Sweet Potato New Varieties Screening Based on Morphology, Pulp Color, Proximal Composition, and Total Dietary Fiber Content via Factor Analysis and Principal Component Analysis.

A sample set of 18 sweet potatoes [Ipomoea batatas (L.) Lam] segmented into six registered cultivars and 12 new varieties were evaluated. The 142 tuberous roots were obtained from a sweet potato germplasm bank (BAG-sweet potato; -27.417713768824555 and -49.64874168439556), specifically from plants belonging to a sweet potato breeding program. All samples were characterized according to their morphology, instrumental pulp color, proximate composition, and total dietary fiber. The analytical results were submitted to parametric and non-parametric statistical tests for sample variance data comparison. Moreover, the screening of the cultivars and new varieties was performed by exploratory statistical analysis, factor analysis (FA), and principal component analysis (PCA). From the sixteen independent variables that characterized the samples, the exploratory FA identified thirteen that had a communality greater than 0.7, with 92.08% of assertiveness. The PCA generated 4 principal components able to account for 84.01% of the explanatory variance. So, among the six registered cultivars, SCS372 Marina and SCS370 Luiza showed the capability to be employed as cultivars for production. Among the 12 sweet potato new varieties, samples 17025-13, 17125-10, and 17117 met the requirements for patent and registration. These results will be useful to farmers who wish to use these sweet potatoes in the development of their crops.

Effect of yerba mate (Ilex paraguariensis) leaves on dough properties, antioxidant activity, and bread quality using whole wheat flour.

This study investigated the effects of different yerba mate (YM) proportions (1.5, 2.5, and 4.5 g YM/100 g whole wheat flour (WWF) and particle sizes (245, 415.5, and 623.9 µm) on dough rheological properties, antioxidant activity, and bread characteristics. The addition of YM leaves led to a possible interaction between its phenolic compounds and the gluten network within the dough, without negative effects on dough formation. However, the larger YM particle size (623.9 µm) caused a weakening of the protein network, resulting in lower quality product compared to the other samples. Improved bread quality was found when the YM leaves were added at 2.5 g YM/100 g WWF. The total amount of phenolic compounds and the antioxidant activity increased as the proportion of YM increased in both flour and bread. Moreover, the phenolic compounds in 2.5 g YM/100 g WWF breads were stable during baking, showing no significant losses in the amount of phenolic compounds and antioxidant activity. These results suggest the YM can be successfully incorporated into baked product, improving its functional characteristics. PRACTICAL APPLICATION: This study evaluates the technological quality of bakery product made by incorporating yerba mate leaves in whole wheat flour. The results will contribute to the production of a bread with greater functional properties due to the presence of polyphenols and phytochemicals.

A comprehensive review on cereal ß-glucan: extraction, characterization, causes of degradation, and food application.

ß-glucan derived from cereal sources are high in soluble dietary fiber and can be used as thickeners, texture enhancers, stabilizers, and fat substitutes in foods. Due to its pronounced viscosity, ß-glucan has physiological activity in the body, such as decreasing the glycemic index of foods and reducing the incidence of cardiovascular disease in people. This review focuses on the characteristics of cereal ß-glucans, extraction methods, and causes of degradation, while presenting the most relevant and recent applications in foods. Today, there is an abundant amount of information regarding extraction and characterization of ß-glucans. However, studies on the degradation and application of fiber are more recent and warrant review. The incorporation of ß-glucan has worked well in high carbohydrate foods (e.g., pasta and snacks), but there are still challenges with its inclusion in protein-rich foods (e.g., dairy and meat products). After a comprehensive search and an objective point of view of these aspects, the primary challenges with the incorporation of ß-glucan in foods are the inclusion of sufficient amounts of dietary fiber to have a significant nutritional contribution, the combination with other ingredients and other components of the food (evaluated synergistically or antagonistically), and the new incorporation of ß-glucan in foods without their degradation during processing.

Incorporation of ß-glucans in meat emulsions through an optimal mixture modeling systems.

The effects of ß-glucans (ßG) in beef emulsions with carrageenan and starch were evaluated using an optimal mixture modeling system. The best mathematical models to describe the cooking loss, color, and textural profile analysis (TPA) were selected and optimized. The cubic models were better to describe the cooking loss, color, and TPA parameters, with the exception of springiness. Emulsions with greater levels of ßG and starch had less cooking loss (<1%), intermediate L* (>54 and <62), and greater hardness, cohesiveness and springiness values. Subsequently, during the optimization phase, the use of carrageenan was eliminated. The optimized emulsion contained 3.13 ±â€¯0.11% ßG, which could cover the intake daily of ßG recommendations. However, the hardness of the optimized emulsion was greater (60,224 ±â€¯1025 N) than expected. The optimized emulsion had a homogeneous structure and normal thermal behavior by DSC and allowed for the manufacture of products with high amounts of ßG and desired functional attributes.

