Potential Age Research Articles

Effect of different yeast-derived products on a red wine polyphenolic composition: influence of the wine age

The name “yeast-derived products” (YDPs) refers to different preparations obtained from yeast cells through various processes. These YDPs have different characteristics and applications in oenology, one being the improvement of the sensory properties of wines. This work aimed to identify the impact of YDPs obtained from different yeast strains and through different downstream inactivation processes on polyphenols in a red wine at different aging times. At an oenological dosage of 40 mg/L in a young wine, the addition of YDPs resulted in a variable decrease in total polyphenol index (TPI) (2 to 9 % depending on the YDPs) and a significant decrease in the precipitation of tannins (15 to 50 %) and high molecular weight (HMW) pigments (19 to 85 %) were obtained in the BSA assay, thus demonstrating the involvement of tannins and HMW pigments in interactions with the studied yeast-derived products. Pigment involvement led to a change in colour indices (L*a*b* and colour intensity), but in most cases this change was not visible to the human eye at the oenological dosage tested (40 mg/L). Experiments conducted on both the young wine and the same wine aged for three months using the same yeast-derived products, dosages and aging conditions revealed the influence of the chemical evolution of polyphenols on their interactions with YDPs. The significant variation observed in this study highlights the critical role of yeast selection and the yeast fragmentation downstream process on YDP efficiency. The high-pressure homogenisation (HPH) yeast fractions were shown to be more efficient than the corresponding whole yeast cells. Increasing the contact surface area between yeast cell constituents and wine matrix enabled by the HPH process may be a key strategy for enhancing the effectiveness of yeast derivatives in red wines, and in aged wines in particular, in which the phenolic compounds underwent changes and exhibited less interaction with the studied yeast-derived products. This research has contributed to increasing our understanding of and the potential for apply these processing aids in oenology.

Region of interest selection in heterogeneous digital image: Wine age prediction by comprehensive two-dimensional gas chromatography

This study integrates genetic algorithm (GA) with partial least squares regression (PLSR) and various variable selection methods to identify impactful regions of interest (ROI) in heterogeneous 2D chromatogram images for predicting wine age. As wine quality and aroma evolve over time, transitioning from youthful fruitiness to mature, complex flavors, which leads to alterations in the composition of essential aroma-contributing compounds. Chromatograms are segmented into subimages, and the GA-PLSR algorithm optimizes combinations based on grayscale, red-green-blue (RGB), and hue-saturation-value (HSV) histograms. The selected subimage histograms are further refined through interval selection, highlighting the compounds with the most significant influence on wine aging. Experimental validation involving 38 wine samples demonstrates the effectiveness of this approach. Cross-validation reduces the PLS model error from 2.8 to 2.4 years within a 10 × 10 subset, and during prediction, the error decreases from 2.5 to 2.3 years. The study presents a novel approach utilizing the selection of ROI for efficient processing of 2D chromatograms focusing on predicting wine age.

Predicting Bordeaux red wine origins and vintages from raw gas chromatograms

Connecting chemical properties to various wine characteristics is of great interest to the science of olfaction as well as the wine industry. We explored whether Bordeaux wine chemical identities and vintages (harvest year) can be inferred from a common and affordable chemical analysis, namely, a combination of gas chromatography (GC) and electron ionization mass spectrometry. Using 12 vintages (within the 1990–2007 range) from 7 estates of the Bordeaux region, we report that, remarkably, nonlinear dimensionality reduction techniques applied to raw gas chromatograms recover the geography of the Bordeaux region. Using machine learning, we found that we can not only recover the estate perfectly from gas chromatograms, but also the vintage with up to 50% accuracy. Interestingly, we observed that the entire chromatogram is informative with respect to geographic location and age, thus suggesting that the chemical identity of a wine is not defined by just a few molecules but is distributed over a large chemical spectrum. This study demonstrates the remarkable potential of GC analysis to explore fundamental questions about the origin and age of wine.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ КОНЦЕНТРАЦИИ ЭКСТРАКТИВНЫХ ВЕЩЕСТВ СУХИХ ВИН ИЗ БЕЛЫХ СОРТОВ ВИНОГРАДА СЕЛЕКЦИИ ВНИИВиВ В ПРОЦЕССЕ БУТЫЛОЧНОЙ ВЫДЕРЖКИ

