1,720,967 research outputs found
Thymol enrichment from oregano essential oil by molecular distillation
Get PDFThe objectives of this study were to obtain fractions enriched in thymol by molecular distillation of oregano essential oil and to evaluate their antioxidant properties. In addition, this operation was modelled considering the effects of evaporation temperature and feeding flow on thymol concentration in the residue fractions by means of artificial neural networks (ANN). All residue fractions had a higher percentage of thymol than the distillates. The thymol composition in the residue fractions reached values up to 2.4-fold higher than in oregano essential oil. Higher concentrations of thymol produced lower values for IC50 according to DPPH technique, indicating an increase in antioxidant properties. During the storage test, all the residue fractions analysed showed better peroxide, conjugated dienes and conjugated trienes values than distillates and OEO when they were used in sunflower oil samples. The results of storage stability showed that residues and BHT are very good antioxidants. The ANN created demonstrated good predictive ability for the operation of molecular distillation of oregano essential oil.Fil: Borgarello, Ana Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Mezza, Gabriela Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Pramparo, Maria del Carmen. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Gayol, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentin
Optimisation of omega-3 concentration and sensory analysis of chia oil
No full textThe objective of this study was to obtain concentrated α-linolenic acid ethyl esters from chia oil with values of chemical indicators permitted by current legislation for edible oils and its sensory quality was determined. In the transesterification reaction, sodium hydroxide catalyst concentration and alcohol: oil molar ratios were studied. The model of transesterification with artificial neural networks showed an optimum at a catalyst concentration of 0.387 gNaOH/100goil and a 12.7:1 alcohol: oil molar ratio. The urea complexation was carried out at weight ratios urea: omega-3 fatty acid ethyl esters of 0.5:1, crystallisation at −10 °C for 24 h. Molecular distillation was carried out in one and two stages, where the best results were provided by using one stage, a distillation temperature of 85 °C and pressure of 1.579 × 10−5 atm. The combination of transesterification, urea complexation and molecular distillation allowed obtaining an increase of 24.50 % of omega -3 fatty acids ethyl esters in the final product. This product contains 781.35 g/ kg omega-3, and values of free fatty acids and peroxide of 0.693 % and 1.052 meqO2/kg, respectively. Chia oil presents the higher values of nutty and cream flavour (positive attributes), and turbidity. In the final product these attributes diminishes considerably.Fil: Sosa, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Magallanes, Leisa Maria. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Grosso, Nelson. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Pramparo, Maria del Carmen. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Gayol, Maria Fernanda. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentin
Simmondsins quantification by spectrophotometry UV–vis in press cake and in jojoba seeds (Simmondsia chinensis (Link) Schneider), from Argentina
Get PDFIn this paper, we describe a simple, fast, and efficient method for the quantification of simmondsins and simmondsin's ferulates in jojoba seeds and residual cakes, without using expensive equipment or laborious techniques. Spectrophotometric measurements (UV–vis) were used for the quantification of the content of simmondsins, total ferulates and total simmondsins in jojoba seeds and residual cakes from the provinces of Catamarca and La Rioja, Argentina. The average values of such components found in seeds, in 100 g of dry and defatted sample, were 11.54 ± 0.91 and 2.24 ± 0.28 g of simmondsins and of simmondsin's ferulates, respectively, whereas the respective values in residual cakes were 10.08 ± 0.31 and 2.93 ± 0.64 g, respectively. A great diversity between the simmondsin contents and their ferulates in seed samples of different origins as well as in different clones was observed. The residual cakes did not present differences respect to the simmondsin contents; however, there were some difference with the simmondsin ferulates. These variations are due to the genetic antecedents of plants and the environmental conditions in which they grow.Fil: Gayol, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Labuckas, Diana Ondina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Nicotra, Viviana Estela. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oberti, Juan Carlos María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; ArgentinaFil: Guzman, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentin
Sensory quality of milk fat with low cholesterol content fractioned by molecular distillation
