Acacia, cherry and oak wood chips used for a short aging period of rosé wines: effects on general phenolic parameters, volatile composition and sensory profile.

BACKGROUND: There is a restricted knowledge about the potential impact of the use of different wood chip species on the rosé wine aging process. Thus, the aim of this work was to evaluate the general phenolic parameters, aroma composition and sensory profile of rosé wines during a short maturation (20 aging days) in contact with wood chips from oak, acacia and cherry. In addition, the different wood chips were added to a rosé wine without a previous clarification process (unfined wine) and to a rosé wine submitted to a clarification process (fined wine). RESULTS: For the brief maturation time considered, the use of different wood chips induced a tendency for an increase of phenolic content, in particular for unfined rosé wine aged in contact with acacia chips. For volatile composition, the differentiation was clearer for aldehyde compounds group. Regarding sensorial overall appreciation the panel test preferred the unfined rosé wine aged in contact with acacia wood chips. CONCLUSIONS: The results show that, in general, the use of different wood chip species (acacia, cherry and oak) for a brief maturation time of rosé wines could play an important role in rosé wine characteristics, in particular in their phenolic composition. © 2019 Society of Chemical Industry.

Effect of Lachancea thermotolerans on the Formation of Polymeric Pigments during Sequential Fermentation with Schizosaccharosmyces pombe and Saccharomyces cerevisiae.

Anthocyanins in red grape musts may evolve during the winemaking process and wine aging for several different reasons; colour stability and evolution is a complex process that may depend on grape variety, winemaking technology, fermentative yeast selection, co-pigmentation phenomena and polymerization. The condensation of flavanols with anthocyanins may occur either with the flavylium ion or with the hemiacetal formation in order to produce oligomers and polymers. The kinetics of the reaction are enhanced by the presence of metabolic acetaldehyde, promoting the formation of pyranoanthocyanin-type dimers or flavanol-ethyl-anthocyanin structures. The experimental design carried out using white must corrected with the addition of malvidin-3-O-glucoside and flavanols, suggests that non-Saccharomyces yeasts are able to provide increased levels of colour intensity and larger polymeric pigment ratios and polymerization indexes. The selection of non-Saccharomyces genera, in particular Lachancea thermotolerans and Schizosaccharomyces pombe in sequential fermentation, have provided experimental wines with increased fruity esters, as well as producing wines with potential pigment compositions, even though there is an important reduction of total anthocyanins.

First Approach to the Aroma Characterization of Monovarietal Red Wines Produced from Varieties Better Adapted to Abiotic Stresses.

Adaptation strategies in the wine sector consist of the use of cultural techniques to limit damages caused by climate change, using, among other resources, varieties better adapted to the scenarios of abiotic stress exacerbation, namely water and thermal stress, as well as those more tolerant to heatwaves. With the intention to determine the aromatic characterization of ten monovarietal wines produced from cultivars with high productive performance in a global warming scenario ('Petit Verdot', 'Marselan', 'Merlot', 'Touriga Franca', 'Syrah', 'Vinhão', 'Bobal', 'Preto Martinho', 'Trincadeira', and 'Alicante Bouschet'), grown in Esporão vineyard (Alentejo, Portugal) and submitted to deficit irrigation (Ks ± 0.5), their aromatic character has been analyzed. Each grape variety was vinified at a small scale, in duplicate, and the wines were evaluated by a sensory panel, which rated several sensory attributes (visual, olfactory, and gustatory). Sensory analysis revealed a discrete appreciation for the monovarietal wines tasted, showing a differentiation at the olfactory level that was not too marked, although present, between the samples. The free volatile compounds were analysed using gas chromatography-olfactometry (GC-O), identified using a gas chromatography-mass spectrometry (GC-MS) technique and semi-quantified using the gas chromatography-flame ionization detector (GC-FID) technique. Based on the interpolation of the results of the various statistical analyses carried out, 49 probable odor active compounds (pOACs) were identified and based on the odor activity values (OAVs), 24 of them were recognized as odor active compounds (OACs) originated mainly during the fermentation processes. An aromatic characterization of the varieties has been proposed.

Grape Flavonoid Evolution and Composition Under Altered Light and Temperature Conditions in Cabernet Sauvignon (Vitis vinifera L.).

