1,485 research outputs found

    Used food oils: physical-chemical indicators of quality degradation

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    Comunicação apresentada em 11th Baltic Conference on Food Science and Technology “Food science and technology in achanging world” FOODBALT 2017 Conference Proceedings. Jelgava, LLUUsed food oil (UFO), designated as frying oil, is a residue. Degradation by reuse or during storage, may occur by contacting, chemical, enzymatic and microbiological pathways, but oxidation is a major concern of the industry, as it affects sensory and nutritional quality of edible oils, with potentially toxic compounds formation. In Portugal, UFO's main destination still is the sewerage system, an environmental problem and waste of raw material, which can be re-qualified for non-food uses. However, quality control applied to UFO's, often results into expensive analysis inappropriate for small laboratories and catering industry. This project, developed with the Musketeers Group Portugal co-promotion (2012-2016), aimed to identify low-cost physicochemical parameters for further implementation as UFO's Quality Degradation Indicators (QDI) indicating defects quickly and accurately. UFO's analysis was tested on the use, for industrial frying, and by degradation induced in the laboratory (frying and heat stability tests) by applying following parameters: moisture, water activity (a(w)), total acidity, peroxide index, iodine index, colour (CIE, CIE Lab), UV absorbency, total polar compounds and microbiological indicators. Internal procedures (ESAS) were validated, redefining working ranges and test conditions, as standards procedures did not provide reliable results for the entire life cycle of oils, whose profile changes with time and reuse. Results demonstrate significant differences with quick response parameters as Total Acidity, Peroxide Index and CIE Lab colour, outlined as QDI's. Moisture, aw and CIE Lab colour proved to be inadequate for this purpose. Iodine Index and UV Absorbency are more complex and time-consuming and were profiled as reference methods.info:eu-repo/semantics/publishedVersio

    Strawberry spread - New Food New Tech

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    This study is part of the Agrio et Emulsion project (POCI-01-0145-FEDER-023583), new food emulsions development. The product innovation results from the addition of a strawberry syrup to a spreadable cream of vegetable origin. Four formulations have been developed and eight syrup spreadable cream, being selected a prototype evaluated by an untrained panel taster. Physicochemical and proximal analyzes were performed: pH, total acidity, soluble solids, energy, moisture, crude protein, total lipids, carbohydrates, fiber and ash. A set of microbial populations was evaluated for microbiological stability control: enumeration of microorganisms at 30 ºC; enumeration of lipolytic microorganisms at 30 ºC; enumeration of Enterobacteriaceae; enumeration of osmophilic or osmotolerant yeasts and moulds; detection of spores of sulfite-reducing Clostridia. Two emerging technologies, ionizing irradiation and hyperpressure were used to study the stability of this new product. The results for the treated and untreated products showed no significant differences. The untreated samples remained stable and showed satisfactory microbiological characteristics under refrigeration at 5 °C after 3 months. Following these results, we conclude that product stability can be ensured by good manufacturing practices.info:eu-repo/semantics/publishedVersio

    Cellulolytic ability of Penicillium strains isolated from soil of the Brazilian Atlantic forest

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    Penicillium spp. are capable of degrading plant wastes by producing large amounts of enzymes such as cellulases. These form a complex capable of acting on cellulosic materials and producing sugars with industrial interest (e.g., ethanol production). Cellulases are also used for (a) pulp and paper industry (b) in the textile industry. The aim of this study was to evaluate the cellulolytic capability of 17 strains of Penicillium isolated from soil of the Brazilian Atlantic Forest and conserved under mineral oil at the URM Culture Collection. All strains were re-grown from mineral oil and re-identifiied. Each strain was grown in synthetic medium with carboxymethylcellulose as the carbon source and incubated for 5 days at 28°C. Strains were subjected to heat shock for 16h at 50°C. Thereafter, onto each colony was added 5 ml of Congo red stain solution in Tris-HCl. After 30 min this solution was removed and the cultures were washed and submerged under 0.1 M NaCl aqueous solution for 5 min. Finally, an enzymatic index was calculated from the ratio of the diameter of the halo around each colony to the diameter of the colony. All of the 17 strains tested showed a halo of cellulose degradation, indicating enzyme production. The enzymatic ratios varied between 0.2 (Penicillium brevicompactum URM5994) and 3.3 (Penicillium glabrum URM6009). Thus, Penicillium glabrum URM6009 is evaluated as a high producer of cellulase. It was selected for quantitative production of this enzyme and additional studies are taking place in order to verify potential industrial application for clarification of fruit juices

    Foraging behaviour and diet of Brown boobies Sula leucogaster from Tinhosas Islands, Gulf of Guinea

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    Seabirds are a highly threatened group, yet the foraging ecology of several species remains poorly understood. Brown boobies breed in all oceans in the tropical region and are common across their range. In Tinhosa Grande (São Tomé and Príncipe), this species breeds in one of the largest colonies of seabirds in the east tropical Atlantic. We studied the foraging ecology of Brown boobies from this colony during the chick-rearing period. Thirty-three birds were tracked with GPS loggers and their diet was analysed from 11 regurgitations, using traditional and DNA barcoding techniques for prey identifcation. A total of 127 completed foraging trips were identifed, 89% of which lasted less than 24 h. Females performed signifcantly longer trips and both sexes foraged preferentially over deep oceanic waters. The diet of Brown boobies included juvenile fsh and squid (Sthenoteuthis pteropus), comprising mostly fsh species whose juvenile phases live in the pelagic environment, and only migrate to coastal waters when adults. The most frequent of those prey found was Flying gurnard (Dactylopterus volitans). The relevance of such prey shows that Brown booby conservation depends not only on the management of their foraging areas and breeding sites but also on the correct management of the coastal adjacent areas that support the adult individuals of some of their prey. Our results suggest that the areas closest to the colony do not have available resources for these birds to feed on and that Brown boobies may be associate with subsurface marine predators or with sargassum patches to forage.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Against all odds: a tale of marine range expansion with maintenance of extremely high genetic diversity