One of the most important quality indicators is the wine extract, which makes it possible to judge the fullness of taste, the harmony of taste, the amount of antioxidant activity, and even the authenticity of the origin of wine products. The purpose of the work is a compar-ative analysis of changes in extractive substanc-es in dry white wines from hybrid grape varie-ties grown in Rostov region during bottle aging. The objects of the study were dry white wines produced from grape varieties of ARRIV&W breeding according to generally accepted tech-nology under the same fermentation conditions – Platovsky, Stanichny, Donus, control – Ali-gote, which were aged in a bottle from 1 to 3 years in the enoteca of the institute. As a result of the research, it was found that the highest content of reduced and residual extract in com-parison with other samples was observed in wines from the Platovsky grape variety. In ex-perimental samples, the amount of organic acids fluctuated within 4.8–6.8 g/dm3 and, as aging in the bottle, decreased in wines from Aligote and Platovsky varieties by 25 %, from Stanich-ny and Donus varieties by 16 and 15.6 %. The maximum concentration of tartaric acid was noted in wines from Stanichny variety (4.1–2.9 g/dm3). In wines from varieties Stanichny, Donus, Aligote aged 1−3 years, the ratio of tar-taric and malic acids was more than 3, and the ratio of the residual extract to the total content of organic acids was less than 3, they also not-ed the development of taste properties in the direction of improvement. In wines from the Platovsky variety, after 2 and 3 years of aging in the bottle, the ratio of tartaric and malic ac-ids was 2 or less, and the ratio of the residual extract to the total content of organic acids was more than 3; they showed a deterioration in or-ganoleptic characteristics during aging, they were distinguished by a rough and discordant taste. It was revealed that the formation of a rounded and harmonious taste of wine during aging in a bottle depends on the ratio of the ex-tract components and their optimal composi-tion, as well as on the varietal characteristics of the grapes and its potential.

Colour properties and tannin concentrations of polymeric phenolic materials extracted from Pinot Noir wines of a single NZ producer

SummaryPolymeric phenolic material (PPM) was separated from monomeric anthocyanins by removing the latter using isoamyl alcohol in 22 Pinot Noir wines of different vintages and grades. The colour and tannin concentrations of PPM were determined using a modified Somers assay and methylcellulose precipitation (MCP) tannin assay, respectively. With wine age increasing, the ratio of absorbance at 520 nm at pH 1.0 to that at 3.4 decreased from 2.6 to 1.1. This decreasing trend with wine age is reported for the first time in Pinot Noir wines. The presence of bleachable polymeric pigments was also observed in PPM, and the degree of ionisation of these bleachable pigments increased along with wine age. Statistical analysis demonstrated the dominant effect of age on colour properties of PPM, regardless of vintage and grade. In contrast, total phenolics and tannin concentration mainly related to vintage, rather than age.

Physicochemical changes in red wines from the São Francisco Valley (Brazil) after aged in a bottle

SummaryThe São Francisco Valley is an exponent region in biotechnology and viticulture, located in the Northeast of Brazil, with tropical cultivation of wine grapes, with more than one harvest a year. Furthermore, wine production in the caatinga biome is unique and has shown commercial potential. Studies related to the physicochemical characterization and stability of wines during aging in the bottle are essential to guarantee and maintain quality. The present study aims to evaluate changes in physicochemical and chromatic parameters of tropical red wines from the São Francisco Valley aging in bottle. Classical physicochemical analyses, profiles of groups of phenolic compounds, antioxidant activity, and chromatic parameters were performed on all red wines from the São Francisco Valley Indication of Origin, with and without storage in oak barrels, and aged in bottles for 36 months. The study showed significant reductions in the levels of physicochemical parameters (acidity, total soluble solids, characterization of phenolic composition, antioxidant power) and color for wines that did not age in oak barrels. However, wines stored in oak barrels showed the highest stability. Thus, red wine storage in oak barrels, an oenological practice that increases quality, can be indicated for tropical red wines.

Effects of high power pulsed microwave on the enhanced color and flavor of aged blueberry wine.

