Morphological, textural analysis and freeze-thaw stability of starches from legume grow in Cameroon / Análise morfológica, textural e de estabilidade de congelamento-descongelamento de amidos de leguminosas cultivadas em Camarões

Starches from some legume grown in Cameroon were evaluated for their granule structure and size, turbidity, firmness and gel strength, thermal and freeze-thaw properties. Amylose contents were in the range of 26.21%-44.85%. Morphological analysis of the starch granules showed bimodal distribution, multiple sizes and shapes from small spherical to the bigger kidney shape. Significant differences were observed among starch in light transmittance, firmness and gel strength. The thermal parameters of starches were evaluated using differential scanning calorimeter and significant differences were observed. The peak gelatinisation temperature was positively correlated to starch granule size but the amylose content showed no evidence of their impact on legume starch properties studied. The data reported can be useful to facilitate the selection of variety of legume and conditions closer to the desired application.

Neste trabalho, amidos de algumas leguminosas cultivadas em Camarões foram avaliados quanto à estrutura e tamanho dos grânulos, turbidez, firmeza e resistência do gel, propriedades térmicas e de congelamento e descongelamento. Os conteúdos de amilose estavam na faixa de 26,21% a 44,85%. A análise morfológica dos grânulos de amido mostrou distribuição bimodal, múltiplos tamanhos e formas desde o pequeno esférico até o maior formato de rim. Diferenças significativas foram observadas entre os amidos na transmissão de luz, firmeza e força do gel. Os parâmetros térmicos dos amidos foram avaliados usando calorímetro diferencial de varredura e diferenças significativas foram examinadas. A temperatura de pico de gelatinização foi positivamente correlacionada com o tamanho do grânulo de amido, no entanto, o teor de amilose não mostrou evidência de impacto nas propriedades do amido de leguminosas estudadas. Os dados informados podem ser úteis para facilitar a seleção de variedades de leguminosas e condições mais próximas da aplicação desejada.

New formulations of fermented milk drinks with fruit pulp added: Physicochemical characteristics during storage and nutritional profile

The aim of this study was to evaluate the nutritional profile and the physicochemical characteristics during storage of newly developed formulations of fermented milk drinks with added pineapple, mango and passion fruit pulp. The fermented drinks showed a high content of protein, iron, and calcium. The passion fruit milk drink had the lowest pH (4.13) and highest acidity (0.95%, expressed in % of lactic acid), which was significantly different (p<0.05) from the pineapple and mango drinks. As for syneresis and sedimentation, the pineapple milk drink had the highest rates at 14 days storage, with 34.33% and 6.50%, respectively and was significantly different (p≤0.05) when compared to the mango and passion fruit milk drinks. In conclusion, newly developed fermented milk drinks with added fruit pulp were a source of several nutrients. We observed physical-chemical characteristics suitable for a fermented milk product during storage.

El objetivo de este estudio fue el desarrollo de nuevas formulaciones de bebidas lácteas fermentadas adicionadas de piña, mango y maracuyá, para evaluar el perfil nutricional y las características fisicoquímicas durante el almacenamiento. Las bebidas fermentadas mostraron un alto contenido en proteínas, hierro y calcio. En cuanto a las características fisicoquímicas durante el almacenamiento, la bebida láctea de maracuyá presentó el pH más bajo (4,13) y la acidez más alta (0,95%, expresada en % de ácido láctico), con una diferencia significativa (p < 0,05), en comparación con las bebidas de piña y mango. En cuanto a sinéresis y sedimentación, la bebida láctea de piña presentó los mayores índices a los 14 días de almacenamiento, con 34,33% y 6,50%, respectivamente, y con diferencia significativa (p ≤ 0,05) al compararla con las bebidas lácteas de mango y maracuyá. En conclusión, las bebidas lácteas fermentadas con adición de pulpa de fruta son una fuente de varios nutrientes, y de características físico-químicas adecuadas para un producto lácteo fermentado durante el almacenamiento.

Natural Gums to Improve the Physicochemical Stability of Cake Creams.

