF with RF blends must be seen in a combined way, because they affect bread production and storage. The results also showed that RVA can be used to help in formulating WF/RF blends with certain pasting properties.

O objetivo do trabalho foi avaliar os parâmetros da extração de β-glucanas de cevada e caracterizar parcialmente o amido residual da extração. Foi desenvolvida metodologia para extração de β-glucanas de cevada sem degradação do amido, avaliando as variáveis pH e temperatura de extração. O percentual de β-glucanas extraída variou de 44,21 a 53,38%, sendo influenciado pela temperatura, e o de amido extraído variou de 65,98% a 77,54%, sendo influenciado pelo pH. O amido residual da extração de β-glucanas de cevada apresentou poder de inchamento e solubilidade de 8,54±0,29% e 6,04±0,073%, respectivamente. O amilograma de ARV desse amido apresentou viscosidade máxima de 164,67±1,30 RVU e quebra de viscosidade de 45,79±2,06 RVU. O espectro de infravermelho do amido residual é típico de amido de cevada nativo e semelhante ao de amidos isolados de milho, trigo e mandioca. De acordo com as micrografias eletrônicas de varredura da fração amido, foi possível visualizar uma mistura de grânulos grandes e lenticulares, com um diâmetro médio de 19,15µm e de granulos pequenos com forma esférica, de 4,78µm. As características demonstradas pelo amido residual da extração de β-glucanas de cevada sugerem sua viabilidade para utilização na indústria de alimentos.

The objective of the study was to evaluate the parameters of the extraction of barley´s β-glucans and partially characterize the residual starch after extraction. A method was developed for the extraction of barley β-glucans without damaging the residual starch, assessing the variables pH and extraction temperature. The percentage of β-glucans in the extracted fraction varied from 44,21 to 53,38% , being influenced by temperature and the extracted starch varied from 65,98% a 77,54%, being influenced by pH. The residual starch from barley's β-glucan extraction had a swelling power and solubility of 8.54±0.29% and 6.04±0.07%, respectively. The RVA´s amylograph for this starch showed a maximum viscosity of 164.67±1.30 RVU and breakdown viscosity of 45.79±2.06 RVU. The infrared spectrum of the residual starch was typical of native barley starch and similar to isolated starch from corn, wheat and cassava. According to the scanning electron micrographs fraction of starch, it was possible to see a mixture of large lenticular granules with an average diameter of 19.15µm and small spherically shaped ones, with 4.78µm. The characteristics showed by the residual starch from barley´s β-glucan extraction, suggest a possible application in the food industry.

A composição química do grão de trigo afeta as características funcionais tecnológicas e, juntamente com as propriedades estruturais e microscópicas, define a qualidade da farinha de trigo. Assim, este trabalho tem como objetivo caracterizar amostras de cultivares de trigo e respectivas farinhas, BRS Louro, BRS Timbaúva, BRS Guamirim e BRS Pardela, visando indicar a aplicabilidade tecnológica. As amostras das cultivares foram caracterizadas fisicamente quanto ao peso do hectolitro, peso de mil grãos, textura, umidade e atividade de água. As farinhas foram caracterizadas quanto aos aspectos físico-químicos, atividade de água, cor, composição centesimal, teor de amilose e identificação das gluteninas de alto peso molecular. As farinhas foram caracterizadas de acordo com aspectos reológicos, granulometria, farinografia, extensografia, número de queda, viscosidade, propriedades do glúten, panificação experimental, e quanto aos aspectos microscópicos. Os dados foram submetidos à análise de variância à análise de componentes principais. As cultivares BRS Timbaúva e BRS Guamirim possuem comportamentos que não permitem direcionar à aplicação tecnológica com tanta veemência. A cultivar BRS Louro possui características à elaboração de produtos com massa de glúten fraco como bolos, tortas e biscoitos e a BRS Pardela, adequada para produtos de panificação e massas em geral.

Functional and technological properties of wheat depend on its chemical composition, which together with structural and microscopic characteristics, define flour quality. The aim of the present study was to characterize four Brazilian wheat cultivars (BRS Louro, BRS Timbauva, BRS Guamirim and BRS Pardela) and their respective flours in order to indicate specific technological applications. Kernels were analyzed for test weight, thousand kernel weight, hardness, moisture, and water activity. Flours were analyzed for water activity, color, centesimal composition, total dietary fiber, amylose content and identification of high molecular weight glutenins. The rheological properties of the flours were estimated by farinography, extensography, falling number, rapid visco amylography, and glutomatic and glutork equipment. Baking tests and scanning electron microscopy were also performed. The data were subjected to analysis of variance and principal component analysis. BRS Timbauva and BRS Guamirim presented results that did not allow for specific technological application. On the other hand, BRS Louro presented suitable characteristics for the elaboration of products with low dough strength such as cakes, pies and biscuits, while BRS Pardela seemed suitable for bread and pasta products.