A new method of high-power pulsed microwave (HPPM) was applied to accelerate the aging of blueberry wine. The color changes of blueberry wines during aging were investigated through Chemical Wine Age and CIE-LAB measurement. Results showed that the blueberry wines treated by HPPM at low frequencies (50 and 100Hz) exhibited improved color characteristics with L* value reaching 47.04 at 100Hz, an increased maturity of wine body, and a shortened chemical wine age from 90 days to 75 days. Moreover, the aroma changes determined by GC-MS showed that HPPM accelerated the formation of esters in blueberry wine, which were increased by 18.44% and 56.97% respectively under the conditions of 50 and 150Hz. The formation of acid substances was reduced compared with the original wine, with contents of acetic acid, caproic acid, and octanoic acid of 29.46µg/mL, 15.60µg/mL, 17.74µg/mL, respectively, displaying an enhanced wine flavor.

Evaluation of volatile and chemical profile of sherry-like white wine Vernaccia di Oristano from Sardinia by comprehensive targeted and untargeted approach

This study investigated the chemical–physical and volatile profile of sherry-like white wines with different aging time from three different areas of Sardinia. Proximate chemical composition, CIELab color coordinates and absorbances at 280 and 420 nm were determined. Volatile compounds were determined by solid-phase microextraction (SPME) followed by gas chromatography coupled with a mass spectrometer (GC/MS) using a targeted and untargeted approach. Significant correlations among the age of the wine and most of the chemical physical parameters, such as alcohol content, total acidity, volatile acidity, glycerol and polyphenols were observed. A280 and A420 values were highest, as expected, in the oldest wines as well as an increase of a* low values for L* were found during aging. Fifty-nine volatile compounds were identified, among which ethyl acetate, amyl/iso-amyl alcohol, ethyl octanoate, benzaldehyde, ethyl decanoate and phenylethyl alcohol were predominant. The untargeted approach was able to discriminate wines according to their production area, and within each group, according to the year of production.

Wine age prediction using digital images and multivariate calibration

The prediction or confirmation of age is an important field in evaluation of wine’s value. Such type of studies commonly requires a number of data sets describing changes in chemical composition and/or related physical properties. Digital images of wines captured by a webcam represent an easy and low-cost approach to prevent frauds connected to the age of wines. In this work, a combination of frequency histograms including grey scale, red-green-blue (RGB) and hue-saturation-value (HSV) colour models extracted from digital images were used to evaluate the age of botrytized and related varietal wines produced during a 1989–2019 period at different countries. The main findings showed that digital images carry the appropriate chemical information for the age assignment and PLS-type models were able to estimate wine age only one latent variable. Grey levels enabled to find figure of merit values similar to the PLS model based on full histogram. An additional interval selection of the histograms with interval PLS allows improving accuracy of variable assessment and achieving lower error at a cross-validation step, RMSECV decreases from 3.6 years to 3.1 years. When models were employed to predict an external set of samples similar results were found, RMSEP equal to 2.8 years and 2.9 years for PLS and iPLS, respectively. However, a slight deterioration of the results was observed for the PLS model based on full grey levels (RMSEP 3.2). In general, these non-destructive measurements do not generate residuals and can be performed without sophisticated equipment with a reasonably accurate response.

Influence of Prefermentative Cold Maceration on the Chemical and Sensory Properties of Red Wines Produced in Warm Climates

Red wines produced in warm climates generally possess a lower content of phenolic compounds and color structure than those produced in colder climates, which hinders bottle evolution. To improve these properties, cold maceration could be a useful procedure. To study the effect of this technique, Tempranillo, Merlot and Syrah grape varieties cultivated in the Jerez area (Southwest Spain) were cold macerated at 4 °C for ten days before alcoholic fermentation. Their composition and characteristics compared to the directly fermented control grapes were analyzed for phenolic content, color, volatile compounds, and sensory properties. It has been verified that phenolic content increased by around 10% during the treatment, which was maintained after the alcohol fermentation, along with an increase in color intensity and aromatic profile. This modification on the composition provided better scores for appearance, aroma intensity, and aroma quality in sensory analysis. The evolution of all studied parameters during 12 months of aging in the bottle is also studied, confirming the advantages of this technique in preserving the compositional and sensory characteristics throughout the period studied.