The physicochemical properties of pastry and confectionery products greatly influence the aesthetic design of a cake topping, since they can be susceptible to physicochemical changes in a very short time, so maintaining a good appearance and texture of the topping becomes a challenge. Generally, cake creams deteriorate over time. The evaluation of the physicochemical properties of natural gums (arabic gum, tara gum, carrageenan, and pectin) is proposed in this work as a way to improve the physicochemical stability of butter-based cake creams (coverage creams) to maintain the initial appearance of the cream and to lengthen the separation time of their phases. For this purpose, some parameters related to the physicochemical stability of the cream, such as viscosity, density, bubble size, syneresis, volume and rheological behavior were measured. The result of the ANOVA and Tukey's tests displayed significant differences for the measured parameters, which shows that natural gums substantially improve the stability of butter cream. The best natural gum found was the tara gum (TG) which improved viscosity 5.6 times with respect to that of the cream without gums (η¯ without gums = 15.49 Pa·s, η¯ with TG = 87.09 Pa·s), while the bubble size remained small, 1.6 times smaller compared to that of the cream without gum (BS¯) without gums = 57 µm, (BS¯) with TG = 35 µm), and the volume loss decreased two times when compared to that of the cream without gums ((ΔV¯) without gums = 1.57 cm3, (ΔV¯) with TG = 0.80 cm3). The cream with TG showed better rheology compared to that of the cream without gums (the cream without gums exhibited a plastic and thixotropic behavior, with permanent elastic deformation, while cream with TG exhibited thixotropic behavior without permanent elastic deformation). Finally, it was found that the cream with TG acquired a higher thixotropic index (TI) compared to that of the cream without gums (TI max. without gums = 17.40 y 71.78 q.u., TI max. with TG = 74.67 and 1559.90 q.u., at 4 °C and 25 °C, respectively) which demonstrates the effective contribution of cream with TG in 66.67% of the measured parameters.

Evaluation of calcium alginate bead formation kinetics: An integrated analysis through light microscopy, rheology and microstructural SAXS.

Ca(II)-alginate beads are being produced for a broad spectrum of biotechnological uses. Despite the simplicity of their manufacturing process, in these highly complex arrangements, the final properties of the material strongly depend on the supramolecular scaffolding. Here we present a cost-effective automatized Optical Video Microscopy approach for in situ evaluation of the kinetics of alginate bead formation. With simple mathematic modeling of the acquired data, we obtained key parameters that reveal valuable information on the system: the time course of gel-front migration correlates with the plateau of the storage module, and total volume shrinkage is highly related to the stabilization of shear strain and shear stress at the yield point. Our results provide feasible and reproducible tools, which allow for a better interpretation of bead formation kinetics and a rapid screening technique to use while designing gelling materials with specific properties for technological applications.

Effect of process variables on the physicochemical and rheological properties of yogurt / Efecto de las variables de proceso sobre las propiedades fisicoquímicas y reológicas de yogur

ABSTRACT In this research, the effect of the lactic starter culture, the fermentation time, the incubation temperature and the percentage of fat on the firmness and consistency of a fermented milk drink was evaluated through physicochemical characteristics of total acidity, pH, syneresis and flow behavior. The purpose was to find the best formulation that extends the shelf life of yogurt, leading to an improvement in the manufacturing process of a local dairy company in Barrancabermeja (Santander, Colombia). Quality criteria were evaluated by means of the percentage of acidity and pH of the yogurt, as well as its syneresis and rheological parameters during a storage time of 24 hours and 7 days in refrigeration. Acceptable quality parameters were obtained for the yogurt prepared with an inoculum concentration of 2%, an incubation temperature of 40°C and an incubation time of 150 minutes. In addition, better properties of firmness and consistency were found, with absence of syneresis and viscosity in the accepted range, for this dairy product.

RESUMEN En esta investigación, se evaluó el efecto del cultivo iniciador láctico, el tiempo de fermentación, la temperatura de incubación y el porcentaje de grasa en la firmeza y consistencia de una bebida de leche fermentada, a través de las características fisicoquímicas de acidez total, pH, sinéresis y comportamiento de flujo. El propósito fue encontrar la mejor formulación que extienda la vida útil del yogur, lo que lleva a un perfeccionamiento del proceso de fabricación de una empresa local de productos lácteos en Barrancabermeja (Santander, Colombia). Se evaluaron criterios de calidad por medio del porcentaje de acidez y pH del yogurt, así como su sinéresis y parámetros reológicos, durante un tiempo de almacenamiento de 24 horas y de 7 días en refrigeración. Se obtuvieron parámetros de calidad aceptables para el yogurt, preparado con una concentración del inóculo de 2%, una temperatura de incubación de 40°C y un tiempo de incubación de 150 minutos. Además, se encontraron mejores propiedades de firmeza y de consistencia, con ausencia de sinéresis y viscosidad en el rango aceptado, para este producto lácteo.

Effect of yam (Dioscorea spp.) starch on the physicochemical, rheological, and sensory properties of yogurt.