The evolution of flavonoids under altered temperature and light conditions in the fruit zone was followed in Cabernet Sauvignon (Vitis vinifera L.) grapes during ripening. The study was conducted over two consecutive seasons in 2010/2011 and 2011/2012 comprising two main treatments in which the light quantity was manipulated in the bunch zone: (1) standard (STD) with no lateral shoot or leaf removal and (2) leaf removal west (LRW) treatment with leaf removal on the western side of the bunch zone. Furthermore, the light quality was altered by installing ultraviolet B-suppression sheets within the bunch zone in both seasons. Tannin evolution was dependent on the prevailing light quality/quantity and temperatures during berry development in a particular season. Grape seed tannin accumulation coincided with seed development and commenced at the early stages of berry development. Seed proanthocyanidin composition was not influenced by the treatments. The largest impact on proanthocyanidin accumulation and structure in the skin was due to seasonal variations highlighting the complex interaction between light quality and/or quantity across the two growing seasons and eventually the complex interaction with temperature. Flavonol accumulation was significantly influenced by the light quality, which is known to be the main abiotic driver of flavonol biosynthesis regulation. Anthocyanin concentration and content were largely dependent on the temperature and light quality in a particular season. Anthocyanin composition was altered by the season rather than the treatment.

Chemical characterization and antioxidant activities of oligomeric and polymeric procyanidin fractions from grape seeds.

Two procyanidin fractions, namely oligomers and polymers isolated from grape seed methanolic extract were characterized. Phenolic composition and procyanidin purity of these fractions were determined by normal-phase and reverse-phase HPLC, thioacidolysis-HPLC, ESI-MS analyses, formaldehyde-HCl precipitation and elemental analysis. Antioxidant activities of these fractions and other well-known antioxidants were measured using xanthine-xanthine oxidase system for generating superoxide radical ({O2(-)}), the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical method and the Fenton system for generating hydroxyl radical (HO). The results showed that both oligomeric and polymeric procyanidin fractions were highly pure, with the degree of polymerization ranging from 2 to 17-18 and 12 to 32-37, respectively. On the basis of molar concentration, polymeric procyanidins appeared the highest antioxidant activities, followed by oligomeric procyanidins, whereas catechins presented a lower antioxidant activity than its oligomers and polymers. These results indicate that the antioxidant activities of grape seed procyanidins are positively related to their degree of polymerization. Moreover, grape seed procyanidins presented higher antioxidant activities than other well-known antioxidants such as vitamin C, suggesting that grape seed procyanidins might be of interest to be used as alternative antioxidants.

Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.

The evolution of mineral composition and wine strontium isotopic ratio 87Sr/86Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87Sr/86Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87Sr/86Sr, not precluding the use of this parameter for wine traceability purposes.

Kinetics of odorant compounds in wine brandies aged in different systems.

The odorants compounds of aged wine brandies comprise compounds deriving from the wood, from the distillate and from the reactions that occur inside the barrel. The aim of this work was to study the kinetics of the odorant compounds of a wine brandy during two years of ageing in two ageing systems. The odorant compounds in the analysed brandies changed significantly over the time, but with different evolution patterns. The wood related compounds increased over time, with the highest increase in the first months of ageing. The kinetics of cis, trans-ß-methyl-γ-octalactone, acetovanillone and of seven volatile phenols are established for the first time in brandies. Moreover, a significant effect of the ageing system was found on the kinetics of the wood related compounds. These results pointed out the interest of these compounds as a tool to discriminate different ageing technologies.

Effects of cultivar and processing method on the contents of catechins and procyanidins in grape juice.

The aim of the presented work was to study the effect of pressing method, pasteurization, cultivar, and vintage on the content of (+)-catechin, (-)-epicatechin, and nine procyanidins in grape juice. The results showed that the concentration of these flavan-3-ols in the juice was influenced, in decreasing order of importance, by pressing method, cultivar, pasteurization, and vintage. Cold pressing without maceration was the least and hot pressing after maceration at 60 degrees C for 60 min the most effective method for extracting the flavan-3-ols. Pasteurization increased the concentration of catechins in cold-pressed juices, but it decreased concentrations in hot-pressed juices. The concentration of most procyanidins was increased by pasteurization. Among the white cultivars, Seyval and Niagara were highest in procyanidins and Elvira and Chardonnay were highest in catechins. Vincent, Foch, and Baco were the red cultivars highest in catechins, and Vincent also had the highest content of procyanidins.

