Search Results (25)

The Tempranillo grape variety is the most widely cultivated red grape cultivar in Spain. However, it has been observed that this variety may not always exhibit the optimal colour properties in warm climates such as Andalusia (southern Spain). Several strategies have been proposed to enhance productivity and resilience to stress or improve the quality of both grapes and wines. The foliar application of agricultural plant extracts has been identified as a highly effective method of promoting the synthesis of secondary metabolites in the grapevine. The objective of the current research was to analyse the incidence of foliar application of different extracts from winemaking by-products (grape stems: GS, grape pomaces: GP and wine lees: WL) on Tempranillo grapevine leaves, studying the impact on the quality of the resulting wines. The oenological and colour characteristics of the wines were assessed to evaluate the impact of these extracts on wines during the winemaking process. The detailed composition of the wines revealed that GS and WL extracts led to significant differences in wine colour properties. Wines derived from grapes treated with both extracts exhibited heightened colour intensity, accompanied by discernible alterations in CIELab coordinates, with lower L* and higher a* and C*ab values in comparison to CT. These results are encouraging, and the foliar application of GS extracts at veraison appears to be a feasible alternative to enhance the colour of wines from red grape cultivars with colour difficulties in warm climates. Full article

Mannoproteins enhance wine stability and sensory properties, but their specific role in modulating viscosity and mouthfeel across wine quality levels remains underexplored. This study explores the nuanced impact of various mannoprotein-producing yeast strains on specific mouthfeel sensations, particularly emphasizing viscosity, across Standard and Premium quality tiers of Cabernet Sauvignon commercial wines. The aim was to understand the intricate relationship between yeast-derived mannoproteins and the broader sensory landscape of red wines. The methodology encompasses a comprehensive mannose extraction method, rheological measurements, and sensory Rate-All-That-Apply evaluations, all of which are integrated into a Principal Component Analysis. The results showed slight color variations due to the wine spending one month on lees. A positive correlation was found between mannose content and viscosity in only Standard-quality wines. The correlation with sensory data indicated a strong relationship between volume, viscosity, and mannose content in Premium-quality wines, which was less pronounced in Standard-quality wines. Furthermore, parameters related to mouthfeel quality, such as roundness and smoothness, were also associated with these findings. Prospects involve further exploration of correlations between mouthfeel sensations, sensory descriptors, and the structural characteristics of mannoproteins, aiming for a more comprehensive understanding of the intricate interplay in wine composition. Full article

This study aimed to evaluate bioactive properties of Teran red wine by-products (grape skins, seeds, and wine lees) from six vinification treatments, including a control (7-day standard maceration). Pre-fermentative cryomaceration (8 °C; 48 h) and hot maceration (50 °C; 48 h), followed by the 13-day (CS15; C15; H15) and 28-day (C30; H30) period, considering fermentation/maceration and extended post-fermentative maceration, were conducted. In CS15, the saignée procedure was applied before fermentation/maceration. After maceration, the separation of by-products was performed, followed by lyophilization and solid–liquid extraction. Then, individual phenols were analyzed using high-performance liquid chromatography (HPLC), and total phenolic content (TPC) and antioxidant activity (FRAP) were analyzed using UV/Vis spectrophotometry. The results showed grape skins and wine lees in all treatments had significantly increased TPC and FRAP values compared to the control. The highest concentration of total phenols (HPLC) in grape skins was found in CS15, at 978.54 mg/100 g DW. In wine lees, the highest concentration of total phenols was detected in the 30-day maceration treatments, at 582.04 mg/100 g DW in C30, and 595.83 mg/100 g DW in H30, despite the pre-fermentative procedure. In grape seeds, the highest concentration of total phenols was found in the control (K7), at 432.42 mg/100 g DW. Pre-fermentative heating together with extended 30-day maceration (H30) strongly reduced the total levels of phenols (HPLC and TPC) in grape seed samples. The findings implied an evident impact of pre- and post-fermentative technologies on phenols and antioxidant activity in wine by-products of cv. Teran (Vitis vinifera L.). Full article