This study investigated the effect of the addition of starch from "hawthorn" yam (Dioscorea rotundata) and "creole" yam (Dioscorea alata) at different concentrations (0.1%, 0.3%, and 0.5% w/w) on the physicochemical and sensory properties of stirred-type yogurt. Pectin (0.3% w/w) was used as a reference stabilizer. Yogurt with yam starch presented 13.38% less syneresis than yogurts with pectin. At the sensory level, the most accepted treatment was yogurt with "creole" yam starch at 0.1% w/w. During 21 days of storage, yogurt with yam starch ("creole" and "hawthorn") at 0.1% w/w showed a decrease in syneresis between 7% and 8%, while in those with pectin, syneresis remained practically constant in this period. Yogurt with yam starch was characterized as a pseudoplastic fluid, with a lactic acid bacterial count according to NTC 805. Yam starch can be used as stabilizer because it improves the physicochemical, sensory, and rheological characteristics of stirred-type yogurt. Especially the "creole" yam starch (0.1% w/w), which presents the best preference by consumers.

Bromatological characterization of a fermented yoghurt-type milk drink from whey with aloe vera crystals (Aloe barbadensis Miller) and granadilla (Passiflora ligularis Juss) / Caracterización bromatológica de una bebida láctea fermentada tipo yogur a partir de lactosuero con cristales de aloe vera (Aloe barbadensis Miller) y granadilla (Passiflora ligularis Juss)

The aim of this research was to characterize a fermented yogurt-type milk drink that was elaborated from whey with the addition of aloe vera crystals and granadilla (Passiflora ligularis Juss). Four formulations for characterization were obtained: F1 (control), F2 (5% aloe vera and 15% granadilla), F3 (10% aloe vera and 10% granadilla) and F4 (15% aloe vera and 5% granadilla). Next, a sensory evaluation through a hedonic test was conducted to choose the formulation with the highest acceptance. After the best formulation was chosen, a bromatological and syneresis characterization was performed. The F4 sample had the best results in the sensory evaluation. Compared to the F1 sample, statistically significant differences (p<0.05) in all parameters except in total carbohydrates was observed for the bromatological analysis. In the percentage of syneresis, at the end of the 15 days, F4 presented a lower value in this parameter with respect to the control sample. It could be determined that the higher percentage of aloe vera and the lower percentage of granadilla had a big influence on the parameters evaluated, where it presented the best results compared to the other samples evaluated.

El objetivo de esta investigación fue caracterizar una bebida láctea fermentada tipo yogur que se elaboró a partir de lactosuero con la adición de cristales de aloe vera y granadilla (Passiflora ligularis Juss). Se obtuvieron cuatro formulaciones para la caracterización: F1 (control), F2 (5% de aloe vera y 15% de granadilla), F3 (10% de aloe vera y 10% de granadilla) y F4 (15% de aloe vera y 5% de granadilla). A continuación, se realizó una evaluación sensorial mediante una prueba hedónica para elegir la formulación de mayor aceptación. Una vez elegida la mejor formulación, se realizó una caracterización bromatológica y de sinéresis. La muestra F4 obtuvo los mejores resultados en la evaluación sensorial. En comparación con la muestra F1, se observaron diferencias estadísticamente significativas (p<0,05) en todos los parámetros, excepto en los carbohidratos totales. En el porcentaje de sinéresis, al final de los 15 días, F4 presentó un valor inferior en este parámetro con respecto a la muestra de control. Se pudo determinar que el mayor porcentaje de aloe vera y el menor porcentaje de granadilla influyeron mucho en los parámetros evaluados, en los que presentó los mejores resultados en comparación con las otras muestras evaluadas.

Structural and sensory analysis of compositionally optimized apple jellies enriched with dietary fibre compared to commercial apple jams.

The objective of this work was to optimize the formulation of apple jellies enriched with 3 g/100 g of dietary fibre and to compare them with commercial apple jams in terms of structural and organoleptic properties. With that aim, a fibre mix with one part of psyllium and three parts of other fibre variety (apple, bamboo or wheat) was added to apple jelly, and the rheological, mechanical and sensory properties, as well as colour and syneresis (water loss) of the samples at different storage times were studied, and compared to two commercial apple jams. Those properties did not suffer significant changes during 30 days of cold storage, meaning that the product was stable. The reduction of psyllium proportion in the fibre mix (from 1:1 to 1:3) reduced the gumminess of the fibre enriched jellies, keeping the syneresis at 0 g/100 g. The jelly enriched with apple and psyllium fibre was the most similar to commercial apple jams in terms of rheological and mechanical properties. Consumers acceptability of fibre enriched jellies was higher than 72%, being the jelly enriched with bamboo and psyllium fibre the closest to a commercial apple jam, which was the consumer's favourite.

