Grape variety, aging on lees and aging in bottle after disgorging influence on volatile composition and foamability of sparkling wines

Biochemical insights into tea foam: A comparative study across six categories

Tea foam properties, crucial indicators of tea quality, have gained renewed interest due to their potential applications in innovative beverages and foods. This study investigated the foaming properties and chemical foundations of six major tea categories through morphological observations and biochemical analyses. White tea exhibited the highest foaming ability at 56.28%, while black tea showed the best foam stability at 84.01%. Conversely, green tea had the lowest foaming ability (10.83%) and foam stability (54.24%). These superior foaming characteristics are attributed to the relatively low lipid content and acidic pH values. Surprisingly, no significant correlation was found between tea saponin content and foaming properties. Instead, specific amino acids (including Tyr, Gaba, Phe, Ile, and Leu) and catechins (GA and CG) were identified as potential contributors. These results deepen our understanding of tea foam formation and offer insights into utilizing tea-derived plant-based foams in food products.

Comparison of ancestral and traditional methods for elaborating sparkling wines

This work compares the ancestral method for elaborating sparkling wines with the most widely used traditional method. Ancestral method is a single fermentation procedure in which the fermenting grape must is bottled before the end of alcoholic fermentation whereas traditional method involves a second fermentation of a base wine inside a bottle. Macabeo grapes were used to elaborate a traditional sparkling wine and two ancestral sparkling wines, one with a low yeast population and one with a high yeast population. The findings indicate that ancestral sparkling wines have lower ethanol content and can be elaborated using lower sulphur dioxide levels. In general, ancestral sparkling wines showed similar protein concentration, higher polysaccharide content, similar or better foamability (HM) than the traditional sparkling wine., No differences were found in the foam stability (HS). In addition, the sensory analysis indicated that ancestral sparkling wines have smaller bubble size, lower CO2 aggressivity, they seemed to have longer ageing time and were scored better than the traditional sparkling wine. These results therefore indicate that the ancestral method is of great interest for the elaboration of high-quality sparkling wines.

Comparison of volatile compounds during biological ageing and commercial storage of Cava (Spanish sparkling wine): The role of lees

Cava is a sparkling wine produced using a traditional method that must be aged in contact with lees for a minimum period of nine months. The contact between wine and lees improves the quality of the final product, and aroma is one of the most important qualitative parameters of a wine. The aim of the work was to study the role of lees in the ageing of Spanish sparkling wine (Cava), by sampling at industrial scale the bottles, from 9 to 30 months of ageing, jointly with the winery and in real time. The volatile profile of Cava during biological ageing and commercial storage, after disgorging, was evaluated by Headspace-Solid Phase Microextraction coupled to gas chromatography-mass spectrometry. More than 60 compounds were identified from several chemical classes including esters, alcohols, terpenes, furans, norisoprenoids, and fatty acids. A reduction in volatile components was observed when the disgorging step took place. When the behaviour of aroma over time was assessed, the principal factor that discriminated between samples was the type of ageing i.e. with or without lees. Evaluation of volatiles over time revealed that furans showed a significant relationship with ageing, indicating that some components of this family could be possible markers of ageing.

Characterization of white and rosé sparkling wine lees surface volatiles

Cava is a sparkling wine that requires a second fermentation in the bottle. Its volatile fraction is conditioned by different parameters (grape, vinification process, fermentative yeast, and aging time). During the autolysis process, yeasts release compounds into the wine, but lees can adsorb certain compounds on their surface. Therefore, the aim of this work was to characterize different white and rosé Cavas, and their lees. For this, white Cavas (CGR1: 40 months; CR1: 16 months) and rosé Cavas (CRR1: multivarietal coupage; CRR2: monovarietal; both 20 months) were studied. Once disgorged, lees were freeze-dried (L-CGR1, L-CR1, L-CRR1 and L-CRR2). In addition, lees waste from the winery were collected. pH, total polyphenol index (TPI) and colour intensity (CI) of Cavas and lees were determined. The volatile fraction was analysed by Head-Space Solid Phase Microextraction followed by gas chromatography coupled to mass spectrometry. Lees showed higher values than their respective Cavas for TPI and CI, especially in the case of the L-CGR1. Most of the volatiles were identified both in Cavas and their lees, esters being the main compounds. Therefore, lees can retain phenolic and volatile compounds on their surface, which could be of interest as a new ingredient in the food industry.

