Chemical Composition Of Wines Research Articles

Effect of strains from different <i>Saccharomyces</i> species used in different inoculation schemes on chemical composition and sensory characteristics of Sauvignon blanc wine

Enhancing the sensory profile of wine using different microorganisms has always been a challenge in winemaking. The aim of our work was to evaluate the impact of different fermentation schemes by using mixed and pure cultures of three different Saccharomyces species at classic and cold inoculation temperatures on wine chemical composition and sensory profile. All the produced wines were analysed for the main oenological parameters (total acidity, volatile acidity, residual sugars, alcohol, and malic acid), as well as for volatile aromatic compounds, such as higher alcohols, acetate esters, ethyl esters and varietal thiols. In addition, implantation monitoring at the strain level and sensory analyses were performed in all fermentation trials. The wines fermented with S. pastorianus strains were characterised by significant lower acetic acid production and greater malic acid degradation compared to the wines fermented with S. cerevisiae strains. Interestingly, when the inoculation process for all trials was performed at a cold temperature (13 °C), the typical aromas of Sauvignon blanc were stronger than those in the classic inoculation temperature (18 °C) trials. Furthermore, the co-inoculation of S. pastorianus and S. bayanus resulted in wines exhibiting a higher intensity of citrus fruit notes than the wines fermented with the commercial S. cerevisiae strains. These results show that some strains from different Saccharomyces species other than S. cerevisiae, such as S. pastorianus and S. bayanus, could be promising starters for Sauvignon blanc wines and their performance can be modulated by the inoculation conditions.

Identification of putative chemical markers in white wine (Chasselas) related to nitrogen deficiencies in vineyards

Aim: Wine quality is influenced by the nitrogen nutrition of grapevines in the vineyard. A deficiency of this nutrient will affect grape quality, decrease yeast available nitrogen (YAN) and influence alcoholic fermentation. Chasselas wines from nitrogen-deficient grapes (YAN < 140 mg N/L) are systematically more astringent and bitter and less fruity than those from grapes with higher YAN content (Spring et al., 2014). The aim of this study was to identify chemical markers in wine linked to nitrogen deficiencies in the vineyard.Methods and results: Wine samples produced from grapes growing in nitrogen-deficient vineyards with nitrogen treatment (HN) and without it (LN) were used over four consecutive years (2006–2009). They were all analysed at the same time (2012) with electronic-nose, GC-MS and UHPLC-TOFMS techniques. A metabolomics approach was used for a comprehensive survey of volatile and nonvolatile compounds in order to identify markers related to nitrogen nutrition. Volatile markers with alcohol and ester functions and nitrogen-containing compounds were found and tentatively identified by GC-MS. Additionally, 16 nonvolatile markers were putatively identified by UHPLC-TOFMS, including compounds from diverse chemical classes, namely, amino acids, vitamins, hormones, organic acids, phenolic compounds and polysaccharides.Conclusion: The nitrogen nutrition of grapevines has a clear but complex effect on the chemical composition of wine. Several markers were tentatively identified and their role in wine composition discussed according to the actual knowledge reported in the literature.Significance of the study: This study is an important starting point for selecting the most relevant chemical markers in wine, and for determining whether organoleptic problems are related to nitrogen nutrition deficiency in the vineyard and changes in vineyard management are needed.

Antimicrobial Activity of Selected Red and White Wines against Escherichia coli: In Vitro Inhibition Using Fish as Food Matrix.

