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Efecto de la temperatura y tiempo de hidrólisis con hidróxido de sodio en la obtención de péptidos solubles de tarwi (Lupinus mutabilis)
No full textLa presente investigación tuvo como objetivo evaluar el efecto de la temperatura y tiempo de hidrólisis con NaOH en la obtención de péptidos solubles de harina de semillas de tarwi (Lupinus mutabilis), variedad criolla. La harina fue previamente deslupinizada (con agua), desgrasada (con etanol) e hidrolizada parcialmente con α-amilasa (57º C, 208 min, pH: 5.5 y 0.1 g enzima/kg sustrato). Se utilizó el método de superficie de respuesta y se empleó un Diseño Compuesto Central Rotable (DCCR), para dos factores (temperatura y tiempo) obteniendo once tratamientos. La caracterización inicial de la harina deslupinizada de semillas de tarwi mostró un alto contenido de proteína (43.53 ± 0.04 g/ 100 g), lípidos (25.41 ± 0.03 g/100 g) y cenizas (1.40 ± 0.07 g /100 g). La hidrólisis alcalina con NaOH se realizó a pH 10, relación harina/solvente 1/25, tiempo entre 10 a 90 minutos y temperatura entre 25 °C – 50 °C. La cuantificación de los péptidos se realizó por el método de Lowry. Los resultados obtenidos indicaron que la mayor concentración de péptidos solubles fue de 7.204 mg/ml que presentó el tratamiento a 46.3 °C por 78 minutos. El modelo matemático que permite predecir la concentración de péptidos solubles en la hidrólisis de harina de tarwi es: Y = -7.8711 + 0.5574*X1 - 0.0084*X12 - 0.0008*X22 + 0.0032*X1*X2. Donde Y es la concentración de péptidos solubles en mg/ml, X1 la temperatura (°C) y X2: tiempo (minutos). El análisis estadístico mostró que existe un alto valor de significancia de las variables independientes (tiempo y temperatura) con respecto a la variable respuesta (péptidos solubles) (p<0.05).ABSTRACT
The present investigation had as objective to evaluate the effect of the temperature and time of hydrolysis with NaOH in obtaining soluble peptides from the flour of tarwi seeds (Lupinus mutabilis), creole variety. The flour was previously deluphuptized (with water), defatted (with ethanol) and partially hydrolyzed with α-amylase (57º C, 208 min, pH: 5.5 and 0.01 g enzyme / kg substrate). The response surface method was used and a Rotable Central Compound Design (DCCR) was used, for two factors (Temperature and time) obtaining eleven treatments. The initial characterization of the tarless meal from tarwi seeds showed a high content of protein (43.53 ± 0.04 g /100 g), lipids (25.41 ± 0.03 g /100 g) and ash (1.40 ± 0.07 g/100 g). The alkaline hydrolysis with NaOH was performed at pH 10, 1/25 flour: solvent ratio, time between 10 to 90 minutes and temperature between 25 ° C - 50 ° C. The quantification of the peptides was carried out by the Lowry method. The results obtained indicated that the highest concentration of soluble peptides was 7,204 mg / ml, which presented treatment at 46.3°C for 78 minutes. The mathematical model that allows predicting the concentration of soluble peptides in the hydrolysis of tarwi flour is: Y = -7.8711 + 0.5574*X1 - 0.0084*X12 - 0.0008*X22 + 0.0032*X1*X2. Where Y is the concentration of soluble peptides in mg / mL, X1 the temperature (° C) and X2: time (minutes). Statistical analysis showed that there is a high significance value of the independent variables (time and temperature) with respect to the response variable (soluble peptides) (p <0.05)
Hidrólisis por α-amilasa en la obtención de azúcares reductores de harina de semillas de tarwi (Lupinus mutabilis) variedad criolla
No full textEl presente trabajo tuvo como objetivo evaluar el efecto de la temperatura y tiempo de hidrolisis con α-amilasa, en la obtención de azúcares reductores (expresado como equivalente en glucosa) en la harina desgrasada de semillas residuales de tarwi (Lupinus mutabilis) variedad criolla, mediante la metodología de superficie de respuesta. El tarwi provino del caserío de Paranshique (Huamachuco) la cual fue previamente deslupinizada (con agua), descascarada (de forma manual), desgrasada (con etanol absoluto) y convertida en harina (secado convectivo). La determinación de azúcares reductores se llevó a cabo mediante el método volumétrico de Lane Eylon. Se planteó un diseño compuesto central rotable con once tratamientos, con dos variables independientes, las cuales fueron temperatura (40 – 60°C) y tiempo (20 – 240 min). La relación enzima/sustrato en todos los tratamientos fue de 0.3g/50 kg de harina, la concentración de la harina en el medio hidrolítico del 20% y pH 5.5. El análisis de varianza mostró efecto estadísticamente significativo (p < 0.05) por parte de las variables tiempo y temperatura de manera lineal, así como la relación lineal de ambas, no siendo así de manera cuadrática. Asimismo, se logró optimizar los parámetros de hidrólisis que permita mayor contenido de azúcares reductores de harina de semillas residuales de tarwi, siendo este 60-62°C y 240-260 min. Mediante el modelamiento se obtuvo la ecuación que relaciona el contenido de azúcares reductores en el permeado de la solución hidrolítica (% Y) con las variables independientes (X1: temperatura (°C), X2: tiempo (min)). Y = 0.407502+0.001707*X1-0.000077*X12-0.004294*X2-0.000003*X22+0.000121*X1*X2ABSTRACT
The present work aimed to evaluate the effect of temperature and hydrolysis time with α- amylase, in obtaining reducing sugars (expressed as glucose equivalent) in the defatted flour of residual seeds of tarwi (Lupinus mutabilis) variety criolla, using the response surface methodology. The tarwi came from the hamlet of Paranshique (Huamachuco) which was previously delupinized (with water), dehulled (manually), defatted (with absolute ethanol) and converted into flour (convective drying). The determination of reducing sugars was carried out by the volumetric method of Lane Eylon. A rotatable central compound design with eleven treatments was proposed, with two independent variables, which were temperature (40 - 60 ° C) and time (20 - 240 min). The enzyme / substrate ratio in all treatments was 0.3g / 50 kg of flour, the concentration of the flour in the hydrolytic medium was 20% and pH 5.5.
The analysis of variance showed a statistically significant effect (p <0.05) by the variables time and temperature in a linear way, as well as the linear relationship of both, not being so in a quadratic way. Likewise, it was possible to optimize the hydrolysis parameters that allow a higher content of reducing sugars in tarwi residual seed flour, this being 60-62 ° C and 240-260 min. Through modeling, the equation that relates the content of reducing sugars in the permeate of the hydrolytic solution (% Y) with the independent variables (X1: temperature (° C), X2: time (min)) was obtained. Y = 0.407502+0.001707*X1-0.000077*X12-0.004294*X2-0.000003*X22+0.000121*X1*X
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
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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