1,721,004 research outputs found
Application of NIR and MIR spectroscopy to extra virgin olive oil classification
No full textThe extra virgin olive oil (EVOO) plays an important role amongst the Mediterranean typical food products. Its typicality is strongly affected by the origin of raw material and the manufacturing technology. The European Union has recognized many EVOOs as Protected Designation of Origin (PDO) or Protected Geographical Indication (PGI). These typical oils are mainly known for their sensory properties (Caporale et al., 2006), which are deeply influenced by the genetic matrix, that is by the cultivar of the olives used in production (Rotondi et al., 2011). Sensory and chemical properties of EVOO are also affected by the soil type on which the olives are grown, as well as by agronomic practices and climatic conditions (Tovar et al., 2002). Since EVOO is one of the more expensive vegetable oils, notably in presence of a PDO or PGI label, it is subjected to several commercial frauds. To protect consumers against fraudulent claims, rapid and easy analytical methods are necessary, at least for screening procedure. Spectroscopic techniques, associated with chemometric methods, have been shown to be useful for olive oil classifications (Galtier et al., 2007; Casale et al., 2010; Sinelli et al., 2010; De Luca et al., 2011; Casale et al., 2012). The aim of this work was to verify the possibility to use NIR and MIR spectroscopy for the classification of EVOOs on the basis of their fruity flavor intensity, geographical origin, and varietal composition
Milk renneting: study of process factor Influences by FT-NIR spectroscopy and chemometrics
No full textThe dairy industry is continuously developing new strategies to obtain healthier dairy products preserving expected properties. However, when modifying a food process, the reassessment of each parameters and their interaction should be considered as highly influencing the final quality. Among others, rennet process features are fundamental for both sensory properties and typical characteristics of a cheese. In this contest, the research addresses the development of a FT-NIR spectroscopic method, coupled with chemometrics, for the study of the effect of process variables on milk renneting. The effects of temperature (30 °C, 35 °C, 40 °C), milk fat concentration (0.1, 2.55, 5 g/100 mL), and pH (6.3, 6.5, 6.7) were investigated by means of a Box-Behnken experimental design. FT-NIR data collected along the 17 trials were explored by interval-PCA (i-PCA) and ANOVA-simultaneous component analysis (ASCA). i-PCA revealed differences in the occurrence and trends of coagulation phases, related to the three considered factors. ASCA allowed the characterization of renneting evolution and the assessment of the factor role, demonstrating that main and interaction effects are significant for the process progress. The proposed approach demonstrated that i-PCA and ASCA on FT-NIR data, highlighting the effects of the operating factors, allow a rapid and accurate analysis of process modifications in cheese manufacturing
Detection of minced beef adulteration with turkey meat by UV-vis, NIR and MIR spectroscopy
No full textThe aim of this work was to investigate the potential of UV-visible (UV-vis), near infrared (NIR) and mid infrared (MIR) spectroscopy, coupled with chemometric techniques, to detect minced beef adulteration with turkey meat. Besides 44 minced meat samples of pure bovine and 44 of pure turkey, 154 mixtures of minced beef adulterated with turkey meat in the range 5-50% (w/w) were prepared and analyzed. The spectral data, standardized by different pre-treatments, were processed, separately or fused, using Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Partial Least Squares (PLS) regression. Moreover, a variable selection method was performed before classification and regression analysis. Among the three spectroscopic techniques, comparing the PLS models in terms of errors in prediction (RMSEP), the best results were obtained with NIR and MIR spectroscopy, whereas the UV-vis results were less satisfactory. Finally, combining information from UV-vis, NIR and MIR spectroscopy improved the overall results
Emulsifying and foaming properties of a hydrophobin-based food ingredient from Trichoderma reesei: A phenomenological comparative study
No full text
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
Sustainability of the olive oil system
Full text linkSustainability is a widely accepted goal across many sectors of our society and, according to new concepts, it includes resilience and adaptive capacity [...]
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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