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Improving winemaking in biodynamics oriented wine farming
No full textImproving winemaking in biodynamics oriented wine farming
Labagnara Tilde1., Toffanin Annita1.
[email protected]
1.University of Pisa, DISAAA-a - Department of Agricultural, Food and Agro-
Environmental Sciences, via del Borghetto, 80, 56124 Pisa
“Natural wines”, nowadays, could appear an evocative recall to what wine was like
before. During the ages, science allowed winemakers to produce wines with the full
control of winemaking, obtained mainly by addition of exogenous components,
supplements and microorganisms. Contrarily, “natural wines” come back to basics
and simplicity as invasive operations are avoided; but, on the other hand, a very
much deeper knowledge and monitoring of winemaking process is required, in order
to obtain high quality products without exogenous supplies. “Natural wines” are
produced by spontaneous fermentation of must conducted by yeasts originated from
the grapes and winery equipment. During fermentation, several strains compete in
the same must, and the dominance of Saccharomyces cerevisiae takes place when
it overcomes all the others. The aim of the present work was to investigate
Saccharomyces cerevisiae diversity and its behaviour in a biodynamic farm in
Tuscany in order to supply knowledge to face vinification difficulties. Yeasts from
Syrah fermentations were isolated from different steps of winemaking and
molecularly characterized in 2009 and 2013 harvests. ITS-PCR methods identified
those belonging to Saccharomyces sensu stricto complex and multiplex PCR
amplification of microsatellite loci (SC8132X, YOR267C and SCPTSY7)
discriminated S. cerevisiae strains. The results of 2009 highlighted peculiar
behaviours of eight biotypes, characterised from two hundred isolates. Not
surprisingly, some of the biotypes collected in 2009 were also found in 2013. In the
last harvest one of the biotypes obtained in 2009 was used as inoculum in
comparison with a multi-strain inoculum and with regular spontaneous fermentation.
Sensorial analyses of wines obtained revealed certain diversity in aroma and flavour
traits, but also in the wine structure
Saccharomyces cerevisiae biodiversity in biodynamics oriented wine farming
No full textIn biodynamic oriented wine farming microbial biodiversity is favoured and it is reasonable to expect a major presence of microbes with interesting traits due to the absence o very scarce use of invasive techniques in the vineyard and in the cellar. The aim of the work was the identification and characterization of Saccharomyces cerevisiae wine strains from biodynamic oriented wine farms in different vintages.
Yeasts from Syrah fermentations were isolated from different steps of winemaking in 2009, 2010 and 2013 harvests. S. cerevisiae biotypes were molecularly characterized using ITS-PCR and multiplex PCR amplification of microsatellite loci (SC8132X, YOR267C and SCPTSY7). Micro-fermentations of genetically diverse S. cerevisiae were set up to study fermentative traits. Sulphur dioxide, ethanol resistance and production of hydrogen sulphide were chosen as main parameters for technological characterization of isolates.
During the harvest of 2009 and 2010, several S. cerevisiae biotypes were individuated during spontaneous fermentation in a biodynamic oriented wine farm located in Tuscany. Some biotypes highlighted good oenological aptitudes allowing their use in guided fermentation. The harvest of 2013 confirmed the presence of several biotypes previously identified in 2009 and 2010.
There is a debate about the persistence of “autochthonous” wine yeast strains in the cellar and during winemaking process in the years. The results indicate the presence of the same S. cerevisiae strain in the examed 3 of 5 vinification processes, attesting its presence in the same terroir in different years and overcoming a possible vintage effect
Oenological characterisation of indigenous strains of S. cerevisiae isolated in a biodynamic winery in the Cortona DOC area
Full text linkGenotypic and technological characterisation of the S. cerevisiae population isolated in a biodynamic winery in the Cortona DOC area was performed to gain better knowledge of the variables that influence winemaking. The oenological performance of 11 S. cerevisiae strains was evaluated with physiological tests; strain typing was performed through analysis of interdelta sequences and 26S rDNA sequencing. The analysis revealed a remarkable variability in terms of S. cerevisiae strains, despite the homogeneity of wine features, underlining the high levels of biodiversity characterising biodynamic agriculture. Some strains were found in wines of different vintages, suggesting the presence of an established microbiota in the winery. Oenological tests demonstrated that while some yeasts provided reliable oenological performance, other strains were not able to accomplish prompt and effective alcoholic fermentation, or were characterised by spoilage characteristics, such as excessive production of volatile phenols or acetic acid. Indigenous strains of S. cerevisiae could be a useful instrument for reliable winemaking without altering the native microbiota of each oenological environment. However, characterisation of their oenological suitability, and the application of practices able to drive the evolution of microbiota, must be employed to reduce the risk of wine spoilage
Biodiversita di lieviti in presenza di dosi crescenti di Anidride Solforosa nella fermentazione vinaria
No full textIl presente lavoro fa parte di uno studio volto a verificare l’effetto dell’impiego di dosi modeste di
anidride solforosa sulla biodiversità dei lieviti nella fermentazione spontanea. L’aggiunta di
diossido di zolfo al mosto tende generalmente a ritardare l’inizio del processo fermentativo,
riducendo il numero e il tipo di lieviti presenti, ma l’azione selettiva nei confronti di ceppi resistenti
o tolleranti, caratterizzati da una migliore attività fermentativa, può portare ad un decorso