ß -glucan from saccharomyces cereviseae in skim yogurt production / ß-Glucana de Saccharomyces cereviseae na produção de iogurte desnatado

The demand for functional foods has increased in recent years, following a market trend in which the consumer values foods associated with health improvements. Skim milk yogurts were produced with yeast ß-glucan (YBG, 0.5 and 1.0 %) isolated from Saccharomyces cerevisiae and compared with full fat (FFY) and skim milk (SMY) yogurt as controls. The samples were analyzed for physical, chemical, color,syneresis, culture starter count, textural, microstructure and sensory attributes. Yeast ß-glucan was not able to retain the serum of yogurts during cold storage. Skim yogurt firmness increased with the addition of 0.5% yeast ß-glucan, presenting a more compact microstructure. Yogurts containing yeast ß-glucan had low scores by the untrained panelists in the sensorial analysis (0.5% YBG overall acceptance 5.2, FFY 6.8, SY 6.3) and low purchase intention. Thus, although similar characteristics were observed, low scores in the sensorial analysis and purchase intention were a barrier to commercializing skim milk yogurt with yeast ß-glucan developed in the present study

A demanda por produtos funcionais tem aumentado recentemente, seguindo um padrão no qual os consumidores valorizam os alimentos que são associados a melhoria da saúde. Iogurte desnatado foi produzido com ß-glucana extraída de Saccharomyces cerevisiae e comparado com iogurte integral e iogurte desnatado. O iogurte desnatado contendo ß-glucana não reteve soro durante a estocagem refrigerada. A firmeza do produto aumentou com a adição de 0,5% de ß-glucana e sua microestrutura foi mais compacta. Iogurtes contendo ß-glucana apresentaram menor escore na análise sensorial. Assim, embora características semelhantes tenham sido observadas, os baixos escores da análise sensorial são uma barreira para a comercialização de iogurte desnatado contendo ß-glucana produzido no presente estudo

Effect of Nanoparticles with Different Chemical Nature on the Stability and Rheology of Acrylamide Sodium Acrylate Copolymer/Chromium (III) Acetate Gel for Conformance Control Operations.

During enhanced oil recovery (EOR), reservoir heterogeneities and fluids distributions promote preferential flow channels formation. Therefore, different types of gels have been proposed to improve swept efficiency on chemical flooding by plugging high permeability zones. The purpose of this article is to evaluate the effect that nanotechnology has on the inhibition of syneresis and the rheological properties of the Acrylamide Sodium Acrylate Copolymer/Chromium (III) Acetate gel system for conformance applications in mature reservoirs. Thus, a methodology is proposed in four stages: First, (I) nanoparticles synthesis, and characterization, followed by (II) bottle tests to monitor gelation kinetics and syneresis degree at 70 °C, then (III) description of the rheological evaluation on static and dynamic conditions to calculate gelation time and viscoelastic modulus (G' and G"), and finally (IV) the displacement test with the best gel system in the presence of nanoparticles. Results showed that the best nanoparticle was the chromium oxide (Cr2O3), which represented the lesser syneresis degree and increased gelation time. Syneresis of gel samples in the presence of Cr2O3 at day 30 was under 1% for gels prepared with 4000, 6000, and 8000 mg·L-1 of polymer, and polymer to crosslinker ratio (p/c) of 40:1. Regarding SiO2, MgO, and Al2O3 nanoparticles, results show an improvement of gel strength. However, their thermal stability in terms of syneresis was lower. Displacement test in a triple parallel Slim Tube was able to recover an additional 37% of oil of the total oil present in the sandpacks, confirming the effectivity of the system when 100 mg·L-1 of Cr2O3 nanoparticles are included.

Syneresis in Gels of Highly Ferulated Arabinoxylans: Characterization of Covalent Cross-Linking, Rheology, and Microstructure.

Arabinoxylans (AXs) with high ferulic acid (FA) content (7.18 µg/mg AXs) were cross-linked using laccase. Storage (G') modulus of AX solutions at 1% (AX-1) and 2% (AX-2) (w/v) registered maximum values of 409 Pa and 889 Pa at 180 min and 83 min, respectively. Atomic force microscopy revealed the grained and irregular surface of the AX-1 gel and the smoother surface without significant depressions of the AX-2 gel. Cured AX gels exhibited a liquid phase surrounding the samples indicating syneresis. The syneresis ratio percentage (% Rs) of the gels was registered over time reaching stabilization at 20 h. The % Rs was not significantly different between AX-1 (60.0%) and AX-2 (62.8%) gels. After 20 h of syneresis development, the dimers of the FA in the AX-1 and AX-2 gels significantly increased by 9% and 78%, respectively; moreover, the trimers of the FA in the AX-1 and AX-2 gels, by 94% and 300%, respectively. Scanning electron microscopy showed that, after syneresis stabilization, AX gels presented a more compact microstructure. Syneresis development in the gels of highly ferulated AXs could be related to the polymer network contraction due to the additional formation of dimers and trimers of the FA (cross-linking structures), which may act like a "zipping" process, increasing the polymer chains' connectivity.

