1,720,965 research outputs found
Accelerated shelf-life model of gluten-free rusks by using oxidation indices
No full textThe demand for gluten-free products has been growing over the last few years as is the need to improve their quality. The objective of this research was to develop a shelf life prediction model of gluten-free rusks. To this aim, a kinetic study of the primary and secondary oxidative process was run and the kinetic parameters (rate constant, activation energy, and temperature quotient) were calculated. The protective effect of the antioxidant included in the recipe was also evaluated, and the prediction model was applied to predict the shelf life of an experimental batch of gluten-free rusks with a lower content of antioxidant. The results highlighted (i) the reliability of the prediction model and (ii) the effectiveness of the antioxidant in reducing the rate of primary oxidation. Moreover, (iii) a possible hexanal threshold (lower than 121 μg/kg), correlated with rancid perception in gluten-free rusks, was also speculated
Effect of baking time and temperature on nutrients and phenolic compounds content of fresh sprouts breadlike product
No full textSprouting has received increasing attention because of the enhanced nutritional values of the derived products. Baking affects the nutrient availability of the end products. The aim of this study was to evaluate how different baking time and temperature affect the nutritional values of bakery products derived from fresh wheat sprouts. Results indicate that the breadlike products showed comparable total polyphenol content and the thermal processes affected the free and bound fractions. Low temperature and high exposure time appear to promote the availability of the free polyphenols and sugars, while high temperature and low exposure time appear to preserve bound polyphenols and starch. Sugar profiles were influenced by baking programs with a higher simple sugar content in the samples processed at low temperature. Phenolic acids showed a strong decrease following processing, and free and bound phenolic acids were positively influenced by high baking temperatures, while an opposite trend was detected at low temperatures. Significant differences in phenolic acid profiles were also observed with a redistribution of hydroxycinnamic acids among the bound and free fractions. It may be concluded that grain type, germination conditions, and the baking programs play a fundamental role for the production of high-nutritional-value bakery products
Low Carbohydrate Beers Produced by a Selected Yeast Strain from an Alternative Source
No full textRecently, the brewing industry has invested significant resources into the development of new specialty beers, in response to increased consumer demand. Low carbohydrate and novel flavored beers have resulted and these are particularly attractive for consumers, even if technologically challenging to produce. The aim of this work was to produce a low carbohydrate and novel flavored beer in a traditional manner. A Saccharomyces cerevisiae strain isolated from an alternative source (i.e., yeast strain DBVPG 6580 was used in a Brazilian bioethanol production facility) was selected because of its starch degrading character and this yeast was employed in a traditional brewery plant to achieve this goal. The strain DBVPG 6580 was used to ferment worts of different densities (12 and 20°P) and at different fermentation temperatures (18 and 25 °C), to explore possible technological applications. The results demonstrated that yeast DBVPG 6580 was able to degrade dextrins to fermentable sugars, giving an apparent attenuation above 100% and allowing for the production of a low carbohydrate beer by traditional methods. Moreover, strain DBVPG 6580 produced novel flavored beers, rich in fruity, floral, banana and pear flavors. This yeast strain demonstrated that under optimal conditions, it possessed the ability to ferment a high density wort, which could lead to important economic advantages for the producer
Near-infrared reflectance models for the rapid prediction of quality of brewing raw materials
No full textCalibration models for quickly and reliably predicting moisture content and total nitrogen, both “as is” and “dry matter” on malt, as well as moisture content and total lipids, both “as is” and “dry matter”, on maize by means of near-infrared (NIR) spectroscopy were developed. The FT-NIR spectra recorded on the finely ground cereals were correlated to the analytical data by means of the multivariate PLS algorithm. In particular, these models were developed on the raw materials, which are used by the main Italian brewing industries. Validation was carried out both by means of cross-validation and test set validation. Regression coefficients (R2) were higher than 97 for both malt and maize moisture content and higher than 85 and 88 for malt total nitrogen and maize total lipids, respectively. The RMSE values (both RMSECV and RMSEP) were lower than 0.1% m/m for both malt and maize moisture contents, whereas they ranged from 0.024 to 0.042% m/m for malt total nitrogen and from 0.042 to 0.055% m/m for maize total lipids. Repeatability was tested by taking into account more than one sample for each calibration and compared, when possible, to those of the standard methods. Repeatability (r95) ranged from 0.060 to 0.158% m/m and from 0.020 to 0.055% m/m for malt moisture and total nitrogen contents, respectively, and from 0.094 to 0.160% m/m and from 0.076 to 0.208% m/m for maize moisture and total lipids contents, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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