This study focuses on improving the second fermentation and the in-bottle ageing over lees process for 9 and 21 months of a red sparkling wine. The aim of the study was to enhance wine quality and try to make it more pleasant for consumers. For this purpose, four different yeast derivatives (yeast walls, yeast walls with tannins, inactivated yeasts and mannoproteins) and β-glucanases were added to a red base sparkling wine and were aged over lees during two different periods: 9 and 21 months. Oenological parameters, total polysaccharides, total proteins, free amino nitrogen, phenolic composition, foaming properties, and volatile compounds were analysed in conjunction with a sensory evaluation. Results show the different incidences of the studied adjuvants on the final parameters, highlighting the importance of the interactions of the studied adjuvants over time. In fact, time itself turned out to be one of the main factors affecting the final characteristics of the wine, so influencing consumers’ opinions and modifying the wine’s acceptability and quality. Full article

Sparkling wines have a relevant economic value, and they are mostly produced worldwide with the Traditional method (in bottles) or with the Charmat method (in autoclaves). Many varieties are employed in different viticultural areas to obtain white or rosé wines and red (Italy and Australia), with different sugar content. This review illustrates the most recent studies (last 5 years) on sparkling wines concerning innovative yeasts, aromatic profile, aging on lees, sugar types, base wine, new varieties, and innovative oenological techniques, which consider the effects on the sensory characteristics and the consumer preferences. Full article

The winery industry generates significant amounts of organic waste, such as pruning firewood, stems, and wine lees, which can cause environmental issues and affect the economic sustainability and competitiveness of the industry. Given the known antioxidant and antimicrobial properties of phenolic compounds, we analyzed these by-products to quantify their phenolic composition and evaluate the effectiveness of pruning firewood and stem extracts from six autochthonous varieties of the Dão Region in inhibiting the growth of bacteria from diabetic foot wounds isolated from hospital patients. The study employed colorimetric methods to measure total phenols, ortho-diphenols, and flavonoids in the phenolic composition. The ABTS, DPPH, and FRAP methods were applied to assess the antioxidant capacity, and the disk diffusion method was applied to determine the antimicrobial activity of Gram-positive and Gram-negative bacteria. The results showed that Jaen had the most ortho-diphenols and flavonoids in pruning firewood, and the highest levels of these compounds were located in stem extracts. Jaen also had the highest antioxidant capacity in both pruning firewood and stems across all methods used. Notably, red wine lees displayed the highest biological and antioxidant activities. Moreover, pruning firewood extract displayed great efficacy in inhibiting the growth of Gram-positive bacteria, making it a promising candidate as a natural alternative against antibiotic resistance, which is a global public health concern. Full article

Annually, wine production is responsible for generating large quantities of residues, which are frequently disposed of and not valorized. So far, different studies have been conducted on grape pomace, yet less attention has been paid to other residues, such as wine lees and diatomaceous earth used in wine filtration. In this context, this study aimed to evaluate and compare the phenolic profile of these underexploited winemaking residues and assess their biological potential based on their antioxidant, antimicrobial, cytotoxic, and anti-aging activities (inhibition of tyrosinase and collagenase). Twenty-nine phenolic compounds, including twelve anthocyanins, were tentatively identified in the residues, with red grape pomace showing the highest diversity of compounds. The diatomaceous earth presented the highest content of non-anthocyanin phenolic compounds, being particularly rich in flavan-3-ols and myricetin-O-hexoside, and also presenting two anthocyanins. This sample also showed a high antioxidant activity, evidencing the best result in the reducing power assay. The red wine lees extract, despite showing a low content of phenolic compounds and less antioxidant activity, presented the highest inhibition capacity of bacteria growth. The extracts did not exhibit cytotoxicity against keratinocyte (up to 400 μg/mL) and fibroblast (up to 100 μg/mL) skin cell lines. However, the capacity of inhibiting tyrosinase and collagenase was low for the lees and diatomaceous earth, contrary to the grape pomace, seeds, and skins extracts that showed promising results, evidencing its potential as a cosmeceutical. Overall, this study highlights for the first time the potential of diatomaceous earth, an underexploited winemaking waste, in the obtention of added-value extracts and/or ingredients for cosmetic industry. Full article