Volatile Composition of Sparkling Wines of cv. Chardonnay Cultivated under Different Training Systems in Serra da Mantiqueira (Brazil)

The grapevine is a climbing plant and allows for the manipulation of vegetative canopies to change the microclimate and exposure of leaves and clusters to solar radiation, affecting the primary and secondary metabolisms of plants. Thus, this work aimed to evaluate how the lyre and Geneva double-curtain (GDC) training systems could contribute to the volatile composition of sparkling wines in replicates of vinifications carried out in the Serra da Mantiqueira (Brazil) in two consecutive summer harvests (2017 and 2018). Fifty-four free volatile compounds were identified by HS-SPME/GC-MS in the wines in both systems and vintages. Multivariate analysis differentiated the vintages in component 1 (22.7%) and the training systems in component 2 (7.1%). The crops were differentiated by aldehydes in 2017 and in 2018 by isoamyl acetate ester, probably derived from the amino acid leucine, the season having been more humid, with lower temperatures and less radiation. For the training systems, besides the alcohol compounds, the GDC was differentiated by the terpenoid compounds geranylacetone and β-damascenone, which may contribute more pleasant aromas to sparkling wines. This work promotes additional research and enables winegrowers, through the management of their vineyards, to achieve sparkling wines with different volatile compositions.

Impact of Cork Closures on the Volatile Profile of Sparkling Wines during Bottle Aging

This study aimed at investigating the impact of different technical cork stoppers on the quality preservation and shelf life of sparkling wines. The volatile compositions of two Italian sparkling wines sealed with a sparkling cork with two natural cork discs (2D) and a microagglomerated (MA) cork were determined during bottle aging (12 to 42 months) after disgorging, by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC/MS). The volatile profile of the sparkling wine #1 sealed with 2D stoppers showed the presence of camphor from 12 to 42 months, along with significant alterations in the levels of several alcohols, ketones, and ethyl esters at 24 and 42 months. The impact of closure type was less pronounced for sparkling wine #2 which also showed the presence of camphor from 12 to 42 months in 2D samples, and significantly higher levels of esters at 24 and 42 months for 2D compared with MA. These results unveiled that the type of closure has a greater impact on the volatile composition of sparkling wines at longer post-bottling periods and 2D stoppers preserve the fruity and sweety aromas of sparkling wines better after 42 months of bottle storage.

Non-Conventional Grape Varieties and Yeast Starters for First and Second Fermentation in Sparkling Wine Production Using the Traditional Method

Sparkling wine production using the traditional method involves a second fermentation of still wines in bottles, followed by prolonged aging on lees. The key factors affecting the organoleptic profiles of these wines are the grape varieties, the chemical and sensory attributes of the base wines elaborated, the yeast strains used for first and second fermentation, and the winery practices. While Chardonnay and Pinot noir are gold standard grape varieties in sparkling wine production, other valuable grape cultivars are used worldwide to elaborate highly reputable sparkling wines. Fundamental research on the chemical and sensory profiles of innovative sparkling wines produced by the traditional method, using non-conventional grape varieties and novel yeast strains for first and/or second fermentation, is accompanying their market diversification. In this review, we summarize relevant aspects of sparkling wine production using the traditional method and non-conventional grape varieties and yeast starters.

