Oxidative stability of baby dehydrated purees formulated with different oils and germinated grain flours of quinoa and amaranth

Fat oxidative stability (OS) is an important food parameter because it causes sensory deterioration and rejection. The aim of this work was to evaluate the OS of the lipid fraction of baby dehydrated purees. Purees (6) were formulated with Andean potato, pumpkin, non-germinated and germinated quinoa and amaranth flours, and different oils: soybean-sunflower (SSO), canola (CO) and sunflower-chia (SChO). Purees were dehydrated by forced air circulation oven. The fat from the purees and the grain flours was extracted by Soxhlet method. Lipid profile, tocopherol contents and OS were analyzed in oils and lipid fractions. Changes of free fatty acids (FFA) during germination were studied. Tertiary-butyl hydroquinone (TBHQ) was determined in the oils used in formulations. During germination, FFA increased in both grains; tocopherols decreased in quinoa and increased in amaranth. Purees with germinated grain flours had lower OS than those made with non-germinated grain flours. SSO had the best OS due to the high content of TBHQ. However, purees made with SSO had OS like those formulated with CO. Purees with SChO had the lowest OS due to its great ω3 content and low antioxidant contents. Germinated grain flours and CO were the best ingredients to formulate baby purees.Fil: Jimenez, María Dolores. Universidad Nacional de Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta-Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa; ArgentinaFil: Lobo, Manuel Oscar. Universidad Nacional de Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta-Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa; ArgentinaFil: Irigaray, Bruno. Universidad de la Republica; UruguayFil: Grompone, María Antonia. Universidad de la República; UruguayFil: Samman, Norma Cristina. Universidad Nacional de Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta-Jujuy. Centro Interdisciplinario de Investigaciones en Tecnologías y Desarrollo Social para el Noa; Argentin

Determinación del contenido de antioxidantes naturales en frutos secos

Los frutos secos contienen un alto contenido de ácido oleico y/o ácidos poliinsaturados, por lo que su ingesta reduce los niveles de colesterol total y colesterol LDL en sangre, lo que se asocia a una menor incidencia de enfermedades cardiovasculares. A su vez, los frutos secos podrían tener efectos beneficiosos en la salud humana debido a la presencia de antioxidantes (polifenoles y tocoferoles). En el presente trabajo se determinó el contenido de lípidos, el perfil en ácidos grasos y el contenido de polifenoles y tocoferoles de algunos frutos secos: nueces, nueces pecan, avellanas, almendras, maní, pistachos y castañas de cajú. Se optimizó la extracción de los polifenoles en avellanas mediante la utilización de diferentes mezclas de solventes y distintas condiciones de temperatura y tiempos de extracción. Con la mezcla agua/acetona (80:20) a 25 ºC, durante 24 horas, se obtuvo el mayor contenido de polifenoles. El contenido de polifenoles de los extractos obtenidos de los frutos secos presentó valores en el rango entre 427 ppm (almendras) y 8805 ppm (nueces), mientras que el contenido de tocoferoles, entre 160 ppm (castañas de cajú) y 358 ppm (nueces). Se concluye que los frutos secos analizados poseen contenidos importantes de antioxidantes, pero en cantidades diferentes. Además, la cáscara ofrece una barrera para enlentecer los procesos de oxidación del aceite presente en el fruto

Efeito do período de armazenamento dos oleogeles comuns de óleo de girassol no seu comportamento térmico e deterioração oxidativa