Molecular Characterization of Successive Yeasts Strains and their Optimal Invertase Producing Conditions in Fresh Palm Wine (Raphiahookeri) Obtained from Lagos, Nigeria

Saccharomyces cerevisiae is known to produce invertase. However, molecular characterization of successive yeast strains and their optimal invertase producing conditions in Nigerian Raphiahookeri has not been documented. In this study, molecular characterization of successive yeast strains and their optimal invertase producing conditions in fresh palm wine (Raphiahookeri) obtained from Lagos, Nigeria was evaluated. To achieve this, sequencing of 18S rDNA was carried out following DNA extraction from the yeast isolates. Invertase production within 5-day period was also monitored at different conditions for the yeast strains. The physicochemical parameters investigated include pH, optical density, titratable acidity, sugar concentration and alcohol content. Out of the 21isolates obtained, 18 were identified by 18S rDNA to beS. cerevisiae, while 3 were Penicillium chrysogenum, Blumeriagraminissp. Tritici and Fusarium culmorum. Thefungal population density decreased from 1.01 x 107 to 0.9 x 105CFU/ml. The pH and sugar concentration decreased with increase in age of the wine ranging from 6.05-3.33 and 3.70-1.10mg/100ml respectively. The optical density, titratable acidity and alcohol content increased with time and ranged from 0.454-0.904, 0.266-0.412 % and 0.920-5.640 % respectively. All isolates produced invertase optimally at pH 6, 30°C after 48 h incubation with S. cerevisiae CP006433.1 having the highest production (1.745U/ml).The results highlight the effect of fermentation conditions on the survival and invertase production of yeast strains in Nigerian palm wine.

Analytical, Chemometric and Sensorial Characterization of Oloroso and Palo Cortado Sherries during Their Ageing in the Criaderas y Solera System.

Oloroso and Palo Cortado are two types of sherry wines, produced in the Sherry Wine Region in Southern Spain, known as Marco de Jerez, where it is aged following the traditional Criaderas y Solera system. All of them are aged through oxidative ageing, even though the peculiar Palo Cortado Sherry wine is also aged biologically under a veil of flor yeasts in the first stage. Total dry extract, organic acids, aldehydes, esters, higher alcohols and phenolic compounds in these sherry wines evolve during their ageing as a consequence of evaporation and/or perspiration processes, chemical reactions, extraction of compounds from oakwood and microbiological activity. Sherry wines develop their characteristic organoleptic profile during their ageing, as could be proven through their tasting sessions. According to the sherry type, some natural groupings of the wines could be observed after their principal component analysis. Furthermore, by multiple linear regression methods, an important correlation between the parameters that were analyzed and the ageing of each specific wine has been confirmed, which allowed us to establish two different models, each corresponding to the sherry type in question. Only five of the variables that were investigated were required to successfully estimate each wine's age at over 99% confidence. This represents a rather convenient tool for wineries to monitor the ageing of these sherry wines.

Non-acylated and acylated anthocynins in red wines of different ages: Color contribution and evaluation

This study investigated the non-acylated and acylated anthocyanins and chromatic characteristics of 108 red wines with a range of ages. The K-means cluster analysis showed that the evolution pattern of cyanidin-3-O-glucoside (Cy) differed among non-acylated anthocyanins and the pattern of malvidin-3-O-(6-O-acetyl)-glucoside (Mv-ac) differed among acylated anthocyanins. Partial least squares regression (PLS) showed that non-acylated anthocyanins, especially Cy, contributed to the red-violet color. Wine age, tawny characteristics, and color density strongly negatively correlated with anthocyanins. Wine age played an essential role in chromatic characteristics and anthocyanins, especially more than 4 years. A prediction model of wine age was established using the chosen variables of color parameters and anthocyanins employing PLS. This model showed good performance in predicting the wine age. Besides malvidin-3-O-glucoside (Mv), other anthocyanins and acylated forms with low content were demonstrated to be promising and practical chemical parameters for predicting the age of dry red wine.