Towards a better understanding of the evolution of odour-active compounds and the aroma perception of sparkling wines during ageing

A native veil-forming yeast and a commercial yeast strain were used to elaborate sparkling wines by the Champenoise method with a grape variety traditionally used for the production of still wines. Wines aged on lees for fifteen months were sampled at five points and their physicochemical and sensory indices were analysed. Unsupervised and supervised statistical techniques were used to establish a comparison between 81 volatile compounds and eight odour descriptors (chemical, fruity, floral, fatty, balsamic, vegetal, empyreumatic and spicy). Principal component analysis of both datasets showed good separation among the samples in relation to ageing time and yeast strain. By using a partial least squares regression-based criterion, 38 odour active compounds were selected as the most influential for the ageing factor and out of them, only 27 were unique to certain aroma descriptors. These results contribute to a better understanding of the aroma perception of sparkling wines.

Using an electronic nose and volatilome analysis to differentiate sparkling wines obtained under different conditions of temperature, ageing time and yeast formats

Effect of yeast inoculation format (F), temperature (T), and "on lees" ageing time (t) factors were evaluated on the composition of sparkling wines by a quantitative fingerprint obtained from volatile metabolites and the response of an electronic nose (E-nose). Wines elaborated according the traditional method at 10 and 14 °C, free cells and yeast biocapsules formats were monitored at 15 and 24 months of ageing time. Sixty-six volatiles identified and quantified in the eight sampling lots were subjected to a pattern recognition technique. A dual criterion based on univariate (ANOVA) and multivariate analysis (PLS-DA) through the variable importance projection (VIP) values, allowed to identify ten volatiles as potential markers for T factor, eleven for t and twelve for F factors. The discriminant models based on E-nose dataset enable a 100% correct classification of samples, in relation with t and F factors and the 83% for T factor.

Using Synchronous Fluorescence to Investigate Chemical Interactions Influencing Foam Characteristics in Sparkling Wines

The appearance of bubbles and foam can influence the likeability of a wine even before its consumption. Since foams are essential to visual and taste attributes of sparkling wines, it is of great importance to understand which compounds affect bubbles and foam characteristics. The aim of this work was to investigate the effect of interactions among proteins, amino acids, and phenols on the characteristics of foam in sparkling wines by using synchronous fluorescence spectroscopy techniques. Results have shown that several compounds present in sparkling wines influence foam quality differently, and importantly, highlighted how the interaction of those compounds might result in different effects on foam parameters. Amongst the results, mannoproteins were found to be most likely to promote foam and collar stability, while phenols were likely to increase the small bubbles and collar height in the foam matrix. In summary, this work contributes to a better understanding of the effect of wine compounds on foam quality as well as the effect of the interactions between those compounds.

The Impact of Non-Saccharomyces Yeast on Traditional Method Sparkling Wine

The interest in non-Saccharomyces yeast for use in sparkling wine production has increased in recent years. Studies have reported differences in amino acids and ammonia, volatile aroma compounds (VOCs), glycerol, organic acids, proteins and polysaccharides. The aim of this review is to report on our current knowledge concerning the influence of non-Saccharomyces yeast on sparkling wine chemical composition and sensory profiles. Further information regarding the nutritional requirements of each of these yeasts and nutrient supplementation products specifically for non-Saccharomyces yeasts are likely to be produced in the future. Further studies that focus on the long-term aging ability of sparkling wines made from non-Saccharomyces yeast and mixed inoculations including their foam ability and persistence, organic acid levels and mouthfeel properties are recommended as future research topics.

Chemical compounds and mechanisms involved in the formation and stabilization of foam in sparkling wines

The visual properties of sparkling wine including foam and bubbles are an indicator of sparkling wine quality. Foam properties, particularly foam height (FH) and foam stability (TS), are significantly influenced by the chemical composition of the wine. This review investigates our current knowledge of specific chemical compounds and, the mechanisms by which they influence the foam properties of sparkling wines. Grape and yeast proteins, amino acids, polysaccharides, phenolic compounds, organic acids, fatty acids, ethanol and sugar are examined with respect to their contribution to foam characteristics in sparkling wines made with the Traditional, Transfer, and Charmat and carbonation methods. Contradictory results have been identified that appear to be due to the analytical methods used to measure and quantify compounds and foam. Biopolymer complexes are discussed and absent knowledge with regards to thaumatin-like proteins (TLPs), polysaccharides, amino acids, oak-derived phenolic compounds and organic acids are identified. Future research is also likely to concentrate on visual analysis of sparkling wines by in-depth imaging analysis and specific sensory analysis techniques.