Effect of extrusion temperature and screw speed on properties of oat and rice flour extrudates.

BACKGROUND: Whole oat and rice flours were mixed to develop instant flours by a high pressure and low mechanical shear extrusion process. The screw profile was designed aiming to obtain an infant food with gelatinized starch and high hydration ability. Response surface methodology was selected to study the impact of operating parameters such as temperature and screw speed (73-186 °C; 109-391 rpm) on physicochemical and pasting properties of the final extruded product. The main challenge of this study was to process high oats content, since they are characterized by high lipid and fiber content, which impact on material processing. RESULTS: The optimal response was achieved at 170 °C and 350 rpm. The optimal expansion ratio, bulk density, water absorption index, and water solubility index were 2.24, 289.65 kg m-3 , 6.42 g g-1 , and 4.75 g g-1 respectively. Overall, both temperature and screw speed affected the responses studied, except for water absorption index (only screw speed affected this response). Although lipids from oats reduce the expansion ratio of extrudates compared with samples containing higher starch proportions, their lipids protect the starch granules from mechanical degradation when higher screw speed values are used. As a result, both ungelatinized and gelatinized starches may be found in extrudates, which was confirmed by pasting property analyses. CONCLUSION: High oat content may be efficiently processed by optimizing the extruder conditions (temperature, screw speed, and profile), improving the nutritional properties of the final product. © 2017 Society of Chemical Industry.

Physicochemical comparison of commercial VS. extracted ß-glucans and structural characterization after enzymatic purification / Comparación fisicoquímica entre ß-glucanos comerciales y extraídos, y caracterización estructural después de purificación enzimática

Background: ß-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 ß-glucans can be lost during the extraction and purification processes. The high viscosity of ß-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 ß-glucans extracted (EßG) and compare them with three commercial ß-glucans (CßG-A, CßG-B and CßG-C) to identify its possible applications in foods and to evaluate if enzymatic purification affects molecular and structurally the ß-glucans. Methods: barley ß-glucans were extracted (EßG), characterized by chemical analyzes, rheological behavior, and color, and compared to three commercial ß-glucans samples. Then, the extract was purified and its structural and molecular characteristics were calculated. Results: EßG contained 64.38 ± 3.54% of ß-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 ßG (69.45 ± 0.81%) and increased brightness (L* = 92.60 ± 1.70). Purified ß-glucans (PßG) 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: EßG 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 PßG and its distinctive molecular structures (species with DP3 and DP4). The commercial samples CßG-A and CßG-B showed a low content of ß-glucans. Finally, CßG-C presented the best physicochemical and rheological properties for its subsequent application in food.

Antecedentes: los ß-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 ß-glucanos pueden perderse durante los procesos de extracción y purificación. La alta viscosidad de los ß-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 ß-glucanos extraídos (EßG) y compararlos con tres marcas comerciales (CßG-A, CßG-B y CßG-C) para identificar su futura aplicación en alimentos y evaluar si la purificación enzimática afecta molecular y estructuralmente los ß-glucanos. Métodos: se extrajeron ß-glucanos de cebada (EßG), caracterizados por análisis químicos, comportamiento reológico y color, y se compararon con tres muestras comerciales. Posteriormente, el extracto (EßG) se purificó y se identificaron sus características estructurales y su peso molecular. Resultados: EßG contenía 64.38 ± 3.54% de ß-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 EßG, la contaminación con almidón y proteína disminuyó (0.85 ± 0.46% y 5.50 ± 0.12%, respectivamente), aumentó el contenido de ßG (69.45 ± 0.81%) y aumentó su luminosidad (L* = 92.60 ± 1.70). Los ß-glucanos purificados (PßG) 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 EßG 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 CßG-A y CßG-B mostraron un bajo contenido de ß-glucanos. Finalmente, la CßG-C presentó las mejores propiedades fisicoquímicas y reológicas para su posterior aplicación en alimentos.

Propriedades de pasta de mesclas de farinha integral com farinha refinada usadas na produção de pães

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.

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.

Propriedades de pasta de mesclas de farinha integral com farinha refinada usadas na produção de pães

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.

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.

Propriedades de pasta de mesclas de farinha integral com farinha refinada usadas na produção de pães

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.

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.

Extração de -glucanas de cevada e caracterização parcial do amido residual

The objective of the study was to evaluate the parameters of the extraction of barley´s -glucans and partially characterize the residual starch after extraction. A method was developed for the extraction of barley -glucans without damaging the residual starch, assessing the variables pH and extraction temperature. The percentage of -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 -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 -glucan extraction, suggest a possible application in the food industry.