The effect of wine age and tannin composition on tannin activity across consecutive Pinotage red wine vintages

The effect of wine age on tannin chemistry and tannin activity values was investigated in red wine extracts according to a chemosensory approach. Sixteen Pinotage red wines of multiple vintages (2003-2018) were each isolated into four distinct polymeric fractions (F1-F4) on Sephadex LH-20 by flash-column chromatography. Tannin activity increased with molecular weight, where F1 was associated with positive values, reported for the first time, suggesting a different interaction mechanism than the usual exothermic value obtained in more polymerised samples such as F2 and F3. Weakly positive correlations were observed between tannin activity and tannin concentration by RPLC. Moderately positive correlations were obtained between either tannin estimation techniques, yet this was highly dependent on wine age and molecular size. Overall, tannin activity decreased across all vintages as a function of wine age, indicative of age-related reactions such as tannin oxidation, cleavage and precipitation. Chemosensory studies showed that while activity values across all fractions explained little variation, lowly positive correlations existed between larger polymeric fractions (F3 and F4) and mouthfeel attributes, namely astringency and bitterness, suggesting that highly polymerised tannins with higher activity values play a significant role in mouthfeel modification. More research is required to understand the actual sensory perception of proanthocyanidin size in red wine proanthocyanidin extracts and tannin-derived pigments (as opposed to wine) and to what extent it is influenced by parameters such as tannin activity across long-term ageing.

Wine Review Descriptors as Quality Predictors: Evidence from Language Processing Techniques

AbstractThere is an ongoing debate on whether wine reviews provide meaningful information on wine properties and quality. However, few studies have been conducted aiming directly at comparing the utility of wine reviews and numeric measurements in wine data analysis. Based on data from close to 300,000 wines reviewed by Wine Spectator, we use logistic regression models to investigate whether wine reviews are useful in predicting a wine's quality classification. We group our sample into one of two binary quality brackets, wines with a critical rating of 90 or above and the other group with ratings of 89 or below. This binary outcome constitutes our dependent variable. The explanatory variables include different combinations of numerical covariates such as the price and age of wines and numerical representations of text reviews. By comparing the explanatory accuracy of the models, our results suggest that wine review descriptors are more accurate in predicting binary wine quality classifications than are various numerical covariates—including the wine's price. In the study, we include three different feature extraction methods in text analysis: latent Dirichlet allocation, term frequency-inverse document frequency, and Doc2Vec text embedding. We find that Doc2Vec is the best performing feature extraction method that produces the highest classification accuracy due to its capability of using contextual information from text documents. (JEL Classifications: C45, C88, D83)

Analytical and Chemometric Characterization of Fino and Amontillado Sherries during Aging in Criaderas y Solera System.

Fino and Amontillado are Sherry wines, produced in Marco de Jerez area (southern Spain), and aged in Criaderas y Solera system. Fino Sherry wine follows a biological aging process, under a veil of flor yeasts, while Amontillado Sherry wine shares the same biological aging firstly, followed by oxidative aging, which gives them special features. Organic acids, esters, higher alcohols, phenolic compounds and total dry extract of Sherries evolve during aging due to evaporation processes, physical-chemical reactions, wood contributions and microbiological activity. During aging, Sherry wines improve their organoleptic profile, as could be proved in the tasting sessions. Hierarchical Cluster Analysis and Factor Analysis with factor extraction using Principal Components of Sherry wines studied were carried out and natural groupings of the wines according to the type of aging and their age were observed. A strong correlation between the parameters analyzed and the aging of each wine has been seen in the Multiple Linear Regression studies, establishing two different models, one for each type of Sherry wine, that, with only four of all the variables studied estimated the wine age with more than 99% of confidence. This constitutes a useful tool to control the age of these Sherry wines in the winery.

Towards Accelerated Autolysis? Dynamics of Phenolics, Proteins, Amino Acids and Lipids in Response to Novel Treatments and during Ageing of Sparkling Wine

Premium sparkling wine produced by the traditional method (analogous to the French méthode champenoise) is characterised by the development of aged wine character as a result of a second fermentation in the bottle with lees contact and lengthy ageing. Treatments (microwave, ultrasound, or β-glucanase enzymes) were applied to disrupt the cell wall of Saccharomyces cerevisiae and added to the tirage liquor for the second fermentation of Chardonnay-Pinot Noir base wine cuvée and compared to a control, to assess effects on the release of phenolics, proteins, amino acids, and lipids at 6, 12 and 18 months post-tirage. General responses to wine ageing included a 60% increase in the total phenolic content of older sparkling wines relative to younger wines and an increase in protein concentration from 6 to 12 months bottle age. Microwave and β-glucanase enzyme treatments of yeast during tirage preparation were associated with a 10% increase in total free amino acid concentration and a 10% increase in proline concentration at 18 months bottle age, compared to control and ultrasound treatment. Furthermore, microwave treatment was associated with elevated asparagine content in wine at 18 months bottle age, relative to the control and the other wines. The β-glucanase enzyme and ultrasound treatments were associated with significant accumulation of total lipids, which were driven by 2-fold increases in the phospholipid and monoacylglycerol components in wine at 18 months bottle age and, furthermore, the microwave treatment was associated with elevated triacylglycerol at 18 months bottle age. This study demonstrates that the use of yeast treatments at the tirage stage of sparkling wine production presents an opportunity to manipulate wine composition.

