Impact of season, rootstock, and cultivar on chemical composition and volatile profiles of ‘Arinto’ and ‘Fernão Pires’ white wines from a tropical climate

Development of a dynamic headspace solid-phase microextraction procedure coupled to GC–qMSD for evaluation the chemical profile in alcoholic beverages

Characterization of the volatile fraction of young wines from the Denomination of Origin “Vinos de Madrid” (Spain)

<p style="text-align: justify;"><strong>Aims</strong>: This study was designed to gain knowledge of three Controlled Denomination of Origin (DOC) Italian sweet white Passito wines (Caluso Passito DOC, Cinque Terre Sciacchetrà DOC and Passito di Pantelleria DOC) produced in several areas of Italy from grapes dried with different systems and vinification techniques.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Physico-chemical and chromatic characteristics, sodium, potassium, gluconic acid, glucono-γ-lactone, acetaldehyde, sorbitol, laccase, organic acids and semi-quantitative free volatile profile were determined on these wines. Caluso Passito DOC wines presented higher contents of organic acids (above all, malic acid), main metabolites from noble Botrytis cinerea (laccase, glycerol, gluconic acid and benzaldehyde) and low contents of total polyphenols. Among the volatile components, normal fatty acid ethyl esters (ethyl hexanoate and ethyl octanoate), branched-chain esters (ethyl 2-methylpropanoate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate) and benzaldeyde characterized this Passito wine. Cinque Terre Sciacchetrà DOC wines showed the lowest total acidity with a lower amount of malic acid and a higher content of polyphenols. This wine was characterized by some predominant acetates (isoamyl acetate), alcohols, benzaldehyde and an isoprenoid, ß-damascenone. Passito di Pantelleria DOC wines presented higher amounts of ashes resulting in higher pH values compared to the other two Passito typologies. Due to its production from aromatic grapes, it showed several varietal components such as terpenes, while ethyl esters/acetates and alcohols were less represented.</p><p style="text-align: justify;"><strong>Conclusion</strong>: This survey provides information allowing the characterisation of three Passito dessert wines at high commercial value.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This study provides oenological information to be utilised to protect and valorise the Controlled Denomination of Origin sweet wine production and contributes to the preservation of traditional and terroir productions and their commercialization.</p>

The aim of this work was to study the effect of different configurations of packaging on the volatile composition and sensory properties of a white wine. Certain oenological parameters were also evaluated. Bag-in-box (BIB) and glass bottles sealed with two different cork stoppers, natural and Neutrocork (technical), were used in the experiments. Analysis were carried out before packaging and after 3, 6 and 12months of storage. Results showed that wines packaged in BIB presented higher levels of brown color than wines in bottles sealed with corks. In all packaging configurations, the content of free SO2 decreased with storage time; however, BIB wines showed a lower content of free SO2 than bottle wines during 12months. Moreover, wines under BIB presented a significant lower amount of 2-phenylethanol, 2-phenylethyl acetate, isoamyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, linalool and β-damascenone than bottled wines.

The head-space volatiles of Gethyllis afra and G. ciliaris fruits collected in the South Western Cape Province of South Africa were analysed by solid phase micro-extraction (SPME) followed by gas chromatography coupled to mass spectrometry (GC-MS). Twenty-nine compounds were characterized in the fruit of G. ciliaris representing 96.5% of the total composition. Major compounds include pentacosane (19.2%); ethyl octanoate (18.0%); ethyl isovalerate (11.7%); ethyl hexanoate (9.1%) and ethyl benzoate (7.4%). These compounds may be the major contributors to the fruity-sweet odour of G. ciliaris. Forty-three compounds were identified in the fruit of G. afra representing 87.9% of the total composition with α-pinene (11.2%), n-butyl n-butyrate (8.5%), isoamyl acetate (8.1%), β-pinene (6.4%) and 2-methylbutyl butyrate (5.8%) as main constituents. These major constituents may impart the banana/piney/fruity odours associated with the G. afra. The compounds identified in the volatiles of the two fruits in amounts greater than 1% include ethyl butyrate, ethyl isovalerate, isobutyl 3-methyl butyrate, ethyl octanoate and ethyl benzoate.