Five different wines (standard Graševina, macerated Graševina with and without sulfur, rosé, and standard Plavac Mali), all typical Croatian wines, were tested to determine the antimicrobial activity against two Escherichia coli bacterial strains (ATCC® 25922 and ATCC® 8739) in vitro and using sea bass (Dicentrarchus labrax) fillets as food matrix. The chemical composition of wines (pH, acidity, alcohol, total phenolics, anthocyanins, tannins, and sulfur content) and antimicrobial activity (minimal inhibitory concentration (MIC), agar-well diffusion method) were determined. The total phenolic content of the wines ranged from 305–3210 mg gallic acid equivalents per liter (GAE/L), and did not correlate to antimicrobial activity. The two wines with the lowest phenolic content (standard Graševina and rosé) had the lowest MIC values (122 and 429 mg GAE/L). A specific relation between the winemaking process and a particular MIC value was not established. There was also no relation found between the pH value, ethanol content, sulfur, or phenolics in regards to the antimicrobial effect. In fish fillets marinated in wine + water mixture (v/v = 1:1) and inoculated with 7 log colony forming units (CFU)/25 g the growth of bacteria was reduced after three days of storage at 4 °C. Subsequent storage resulted in the growth of bacteria in all samples, with the lowest growth of E. coli ATCC® 25922 in macerated Graševina and E. coli ATCC® 8739 in standard Graševina. All wines showed the capacity to reduce the number and growth of heavily infected sea bass filets, but correlation with specific wine constituents was not found. Taking into account the numerous reactive mechanisms between food and wine, all in vitro studies in controlled laboratory conditions should be further verified in the relevant environment, and additional research is needed to clarify the role of individual wine components in the mechanism of antimicrobial activity.

Impact of different temperature profiles on simultaneous yeast and bacteria fermentation

PurposeThe role of fermentation temperature was studied for its impact on the evolution of malolactic fermentation performed by simultaneous inoculum of yeast and bacteria in grape must. Results were discussed considering the different fermentative kinetics and the composition of obtained wines.MethodsTwo strains of bacteria belonging to the O. oeni and L. plantarum species were inoculated 24 h after the beginning of the alcoholic fermentation in 2 grape musts having different acidic and sugar profiles. Fermentations were conducted at 3 different temperature profiles (16/22 °C in 3 days, 18/24 °C in 3 days, 22/32 °C in 5 days). Evolution of microbiota was followed by flow cytometry and plate count. Chemical analysis of grape musts and wines were performed by instrumental approaches (FT-IR, enzymatic quantification of malic acid, GC-MS).ResultsL. plantarum resulted more efficient in malic acid consumption in the entire set of tests. These results are unexpected because, generally, Lactobacillus has been reported to be more sensitive to an oenological environment than O. oeni. In our experiments, O. oeni resulted inhibited by the highest fermentation temperature profile, causing incomplete malic acid degradation. Similarly, S. cerevisiae showed a higher sensitivity to environmental limiting factors in respect to what is generally known. Differences in the chemical composition of wines were observed in relation to the bacteria strain and the temperature profile. However, the statistical treatment of data identified temperature as the main variable able to influence the features of wines.ConclusionsSimultaneous inoculum of yeast and bacteria in grape must is an alternative approach in the management of malolactic fermentation which showed some interesting features. However, it is necessary to consider that the dynamics of the microbial population are different to that observed in traditional winemaking and the environmental variables act against the microorganisms in a peculiar, and in certain cases unexpected, way.

Influence of partial dealcoholization on the composition and sensory properties of Cabernet Sauvignon wines

Worldwide, winemakers are increasingly adopting alcohol management strategies to counter the higher wine ethanol concentrations observed over the past ~30 years. Wines with high ethanol levels exhibit increased ‘hotness’ on the palate, which is generally considered to negatively impact wine quality. This study investigated changes in the chemical and sensory profiles of five Cabernet Sauvignon wines following their partial dealcoholization by reverse osmosis-evaporative perstraction (RO-EP). Descriptive analysis (DA) of wine before and after RO-EP treatment indicated dealcoholization did not strongly affect wine aroma and flavor, consistent with the small changes observed in wine chemical composition. However, significant differences in the perception of wine palate attributes were observed, with dealcoholized wines found to exhibit lower acidity, sweetness, bitterness, saltiness and/or body. Astringency was enhanced following partial dealcoholization of one wine, but diminished in another. Sensory trials were also undertaken to determine the optimal ethanol concentration of wines, or the ‘alcohol sweetspot’. Two approaches to alcohol sweetspotting of dealcoholized wines were evaluated, together with two methods of statistical analysis, chi-squared goodness of fit and one proportion tests.

