Current and future strategies for wine yeast lees valorization

Efficacy and Safety of Oral Administration of Wine Lees Extract (WLE)-Derived Ceramides and Glucosylceramides in Enhancing Skin Barrier Function: A Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND

Our search for plant-derived ceramides from sustainable sources led to the discovery of ceramides and glucosylceramides in wine lees.

OBJECTIVE

This study evaluated the efficacy and safety of wine lees extract (WLE)-derived ceramides and glucosylceramides in enhancing skin barrier function.

METHODS

A randomized, double-blind, placebo-controlled study was conducted with 30 healthy Japanese subjects aged 20-64. Subjects were allocated to receive either the WLE-derived ceramides and glucosylceramides (test group) or placebo for 12 weeks. The primary outcome was transepidermal water loss (TEWL), and secondary outcomes included skin hydration, visual analog scale (VAS) of itching sensation, and the Japanese Skindex-29.

RESULTS

One participant withdrew for personal reasons, resulting in 29 subjects for data analysis (placebo n = 15; test n = 14). The test group showed a tendency of lower TEWL compared to the placebo after 8 weeks (p = 0.07). Furthermore, after 12 weeks of administration, the test group had significantly lower TEWL than the placebo (p = 0.04). On the other hand, no significant differences were observed in the secondary outcome parameters. No adverse events related to the supplements were reported.

CONCLUSIONS

Oral supplementation of WLE-derived ceramides and glucosylceramides is a prominent and safe approach to enhancing skin barrier function and health.

TRIAL REGISTRATION

(UMIN000050422).

Copper (II) Level in Musts Affects Acetaldehyde Concentration, Phenolic Composition, and Chromatic Characteristics of Red and White Wines

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.

Valorization of Peach Fruit and Wine Lees through the Production of a Functional Peach and Grape Juice

The valorization of agri-food products not only represents important economic and environmental benefits but can also be a source of potentially profitable, functional, and safe ingredients. This study aimed to valorize peach fruit and wine lees (WL) by producing functional juice. WL were incorporated at different concentrations (1.5 and 2%; w:w) in unpasteurized peach and grape juice and subsequently stored under refrigeration (5 °C). The antimicrobial activity of WL in peach and grape juices was assessed against Listeria monocytogenes and Saccharomyces cerevisiae as well as physicochemical, nutritional microbiological, and sensory acceptability. The maximum addition of WL to the juice (2%) showed a significant inhibitory effect against L. monocytogenes (4-log reduction) and increased the content of total soluble solids (TSS) (10%), total polyphenol content (TPC) (75%), and total antioxidant activity (AOX) (86%). During storage, AOX, TPC, TSS, pH, and titratable acidity (TA) remained stable. A significant correlation was observed between TPC and AOX. Total mesophilic aerobic bacteria and yeast counts increased during storage. Fifty-seven percent of tasters (n = 26) rated the functional juice positively. Thus, these agri-food products could be useful for producing functional juices with a longer shelf life, contributing to their valorization.

Chemical and Electrochemical Assessment of Wine Lees Extracts Tested as Novel Antioxidant Additives in Model Wine

Yeast derivatives are used in winemaking for a variety of purposes, including the protection of wines from oxidation. In this work, by the application of an autoclave extraction method, different fractions were obtained from red wine lees and a lab-grown culture of the same yeast strain. Each extract was characterized for their protein, polysaccharide, glutathione, thiol, and polyphenol contents. The antioxidant activity was tested by adding each extract in a model wine enriched with catechin and saturated with oxygen. The presence of both wine lees and lab-grown yeast extracts delayed oxygen consumption when compared to the untreated control. This delay was confirmed by the development of a yellow color, which was lower in 5 out of 6 of the samples added with yeast/lees extracts. The electrochemical behavior of the samples also showed a greater resistance to oxidation, thus suggesting a protective role of the wine lees extracts against wine oxidative phenomena.