Determination of the age of dry red wine by multivariate techniques using color parameters and pigments

Vintage is a decisive factor for market price of commercial bottled dry red wines. Aim of this study was to use color parameters and pigments for the prediction of the age of dry red wine by means of partial least squares (PLS) and multiple linear regression (MLR). Both models allow the prediction of the age accurately, with high coefficients of determination (R 2 ), and low enough root mean square error of cross-validation (RMSECV). Although less variables were required to obtain a successful MLR model, its prediction results were as accurate as the model obtained by PLS. The ratio of the first polymeric pigments (TFPP) and malvidin-3-glycoside was demonstrated to be a promising and practical chemical parameter for the rapid and simple age assessment of the dry red wines. • Significant pigmented polymers for wine age is analyzed by HPLC-DAD. • Color parameters and pigments highly correlated with dry red wine age are obtained. • PLS and MLR models are established to predict the vintage of dry red wine. • The predictive ability of dry red wine vintage of best PLS and MLR models is compared.

Historical Wines of Portugal: The Classification, Consumer Associations and Marketing Implications.

Geographical origin, use of traditional varieties and ancestral viticulture/oenology practices characterize wines classified as Historical Wines of Portugal (HWP). This study identifies the authenticity attributes consumers associate with this classification and assesses the relative strength of associations. A review of brand authenticity research and interviews with Portuguese wine producers (n = 3) and consumers (n = 12) were conducted to identify HWP classification attributes. Strength of attribute association was subsequently evaluated in an online questionnaire with a convenience sample of Portuguese wine consumers (n = 641), which included a measure of general wine knowledge and questions about the adequacy of different contexts for HWP purchase and consumption. Wine knowledge markedly affected the nature and strength of consumer associations. Compared to Aspirational Explorers, wine connoisseurs emerged as Heritage Gatekeepers, associating origin, cultural heritage, quality, production and at-home consumption more strongly with HWP, and tradition, wine age and out-of-home consumption less strongly. Market recognition of HWP as a novel and distinctive table wine classification, with well-defined and unique attributes, is thus likely to depend on consumers’ general wine knowledge. Related promotional activities targeting wine novices should first focus on educating them on HWP classification, whereas those directed at savvier consumers should emphasize wine authenticity cues instead.

Wine Consumption Determinants in Albania Using Categorical Regression Model

The increasing trend of wine consumption in Albania has led the development of the respective subsectors, viticulture and the wine industry. In the order for the domestic wine production industry to be competitive, a detailed understanding of the consumer’s buying behavior is a prerequisite. To this end, this study offers an actual perspective of the consumption behavior of wine customers in Tirana region. One of the goals of this paper is to identify and quantify determinants of wine consumption by using a regression model called “Categorical Regression Estimation” for non-numeric response variables. A questionnaire has been designed for this purpose, which is based on the literature but also on the recognition of the customer profile in the country, considering several socio-economic factors. Through 230 face-to-face interviews, the aim is to evaluate the impact on wine consumption of income, age, education, religion, nutrition culture, wine prices, wine origin as well as other socio-demographic factors related to the profile of the consumer. The analysis and interpretation of the results reveal interesting factors that determine the wine consumption. Age, education, income level and price of the wine are the main factors affecting the consumer decision to buy wine. Older people (over 40 years old) represent 1.4 times higher willingness to buy wine relatively to the younger people. Meanwhile, among people with higher income level chances that they will buy wine are 2.15 higher relatively to the people with lower monthly income level. From the results appears that education have positive impact on wine consumption while gender does not represent a significant difference.