1,721,267 research outputs found
Aromatic complexity in Verdicchio wines. An overview of volatile compounds.
No full textThe evolution of analytical instruments is leading to the production of data of increasing size, with over 1000 volatiles being frequently observed within a single run of comprehensive gas chromatography coupled to mass spectrometry. The interpretation of such rich dataset require to focus on the much more limited number of key odorants, and on their characteristic ratios present in each wine. This study was aimed to the recognition and detection of odorous molecules in the white variety Verdicchio, considering the wines produced in multiple vintages from some of the best Cru from Marche region, in the Castelli di Jesi Classico area.
Selected wines were analyzed with GCXGC-ToF-MS, GC-MS-MS and GC-O by aroma extract dilution analysis, after Solid Phase Extraction or Solid Phase Microextraction. The comprehensive profile with more than 1000 compounds allowed to separate well the different type of product. By GC-O analysis 28 main odorants were found. This survey led to the identification of 3-methyl-2,3-nonanedione (3-MND) as a possible key odorant characteristic in Verdicchio.
Verdicchio from the best production areas develops a typical, positive note, described as anise. The systematic characterization of several wines, and comparison with true standard of the candidate compounds having anise among the putative descriptors (trans-anethole, cis-anethole, estragole, 3-MND, and carvone) lead us to suggest that the presence at low concentration of 3-MND is likely to explain the anise flavor in Verdicchio wines. From previous studies [1] we had discovered that this grape variety is very rich in methyl salicylate both in the free form and in the bound form (-D-glucoside and -primeveroside). In such research, we put in evidence the possible contribution of methyl salicylate to the aroma as well as its possible remarkable presence as bound forms in Verdicchio. The synergic effect of methyl salicylate and MND was now investigated.
Acknowledgements The financial support of Fazi Battaglia winery
Reference style:
[1] Versini, G.; Moser, S.; Carlin, S. Abstract Proceed. ‘In VinoAnalytica Scientia’ Montpellier. (2005) Methyl salicylate as a remarkable almost bound compound in some renowned Italian varietal wines
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
Kinetic investigations of the Gewürztraminer volatile organic compounds and color at different temperatures and pHs
No full textGewürztraminer is a well-known wine famous for its aroma profile, which is characterized by rose petals, cloves, lychees, and other tropical fruit notes. It is cultivated worldwide, including the Trentino Alto Adige region located in northern Italy, especially in the Tramin zone, and it has long been studied trying to understand what the most characterizing volatile aroma components are [1-4]. The terpenes (geraniol, cis rose oxide, citronellol, and linalool) are between the major responsible for the characteristic floral aroma of this cultivar’s grapes and wines. Throughout the winemaking and storage, acid-catalysed rearrangements take place producing cyclic and hydroxylated forms of the above terpenes, which generally have minor perception thresholds and so the wine’s floral aroma character decreases [5]. It has been demonstrated that the temperature and pH strongly influence these reactions, however their kinetics are not studied in detail. The first aim of this work was to develop and validate a fast, modern, sensitive, selective, robust, and comprehensive protocol for the quantification of primary, secondary, and tertiary wine volatile compounds by using solid-phase extraction (SPE) cartridges for the sample preparation and a fast GC-MS/MS for analysis [1]. Second aim was to apply this protocol and study the kinetics of the reactions occurring on the Gewürztraminer wine volatile compounds during its storage at various temperatures and pHs. In parallel also the colour of the wines was monitored by using the CIELAB method. The produced method gave us the possibility to measure 64 aroma compounds, with big importance in wine science, by using fewer organic solvents, having short chromatographic run, and increasing specificity and sensitivity due to the MRM MS-mode used. The results of the second part of the study, demonstrated the behaviour of volatile aroma compounds, with their absolute concentrations. The investigated reactions included the degradation of the linear terpenes (linalool, geraniol, nerol, etc), the ethyl esters of fatty acids and volatile phenols on the one hand; and the formation of the cyclic terpenes (1,4-cineole, 1,8-cineole, terpineol, etc), the norisoprenoids (e.g. TDN and safranal) and the diprotic organic acids esters on the other hand. In conclusion, we developed a modern protocol for the analysis of the wine aroma compounds and we underlined some key characteristics that a winemaker should take in consideration in the Gewürztraminer production and aging/storage. References 1. Carlin, S.; Lotti, C.; Correggi, L.; Mattivi, F.; Arapitsas, P.; Vrhovsek, U. “Measurement of the effect of accelerated aging on the aromatic compounds of Gewürztraminer and Teroldego wines, using a new SPE-GC-MS /MS protocol” Metabolites 2022, 12(2), 180. 2. Versini, G. Sull’aroma Del Vino “Traminer Aromatico” o “Gewürztraminer.” VIGNEVINI 1985, 12, 57–65. 3. Guth, H. Identification of Character Impact Odorants of Different White Wine Varieties. J. Agric. Food Chem. 1997, 45, 3022–3026. 4. Román, T.; Tonidandel, T.; Larcher, R.; Celotti, E.; Nicolini, G. Importance of Polyfunctional Thiols on Semi-Industrial Gewürztraminer Wines and the Correlation to Technological Treatments. Eur. Food Res. Technol. 2018, 244, 379–386. 5. Slaghenaufi, D.; Ugliano, M. “Norisoprenoids, Sesquiterpenes and Terpenoids Content of Valpolicella Wines During Aging: Investigating Aroma Potential in Relationship to Evolution of Tobacco and Balsamic Aroma in Aged Wine.” Front. Chem. 2018, 6
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
- …