Monomeric, oligomeric, and polymeric flavan-3-ol composition of wines and grapes from Vitis vinifera L. Cv. Graciano, Tempranillo, and Cabernet Sauvignon.

The monomeric, oligomeric, and polymeric flavan-3-ol composition of wines, grape seeds, and skins from Vitis vinifera L. cv. Graciano, Tempranillo, and Cabernet Sauvignon has been studied using (1) fractionation by polyamide column chromatography followed by HPLC/ESI-MS analysis, (2) fractionation on C(18) Sep-Pak cartridges followed by reaction with vanillin and acid-catalyzed degradation in the presence of toluene-alpha-thiol (thiolysis). The content of monomers ((+)-catechin and (-)-epicatechin), procyanidin dimers (B3, B1, B4, and B2), trimers (T2 and C1), and dimer gallates (B2-3-O-gallate, B2-3'-O-gallate, and B1-3-O-gallate) ranged from 76.93 to 133.18 mg/L in wines, from 2.30 to 8.21 mg/g in grape seeds, and from 0.14 to 0.38 mg/g in grape skins. In wines, the polymeric fraction represented 77-84% of total flavan-3-ols and showed a mean degree of polymerization (mDP) value of 6.3-13.0. In grapes, the polymeric fraction represented 75-81% of total flavan-3-ols in seeds and 94-98% in skins and showed mDP values of 6.4-7.3 in seeds and 33.8-85.7 in skins. All the monomeric flavan-3-ols and oligomeric procyanidins found in wines were also present in seeds, although differences in their relative abundances were seen. The skin polymeric proanthocyanidins participated in the equilibration of the wine polymeric proanthocyanidin fraction, especially contributing to the polymer subunit composition and mDP.

Vitis vinifera secondary metabolism as affected by sulfate depletion: diagnosis through phenylpropanoid pathway genes and metabolites.

Grapevine (Vitis vinifera L.) is rich in phenylpropanoid compounds, namely flavonoids and stilbenes which, present in most tissues, are described as antioxidants and known to accumulate in response to biotic and abiotic stress. Grapevine is then a choice model for studying the interplay between the phenylpropanoid pathway and nutrient deficiency. Here we report the response to sulfur deficiency (-S) of flavonoids and stilbenes biosynthetic pathways in chlorophyll tissues (plantlets) and cell culture. Anthocyanins and trans-resveratrol accumulated in plantlets and trans-resveratrol glucoside in cell cultures in response to sulfur deficiency, while a significant decrease in chlorophyll was observed in -S plantlets. The up-regulation of chalcone synthase gene and the downstream flavonoid biosynthesis genes dihydroflavonol reductase and anthocyanidin synthase matched the accumulation of anthocyanins in -S V. vinifera plantlets. The mRNA level of stilbene synthase gene(s) was correlated tightly with the increase in trans-resveratrol and trans-resveratrol glucoside levels, respectively in -S plantlets and cell cultures. As a whole, the present study unveil that V. vinifera under sulfur deficiency allocates resources to the phenylpropanoid pathway, probably consecutive to inhibition of protein synthesis, which can be advantageous to resist against oxidative stress symptoms evoked by -S conditions.

Comparative study of the phenolic composition of seeds and skins from Carménère and Cabernet Sauvignon grape varieties (Vitis vinifera L.) during ripening.

The phenolic composition of skins and seeds from Vitis vinifera L. cv. Carménère and Cabernet Sauvignon grapes during ripening was evaluated by high-performance liquid chromatography-diode array detection and spectrophotometric analysis. As compared to Cabernet Sauvignon grape skins, Carménère grape skins presented higher contents of total anthocyanins, monomeric flavan-3-ols, and total flavonoids, a higher mean degree of polymerization, a higher percentage of galloylation, a higher average molecular weight of the flavanol fraction, and a higher color intensity. As compared to Cabernet Sauvignon grape seeds, Carménère grape seeds presented a lower content of monomeric flavan-3-ols, a higher mean degree of polymerization, a higher percentage of galloylation, a higher average molecular weight of the flavanol fraction, a lower content of (+)-catechin, and higher contents of (-)-epicatechin, epicatechin-3-O-gallate, gallic acid, and dimeric procyanidins esterified with gallic acid. Altogether, we conclude that Carménère grapes present a differential composition and evolution of phenolic compounds when compared to Cabernet Sauvignon grapes.