Get PDFAnhydrous milk fat (AMF) is a valuable ingredient in several industries, but its cholesterol content is a disadvantage because it is associated with several diseases. The objective of this study was to remove the largest possible amount of cholesterol from AMF by molecular distillation and to analyze the sensory properties of the obtained product. AMF was subjected to various molecular distillation arrangements. RESULTS: The first set of experiments involved molecular distillations performed over a range of evaporation temperatures. Then, according to the outcome of the first set of experiments, a second set of experiments was carried out in order to study the effect of the feeding flow rate. Finally, the number of distillation stages was modified. The best results were obtained in a three-stage arrangement, in which ∼60% of cholesterol was removed with a 30.48% distillate yield. The sensory properties of this distillation cut were also the most similar to those of the untreated milk fat.Fil: Berti, Julia. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Grosso, Nelson. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Fernandez, Hector. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Pramparo, Maria del Carmen. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Gayol, Maria Fernanda. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Optimization of the protein concentration process prepared from residual peanut oil-cake
No full textThe objective of this study was to find the best process conditions for preparing protein concentrate from residual peanut oil-cake (POC). The study was carried out on POC from industrial peanut oil extraction. Different protein extraction and precipitation conditions were used: water/ flour ratio (10:1, 20:1 and 30:1), pH (8, 9 and 10), NaCl concentration (0 and 0.5 M), extraction time (30, 60 and 120 min), temperature (25, 40 and 60°C), extraction stages (1, 2 and 3), and precipitation pH (4, 4.5 and 5). The extraction and precipitation conditions which showed the highest protein yield were 10:1 water/flour ratio, extraction at pH 9, no NaCl, 2 extraction stages of 30 min at 40°C and precipitation at pH 4.5. Under these conditions, the peanut protein concentrate (PC) contained 86.22% protein, while the initial POC had 38.04% . POC is an alternative source of protein that can be used for human consumption or animal nutrition. Therefore, it adds value to an industry residue.Optimización del proceso de preparación de concentrado de proteína de la torta residual de maní: El objetivo de este trabajo fue encontrar las mejores condiciones para obtener un concentrado de proteínas a partir de la torta residual de maní (POC). El estudio se llevó a cabo en POC provenientes de la extracción industrial de aceite de maní. Se utilizaron distintas condiciones para la extracción y precipitación de proteínas: relación agua / harina (10:1, 20:1 y 30:1), pH de extracción (8, 9 y 10), concentración de NaCl (0 y 0,5 M), tiempo de extracción (30, 60 y 120 min), temperatura (25, 40 y 60°C), número de etapas de extracción (1, 2 y 3), y el pH de precipitación (4, 4,5 y 5). Las condiciones de extracción y de precipitación que mostraron mayor rendimiento de proteína fueron: relación de 10:1 en agua / harina, pH de extracción de 9, en ausencia de NaCl, 2 etapas de extracción de 30 min cada una a 40°C y el pH de precipitación de 4,5. En estas condiciones, el concentrado de proteí- na de maní (PC) fue de 86,22%, mientras que el porcentaje de proteínas de la POC inicial fue de 38,04%. Las POC son una fuente alternativa de proteínas que pueden ser utilizadas para el consumo humano o la alimentación animal. De esta manera, se le puede dar un valor agregado extra a un residuo de la industria del aceite del maní.Fil: Gayol, Maria Fernanda. Universidad Nacional de Rio Cuarto. Facultad de Ingenieria. Departamento de Tecnologia Quimica; ArgentinaFil: Pramparo, María del C. . Universidad Nacional de Rio Cuarto. Facultad de Ingenieria. Departamento de Tecnologia Quimica; ArgentinaFil: Nepote, Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Fernandez, Hector. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; ArgentinaFil: Grosso, Nelson. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentin
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Recovery of acid corn oil from the bioalcohol industry by molecular distillation
No full textThe objective of this work was to reduce the acidity of acid corn oil for its subsequent use as edible oil. Also, its composition in tocopherols was determined. This oil is obtained as a by-product of corn alcohol production on an industrial scale and is currently used as a raw material in the biodiesel industry. The composition in tocopherols and fatty acids of acid corn oil was determined by gas chromatography and experiments of molecular distillation were carried out at different temperatures between 110 °C and 190 °C with a Volumetric flow rate of 0.5 to 2 mL min-1 and a pressure of 5.10-5 atm. It was possible to reduce its acidity from 9.44% up to values less than 0.3% in the residue, with distillation temperatures higher than 180 °C; also, in the distillate the tocopherols were recovered, with concentrations up to 13360 ppm.CONCLUSION: It was possible to decrease the acidity and purify tocopherols from acid corn oil by molecular distillation, obtaining a residue with an acidity acceptable for human consumption and a distillate with a high tocopherols content. Therefore, using molecular distillation, added value was given to a by-product of the bioalcohol industry.Fil: Miró Erdmann, Silvia Marcela. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias; ArgentinaFil: Magallanes, Leisa Maria. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tarditto, Lorena Viviana. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Prizzon, Antonella. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Pramparo, Maria del Carmen. Universidad Nacional de Río Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Gayol, Maria Fernanda. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentin
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