O objetivo do trabalho foi avaliar os parâmetros da extração de -glucanas de cevada e caracterizar parcialmente o amido residual da extração. Foi desenvolvida metodologia para extração de -glucanas de cevada sem degradação do amido, avaliando as variáveis pH e temperatura de extração. O percentual de -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 -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 -glucanas de cevada sugerem sua viabilidade para utilização na indústria de alimentos.

Extração de -glucanas de cevada e caracterização parcial do amido residual

The objective of the study was to evaluate the parameters of the extraction of barley´s -glucans and partially characterize the residual starch after extraction. A method was developed for the extraction of barley -glucans without damaging the residual starch, assessing the variables pH and extraction temperature. The percentage of -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 -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 -glucan extraction, suggest a possible application in the food industry.

O objetivo do trabalho foi avaliar os parâmetros da extração de -glucanas de cevada e caracterizar parcialmente o amido residual da extração. Foi desenvolvida metodologia para extração de -glucanas de cevada sem degradação do amido, avaliando as variáveis pH e temperatura de extração. O percentual de -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 -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 -glucanas de cevada sugerem sua viabilidade para utilização na indústria de alimentos.

Microstructure, nutrient composition and antioxidant capacity of king palm flour: a new potential source of dietary fibre.

The objective of this research was to evaluate the chemical composition, microstructure, and antioxidant capacity of king palm flour obtained from residues from organic king palm (Archontophoenix alexandrae) processing. King palm flour exhibited high levels of dietary fibre (70.85%) and total ash (3.27%); low contents of protein (3.51%) and lipid (0.91%). Iron, magnesium, calcium and potassium contents were 7.31, 517.03, 801.33 and 1041.95 mg/100g, respectively. The high concentration of glucose, xylose and arabinose suggests the presence of some polysaccharides, such as cellulose and hemicelluloses (xyloglucans and arabinoxylans). Methanol and aqueous extracts of king palm flour showed 1.27 and 0.95 mg/g (Gallic Acid Equivalents) of total polyphenols, respectively. Methanol extract yielded the best antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH()) and 2,2'-azino-di(3-ethylbenzthiazoline sulphonate) (ABTS()(+)) methods. The micrographs of leaf sheath showed the presence of druses, which are characterized as calcium oxalate deposition, contributing to the calcium content in king palm flour. The presence of primary and secondary cell walls lignified in leaf sheath contributed to high levels of dietary fibre detected in king palm flour.

Influencia de bacteriocinas producidas por Lactobacillus plantarum LPBM10 sobre la vida útil de filetes del híbrido de cachama Piaractus brachypomus x Colossoma macropomum empacado al vacío / Influence of bacteriocins produced by Lactobacillus plantarum LPBM10 on shelf life of cachama hybrid fillets Piaractus brachypomus x Colossoma macropomum vacuum packaged

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

Perdida de la textura post motem de la carne de pescado durante el almacenamiento en frio / Post Mortem Lost of Texture of Fish Meat During Cold Storage

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.

Efecto de la super refrigeración sobre la textura de la carne de matrinxã (Brycon cephalus) / Chilling effect on the post-mortem texture of the Matrinxã fish muscle Brycon cephalus

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 ºC. 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.

Genetic similarity of Brazilian hull-less and malting barley varieties evaluated by RAPD markers

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.

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.

Genetic similarity of Brazilian hull-less and malting barley varieties evaluated by RAPD markers

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.

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.

Chemical characterization of Brazilian hulless barley varieties, flour fractionation, and protein concentration

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.

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.

Chemical characterization of Brazilian hulless barley varieties, flour fractionation, and protein concentration

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.

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.

[Comparative studies of oat cultivars from Southern Brazil: effect of grain morphology on industrial yield]. / Estudo comparativo de cultivares de aveia (Avena sativa L.) do sul do Brasil: efeito da morfologia do grão no rendimento industrial.

The purpose of this work was to study the effect of grain morphology of oats on their industrial yield. The five cultivars studied: CTC3, UFRGS7, UFRGS14, UPF7 and UPF16 were grown in three localities with different soil and climate conditions, for two consecutive years. The parameters evaluated in the oat samples before and after dehulling were grain size and shape (by image analysis), comparing them to industrial yield, weight of a thousand kernels and hectoliter weight. The results showed that image analysis of oat samples (with hulls), does not have any relation to industrial yield, different from what was observed with groat samples (dehulled). Industrial yield varied according to genotype, locality and year, while area, minimum and maximum diameters and grain shape were only affected by the genetic factor. It was observed that longer grains (UPF16) had the highest industrial yield, differently to rounder and shorter grains (UFRGS14) which had a lower yield due to the ease of breakage during hulling; the smallest grains also gave a low industrial yield.