Caracterização do amido extraído das raízes da Cissus simsiana Roem. & Schult / Characterization of starch extracted from the roots of Cissus simsiana Roem. & Schult

O objetivo do presente estudo foi estudar a caracterização do amido extraído das raízes da Cissus simsiana Roem. & Schult. A extração do amido foi por via úmida e por decantação, calculando-se seu rendimento. Do amido isolado foram estudados sua composição química, morfologia e distribuição de tamanho dos grânulos, difração de raios-X, espectros no infravermelho médio, poder de inchamento e solubilidade, propriedades de pasta e térmicas, claridade e sinerese. O rendimento de amido, com base na presença de amido na raiz, que pode ser isolado, foi de 13,68% com 3,12 10-3 mg/g de carotenóides. Os grânulos de amido são predominantemente elipsoidais com 50-60 mm de comprimento e 20-30 mm de largura. Exibiram padrão de difração de raios-X tipo B, com 41,2% de cristalinidade, teor de amilose aparente de 26,2% e espectros de infravermelho médio semelhante de outros amidos de raízes. As temperaturas de pico de gelatinização inicial e final foram 64,2 e 68,56C, respectivamente, e a entalpia de gelatinização foi de 19,2 J/g. O perfil de viscosidade aparente foi semelhante àquele do amido de mandioca, porém, com maior pico de viscosidade (6500 cP), menor tendência à retrogradação (600 cP) e com géis menos claros mostrando sinerese. Cissus simsiana raízes tem uso potencial para a produção de amido e há espaço para aumentar o seu rendimento. Cissus simsiana amidos tem um grânulo de tamanho médio de fécula de batata com clara tipo B padrão de difração de raios-X, típico de tubérculos com arranjo de cadeias moleculares diferentes de amidos de cereais. Cissus simsiana amidos tinham temperaturas e entalpias de gelatinização semelhantes a mandioca e outros amidos isolados a partir de fontes não-convencionais, que podem ser interessantes para a possível utilização como uma alternativa tecnológica em algumas aplicações industriais.(AU)

The aim of this study was to investigate the characterization of starch from Cissus simsiana Roem. & Schult. roots. The starch was extracted by steeping, wet grinding and sedimentation processes and its yield was calculated. Isolated starch was then characterized for chemical composition, morphology and granules size distribution, X-ray diffraction, mid-infrared spectra, swelling powder and solubility, pasting and thermal properties and clarity and syneresis behavior. The starch yield, based on starch presence in the root that can be isolated, were between 13.68% with 3.12 10-3 mg/g of carotenoids. C. simsiana granules were predominantly ellipsoids with 50-60 mm length and 20-30 mm wide. They exhibited B-type X-ray diffraction pattern with 41.2% of crystallinity, apparent amylose content of 26.2% and presented similar mid-infrared spectra to other starches. Onset and peak gelatinization temperatures were 64.2 and 68.56C, respectively, and gelatinization enthalpy was 19.2 J/g. The apparent viscosity profile was comparable to cassava starch, but with higher peak viscosity (6500 cP), lower set back viscosity (600 cP) and less clear gel showing syneresis.(AU)

Caracterização do amido extraído das raízes da Cissus simsiana Roem. & Schult / Characterization of starch extracted from the roots of Cissus simsiana Roem. & Schult