fermentativo complessivamente più favorevole. Il presente lavoro, svolto in collaborazione con
l’azienda Caiarossa, Riparbella (Pisa), ha incluso l’identificazione dei lieviti presenti durante la
vinificazione di uve Syrah durante la vendemmia 2009, in relazione all’aggiunta di 0, 2 e 7 g/hL di
anidride solforosa in forma di metabisolfito di potassio. Campioni di mosto sono stati sottoposti a
diluizione seriale e inoculo su mezzi selettivi e non, allo scopo ottenere isolati microbici in coltura
pura da sottoporre a successive analisi molecolari tra cui l’identificazione molecolare mediante
amplificazione ITS e RFLP dell’amplificato ITS. Sono stati isolati e identificati lieviti appartenenti
alle seguenti specie: Hanseniaspora uvarum, Pichia guilliermondii, Saccharomyces spp.,
Metschnikowia pulcherrima, Metschnikowia spp., Candida boidinii. I lieviti ritenuti appartenere al
genere Saccharomyces, la cui presenza è stata rilevata già dai primi campionamenti, sono stati
utilizzati per le successive prove di caratterizzazione mediante analisi di microsatelliti e RFLP di
DNA mitocondriale. L’analisi dei profili di restrizione ha permesso di evidenziare la presenza di
almeno sette diversi tipi di lievito appartenenti al genere Saccharomyces, che si sono alternati nei
diversi trattamenti con dosi crescenti di anidride solforosa. In particolare alcuni degli isolati
risultano particolarmente interessanti, in quanto rilevati a fine fermentazione nelle tesi in presenza
di anidride solforosa e tra questi un’isolato risulta essere numericamente prevalente con contenuto
di anidride solforosa maggiore. I ceppi isolati sono stati comparati con ceppi commerciali di ampia
diffusione e non sono state rilevate similitudini
“Wine yeast biodiversity during spontaneous fermentation in response to environmental stress”
No full text“Natural wines”, nowadays, could appear an evocative recall to what wine was like before. During the ages, science allowed winemakers to produce wines with the full control of vinification condition, obtained mainly by addition of exogenous components, supplements and microorganisms. Contrarily, “natural wine” come back to basics and simplicity as invasive operations are avoided; but, on the other hand, a deeper knowledge and monitoring of winemaking process is required, in order to obtain high quality products without exogenous substances. Natural wine has been produced by spontaneous fermentation of must by yeasts originated from grapes and winery equipment. The wide variety of natural yeasts reflects the biodiversity, which is still under-exploited despite the large use of commercial Saccharomyces cerevisiae in most grape musts. During fermentation, several strains compete in the same fermenting must, and the dominance of Saccharomyces cerevisiae takes place when it overcomes all the others. The aim was to investigate Saccharomyces cerevisiae diversity and its technological behavior in two biodynamic wine farms in Tuscany. Autochthonous S. cerevisiae from Syrah fermentations were isolated and molecularly characterized in 2009 and 2013 harvests. Saccharomyces cerevisiae strains were isolated starting from Syrah musts with zero or low levels of sulphite added, according with the tendency of natural wines producers to abait every invasive operation during wine making. Samples were collected in different steps of winemaking. ITS-PCR method confirmed isolates belong to Saccharomyces sensu stricto complex. The multiplex PCR amplification of microsatellite loci (SC8132X, YOR267C and SCPTSY7) discriminated S. cerevisiae strains. Genetically diverse S. cerevisiae strains were subsequently subjected to technological characterization. Micro-fermentations were set up to study fitness and quality traits of biotypes characterized. Weight loss kinetics were measured and chemical analyses were performed. Collected Saccharomyces cerevisiae strains were tested also in order to verify the effect of low sulphite additions on biodiversity pursuing information about stress-adaptation mechanisms that allow the survival in the challenging environment of fermenting must. Sulphite addition may act as a selective factor to induce the presence and the activity of strains with diverse features about sulphite metabolism. The addition of different dose of sulphite induced a considerable variability among strains. However, some biotypes exhibited tolerance to certain concentration and only one biotype was classified as resistant to a determinate concentration. In addition, biotypes were subjected to an other environmental stress factor such as ethanol. The increasing of levels of ethanol limited considerably the activity of selected strains, but some of them highlighted a positive tolerance to various ethanol concentrations. During the harvest of 2013, the alcoholic fermentation was conducted inoculating a biotype characterized previously, which expressed good fermentative performance and a multi-strains culture of other S. cerevisiae strains characterized in the same harvest (2009) in a biodynamic farm from a workgroup of Edmund Mach Foundation of San Michele all'Adige (TN). The results of 2009 highlighted peculiar behaviors of 13 biotypes (characterized from four hundred isolates) that dominate the spontaneous fermentations. Not surprisingly, some biotypes were also found in fermentations of 2013, demonstrating yeasts are ubiquitous in that environment. Sensorial analyses of wine, originated by biotypes fermentation, revealed certain diversity in aroma and flavor traits, but also in the structure. Overall, this work suggests the consolidate relationship existing between autochthonous yeasts and the terroir, where yeasts are ubiquitous. Furthermore, autochthonous yeasts surely contribute to the unique identity of wine. In addition, this work suggests that the use of isolated and characterized autochthonous yeast strains could help the winemaking process, where the vintage could be inadequate to develop a particular product such as the wine of a specific wine farm
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
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