Carignan noir is one of the minor and ancient varieties from the Chilean wine scenario that has had a resurgence as a result of to its rediscovered oenological potential when cultivated under the conditions of the interior dryland area. Under these growing conditions Carignan noir wines stand out as fruit driven and fresh compared to those originating from other growing areas. On the other hand, it is well known that wine aroma composition depends mainly on variety, viticultural management and winemaking. Thus, the present study aimed to investigate the volatile composition of wines from Carignan noir grapes originating from ungrafted and grafted onto País grapevines, in ten sites of the Maule Valley (Chile) during two consecutive vintages. Higher alcohols were the most abundant volatile compounds, whereas ethyl esters and ß-damascenone were the most odoriferous compounds according to their odorant activity value. The dominant factor in Carignan noir wine volatile composition was season, whereas rootstock did not have a significant effect in differentiating the wines. In terms of climate, cold nights during the month prior to harvest correlated with higher linalool, α-terpineol and trans-3-hexen-1-ol content. The biologically effective degree-days index was inversely correlated with isoamyl acetate and 2-phenylethyl acetate content. Huglin's heliothermal and the average mean temperature of the warmest month indices were inversely correlated with ethyl vanillate, ethyl hexanoate and ethyl octanoate content. Site climate conditions were related to the accumulation of certain wine volatile compounds. This information may be useful for devising new Carignan noir vineyard management strategies when aiming to improve wine quality or adjust site selection approaches to maximize grape/wine volatile composition according to wine style. © 2018 Society of Chemical Industry.

The effect of heat and light on the composition of some volatile compounds in wine

SummaryGlutathione and N‐acetylcysteine, each at 20 mg L−1, were tested as inhibitors of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by glutathione and N‐acetylcysteine, each at 0–20 mg L−1, was also tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. Glutathione or N‐acetylcysteine significantly restricted the decrease of these volatiles. In the model medium, each thiol inhibited the decrease of the three volatiles in a dose‐dependent manner. N‐acetylcysteine inhibited the decrease of all three volatiles at 2.5 mg L−1 while glutathione at 2.5 or 5.0 mg L−1. The present results indicate that glutathione and N‐acetylcysteine may be taken into account as potent inhibitors of the disappearance of aromatic esters and terpenes in wines.

A mixture of N-acetyl-cysteine + caffeic acid, at 10 + 30 mg/L respectively, was tested as inhibitor of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by the mixture, at 1.25 + 3.75 to 10 + 30 mg/L, was tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. The mixture of N-acetyl-cysteine + caffeic acid restricted the decrease of these volatiles to a large extent. In the model medium, the mixture inhibited the decrease of the three volatiles in a dose dependent manner. It was active at any concentration tested. The present results indicate that mixture of N-acetyl-cysteine + caffeic acid, containing each compound at low concentration, may be taken into account as an effective inhibitor of the disappearance of volatile aroma in wines.

Co-cultivation of non-conventional yeast with Saccharomyces cerevisiae to increase the aroma complexity of fermented beverages

Chemical composition and larvicidal activity of edible plant-derived essential oils against the pyrethroid-susceptible and -resistant strains of Aedes aegypti (Diptera: Culicidae)

Volatile components of Zalema white wines

The effects of several enological practices on ochratoxin A (OTA) concentration in wines were evaluated. Analysis of OTA was performed by reverse-phase high-performance liquid chromatography (HPLC) after immunoaffinity cleanup. Higher...

The effects of several enological practices on ochratoxin A (OTA) concentration in wines were evaluated. Analysis of OTA was performed by reverse-phase high-performance liquid chromatography (HPLC) after immunoaffinity cleanup. Higher toxin levels were found in red wines (0.017 to 0.050 μg/L) than white wines (0.006 to 0.022 μg/L). Intensive pressing of pomace, prolonged drying of grapes, and storage in partially empty tanks increased OTA contamination of wines. Poor winery sanitation practice was the primary source of OTA contamination, as wines from contaminated wineries had the highest OTA values (0.130 to 1.300 μg/L). Filtration through a 10-μm membrane and heating on hot plates at 55°C did not cause a significant decrease in the toxin level. An 80% decrease of OTA was observed after wine filtration through a 0.45-μm membrane (<i>p</i> &lt; 0.05). Eleven enological fining agents were tested to study their ability to remove OTA from wine. Enological decolorizing carbon removed (at 30 g/hL) up to 72% of OTA. The Freundlich isotherm was used to model OTA adsorption on carbon. Results showed that carbon had selective adsorption (K_F = 3.172 (mg/g)/(mg/L)^0.8474), but it did not affect polyphenol content and color of red wine. Nevertheless, a decrease of key sensory odorants of wine, such as 3-methylbutyl acetate, ethyl hexanoate, ethyl octanoate, and geraniol, was observed.

Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by Saccharomyces cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated wines, most of the compounds with fresh fruit odor descriptors, including those with the greatest odor activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated wines the low-relative-concentration compounds with dried fruit and pastry odors. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S. cerevisiae.