O objetivo do presente estudo foi estudar a caracterização do amido extraído das raízes da Cissus simsiana Roem. & Schult. A extração do amido foi por via úmida e por decantação, calculando-se seu rendimento. Do amido isolado foram estudados sua composição química, morfologia e distribuição de tamanho dos grânulos, difração de raios-X, espectros no infravermelho médio, poder de inchamento e solubilidade, propriedades de pasta e térmicas, claridade e sinerese. O rendimento de amido, com base na presença de amido na raiz, que pode ser isolado, foi de 13,68% com 3,12 10-3 mg/g de carotenóides. Os grânulos de amido são predominantemente elipsoidais com 50-60 mm de comprimento e 20-30 mm de largura. Exibiram padrão de difração de raios-X tipo B, com 41,2% de cristalinidade, teor de amilose aparente de 26,2% e espectros de infravermelho médio semelhante de outros amidos de raízes. As temperaturas de pico de gelatinização inicial e final foram 64,2 e 68,56C, respectivamente, e a entalpia de gelatinização foi de 19,2 J/g. O perfil de viscosidade aparente foi semelhante àquele do amido de mandioca, porém, com maior pico de viscosidade (6500 cP), menor tendência à retrogradação (600 cP) e com géis menos claros mostrando sinerese. Cissus simsiana raízes tem uso potencial para a produção de amido e há espaço para aumentar o seu rendimento. Cissus simsiana amidos tem um grânulo de tamanho médio de fécula de batata com clara tipo B padrão de difração de raios-X, típico de tubérculos com arranjo de cadeias moleculares diferentes de amidos de cereais. Cissus simsiana amidos tinham temperaturas e entalpias de gelatinização semelhantes a mandioca e outros amidos isolados a partir de fontes não-convencionais, que podem ser interessantes para a possível utilização como uma alternativa tecnológica em algumas aplicações industriais.

The aim of this study was to investigate the characterization of starch from Cissus simsiana Roem. & Schult. roots. The starch was extracted by steeping, wet grinding and sedimentation processes and its yield was calculated. Isolated starch was then characterized for chemical composition, morphology and granules size distribution, X-ray diffraction, mid-infrared spectra, swelling powder and solubility, pasting and thermal properties and clarity and syneresis behavior. The starch yield, based on starch presence in the root that can be isolated, were between 13.68% with 3.12 10-3 mg/g of carotenoids. C. simsiana granules were predominantly ellipsoids with 50-60 mm length and 20-30 mm wide. They exhibited B-type X-ray diffraction pattern with 41.2% of crystallinity, apparent amylose content of 26.2% and presented similar mid-infrared spectra to other starches. Onset and peak gelatinization temperatures were 64.2 and 68.56C, respectively, and gelatinization enthalpy was 19.2 J/g. The apparent viscosity profile was comparable to cassava starch, but with higher peak viscosity (6500 cP), lower set back viscosity (600 cP) and less clear gel showing syneresis.

Avaliação das características físicas de presuntos cozidos comercializados em Chapecó, SC / Evaluation physical characteristics of cooked hams commercialized in Chapeco, SC

o presunto é um produto nobre, de valor agregado e apreciado pelo seu sabor e textura sendo muito consumido principalmente pelas classes de maior poder aquisitivo. As características físicas do produto apresentam relação entre si e influenciam nos atributos de suculência, maciez, cor e sabor final do presunto. O pH e a capacidade de retenção de água (CRA) estão relacionados com as perdas do produto. Neste trabalho avaliaram-se as características físicas de duas marcas de presuntos cozidos comercializados no município de Chapecó (SC). Não houve diferenças significativas (p>O,05) para pH, sinerese, CRA e para perdas por resfriamento. Os resultados de atividade de água (Aw), cor instrumental L *, a * e b * (antes e após a oxidação) e as perdas por congelamento e reaquecimento apresentaram diferença significativa entre si (p < O,05). A amostra A apresentou os melhores resultados para a maioria das propriedades físicas avaliadas. Essas diferenças podem influenciar na escolha do produto pelo consumidor ou ainda interferir na qualidade de pratos prontos (como pizzas ou lasanhas) que utilizam presunto como matéria-prima ou ingrediente. (AU)

The ham is a nob/e product, value added and appreciated for its taste and texture is very consumed mainly by the more affluent classes. The physical characteristics of the product show the relationship between themselves and influence the attributes of juiciness, tenderness, flavor and color the end of the ham. The pH and water holding capacity (WHC) are related to the loss of the product. In this work we evaluated the physical characteristics of two brands of cooked ham marketed in Chapecó (SC). There were no significant differences (p>O.05) for pH, synerisis, CRA and cooling fosses. The results of water activity (Aw), instrumental color L * , a * and b * (before and afire oxidation) and losses due to freezingand reheating showed a significant difference between groups (p < O.05). The sample A presented better results for most of the physical properties. These differences may influence the choice of the product by consumers or interfere with the quality of prepared foods (like pizza or lasagna) using ham as raw material or ingredient. (AU)

Technological functional properties of soy, oat and wheat fibers and soy products with added fibers and fermented with kefir culture / Propriedades funcionais tecnológicas das fibras de soja, aveia e trigo e produtos de soja com adição de fibras e fermentados com cultura de kefir