El uso de algunos de los géneros de las bacterias ácidolácticas (BAL) como Lactobacillus, Leuconostoc, Lactococcus, o sus productos antimicrobianos como las bacteriocinas, son alternativas en la biopreservación de productos mínimamente procesados que son mantenidos bajo refrigeración. El potencial de biopreservación de un extracto crudo de bacteriocinas producidas por una cepa nativa de Lactobacillus plantarum LPBM10, se evalúa sobre filetes de híbrido de cachama Piaractus brachypomus x Colossoma macropomum empacados al vacío durante 30 días de almacenamiento a 3±0,5 0C. La evaluación se realiza por medio del recuento: mesófilos (heterótrofos), psicrófilos, esporas sulfitoreductoras, coliformes totales y fecales y presencia de Salmonella, teniendo en cuenta tres tratamientos: extracto crudo de bacteriocinas, ácido láctico y el control. El recuento de heterótrofos no presenta diferencia entre los tratamientos, mientras el recuento de psicrotrófilos alcanza valores de 5.2 ciclos log, 6.7 ciclos log y 6.4 ciclos log (P<0.05) para los filetes tratados con extracto crudo de bacteriocinas, ácido láctico y control, respectivamente. Con respecto a los coliformes totales se obtiene un recuento inicial de 2.6 ciclos log, el cual no cambió durante todo el estudio. En cuanto al recuento de coliformes fecales, al finalizar el periodo de almacenamiento, disminuyó 1.3, 1.5 y 2.1 ciclos log para los filetes control, tratados con extracto crudo de bacteriocinas y ácido láctico, respectivamente. El análisis de BVT-N muestra los mejores resultados para el tratamiento con extracto crudo de bacteriocinas y finaliza con 19.3 mg BVT-N/100g. Los resultados del análisis sensorial muestran el mayor rango de aceptabilidad para el tratamiento con extracto crudo de bacteriocinas.

Some lactic acid bacteria genera (BAL) as Lactobacillus, Leuconostoc, Lactococcus or their antimicrobial products as bacteriocins are used as alternatives biopreservation of minimally processed foods kept under refrigeration. Potential Biopreservatives from a bacteriocin producer native strain, Lactobacillus plantarum LPBM10, was evaluated on fillets of cachama hybrid Piaractus brachypomus x Colossoma macropomum, vacuum-packed and stored at 30±0,5°C during 30 days. The evaluation was undertaken using three treatments, bacteriocins raw extract, lactic acid and control. There were not differences among treatments on Mesophylls count. Meanwhile, psychotrophylls count reached values for fillets treated with raw extract of bacteriocins, lactic acid and control, 5.2 cycles log, 6.7 cycles log and 6.4 cycles log (P<0.05), respectively. Regarding total coliforms, 2.6 cycles log of initial count was obtained, maintaining the same value until the end of storage. Faecal coliforms count, at the end of storage period diminished 1.3, 1.5 and 2.1 cycles log for fillets control treated with raw extract of bacateriocins and lactic acid, respectively. BVT-N analysis showed the best results on treatment with raw extract of bacteriocins and end with 19.3 mg BVT-N/100g. Sensorial analysis results showed the greater acceptability range for bacteriocins raw extract treatment.

Este trabajo es una revisión sobre la conformación e importancia del tejido conectivo de la carne de los peces. El ablandamiento post mortem en los peces es un factor de calidad directamente influenciado por las características de los colágenos presentes en cada especie. La degradación del colágeno está relacionada con los fenómenos que acontecen durante el almacenamiento en frío o congelamiento. Varias investigaciones han demostrado a través de análisis bioquímicos y, principalmente, a través de microscopia electrónica de barrido y transmisión, que la pérdida de la textura en la carne de los peces es uno de los efectos ocasionados por la degradación del tejido conectivo pericelular y no por el tejido conectivo intersticial. En la actualidad son propuestas algunas prácticas postcosecha para disminuir este fenómeno.

This work is a review on the conformation and importance of connective tissue of fish meat. The post mortem softening of fish meat as a quality factor is influenced by the characteristics of the collagens present in each species. The degradation of collagen appears to be related to freezing. By biochemical analysis as well as electronic microscopy many researches have demonstrated that the loss of texture is related to pericelular connective tissue degradation. Currently some post crop practices are proposed to reduce this phenomenon.