Exploring yeast interactions through metabolic profiling

As a complex microbial ecosystem, wine is a particularly interesting model for studying interactions between microorganisms as fermentation can be done by microbial consortia, a unique strain or mixed culture. The effect of a specific yeast strain on its environments is unique and characterized by its metabolites and their concentration. With its great resolution and excellent mass accuracy, ultrahigh resolution mass spectrometry (uHRMS) is the perfect tool to analyze the yeast metabolome at the end of alcoholic fermentation. This work reports the change in wine chemical composition from pure and mixed culture fermentation with Lachancea thermotolerans, Starmerella bacillaris, Metschnikowia pulcherrima and S. cerevisiae. We could clearly differentiate wines according to the yeast strain used in single cultures and markers, which reflect important differences between the yeast species, were extracted and annotated. Moreover, uHRMS revealed underlining intra species metabolomics differences, showing differences at the strain level between the two Starmerella bacillaris. Non volatile metabolomics analysis of single and sequential fermentations confirmed that mixed fermentations lead to a different composition. Distinct metabolites appeared in wines from sequential fermentation compared to single fermentation. This suggests that interactions between yeasts are not neutral.

Co-Existence of Inoculated Yeast and Lactic Acid Bacteria and Their Impact on the Aroma Profile and Sensory Traits of Tempranillo Red Wine

This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria used.

Statistical Modelization of the Descriptor “Minerality” Based on the Sensory Properties and Chemical Composition of Wine

When speaking of “minerality” in wines, it is common to find descriptive terms in the vocabulary of wine tasters such as flint, match smoke, kerosene, rubber eraser, slate, granite, limestone, earthy, tar, charcoal, graphite, rock dust, wet stones, salty, metallic, steel, ferrous, etc. These are just a few of the descriptors that are commonly found in the tasting notes of wines that show this sensory profile. However, not all wines show this mineral trace at the aromatic and gustatory level. This study has used the statistical tool partial least squares regression (PLS) to mathematically model the attribute of “minerality” of wine, thereby obtaining formulas where the chemical composition and sensory attributes act jointly as the predictor variables, both for white wines and red wines, so as to help understand the term and to devise a winemaking approach able to endow wines with this attribute if desired.

Oenological potential of non-Saccharomyces yeasts to mitigate effects of climate change in winemaking: impact on aroma and sensory profiles of Treixadura wines.

The effects of climate change on wine include high-alcohol content, low acidity and aroma imbalance. The potential of several non-Saccharomyces wine yeasts to mitigate these effects was evaluated by sequential fermentation of Treixadura grape must. Fermentations with only Saccharomyces cerevisiae ScXG3 and a spontaneous process were used as control assays. All yeast strains were obtained from the yeast collection of Estación de Viticultura e Enoloxía de Galicia (EVEGA), Galicia, Spain. Fermentation kinetics as well as yeast dynamics and implantation ability varied depending on inoculated yeasts. In addition, the results showed significant differences in the chemical composition of wine. Starmerella bacillaris 474 reduced the alcohol content (1.1% vol) and increased the total acidity (1.2 g L-1) and glycerol of wines. Fermentation with Lachancea thermotolerans Lt93 and Torulaspora delbrueckii Td315 also decreased the alcohol content, although to a lesser extent (0.3% and 0.7% vol, respectively); however, their effect on wine acidity was less significant. The wines also differed in their concentration of volatile compounds and sensory characteristics. Thus, wines made with Metschnikowia fructicola Mf278 and S. cerevisiae ScXG3 had higher content of esters, acetates and some acids than other wines, and were most appreciated by tasters due to their fruity character and overall impression.

E-Beam Irradiation and Ozonation as an Alternative to the Sulphuric Method of Wine Preservation.