Ageing on lees can be a good technique to enhance the quality of red sparkling base wines. Ultrasound treatment of the lees, prior to addition to the wine, can improve the releasing of their components into the wine. This study carries out a four month ageing on lees of a red sparkling base wine by the addition of lees sonicated at different amplitude levels: 30%, 60% and 90% for 10 min. The ageing on ultrasound-treated lees improved the quality of the red base wine, with a greater impact the higher the amplitude of the applied ultrasound. Sonicated lees at an amplitude of 90% enlarged the concentration of neutral polysaccharides in the wine and reduced its astringency, which was evaluated chemically. Furthermore, this treatment enhanced the concentration of some volatile compounds in the wine, mainly acetates, esters and terpenes with floral and fruity aromatic notes. This trend was also found for some fused alcohols, contributing to the aromatic complexity of wines, as well as for 2-phenylethanol, an alcohol with a rose-like aroma, and also for C6-alcohols with a green-herbaceous aroma. The results indicate that ultrasonication is a promising tool to increase the benefits of ageing on lees on the quality of red sparkling base wines. Full article

Wine lees, a sub-exploited byproduct of vinification, is considered a rich source of bioactive compounds, such as (poly)phenols, anthocyanins and tannins. Thus, the effective and rapid recovery of these biomolecules and the assessment of the bioactive properties of wine lees extracts is of utmost importance. Towards this direction, microwave-assisted extraction (MAE) factors (i.e., extraction time, microwave power and solvent/material ratio) were optimized using experimental design models in order to maximize the (poly)phenolic yield of the extracts. After optimizing the MAE process, the total phenolic content (TPC) as well as the antiradical, antioxidant and antimicrobial activity of the extracts were evaluated. Furthermore, Fourier transform infrared spectroscopy (FTIR) was employed to investigate the chemical profile of wine lees extracts. Red varieties exhibited higher biological activity than white varieties. The geographical origin and fermentation stage were also considered as critical factors. The white variety Moschofilero presented the highest antioxidant, antiradical and antimicrobial activity, while Merlot and Agiorgitiko samples showed noteworthy activities among red varieties. Moreover, IR spectra confirmed the presence of sugars, amino acids, organic acids and aromatic compounds. Thus, an efficient, rapid and eco-friendly process was proposed for further valorization of wine lees extracts. Full article

The vinification process produces a considerable amount of waste. Wine lees are the second most generated byproduct, representing around 14% of total vinification wastes. They are a valuable source of natural antioxidants, mainly polyphenols, as well as organic acids, such as tartaric acid. This paper deals with the application of an integrated, environment friendly membrane separation process to recover polyphenols and organic acids. A two-step membrane process is described, consisting of an ultra- and a nano-filtration process. The physicochemical and antioxidant properties of all the process streams were determined. High Pressure Liquid Chromatography (HPLC) was employed for identifying certain individual organic acids and polyphenols, while the antioxidant potential was determined by the 2,2′-diphenyl-1-picrylhydrazyl radical) (DPPH) radical scavenging ability and ferric reducing ability. A liquid concentrate stream containing 1351 ppm of polyphenols was produced and then spray dried. The resulting powder retained most of the polyphenols and antioxidant properties and was successfully applied to a real food system to retard lipid oxidation, followed by Thiobarbituric Acid Reactive Substances (TBARS) and the determination of oxymyoglobin content. The results show that membrane separation technology is an attractive alternative process for recovering value-added ingredients from wine lees. Full article

The winemaking process in Spain generates a significant amount of wastes such as wine lees. Currently, the nanofiltration process is a viable technique for the revalorization of compounds from wastes. In this aspect, this technique can be used for the recovery of compounds, such as polyphenols, as well as active principles widely used in industries, such as pharmaceuticals or cosmetics. Polyphenols are found in acceptable amounts in wine lees wastes and it is interesting to study the nanofiltration process viability to recover them. In order to study this possibility, it is necessary to determine the choice of the best membrane to use and the effect of operational parameters such as pressure, temperature, cross-flow rates, and concentration. In addition, it is important to be able to develop a mathematical model that can help in the future design of lees treatment plants. The treatment of red wine lees to concentrate polyphenols has been studied in a laboratory plant using different membranes (RO and NF) at different pressures (4.5, 9.5, and 14.5 bar), different temperatures (293, 303, and 308 K), and two concentrations (2100 and 1100 mg tyrosol eq·L⁻¹). The results have been encouraging to consider nanofiltration as a viable technique for the treatment and revalorization of this waste. The most suitable membrane has been the NF270, in which 96% rejection rates have been obtained, with a flux of 30 L·h⁻¹·m⁻². Moreover, in this study, the Spiegler–Kedem model (SKM) was used to calculate mass transfer constants and permeabilities. Suitable adjustments of these parameters were obtained to validate this mathematical model. For this reason, the SKM might be used in future studies to continue in the research work of the treatment of wine lees wastes. Full article