The effect of sucrose addition at dosage stage on the foam attributes of a bottle-fermented English sparkling wine

BACKGROUND

Approximately two-thirds of wine produced in the UK is bottle-fermented sparkling wine. Effervescence and foamability are key features used to assess English sparkling wine (ESW) quality. A critical, yet understudied, area of research is the potential for dosage to influence foam behaviour via associated changes in wine viscosity.

RESULTS

In this study, dosage treatments of five increasing levels of sucrose (from 0 to 31 g L^-1 ) were added to an ESW. After storage, the foamability attributes of the wines were analysed via an adapted Mosalux method and a novel image analysis method combined with free pour of the wine. Results indicate that increasing sucrose concentration improved foam formation, but reduced foam stability, likely due to the sucrose added causing a modification in wine viscosity.

CONCLUSIONS

These results highlight the impact that dosage treatments can have on the quality of foam produced upon pouring, and therefore have the potential to inform future sparkling winemaking practices. © 2017 Society of Chemical Industry.

Characterization of the Key Aroma Compounds in Chinese Syrah Wine by Gas Chromatography-Olfactometry-Mass Spectrometry and Aroma Reconstitution Studies

The key aroma compounds and the organoleptic quality of two Chinese Syrah wines from the Yunnan Shangri-La region and Ningxia Helan mountain region were characterized. The most important eighty aroma-active compounds were identified by Gas Chromatography-Olfactometry. In both Syrah samples, ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, 2- and 3-methyl-1-butanol, ethyl hexanoate, ethyl octanoate, 2-phenethyl acetate, methional, 3-methylbutanoic acid, hexanoic acid, octanoic acid, β-damascenone, guaiacol, 2-phenylethanol, trans-whiskylactone, 4-ethylguaiacol, eugenol, 4-ethylphenol, and sotolon were detected to have the highest odor intensities. In the chemical analysis, 72 compounds were quantitated by Stir Bar Sorptive Extraction combined with Gas Chromatography Mass Spectrometry. Based on the Odor Activity Value (OAV), the aromas were reconstituted by combining aroma compounds in the synthetic wine, and sensory descriptive analysis was used to verify the chemical data. Fatty acid ethyl esters, acetate esters, and β-damascenone were found with higher OAVs in the more fruity-smelling sample of Helan Mountain rather than Shangri-La.

Quantitative Profiling of Ester Compounds Using HS-SPME-GC-MS and Chemometrics for Assessing Volatile Markers of the Second Fermentation in Bottle

A quantitative approach using HS-SPME-GC-MS was performed to investigate the ester changes related to the second fermentation in bottle. The contribution of the type of base wine to the final wine style is detailed. Furthermore, a discriminant model was developed based on ester changes according to the second fermentation (with 100% sensitivity and specificity values). The application of a double-check criteria according to univariate and multivariate analyses allowed the identification of potential volatile markers related to the second fermentation. Some of them presented a synthesis-ratio around 3-fold higher after this period and they are known to play a key role in wine aroma. Up to date, this is the first study reporting the role of esters as markers of the second fermentation. The methodology described in this study confirmed its suitability for the wine aroma field. The results contribute to enhance our understanding of this fermentative step.

Use of Commercial Dry Yeast Products Rich in Mannoproteins for White and Rosé Sparkling Wine Elaboration

In sparkling wines, mannoproteins released during yeast autolysis largely affect their final quality. This process is very slow and may take several months. The aim of this work was to study the effect of several commercial dry yeast autolysates on the chemical composition, foam, and sensory properties of white and rosé sparkling wines aged on lees for 9 months during two consecutive vintages. The addition of these products in the tirage phase did not affect either the content of phenolic compounds, amino acids, and biogenic amines or the foam properties. The commercial product with the highest mannoprotein content and the highest purity caused significant changes in the volatile composition of the wines and enhanced the fruity aromas in both Verdejo and Godello sparkling wines.