Oleogels are particularly important as they can be used as a replacement for fatty materials for food use, although their use is conditioned by their shelf life. In this context, thermal properties of sunflower oil (AG) oleogels with beeswax (CA) and carnauba wax (CC) as structurants at different concentrations were studied by differential scanning calorimetry, and their oxidative deterioration at room temperature as a function of storage time. According to oleogels melting thermograms, the increase of the structurant concentration caused an increase in the peak temperatures. The ranges associated with the destructuring temperature were between 26.3 and 60.8 °C and 35.9 and 86.1 °C while the corresponding enthalpies ranged from 1.5 to 6.5 J/g and 3.3 to 13.3 J/g for CA and CC, respectively. The results for oxidative deterioration were higher for the CC oleogels. This indicates that CA oleogels have a higher resistance to oxidation and thus higher oxidative stability. In conclusion, the oleogels studied could only be used in foods with a shelf life of less than 6 months.Los oleogeles son especialmente importantes ya que pueden ser empleados como reemplazo de materiales grasos para uso alimentario, aunque su utilización queda condicionada por su vida útil. En este marco, se estudiaron las propiedades térmicas de los oleogeles de aceite de girasol común (AG) con ceras de abeja (CA) y de carnauba (CC) como estructurantes, a distintas concentraciones, por calorimetría diferencial de barrido, y el deterioro oxidativo a temperatura ambiente en función del tiempo de almacenamiento. De acuerdo con los termogramas de fusión de los oleogeles, el aumento de la concentración de estructurante provocó un incremento en las temperaturas de pico. Los rangos asociados a la temperatura de desestructuración variaron entre 26.3 y 60.8 °C, y, 35.9 y 86.1 °C, mientras que las entalpías correspondientes variaron desde 1.5 a 6.5 J/g y 3.3 a 13.3 J/g para las ceras CA y CC, respectivamente. Los resultados de los parámetros asociados al deterioro oxidativo de los oleogeles con CC fueron los más elevados. Ello indica que los oleogeles con CA tienen una mayor resistencia a la oxidación y, por ende, mayor estabilidad oxidativa. En conclusión, los oleogeles estudiados solo podrían ser utilizados en alimentos con una vida útil menor a 6 meses.Os oleogeles são particularmente importantes porque podem ser utilizados como substitutos de materiais gordos para uso alimentar, embora a sua utilização esteja condicionada pelo seu prazo de validade. Neste contexto, as propriedades térmicas dos oleogeles de óleo de girassol (AG) com cera de abelha (CA) e cera de carnaúba (CC) como estruturantes em diferentes concentrações foram estudadas por calorimetria diferencial de varrimento, e a sua deterioração oxidativa à temperatura ambiente (20 °C) em função do tempo de armazenamento. De acordo com os termogramas de fusão dos oleogeles, o aumento da concentração estruturante provocou um aumento das temperaturas de pico. Os intervalos associados à temperatura de desestruturação situavam-se entre 26,3 e 60,8 °C, e, 35,9 e 86,1 °C enquanto as entalpias correspondentes variaram de 1,5 a 6,5 J/g e 3,3 a 13,3 J/g para CA e CC, respectivamente. Os resultados para a deterioração oxidativa foram mais elevados para os oleogeles CC. Isto indica que os oleogeles CA têm uma maior resistência à oxidação e, portanto, uma maior estabilidade oxidativa. Em conclusão, os oleogeles formados só poderiam ser utilizados em alimentos com prazo de validade inferior a 6 meses

Determinação do conteúdo de antioxidantes naturais em frutos secos

Nuts contain a high content of oleic acid and/or polyunsaturated acids, so their intake reduces the level of total cholesterol and LDL cholesterol in the blood, which is associated with a lower incidence of cardiovascular diseases. Besides, nuts have beneficial effects on human health due to the presence of antioxidants (polyphenols and tocopherols). In this study, lipid content, fatty acid profile and polyphenols and tocopherols content of some nuts were determined: walnuts, pecans, hazelnuts, almonds, peanuts, pistachios and cashews. The extraction of polyphenols in hazelnuts was optimized by using different mixtures of solvents as well as several conditions of temperature and extraction times. The mixture water/acetone (80:20) at 25 °C during 24 hours showed the highest content of polyphenols. The polyphenol content of the extracts obtained from the nuts showed values in the range between 427 ppm (almonds) and 8805 ppm (walnuts), while the content of tocopherols, ranges between 160 ppm (cashews) and 358 ppm (walnuts). Thus, the analyzed nuts have important antioxidant contents but in different amounts. Furthermore, the nutshell offers a barrier to slow down the oxidation processes of the oil present in the product.Los frutos secos contienen un alto contenido de ácido oleico y/o ácidos poli-insaturados, por lo que su ingesta reduce los niveles de colesterol total y colesterol LDL en sangre, lo que se asocia a una menor incidencia de enfermedades cardiovasculares. A su vez, los frutos secos han demostrado tener efectos beneficiosos en la salud humana debido a la presencia de antioxidantes (polifenoles y tocoferoles). En el presente trabajo se determinó el contenido de lípidos, el perfil en ácidos grasos y el contenido polifenoles y tocoferoles de algunos frutos secos: nueces, nueces pecan, avellanas, almendras, maní, pistachos y castañas de cajú. Se optimizó la extracción de los polifenoles en avellanas mediante la utilización de diferentes mezclas de solventes y distintas condiciones de temperatura y tiempos de extracción. Con la mezcla agua/acetona (80:20) a 25ºC, durante 24 horas, se obtuvo el mayor contenido de polifenoles. El contenido de polifenoles de los extractos obtenidos de los frutos secos presentó valores en el rango entre 427 ppm (almendras) y 8805 ppm (nueces), mientras que el contenido de tocoferoles, entre 160 ppm (castañas de cajú) y 358 ppm (nueces). Se concluye que los frutos secos analizados poseen contenidos importantes de antioxidantes, pero en cantidades diferentes. Además, la cáscara ofrece una barrera para enlentecer los procesos de oxidación del aceite presente en el fruto.Os frutos secos possuem alto teor de ácido oleico e/ou ácidos poliinsaturados, razão pela qual sua ingestão reduz os níveis de colesterol total e LDL no sangue, que está associado à menor incidência de doenças cardiovasculares. Além disso, os frutos secos apresentam efeitos benéficos à saúde humana devido à presença de antioxidantes (polifenóis e tocoferóis). No presente trabalho, foram determinados o teor de lipídios, o perfil de ácidos graxos e o teor de polifenóis e tocoferóis de alguns frutos secos: nozes, noz-pecã, avelã, amêndoa, amendoim, pistache e castanha de caju. A extração dos polifenóis nas avelãs foi otimizada pelo uso de diferentes misturas de solventes em diferentes condições de temperatura e tempos de extração. Com a mistura água/acetona (80:20) a 25 °C por 24 horas, obteve-se o maior teor de polifenóis. O teor de polifenóis dos extratos obtidos dos frutos secos apresentou valores na faixa de 427 ppm (amêndoas) a 8805 ppm (nozes), enquanto o teor de tocoferol, entre 160 ppm (castanha de caju) e 358 ppm (nozes). Consequentemente, os frutos secos analisados têm um conteúdo antioxidante significativo, mas em quantidades diferentes. Além disso, a casca oferece uma barreira para retardar os processos de oxidação do óleo presente