The final concentration of phenolic compounds in wines is usually lower than what might be expected, given their concentration in grapes. This is in part due to the interactions between cell walls from grapes and yeast with phenolics during red winemaking. Most of these aggregates are insoluble and end up precipitating, forming part of the lees. The objective of this study is to determine the capacity of ultrasounds and/or enzymes treatments (β-glucanase and a pectolytic enzyme) to release the anthocyanins and tannins adsorbed in the lees. The ultrasound (US) applied for 120 min slightly favored the extraction of anthocyanins and doubled tannin extraction. Shorter sonication times did not show any positive effect. The combination of β-glucanase and pectolytic enzyme was always more effective in the liberation of anthocyanins (both no-acylated and acylated anthocyanins) and tannins than the enzymes acting separately. The combination of US (120 min), β-glucanase and pectolytic enzyme showed an additive effect, increasing the extraction of phenolic compounds with respect to the individual treatments and also releasing a large quantity of low molecular weight polysaccharides, compounds of enological importance. These results of this study could be of enological interest, facilitating and accelerating the aging on lees process, through the liberation of polysaccharides and the recovery of the phenolic compounds lost during vinification. Full article

The winemaking process generates a large amount of residues such as vine shots, stalks, grape pomace, and wine lees, which were only recently considered for exploitation of their valuable compounds. The purpose of this work was to investigate the performance of nanofiltration for the recovery of phenolic compounds, with bioactive capacity like antioxidant, from red grape pomace extract. Four membranes were compared in this study—three cellulose acetate (CA series: lab-prepared by phase inversion) and one commercial (NF90). All membranes were characterized for their hydraulic permeability and rejection coefficients to reference solutes like saccharose, glucose, raffinose, polyethylene glycol, sodium chloride, and sodium sulfate. Permeation flowrates and rejection coefficients towards total phenolics content, antioxidant activity, proanthocyanidins, glucose and fructose were measured in the nanofiltration of grape pomace extract using selected operating conditions. Among the investigated membranes, the CA400-22 exhibited the highest permeate flux (50.58 L/m² h at 20 bar and 25 °C), low fouling index (of about 23%), the lowest rejection coefficients towards the reference solutes and the best performance in terms of separation between sugars and phenolic compounds. Indeed, the observed rejections for glucose and fructose were 19% and 12%, respectively. On the other hand, total phenolics content and proanthocyanidins were rejected for 73% and 92%, respectively. Full article

In this study, the recovery of polyphenols from olive oil mill and winery waste was investigated. The performance of ultrasound assisted extraction (UAE), microwave assisted extraction (MAE), and pressurized liquid extraction (PLE) was assessed using ethanol–water mixtures, which are compatible with food, nutraceutical, and cosmetic applications. The extraction efficiency from olive pomace and lees samples was evaluated in terms of total polyphenol content (TPC), determined by high performance liquid chromatography (HPLC) and Folin–Ciocalteu assay. The effect of solvent composition, temperature, and time was analyzed by response surface methodology. Ethanol:water 50:50 (v/v) was found to be a suitable solvent mixture for both kinds of samples and all three extraction techniques. The performance of the extraction techniques was evaluated, under optimal experimental conditions, with a set of different representative samples of residues from olive oil and wine production. Overall, the best extraction efficiency for olive pomace residues was provided by MAE (ethanol:water 50:50 (v/v), 90 °C, 5 min), and for wine residues by PLE (ethanol:water 50:50 (v/v), 100 °C, 5 min, 1 cycle). However, the results provided by UAE (ethanol:water 50:50 (v/v), 30 min) were also suitable. Considering not only extraction performance, but also investment and operational costs, UAE is proposed for a future scaling up evaluation. Regarding olive pomace as a source for natural phenolic antioxidants, olive variety and climatic conditions should be taken into account, since both influence TPC in the extracts, while for winery residues, lees from red wines are more suitable than those from white wines. Full article