Potassium metabisulphite is usually used for microbial stabilization in the process of vinification and wine preservation, but it is considered to be allergenic. The objective of the present study was to assess the efficiency of ozonation and ionizing radiation as alternatives to wine sulphurization. The efficiency of yeast removal and the retention of the chemical quality of wine were evaluated. Wine was subjected to 60 min of ozonation, and radiation doses were set at 1–10 kGy. Moreover, a combination of ozonation and ionizing radiation treatment was used. The ozonation of wine did not produce the expected results. That is, it did not limit the number of yeast cells. From the sixth minute, a significant deterioration in the taste and the color of the wine was found. Ionizing radiation at a dose of 1 kGy reduced the yeast count by 95.5%, and a reduction of 99.9% was seen after the application of 2.5 kGy. Moreover, these doses did not have a significant effect on the organoleptic properties or the chemical composition of wine. The total amount of polyphenols reduced from the maximum of 1127.15 to 1023.73 mg at the dose of 5 kGy. Radiation is widely used to preserve food products. Its use for finished wine preservation may be an alternative to sulphurization.

Effect of Sequential Inoculation with Non-Saccharomyces and Saccharomyces Yeasts on Riesling Wine Chemical Composition

In recent years, studies have reported the positive influence of non-Saccharomyces yeast on wine quality. Many grape varieties under mixed or sequential inoculation show an overall positive effect on aroma enhancement. A potential impact by non-Saccharomyces yeast on volatile and non-volatile compounds should benefit the flavor of Riesling wines. Following this trend, four separate sequential fermentations (using the non-Saccharomyces yeasts Torulaspora delbrueckii, Metschnikowia pulcherrima, Pichia kluyveri, and Lachancea thermotolerans with Saccharomyces cerevisiae) were carried out on Riesling must and compared to a pure culture of S. cerevisiae. Sequential fermentations influenced the final wine aroma. Significant differences were found in esters, acetates, higher alcohols, fatty acids, and low volatile sulfur compounds between the different trials. Other parameters, including the production of non-volatile compounds, showed significant differences. This fermentation process not only allows the modulation of wine aroma but also chemical parameters such as glycerol, ethanol, alcohol, acidity, or fermentation by-products. These potential benefits of wine diversity should be beneficial to the wine industry.

Effects of high power ultrasound treatments on the phenolic, chromatic and aroma composition of young and aged red wine.

In this study, the effects of both ultrasonic bath and probe treatments on the phenolic, chromatic and aroma composition of young red wine Cabernet Sauvignon were studied and modeled by artificial neural networks (ANNs). Moreover, the effect of high power ultrasound (HPU) along with antioxidants addition (sulfur dioxide and glutathione) was investigated during 6 months of aging in bottles. Lower amplitude and temperature, shorter treatment duration and particularly lower frequency showed a more favorable and milder effect on the chemical composition of wine. In the case of the ultrasonic probe treatment, similar effect was achieved primarily by a larger probe diameter as well as lower amplitude and treatment duration. Selected ANN models showed the best predictions for the chromatic characteristics followed by total phenolics and anthocyanins. The changes induced by HPU treatment after 6 months of aging were mainly detected in the composition of phenolic compounds (both total and individual), where higher concentration of antioxidants (sulfur dioxide and glutathione) slowed down the decrease rate of these compounds during aging. However, HPU treatment did not influence most of the chromatic characteristics and aroma compounds, except lightness and fatty acids. The obtained results indicated that suitable ultrasound treatment might accelerate some aging reactions and shorten the period of wine aging.

Modelling wine astringency from its chemical composition using machine learning algorithms

Aims: The present work aims to predict sensory astringency from wine chemical composition using machine learning algorithms.Material and results: Moristel grapes from different vineblocks and at different stages of ripening were collected. Eleven different wines were produced in 75 L tanks in triplicate, and further sensory factors were described by the rate-all-that-apply method with a trained panel of participants. The polyphenolic composition was characterised in wines by measuring the concentration and activity of tannins using UHPLC-UV/VIS, the mean degree of polymerisation (mDP. and the composition of tannins using thiolysis followed by UHPLC-MS. Conventional oenological parameters were analysed using FTIR and UV-Vis. Machine learning was applied to build models for predicting a wines astringency from its chemical composition. The best model was obtained using the support vector regressor (radial kernel) algorithm presenting a root-mean-square error (RMSE) value of 0.190.Conclusions: The main variables of the astringency model were the % of procyanidins constituting tannins and ethanol content, followed by other eight variables related to tannin structure and acidity.Significance of the study: These results increase the knowledge of chemical variables related to the perception of wine astringency and provide tools to control and optimise grape and wine production stages to modulate astringency and maximise quality and the consumer appeal of wines.

