1,720,984 research outputs found
Characterization of “Aceto Balsamico Tradizionale di Modena” Ageing Process by Application of a Wavelet Based Algorithm on HS-SPME/GC Signals
No full textThe aceto balsamico tradizionale di Modena received the PDO certification from the EU two years ago
Three-way principal component analysis of the volatile fraction by HS-SPME/GC of aceto balsamico tradizionale of modena
Full text linkThe present research is aimed at monitoring the evolution of the volatile organic compounds of different samples of Aceto Balsamico Tradizionale of Modena (ABTM) during ageing. The flavouring compounds, headspace fraction, of the vinegars of fourbatterie were sampled by Solid Phase Micro Extraction technique (SPME), and successively analysed by gas chromatography. Obtaining a data set characterized by different sources ofvariability such as, different producers, samples of different age and chromatographic profile. The gas chromatographic signals were processed by a three-way data analysis method (Tucker3), which allows an easy visualisation of the data by furnishing a distinct set of graphs for each source of variability.The obtained results indicate that the samples can be separated according to their age highlighting the chemical constituents, which play a major role for their differentiation. The present study represents an example of how the application of Tucker3 models, on Gas Chromatographic signals may help to follow the transformation processes of food products
Study of the monosaccharides and furfurals evolution during the preparation of cooked grape musts for Aceto Balsamico Tradizionale production
No full textCooked must is the starting raw material used to produce Aceto Balsamico Tradizionale (ABT). It is obtained from grape musts that are condensed by a gentle simmering in uncovered pans over an open fire. Concentrations of fructose, glucose, furfural and 5-Hydroxymethylfurfural (HMF) during must preparation were evaluated as quality indicator of the final product. High pressure liquid chromatography (HPLC) technique was used for the determination of the analytes content in cooked musts sampled at different time during their preparation. Two varieties of grapes (Trebbiano Montanaro and Salamino), and different cooking apparatus were tested by using vats with different surface/volume ratio. The concentrations of the analytical species were found to be dependent on both the kind of grape and the cooking technology. Sugars concentration increases during cooking following almost a linear trend; on the contrary, furfural compounds, produced by monosaccharides degradation, significantly increase with an exponential trend only in the final step of the process. The analytical method gives good recovery values for all the investigated species, ranging from 91% to 104 %. (c) 2006 Elsevier Ltd. All rights reserved
Determination of carboxylic acids in vinegars and in aceto balsamico tradizionale di modena by HPLC and GC methods
No full textThe presence of carboxylic acids in grape products has been investigated for a long time by researchers, from both the qualitative and quantitative points of view. Evaluation of carboxylic acids requires the study and optimization of some operative variables which are strictly related to the matrix. In particular, the determination of organic acids in real matrixes such as Aceto Balsamico Tradizionale of Modena (ABTM; a traditional balsamic vinegar made from cooked grape must) is often difficult because of the presence of numerous interferences that need to be removed by separation techniques. To this aim, in the present work a solid-phase extraction (SPE) method with C18 and NH2 exchangers was used to clean the ABTM samples prior to analysis or further treatments. Both HPLC and GC techniques were used to determine organic acids. The efficiency of these two different analytical techniques in the study of ABTM acidic composition has been evaluated. Both methods separately were not able to supply all the data related to carboxylic acids. In particular, HPLC allows acetic and lactic acids quantification, but gluconic and succinic acids are better determined by GC. As far as tartaric, citric, and malic acids are concerned, both HPLC and GC methods give statistically equivalent results. The variation of the single acidic species composition along a series of casks furnished interesting information regarding the chemical transformations taking place during the aging process of this product
Valutazione di Modificazioni Superficiali Indotte dalla Sterilizzazione per Irraggiamento di Materiali Plastici per Uso Biomedicale
No full textComunicazione oral
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
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