Estudo cinético da cristalização de misturas graxas com adição de fitoesteróis por calorimetria diferencial de varredura (DSC)

The aim of the work was to study the kinetic parameters of the isothermal crystallization of fat blends at different temperatures by differential scanning calorimetry (DSC). The fat blends are composed of fully hydrogenated rice bran oil (FHRBO) and soybean oil (SBO) at different proportions (20, 25, 30, 30, 35 and 40 % FHRBO), being both materials previously purified. In addition, some blends were selected and added a known amount of phytosterols. Kinetic parameters were quantified by applying the Avrami model that determines the induction time (generation of crystal nuclei, ti), nucleation mechanism (Avrami exponent, n) and crystal growth (kinetic constant, k). It was observed that higher percentage of FHRBO and lower crystallization temperature ti decrease and k increase. The faster kinetics observed is due to the contribution of tri-saturated triglycerides and a higher degree of supercooling. In the blend with 35 % of FHRBO, the addition of phytosterols at the concentrations studied promoted an increase in ti and a reduction in k, prolonging nucleation and generating a slow crystal growth. However, for the blend with 20% of FHRBO an increase in ti and k was observed.El objetivo de este trabajo fue el estudio de los parámetros cinéticos de la cristalización isotérmica de fases grasas a distintas temperaturas mediante calorimetría diferencial de barrido (DSC, por su sigla en inglés). Las fases grasas consistieron en mezclas de aceite de salvado de arroz completamente hidrogenado (FHRBO) y aceite de soja (SBO) en diferentes proporciones (20, 25, 30, 35 y 40 % de FHRBO), siendo ambos materiales previamente purificados. Además, se seleccionaron algunas de las mezclas y se les adicionó una cantidad conocida de fitoesteroles. Los parámetros cinéticos fueron obtenidos aplicando el modelo de Avrami, el cual determina el tiempo de inducción (generación de núcleos cristalinos, ti), el mecanismo de nucleación (exponente de Avrami, n) y el grado de crecimiento cristalino (constante cinética de velocidad, k). Se observó que a mayor contenido de FHRBO y menor temperatura de cristalización, ti se reduce y k aumenta, llevando a una cinética más rápida, lo cual era esperable por el aporte de triglicéridos tri-saturados y un mayor grado de sobreenfriamiento. En la mezcla con 35 % de FHRBO, el agregado de fitoesteroles enlenteció la cinética (aumento de ti y reducción de k); sin embargo, en la de 20 % de FHRBO aumentó tanto ti como k.O objetivo deste trabalho foi estudar os parâmetros cinéticos da cristalização isotérmica de misturas graxas em diferentes temperaturas por calorimetria diferencial de varredura (DSC). As misturas graxas consistiam em óleo de farelo de arroz totalmente hidrogenado (FHRBO) e óleo de soja (SBO) em diferentes proporções (20, 25, 30, 30, 35 e 40 % FHRBO), sendo ambos os materiais previamente purificados. Além disso, algumas das misturas foram selecionadas e uma quantidade conhecida de fitoesteróis foi adicionada a elas. Os parâmetros cinéticos foram quantificados pela aplicação do modelo de Avrami que determina o tempo de indução (geração de núcleos cristalinos, ti), o mecanismo de nucleação (expoente de Avrami, n) e o grau de crescimento do cristal (constante cinética, k). Observou-se que quanto maior e a proporçõe de FHRBO e menor a temperatura de cristalização ti diminui e k aumenta, levando a uma cinética mais rápida, o que é consistente com a contribuição de triglicerois tri-saturados e maior grau de super-resfriamento. Na mistura com 35 % de FHRBO, a adição de fitoesteróis promoveu um aumento de ti e redução de k, prolongando a nucleação e retardando o crescimento dos cristais. Por outro lado, na mistura com 20% de FHRBO observou-se aumento de ti e k