Chemical composition and sensory profile of Syrah wines from semiarid tropical Brazil – Rootstock and harvest season effects

This study aims to characterise the chemical compositions and sensorial profiles of wines made with Syrah grapes over two harvest seasons (first and second semester), over in different calendar years, from vines on two different rootstocks (1103P and IAC 313). Wine chemical composition and sensory profile were influenced by both rootstock and harvest season. Syrah wines on IAC 313 were favoured with higher concentrations of, petunidin 3-O-acetylglucoside (3.7 mg/L), malvidin 3-O-acetylglucoside (17.8 mg/L), malvidin 3-O-coumarylglucoside (4.4 mg/L), petunidin 3-O-coumarylglucoside (2.0 mg/L), peonidin 3-O-coumarylglucoside (1.4 mg/L), monomeric flavanols (23.6 mg/L), oligomeric tannins (183.0 mg/L), total condensed tannins (1037.7 mg/L), dimer B1 (9.8 mg/L), B4 (5.0 mg/L), trimer C1 (3.1 mg/L) and calcium (80 mg/L). Syrah wines on 1103P had higher concentrations of total anthocyanins (375.6 mg/L, catechin (8.6 mg/L), epicatechin (12.6 mg/L), dimer B2 (21.0 mg/L), B1 3-O-gallate (1.8 mg/L), B2 3′-O-gallate (6.0 mg/L) and total flavanols (53.4 mg/L). The sensory profiles of the Syrah wines were influenced by rootstock followed by, mainly in relation to aromatic attributes. Syrah wines on IAC 313 were scored more highly by the tasters.

Corrigendum: Investigating the Effect of Selected Non-Saccharomyces Species on Wine Ecosystem Function and Major Volatiles.

[This corrects the article DOI: 10.3389/fbioe.2018.00169.].

Effect of different levels of skin disruption and contact with oxygen during grape processing on phenols, volatile aromas, and sensory characteristics of white wine

To investigate the changes in wine chemical composition, sensory quality, and style induced by various levels of skin disruption and contact with oxygen during grape processing, five treatments were applied: whole grape cluster pressing in semi-reductive conditions (WCP-R), whole grape cluster pressing in standard conditions (WCP), standard grape mash pressing as a control (GMP), light (LOX), and heavy oxidation of grape juice (HOX). Produced wines were subjected to analysis of phenols (HPLC-DAD) and volatiles (HS-SPME-GC/MS), as well as quantitative descriptive sensory analysis. WCP-R wines stood out with the highest amounts of hydroxycinnamates and preserved aromas, and the highest intensities of positive sensory attributes. Both WCP and LOX treatments significantly reduced phenols when compared to GMP, while HOX treatment was detrimental in general. Apparently, the level of contact with oxygen exhibited a predominant effect on hydroxycinammates and aromas, while the level of grape skin disruption affected primarily hydroxybenzoic acids and flavan-3-ols. Practical applications This study has demonstrated that by choosing grape processing techniques which are different from respect to degree of skin cell disruption and contact with juice, as well as contact with oxygen, it is possible to obtain a variety of white wine styles differing in the content and composition of phenols and volatile aromas, which significantly reflect on their sensory quality. This could be of particular interest for grape varieties with deficient or excessive phenol and aroma potentials, which have to be specifically processed to achieve a satisfactory balance within a desired wine style. Besides deepening the existing and providing new knowledge on the broad topic of grape processing in winemaking, the results obtained are characterized by high level of transferability to wine industry. They may serve experts and producers to draw more precise conclusions on the relative effectiveness of different grape processing techniques, and choose adequate options for their specific needs.