Para determinar los mecanismos que causan el ablandamiento post-mortem de la carne del pez matrinxã, fueron observados los cambios en la micro estructura del tejido muscular inmediatamente después de la muerte y después de 12 horas de almacenamiento a -3 °C. Las observaciones realizadas con microscopio electrónico de transmisión, presentan concordancia con los resultados obtenidos en la fuerza de ruptura muscular obtenidos con texturómetro. Los valores de la fuerza de ruptura fueron menores para la carne del matrinxã después de la súper refrigeración. Al mismo tiempo, se observó que las fibras del tejido conectivo pericelular fueron desintegradas. Además, fue observada poca degradación de la línea Z. Se sugiere que el ablandamiento post-mortem de la carne del matrinxã, como efecto de la súper refrigeración, sea debido a la desintegración de las fibras de colágeno en el tejido conectivo pericelular y en menor grado a la degradación de la línea Z.

To determine the mechanisms that cause the post mortem muscle softness of the matrinxã, the changes were observed immediately after death in the micro structure of the muscle and after 12 hours of storage at -3 °C. Observations by transmission electron microscope agree with the results obtained noting the breaking strength in the muscle measured with a texturometer. The values of the breaking strength on the fish muscle were smaller after chilling. At the same time, it was observed that collagen fibers in the pericellular connective tissue had disintegrated. On the other hand, no evident breakdown of Z-discs was observed. It is suggested that the post-mortem tenderization of matrinxã muscle during chilled storage was due to the disintegration of collagen fibers in the pericellular connective tissue, and, to a smaller degree, to the weakening of Z-disk.

A cevada (Hordeum vulgare L.) é amplamente empregada na produção de cerveja e na ração animal. Recentemente, este cereal tornou-se desejável na alimentação humana devido ao seu alto valor nutricional, principalmente da cevada nua ou sem casca. Existem diferenças nas características nutricionais e para malteação entre as diversas variedades de cevada. O procedimento RAPD é capaz de separar as variedades de cevada em vários níveis de similaridade. O objetivo desse trabalho foi analisar por RAPD seis variedades brasileiras de cevada nua e sete variedades de cevada cervejeira. Reações de PCR foram realizadas com onze iniciadores aleatórios. Um total de 34 fragmentos de amplificação foi obtido com cinco destes iniciadores. Baseado no coeficiente de similaridade de Jaccard, um dendrograma foi construído. As variedades de cevada apresentaram índice médio de similaridade de 0,53. Fragmentos monomórficos intravariedades permitiram a diferenciação entre as variedades. Os coeficientes médios de similaridade intravariedades encontram-se entre 0,53 e 0,85. Os marcadores RAPD detectados neste trabalho foram adequados para a diferenciação entre as variedades brasileiras de cevada.

Barley (Hordeum vulgare L.) is widely used for brewing and animal feed. Recently, it has become desirable for human consumption due to its high nutritional significance, specially hull-less or naked barley. There are differences in nutritional and malting characteristics among barley varieties. RAPD procedure is able to separate barley varieties at various similarity levels. The aim of this work was the RAPD analysis of six Brazilian hull-less varieties and seven malting varieties. PCR reactions were performed with eleven random primers. A total of 34 RAPD fragments was obtained with five primers. A dendrogram was constructed based on the Jaccard similarity coefficient. Barley varieties displayed an average similarity coefficient of 0.53. Intravarietal monomorphic fragments allowed differentiation among varieties. The averages of intravarietal similarity coefficients ranged from 0.53 to 0.85. RAPD markers, detected in this work, were suitable for differentiation among Brazilian barley varieties.

Apesar de a cevada nua ser amplamente conhecida por seu potencial nutricional, no Brasil é apenas cultivada em poucas estações experimentais agronômicas. Em relação as variedades brasileiras de cevada nua, não se têm dados sobre a composição química, entretanto instituições de pesquisa têm estudado suas características agronômicas. Os objetivos deste estudo foram apresentar a caracterização química e o efeito no fracionamento da farinha obtida visando à concentração de proteína de seis variedades brasileiras de cevada nua: IAC IBON 214/82, IAC 8612/421, IAC 8501/31, IAC 8501/12, IAPAR 39-Acumaí, e IAC 8501/22. Foram realizadas análises de: cinzas, extrato etéreo, proteína total, amido, fibra alimentar total, solúvel e insolúvel e beta-glucanas. As frações das farinhas foram obtidas por peneiramento e avaliadas quanto aos teores de proteína bruta, proteína, nitrogênio protéico e não protéico. Houve variação entre as variedades testadas (P < 0,05). As variedades IAC 8501/22, IAC 8501/31 e IAC 8501/12 apresentaram o maior teor de proteína (15,69; 15,25 e 14,94% respectivamente). Foi observada diferença (P < 0,05) quanto ao teor de proteína nas frações de farinha de cada variedade, a qual pode ser atribuída principalmente às características genéticas, uma vez que todas as variedades foram cultivadas sob as mesmas condições ambientais. Após o fracionamento, foi observada concentração, em algumas frações, de no máximo 2% em relação a farinha integral. As variedades brasileiras de cevada nua apresentam potencial para consumo humano bem como para a produção de farinhas enriquecidas com alta proteína.