‘Not a country at all’: landscape and Wuthering Heights

This article explores the issue of women’s representational genealogies through an analysis of Andrea Arnold’s 2011 Wuthering Heights. Beginning with 1970s feminist arguments for a specifically female literary tradition, it argues that running through both these early attempts to construct an alternative female literary tradition and later work in feminist philosophy, cultural geography and film history is a concern with questions of ‘alternative landscapes’: of how to represent, and how to encounter, space differently. Adopting Mary Jacobus’ notion of intertextual ‘correspondence’ between women’s texts, and taking Arnold’s film as its case study, it seeks to trace some of the intertextual movements – the reframings, deframings and spatial reorderings – that link Andrea Arnold’s film to Emily Brontë’s original novel. Focusing on two elements of her treatment of landscape – her use of ‘unframed’ landscape and her focus on visceral textural detail – it points to correspondences in other women’s writing, photography and film-making. It argues that these intensely tactile close-up sequences which puncture an apparently realist narrative constitute an insistent presence beneath, or within, the ordered framing which is our more usual mode of viewing landscape. As the novel Wuthering Heights is unmade in Arnold’s adaptation and its framings ruptured, it is through this disturbance of hierarchies of time, space and landscape that we can trace the correspondences of an alternative genealogy

Effect of vacuum thermoxidation on sunflower oil

In recent years vacuum frying was developed as an alternative methodology to traditional frying.In this study, sunflower oil thermoxidation was evaluated using conventional process conditions (180 °C and atmospheric pressure) and vacuum technology conditions (130 °C and 0,1 bar). Traditional thermoxidation lasted 20 h while vaccum thermoxidation was completed after 56 h.Total polar compounds reached 23 and 7,1 % at the end of atmospheric and vacuum thermoxidation respectively, while polymers content was 9,3 and 2,2 % for each oil.Tocopherols contents decreased 45 % for atmospheric thermoxidized oil and were reduced to 17 % for vacuum thermoxidized oil.These results clearly proved vacuum thermoxidation achieved a significantly lower deterioration rate than atmospheric thermoxidation of sunflower oil, conferring it much longer useful life and better nutritional qualities. Accordingly, a singnificantly slower vanishing rate of tocopherols was observed in vacuum thermoxidation

Análise ambiental urbana com o uso de imagens Google Earth

This paper aims to analyze satellite images in order to identify changes in the geographical space. Considering images of 1979 (topographic map) and 2010 (Google Earth/Geo Eyes) that enabled to follow multitemporal aspects such as urban environment, hydrography and ciliary wood areas in the city of Rosário do Sul. This work objectifies to distinguish the different environments that suffered shifts over time, interpreting the areas that have suffered environmental impacts around the river Ibicuí and Santa Maria, making use of ArcGIS and Envi Geoprocessing applications. With the result of images overlapping through the Arcgis application obtained a detailed mapping of the area, which emphasized the evolution of fragmentation that occurred in the city. At analyzing the image regarding the city of Rosario do Sul, we realized an increase in the urban area. One notable consequence of the urban area growth was the decrease of forest around the city. Lastly, rivers aggradation was visualized, which, besides being a natural process, it can be accelerated by anthropic action. Thus, it was developed a map, through specific techniques, in which emphasized the existing differences between the forest, hydrography and the urban area of Rosario do Sul in the period between 1979 and 2010. Palavras-chave: satellite images; geographical changes; ArcGis\uae; Google earth, imagens de satélite; alterações geográficas; arcGis\uae; google earth.Pages: 3805-381