Influence of dipping pretreatments in drying of ‘Pedro Ximenez’ grapes in chamber at controlled temperature
The influence of dipping pretreatments on drying of ‘Pedro Ximenez’ grapes, destined to the elaboration of sweet wines, in chamber at controlled temperature, has been studied. Changes in color and phenolic composition of raisins produced were observed during the process of raisining.
Chemical systems behind wine aroma perception: overview, genesis and evolution
This talk presents a revision of our knowledge and understanding of the role played by the different aroma chemicals in the positive aroma attributes of wine. A systematic approach to classifying the different aroma chemicals of wine is presented .
Uvalino wine: chemical and sensory profile
The evaluation of different chemical compounds present in Uvalino wines was correlated with sensory analysis. The analysis showed a high content of polyphenolic compounds responsible for the organoleptic properties of wine, including color, astringency and bitterness.
Different oxygen and sulphur dioxide concentrations in ‘Sauvignon blanc’ must: effect on the composition of the must and wine
The effects of different oxygen and sulphur dioxide additions to South African ‘Sauvignon blanc’ musts were investigated. Oxygen addition without SO2 protection led to lower levels of certain volatile thiols in the wines, with a corresponding decrease in certain phenols and glutathione concentrations.
Aroma profile of ‘Pedro Ximenez’ sweet musts obtained from dried grapes by different methods
Aroma fraction of musts from grapes ‘Pedro Ximenez’ traditionally sun-dried and chamber-dried at 40 ºC and at 50 ºC during 8, 5 and 4 days respectively, destined for the production of sweet wines in Montilla-Moriles region (southern Spain) was studied.
Spur-pruning cordon for ‘Barbera’ vines in Piedmont
The traditional pruning system in Piedmont (North-West Italy) is the Guyot system; it requires trained personnel, difficult to find, and it does not permit the mechanization of winter pruning, thus it is very expensive. An alternative technique that could allow the reduction of the vineyard management costs could be the spur-pruning which is simpler to perform and fully mechanized.
Immunotestπ: a new test for the determination of proteic stability in white and rosé wines
Proteic haze is a problem which may occur in all fruit-based beverages and fermented juices (beer, cider, wine). When it occurs, the economic loss is important.
Optimization of aroma production in grape cell suspensions induced by chemical elicitor
Methyl-jasmonate (MeJA) induces the production of at least 25 compounds with sesquiterpene- like mass spectra in ‘Cabernet sauvignon’. Tost effective concentration of MeJA in stimulating the production of sesquiterpenes was found to be 500 µM if added when the cell suspensions had a PCV of 35 %, and 1000 if added when the cell suspensions had a PCV of 70 %.
Postharvest elicitors and metabolic changes in wine grape berries
Wine grape berries respond to postharvest treatments with specific gaseous elicitors in terms of metabolic changes and composition. Short-term (3 days) high (30 KPa) CO2 treatment affects phenol compound concentration in skins of ‘Trebbiano toscano’ berries.
Effect of Botrytis cinerea and esca on phenolic composition of berries and wines
This study showed that Botrytis cinerea could degrade the phenolic compounds by its enzymatic activity. It led to a diminution of skin’s anthocyanins from 20 % to 50 % and an increase level up to 40 % of individual proanthocyanins, 30 % of the %G and 25% of the %P.
Evaluation of winegrape anthocyanins in the vineyard using a portable fluorimetric sensor: seasonal and water regime effects
Accumulation of anthocyanins (Anth) on whole winegrape (Vitis vinifera L.) bunches attached to the vine was monitored by a fluorescence-based sensor (Multiplex) on ‘Aleatico’ and ‘Nero d’Avola’. Different water regimes were applied.
Outside and inside grapevine roots: arbuscular mycorrhizal fungal communities in a ‘nebbiolo’ vineyard
In field conditions, grapevine roots are colonized by arbuscular mycorrhizal fungi (AMF). Little is known about the species composition of AMF communities associated to grapevine.
Influence of different environments on grape phenolic and aromatic composition of threeclone of ‘nebbiolo’ (Vitis Vinifera L.)
The interaction between cultivar and growing environment is the base of wine quality and typicality. In recent time the behaviour of different clones within the same cultivar became another fundamental factor influencing the enological result. In order to clarify cultivar/clone/environment relations, a trial was carried out in 2008 studying the performances of three clones of ‘Nebbiolo’, grown in different environments: south-east Piedmont (hilly and characterized by a loamy and alkaline soil) and north-east Piedmont (a plain area characterized by a sandy and acidic soil).
Ultra high pressure liquid chromatography for stilbenes separation and their determination in Burgundy red wines
In this study for the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)-trans-s-viniferin, pallidol and hopeaphenol) isolated and purified from Vitis vinifera, were simultaneously separated and analysed within 5 mn by ultra high pressure liquid chromatography coupled with photodiode array detection.
Evolution of biogenic amines content in wine during sample conservation – method optimisation for analysis of biogenicamines
The present paper reports the development of an optimized method for simultaneous analysis of
8 biogenic amines (Histamine, Methylamine, Ethylamine, Tyramine, Putrescine, Cadaverine, Phenethylamine, and Isoamylamine). It is based on a method developed by Gomez-Alonso et al. in 2007.
Phenolic composition of Bordeaux grapes 2009 vintage: comparison with 2006, 2007 and 2008 vintages
‘Cabernet sauvignon’ and ‘Merlot’ are among the most recognized red wine grape cultivars. This work is aimed at investigating the proanthocyanidin composition of skins and seeds to determine the grape variety and the vintage effects on the phenolic composition of Bordeaux grapes.
Changes in wine secondary metabolites composition by the timing of inoculation with lactic acid bacteria: impact on wine aroma
For the first time, it was established that the timing of inoculation with LAB could significantly impact the concentration of many secondary metabolites leading to significant aromatic changes. From studied compounds, the most influenced were esters and diacetyl.
Investigation of the effect of gelatine and egg albumin fining and cross-flow microfiltration on the phenolic composition of Pinotage red wine
Results indicated that cross-flow microfiltration removed similarly to fining treatments the most astringent tannins, but cross-flow microfiltration also removed up to 14 % more colour. RP-HPLC and spectrophotometric results showed that egg albumin is a softer fining treatment compared to gelatine and cross-flow microfiltration.
Identification and quantification of c-glucosidic ellagitannins and their derivative in red wine aged in oak barrels
The C-glycosidic ellagitannins constitute a subclass of hydrolyzable tannins of remarkable structural diversity. In this work we first achieved the hemisynthesis of flavano-ellagitannins, then we used them to develop a new efficient detection and quantification procedure for the C-glycosidic ellagitannins as well as flavano-ellagitannins.
Interaction between commercial mannoproteins and phenolic compounds of two red wines from different Portuguese grape cultivars
The interaction between mannoproteins and wine phenolic compounds is a subject of great interest as some studies show the possible impact in color stability and an improvement in the sensory characteristics namely the reduction of red wine astringency.