The objective of this study was to characterize the technological functional properties of soy, oats and wheat fibers and evaluate soy products with added fiber and fermented with kefir. The fibers were characterized with regard to pH, water adsorption capacity, water and oil absorption capacity and swelling volume. Soy products were developed with the addition of 3% soy fiber, oat and wheat and fermented with kefir. The fermented products were characterized for pH, acidity, syneresis, viscosity and firmness, Lactococcus lactis counts and analysis of sanitary conditions. The soy fiber showed a higher content of protein and lipids, pH, water adsorption and adsorption capacity. The wheat fiber showed a higher oil absorption capacity. The addition of soy, oat and wheat fibers influence pH, acidity, syneresis, viscosity and firmness of fermented soy products with kefir. The lowest syneresis and highest viscosity and firmness were obtained with the soy fermented products with soy fiber. The addition of soy fiber stimulated Lactococcus lactis growth. The fermented soy products had enough Lactococcus lactis counts to be considered probiotics. The products presented satisfactory hygienic sanitary conditions.

O objetivo deste trabalho foi caracterizar as propriedades funcionais tecnológicas das fibras de soja, aveia e trigo e avaliar os produtos de soja com adição de fibras e fermentados com cultura de kefir. As fibras foram caracterizadas quanto a composição química, pH, capacidade de adsorção e absorção de água, capacidade de absorção de óleo e volume de intumescimento. Foram desenvolvidos produtos de soja com adição de 3% de fibra de soja, aveia e trigo e fermentados com cultura de kefir. Os produtos fermentados foram caracterizados quanto o pH, acidez, sinerese, viscosidade e firmeza, contagem de Lactococcus lactis e análise das condições higiênico-sanitárias. A fibra de soja apresentou maior teor de proteínas e lipídios, pH, capacidade de adsorção e adsorção de água. A fibra de trigo apresentou maior capacidade de absorção de óleo. A adição de fibras de soja, aveia e trigo influenciaram o pH, acidez, sinerese, viscosidade e firmeza dos produtos de soja fermentados com kefir. A menor sinerese e maior viscosidade e firmeza foram obtidos para os produtos fermentados com fibra de soja. O crescimento de Lactococcus lactis foi favorecido no produto fermentado com adição de fibra de soja. Por conterem suficiente contagem, ou seja, acima de 6 log UFC.g-1 de Lactococcus lactis, os produtos fermentados podem ser considerados probióticos. Os produtos apresentaram condições higiênico-sanit

Technological functional properties of soy, oat and wheat fibers and soy products with added fibers and fermented with kefir culture / Propriedades funcionais tecnológicas das fibras de soja, aveia e trigo e produtos de soja com adição de fibras e fermentados com cultura de kefir

The objective of this study was to characterize the technological functional properties of soy, oats and wheat fibers and evaluate soy products with added fiber and fermented with kefir. The fibers were characterized with regard to pH, water adsorption capacity, water and oil absorption capacity and swelling volume. Soy products were developed with the addition of 3% soy fiber, oat and wheat and fermented with kefir. The fermented products were characterized for pH, acidity, syneresis, viscosity and firmness, Lactococcus lactis counts and analysis of sanitary conditions. The soy fiber showed a higher content of protein and lipids, pH, water adsorption and adsorption capacity. The wheat fiber showed a higher oil absorption capacity. The addition of soy, oat and wheat fibers influence pH, acidity, syneresis, viscosity and firmness of fermented soy products with kefir. The lowest syneresis and highest viscosity and firmness were obtained with the soy fermented products with soy fiber. The addition of soy fiber stimulated Lactococcus lactis growth. The fermented soy products had enough Lactococcus lactis counts to be considered probiotics. The products presented satisfactory hygienic sanitary conditions.

O objetivo deste trabalho foi caracterizar as propriedades funcionais tecnológicas das fibras de soja, aveia e trigo e avaliar os produtos de soja com adição de fibras e fermentados com cultura de kefir. As fibras foram caracterizadas quanto a composição química, pH, capacidade de adsorção e absorção de água, capacidade de absorção de óleo e volume de intumescimento. Foram desenvolvidos produtos de soja com adição de 3% de fibra de soja, aveia e trigo e fermentados com cultura de kefir. Os produtos fermentados foram caracterizados quanto o pH, acidez, sinerese, viscosidade e firmeza, contagem de Lactococcus lactis e análise das condições higiênico-sanitárias. A fibra de soja apresentou maior teor de proteínas e lipídios, pH, capacidade de adsorção e adsorção de água. A fibra de trigo apresentou maior capacidade de absorção de óleo. A adição de fibras de soja, aveia e trigo influenciaram o pH, acidez, sinerese, viscosidade e firmeza dos produtos de soja fermentados com kefir. A menor sinerese e maior viscosidade e firmeza foram obtidos para os produtos fermentados com fibra de soja. O crescimento de Lactococcus lactis foi favorecido no produto fermentado com adição de fibra de soja. Por conterem suficiente contagem, ou seja, acima de 6 log UFC.g-1 de Lactococcus lactis, os produtos fermentados podem ser considerados probióticos. Os produtos apresentaram condições higiênico-sanit