Even though hulless barley is widely known due to its nutritional potential, in Brazil it is only grown at a few agricultural experimental stations. There is no published data about the chemical composition of Brazilian hulless barley varieties; however, research laboratories have studied their agronomical characteristics. The objectives of this study were to present the chemical characterization and effect of flour fractionation on protein concentration of six Brazilian hulless barley varieties, namely IAC IBON 214/82, IAC 8612/421, IAC 8501/31, IAC 8501/12, IAPAR 39-Acumaí, and IAC 8501/22. The analyses included: ash, ether extract, total protein, starch, total insoluble and soluble dietary fiber, and beta-glucans. Flour fractionation was carried out by sieving. The flour fractions were evaluated for crude protein, protein, and protein and non-protein nitrogen. Chemical composition varied (P < 0.05) among all the varieties. IAC 8501/22, IAC 8501/31, and IAC 8501/12 showed the highest protein content (15.69, 15.25, and 14.94% respectively). Differences (P < 0.05) among the protein of the fractionated flours were detected, and might be attributed primarily to genetic background since all varieties were grown under the same environmental conditions. Fractionating the flour increased the total protein content, in some fractions, by up to 2%. These results may be useful in the food industry for the selection of hulless barley varieties for human consumption and to produce substantially protein-enriched flour fractions.

Com o crescente interesse em alimentos funcionais e nutracêuticos, a aveia (Avena sativa L.) tem se destacado, devido ao seu teor de fibras alimentares e principalmente às beta-glucanas. As (1,3)(1,4)-beta-D-glucanas, fibras alimentares na maioria solúveis, atuam na redução do colesterol em indivíduos com hipercolesterolemia. Existem estudos para determinar as causas de variação do teor desta fibra em aveia, porém, pouco se sabe sobre a aveia cultivada no Brasil. O objetivo deste trabalho foi verificar se existem diferenças no conteúdo de beta-glucanas entre cultivares brasileiros e se há variação na porcentagem desta fibra devido ao ano de cultivo. Os cultivares IAC7, UFRGS14, UPF16 e UPF17 (3 amostras de cada), e ainda três amostras do cultivar IAC7 para cada ano de cultivo (97 e 98), foram analisados segundo os métodos da AACC (American Association of Cereal Chemists). Os teores médios (peso seco) de beta-glucanas foram 6,50% (IAC7), 4,30% (UFRGS14), 3,51% (UPF16) e 3,78% (UPF17), com erro padrão de ±0,084 e coeficiente de variação de 7,89 %. Observou-se efeito significativo dos cultivares (p=0,03) e grande variabilidade entre as amostras (p=0,0001). O cultivar IAC7 apresentou média de beta-glucanas de 5,11% em 97 e 6,50 % em 98 (erro padrão ±0,14; CV=10,53%) e observou-se efeito significativo do ano de cultivo.

With the increasing interest in functional foods and nutraceuticals, oats (Avena sativa L.) have received special attention because of their dietary fiber contents, and specially of their beta-glucans. The mostly soluble dietary fibers (1,3)(1,4)-beta-D-glucans, reduce serum cholesterol in individuals with hypercholesterolemia. There are studies about the causes of variation in the contents of this fiber in oats, however, very little is known about Brazilian cultivars. The objective of this work was to verify if there were differences in the beta-glucan contents among brazilian cultivars and if there was variation in the percentage of this fiber due to the crop year. The cultivars IAC7, UFRGS14, UPF16 and UPF17 (3 samples each), and even three more samples of cultivar IAC7 for each year (97 and 98), were analyzed according to the AACC methods for beta-glucans. The mean content was 6.50% (IAC7), 4.30% (UFRGS14), 3.51% (UPF16) and 3.78% (UPF17), with standard error (S.E.) of ±0.084 and variation coefficient (C.V.) of 7.89%. A significant effect of the cultivars (p=0.03) and a great variability among the samples (p=0.0001) was observed. IAC7 had a mean beta-glucan content of 5.11% for 1997 and 6.50% for 1998 (S.E.±0.14; C.V.=10.53%) and a significant effect for the crop year was observed.