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    The displacement of species from equatorial latitudes to temperate locations following the increase in sea surface temperatures is among the significant reported consequences of climate change. Shifts in the distributional ranges of species result in fish communities tropicalisation, i.e., high latitude colonisations by typically low latitude distribution species. These movements create new interactions between species and new trophic assemblages. The Senegal seabream, Diplodus bellottii, may be used as a model to understand the population genetics of these invasions. In the last decades, this species has undergone an outstanding range expansion from its African area of origin to the Atlantic coast of the Iberian Peninsula, where now occurs abundantly. Mitochondrial and nuclear markers revealed a striking high haplotypic nucleotide and genetic diversity values, along with significant population differentiation throughout the present-day geographical range of the Senegal seabream. These results are not consistent with the central-marginal hypothesis, nor with the expectations of a leptokurtic distribution of individuals, as D. bellottii seems to be able to retain exceptional levels of diversity in marginal and recently colonised areas. We discuss possible causes for hyperdiversity and lack of geographical structure and subsequent implications for fisheries.Portuguese Foundation for Science and Technology: UID/MAR/04292/2019/ UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio

    Desenvolvimento e aquisição do processo lógico-matemático

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    Esta pesquisa teve o objetivo de desenvolver estudos referentes ao desenvolvimento do raciocínio lógico-matemático e as dificuldades de interpretação e resolução de problemas matemáticos no ensino e aprendizagem. É importante que a criança conclua a educação básica sabendo aproveitar de forma positiva seu raciocínio lógico para resolver situações envolvendo, ou não, matemática. No momento em que a criança nasce já está sendo estimulada ao aprendizado, por exemplo quando é estimulado o reflexo da criança, sua percepção, coordenação motora são características de que seu aprendizado não está relacionado apenas no momento de sua escolarização. Ao ser estimulado seu raciocínio-lógico estará modificando também funções essenciais em seu desenvolvimento integral. Dessa forma é importante ressaltar que a matemática possibilita à criança diversas formas diferentes de aprender não somente a calcular, mas também a solucionar, buscar novas alternativas para aprender a pensar e utilizar seu pensamento de maneira produtiva e significativa

    Mito-nuclear sequencing is paramount to correctly identify sympatric hybridizing fishes

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    Background. Hybridization may drive speciation and erode species, especially when intrageneric sympatric species are involved. Five sympatric Luciobarbus species—Luciobarbus sclateri (Günther, 1868), Luciobarbus comizo (Steindachner, 1864), Luciobarbus microcephalus (Almaça, 1967), Luciobarbus guiraonis (Steindachner, 1866), and Luciobarbus steindachneri (Almaça, 1967)—are commonly identified in field surveys by diagnostic morphological characters. Assuming that i) in loco identification is subjective and observer-dependent, ii) there is previous evidence of interspecific hybridization, and iii) the technical reports usually do not include molecular analyses, our main goal was to assess the concordance between in loco species identification based on phenotypic characters with identifications based on morphometric indices, mtDNA only, and a combination of mito-nuclear markers. Materials and methods. Specimens of Luciobarbus from six Guadiana River sub-basins were collected and sequenced for the cytochrome b and beta-actin genes. For comparative purposes, samples of Luciobarbus from other 12 river basins were also used. Four levels of taxonomical identification were conducted based on: identification made in the field (in loco identification), cytb gene only, beta-actin gene only, and mito-nuclear combined genomes. Results. Results showed that interspecific hybridization seems to be high (around 41%) and likely favoured by non-random mating and the loss of fluvial connectivity. About 34% of the hybrids showed mito-nuclear discordance. Misidentifications were frequent when only phenotypic characters are considered, and the use of a single mitochondrial gene is not sufficient: the use of two mito-nuclear markers showed that around 82% of the in loco identifications based on the phenotype were not correct. Conclusion. Incorrect species assignment likely generated biased results in previous studies on the biology and ecology of Guadiana barbels and in the assignment of conservation status and, consequently, on the establishment of conservation management measuresinfo:eu-repo/semantics/publishedVersio

    Curadoria digital interativa: espaços coletivos e ambiências de pesquisa e de formação

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    Este artigo é um recorte da pesquisa "Educação Aberta e Cultura Digital: docênciaS, curadoria, redes sociais, percursos e espaços (trans)formativos", coordenada pela primeira autora deste texto, financiada pelo CNPq e por uma Universidade Pública Federal, e trata da Curadoria Digital Interativa. O objetivo inicial era mapear e dialogar com os grupos de pesquisas brasileiros que investigam(ram) e interatuam(ram) na/com as singularidades da cultura digital, e seus artefatos, durante o período pandêmico da COVID-19, entre 2020-2022. Porém, evidenciou-se a necessidade de ampliação, e pesquisadores e grupos de pesquisa de outros países foram convidados a participar, bem como integrados dados acerca do período de retorno às aulas nos espaços de presença física. O espaço digital utilizado foi o Google Maps e neste espaço os participantes poderão interagir com os demais e editar suas próprias informações. Esta ambiência é compreendida na investigação como Curadoria Digital Interativa, e os dados, mostrados ao longo do texto, evidenciam que este pode ser um ótimo recurso para contatar/acessar pesquisadores e grupos de pesquisa que investigam a cultura digital, e também possibilitar o diálogo entre todos, especialmente sobre suas pesquisas, publicações e estudos
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