Modificación fíiica del almidón de yuca y evalución de la susceptibilidad a laa hidrólisis enzimática por una alfa miilasa / Physial modificaation of cassava starh and evaluation of susceptibillity to enzyme hydrolysis by alpha amylase / Modificção físicca do amido de mandiocay avaliação do susceptibilidadee à hidrólise enzimática com uma alfa mmilase

Almidón de yuca comercial (variedad MTAI8) se sometió a modificación física por sinéresis, extrusión, gelatinización y secado por rodillos. Al almidón nativo y a los almidones modificados se les determinó su morfología, cristalinidad, distribución molecular y susceptibilidad a la hidrólisis enzimática con una alfa amilasa porcina pancreática. En los almidones modificados físicamente se incrementó el grado de hidrólisis, en comparación con el almidón nativo. Sin embargo no se observaron diferencias estadísticamente significativas en el grado de hidrólisis entre los almidones modificados. El patrón de difracción de rayos X tipo A, presentado por el almidón de yuca nativo y su propiedad birrefringente se alteraron por los pretratamientos, presentándose difractogramas de estructuras amorfas y pérdida de la cruz de malta en los almidones modificados. La microscopía electrónica de barrido (MEB) demostró alteración en la apariencia y estructura del gránulo nativo, dando lugar a partículas de formas irregulares con superficies fragmentadas y rugosas como resultado del proceso de modificación. La cromatografía de exclusión sobre sepharosa 6B confirmó la desaparición de la fracción de alto peso molecular presente en el almidón nativo, con el consecuente incremento de las fracciones de bajo peso molecular en los almidones modificados.

Cassava starch (MTAI 8 variety) was subjected to syneresis, gelatinization, extrusion and processing by drum dryers. The morphology, crystallinity, molecular weight distribution and susceptibility to enzyme hydrolysis by porcine pancreatic a-amylase were determined before and after the physical treatments. The physically modified starches increased the extent of a-amylolysis, compared to the native one. However, there were not significant differences in the degree of amylolisis between the treatments during the procedure. Both the X-ray pattern type-A, presentedinthecassavastarch, and its birrefringent property, observed in polarized light, were altered by the treatments causing amorphous structures and the loss of the Maltese cross. When the modified starches were observed n scann ng electron micrographs (SEM), an alteration in the appearance and structure of the native granule was shown, where particles with irregular shape and fragmented and wrinkled surfaces could be seen as a result of the modification process. The profile of the size exclusion chromatography on sepharose 6B showed two characteristic fractions of high and low molecular weight in the native starch, while in modified starches only one peak was obtained showing low molecular weight. The data showed that the treatments modified the physical structure of the starch granule, allowing more accessibility for the enzyme to the amorphous and crystalline regions of starch.

Amido de mandioca comercial (variedade MTAI 8) foi submetido a modificação física por sinérese, extrusão, gelatinização e secado por tambor. Foram determinados para o amido nativo e os amidos modificados a sua morfologia, cristalinidade, distribuição molecular y susceptibilidade à hidrólise enzimática com uma alfa amilase porcina pancreática. Nos amidos modificados fisicamente foi verificado um aumento do nível de hidrólise, em comparação com o amido nativo. Porém, não se observaram diferenças estatisticamente significativas no nível de hidrólise entre os almidões modificados. O padrão de difracção de raios-X tipo A apresentado pelo amido de mandioca nativo e a sua propriedade birrefringente, foram alterados pelos prétratamentos, apresentando-se difractogramas de estruturas amorfas y perda da cruz de malta nos almidões modificados. A microscopia electrónica de barrido (MEB) demonstrou alteração na aparência e estrutura do granulo nativo, dando lugar a partículas de formas irregulares com superfícies fragmentadas e rugosas como resultado do processo de modificação. A cromatografia de exclusão sobre sepharosa 6B corroborou a desaparição da fracção de alto peso molecular presente no amido nativo, com o consequente aumento das fracções de baixo peso molecular nos almidões modificados.