Chemical and Sensorial Characterization of Tropical Syrah Wines Produced at Different Altitudes in Northeast of the Brazil

Over the years, viticulture has expanded to new regions outside the temperate zones, such as Northeast Brazil, India, Thailand, Myanmar, Vietnam, Bangladesh and Venezuela, characterized by the production of tropical wines. It is important for the productive sector to comprehend the effects of grapevine interaction with the characteristics of each new region on wines composition. In this study, the composition of wines of Syrah from two regions with different altitudes in Northeast Brazil were analyzed by different methodologies to characterize chemical compounds as sugar, acids, minerals, phenolics (anthocyanins, flavonols, stilbenes and condensed tannins) and the sensory profile. The wines of the Bahia region (1100 m of altitude) obtained high concentrations for chemical parameters related to color, monomeric anthocyanins, stilbenes and monomeric and oligomeric tannins. Wines of the low altitude region, Pernambuco (350 m of altitude) were characterized by higher concentrations of flavonols (kaempferol, isorhamnetin, quercetin and rutin) and polymerized tannins. The chemical composition of wines from the two studied regions was influenced by altitude. A trend towards higher concentrations in most for phenolic compounds analyzed was observed in wines from the higher altitude region during the two years of study. Regarding the sensory profile, fruity, floral, herbaceous and empyreumatic attributes aromatic obtained highest scores in wines of the 350 m altitude region, the other attributes were dependent on the year of harvest.

Winemaking with vine-shoots. Modulating the composition of wines by using their own resources.

Vine-shoots from two important Vitis vinifera, Airén and Cencibel, have been prepared in two different formats (chip and granule) and added (12 g/L) in their own wines in different winemaking steps. Results have shown significant differences depending in all conditions tested, and wine chemical composition was modulated while in contact with vine-shoots. Compounds such as trans-resveratrol, increased its concentration up to 4 mg/L in Airén white wines. In Cencibel red wines, vanillin was found in a concentration four times above its odor threshold and independently of the vine-shoot variety, format and moment of addition, compounds such as (-)-epicatechin and (+)-catechin increased the concentration with respect to the control wine. When vine-shoots were added after fermentation, β-ionol appeared for first time in all wines. In case of guaiacol, the higher increment was observed for Airén wines. Therefore, it is possible to elaborate distinctive wines using their own resources.

Prediction Models to Control Aging Time in Red Wine.

A combination of physical-chemical analysis has been used to monitor the aging of red wines from D.O. Toro (Spain). The changes in the chemical composition of wines that occur over the aging time can be used to distinguish between wine samples collected after one, four, seven and ten months of aging. Different computational models were used to develop a good authenticity tool to certify wines. In this research, different models have been developed: Artificial Neural Network models (ANNs), Support Vector Machine (SVM) and Random Forest (RF) models. The results obtained for the ANN model developed with sigmoidal function in the output neuron and the RF model permit us to determine the aging time, with an average absolute percentage deviation below 1%, so it can be concluded that these two models have demonstrated their capacity to predict the age of wine.

TIMING OF INOCULATION WITH SELECTED WINE BACTERIA ON THE KINETICS OF MALOLACTIC FERMENTATION AND SENSORY PROPERTIES OF VRANEC WINE FROM TIKVESH WINE REGION

The aim of this investigation is to determine the influence of timing of inoculation of four different lactic bacterias by co-inoculation during the fermentation and post-fermentation of Vranec variety, to obtain more balanced wines with refined aromas. VP 41, ML Prime, O-Mega and PN4 are the types of commercial available lactic bacterias produced by Lallemand producer, used in malolactic fermentation (MLF) of wine Vranec. The kinetic of transformation of malic into lactic acid was measured. Also, chemical composition of wine (alcohol strength, specific gravity, total extract, total acids, volatile acids, pH, free and total SO2) was performed. The sensory descriptive analysis was performed. Seven wine experts were involved for the descriptive evaluation of the investigated wines.