0000000001197545
AUTHOR
Rocco Di Stefano
showing 46 related works from this author
Principal Parameters of Grape Ripening and Wine Fermentation
2008
Over-evaluation of total flavonoids in grape skin extracts containing sulphur dioxide
2015
Abstract Sulphur dioxide (SO 2 ) proved to increase absorbance at 280 nm of grape skin and seed extracts containing it, diluted with ethanol–HCl to assess total flavonoids and anthocyanins in the same analysis. Additional absorbance at 280 nm was also observed in acetone:H 2 O extracts, if the acetone had not completely evaporated before the extracts were diluted with a solvent. Flavonoids were correctly quantified in the extracts when SO 2 or acetone were removed by solid-phase extraction with a C 18 RP as sorbent and methanol as eluting solvent.
Glycosidic aroma compounds of some Portuguese grape cultivars
2006
In order to evaluate the potential aroma of some Portuguese grapes, several glycosidically bound aroma compounds of ten grape varieties grown in Evora, Alentejo, Portugal, were released, identified and quantified using gas chromatography–mass spectrophotometry. White varieties were Arinto, Perrum, Rabo-de-Ovelha, Roupeiro and Antao Vaz. Red varieties were Trincadeira, Aragonez, Tinta Caiada, Moreto and Castelao. Grapes of Roupeiro and Trincadeira from five other vines in the Alentejo region were also studied. For each variety pulp and skin were analyzed separately. The compounds produced by enzymatic hydrolysis of glycoside precursors extracted from pulps and skins of these grapes were simi…
High Performance Liquid Chromatography Analysis of Grape and Wine Polyphenols
2008
Modulation of geraniol metabolism during alcohol fermentation
2004
J. Inst. Brew. 110(3), 213–219, 2004 Geraniol is the main monoterpenol present in Gewurtztraminer white grapes and in some red aromatic grapes from northern Italy. During fermentation, the geraniol concentration showed a dramatic drop and a small amount was transformed into linalool and -terpineol by an acid catalysed chemical reaction. Yeast are responsible for changing most of the geraniol to citronellol through enzymatic reactions. The final aroma of wine is due mainly to both the untransformed geraniol and the formed citronellol. In this study, competition between the geraniol-citronellol transformation and another metabolic process, in which according to our hypothesis sterol biosynthe…
Evolution of anthocyanin profile from grape to wine
2010
<p style="text-align: justify;"><strong>Aims</strong>: This study aimed at acquiring knowledge of the evolution of anthocyanins from grape to wine and the possibility of deducing the varietal origin of a wine from its anthocyanin profile.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The anthocyanin « fingerprint », or profile, of a series of autochthonous Sicilian accessions and their respective young wines was determined by HPLC-DAD in 2008. Data were evaluated by taking into account the evolution of the percentages of side-ring dioxygenated and tri-oxygenated anthocyanins, the ratio between acetylated and p-coumaroylate…
Treatment with yeast to reduce the concentration of ochratoxin A in red wine
2005
Evoluzione degli aromi varietali durante l’appassimento dell’uva Moscato d’Alessandria
2009
Studio dell’appassimento di uva Moscato bianco in fruttaio condizionato, nella zona dell’Asti
2007
Variazione territoriale della temperatura alla toposcala e qualità dell'uva della cv Nero d'Avola
2010
Valorizzare gli antociani dei vitigni siciliani
2007
Influence of yeast strain on ochratoxin A content during fermentation of white and and red must
2006
Evoluzione degli aromi varietali durante il processo di appassimento dell’uva Moscato bianco in fruttaia condizionata
2006
Tecnica dell'acidificazione dei vini
2008
Nuove acquisizioni sperimentali sul colore dei vini rossi
2008
Extraction of polyphenolic compounds and colour stabilization during ageing in different red winemaking procedures
2004
Relazioni fra i percorsi biosintetici degli HTCA, dei flavonoli e degli antociani nell'acini d'uva
2007
Impiego della lmax del vino nel visibile come indicatore della presenza di antociani copigmentati
2007
Profili aromatici dell'uva e del vino Sagrantino
2009
Trattamenti utili per abbassare il contenuto di Ocratossina A nei vini
2006
Tecnica dell’acidificazione dei vini per diminuire il pH o incrementare l’acidità totale
2009
Behaviour of some compounds with lmax at 280 nm in determination of total flavonoids of grape skin extracts made from a hydroalcoholic SO2-rich solve…
2010
This paper reports the results of a study on the ambiguous behaviour of substances with lmax at 280 nm in the determination of total flavonoids in whole grape skin extracts made from a hydroalcoholic SO2-rich solvent, apparently not eluted with methanol after absorption on a C18 cartridge employed for sample pre-concentration and SO2 removal. After rejecting the hypothesis that they were irreversibly absorbed on the C18 cartridge, it seemed that they reacted with other phenolics during passage through the C18 cartridge and were totally eluted with methanol in this new combined form. This new hypothesis seems very probable and is in accord with the more recent acquisition about the synthesis…
Esaltare gli aromi varietali con la tecnica enologica
2008
EVOLUTION OF ANTHOCYANIN PROFILES FROM GRAPE TO WINE
2010
Aims: This study aimed at acquiring knowledge on the evolution of anthocyanins from grape to wine and the possibility of deducing the varietal origin of a wine from its anthocyanin profile. Methods and results: The anthocyanin “fingerprints”, or profiles, of a series of autochthonous Sicilian accessions and in the respective young wines were determined by HPLC-DAD in 2008. Data were evaluated by taking into account the development of percentages of side-ring disubstituted and trisubstituted anthocyanins, the ratio between acetylated and p-coumaroylated derivatives, and PCA results. From grape until the end of alcoholic fermentation, percentages of 3-glucosides of cyanidin, peonidin, delphin…
La criomacerazione con neve carbonica abbinata alla tecnica dell'estrazione differita degli antociani
2006
Vitigni autoctoni siciliani, un valore aggiunto che cresce
2008
Produzione di vini rosati con affinamento sur lies
2009
Influenze climatiche sull’accumulo degli antociani di vitigni autoctoni ed internazionali
2008
Evoluzione di alcune classi di polifenoli durante la maturazione dell’uva in diversi ambienti dell’Etna.
2010
Evoluzione degli antociani e dei flavonoidi durante la maturazione di uve autoctone e internazionali nell’ambiente della Sicilia Occidentale.
2009
In the 2006 vintage was followed the evolution of total anthocyanis and total flavonoids of skins as well as of monomer catechins, dimer procyanidins and total flavonoids of seeds of Nero d’Avola, Syrah, Merlot and Cabernet sauvignon berries, in environments of average hill of western Sicily, warm - arid during the maturation period (from 18 to 21 August the temperatures overcome 40 °C). The situation of stress, caused by the high temperatures registered in the above period, even if negatively influenced the synthesis of the anthocyanis, did not induce important variations in the profiles of these molecules that remained quite invariant especially in Nero d’Avola and Syrah. The consequences…