Potential bioactive peptides obtained after in vitro gastrointestinal digestion of wine lees from sequential fermentations

The biotechnological reuse of winery by-products has great potential to increase the value and sustainability of the wine industry. Recent studies revealed that yeast biomass can be an exciting source of bioactive peptides with possible benefits for human health, and its incorporation in plant-based foods is considered innovative and sustainable. In this study, we aimed to identify, through in silico analyses, potential bioactive peptides from yeast extracts after in vitro digestion. Wine lees from a non-Saccharomyces oenological yeast, Starmerella bacillaris FRI751, Saccharomyces cerevisiae EC1118, and sequential fermentation performed with both strains (SEQ) were recovered in a synthetic must. Cellular pellets were enzymatically treated with zymolyase, and the yeast extracts were submitted to in vitro gastrointestinal digestions. LC-MS/MS sequenced the hydrolyzed peptides, and their potential bioactivity was inferred. S. bacillaris FRI751 fermentation showed 132 peptide sequences, S. cerevisiae EC1118 60, SEQ 89. A total of 243 unique peptide sequences were identified across the groups. Furthermore, based on the peptide sequence, the FRI751 extract showed the highest potential antihypertensive with 275 bioactive fragments. Other bioactivities, such as antimicrobial and immunomodulatory, were also identified in all yeast extracts. A potential antiobesity bioactive peptide VVP was identified only in the yeast extract from S. bacillaris single strain. The wine lees from S. bacillaris single strain and SEQ fermentation are a richer source of potential bioactive peptides than those from S. cerevisiae fermentation. This study opens new possibilities in the valorization of winemaking by-products.

Characterization of Mannoprotein Structural Diversity in Wine Yeast Species

The structure of yeast cell wall (CW) mannoproteins (MPs) influences their impact on wine properties. Yeast species produce a diverse range of MPs, but the link between properties and specific structural features has been ill-characterized. This study compared the protein and polysaccharide moieties of MP-rich preparations from four strains of four different enologically relevant yeast species, named Saccharomyces boulardii (SB62), Saccharomyces cerevisiae (SC01), Metschnikowia fructicola (MF77), and Torulaspora delbrueckii (TD70), and a commercial MP preparation. Monosaccharide determination revealed that SB62 MPs contained the highest mannose/glucose ratio followed by SC01, while polysaccharide size distribution analyses showed maximum molecular weights ranging from 1349 kDa for MF77 to 483 kDa for TD70. Protein identification analysis led to the identification of unique CW proteins in SB62, SC01, and TD70, as well as some proteins shared between different strains. This study reveals MP composition diversity within wine yeasts and paves the way toward their industrial exploitation.

Enhancing Anthocyanin Extraction from Wine Lees: A Comprehensive Ultrasound-Assisted Optimization Study

Wine lees, an important by-product of the wine industry, pose a major environmental problem due to the enormous quantities of solid-liquid waste that are discarded annually without defined applications. In this study, the optimization of a method based on a Box-Behnken design with surface response has been carried out to obtain extracts with high anthocyanin content and potent antioxidant activity. Six variables have been considered: %EtOH, temperature, amplitude, cycle, pH, and ratio. The developed method exhibited important repeatability properties and intermediate precision, with less than 5% CV being achieved. Furthermore, these novel methods were successfully applied to diverse wine lees samples sourced from Cabernet Sauvignon and Syrah varieties (Vitis vinifera), resulting in extracts enriched with significant anthocyanin content and noteworthy antioxidant activity. Additionally, this study evaluated the influence of grape variety, fermentation type (alcoholic or malolactic), and sample treatment on anthocyanin content and antioxidant activity, providing valuable insights for further research and application in various sectors. The potential applications of these high-quality extracts extend beyond the winemaking industry, holding promise for fields like medicine, pharmaceuticals, and nutraceuticals, thus promoting a circular economy and mitigating environmental contamination.

Exploring the Antioxidant Potential of Phenolic Compounds from Winery By-Products by Hydroethanolic Extraction

The residues generated in the wine industry (pomace, stems, seeds, wine lees, and grapevine shoots) are a potential source of bioactive compounds that can be used in other industries despite being sometimes underestimated. Different extraction methods using various solvents and extraction conditions are currently being investigated. Due to its natural occurrence in wines, safe behavior, and low toxicity when compared to other organic solvents, ethanol is used as an extracting agent. The aim of this study was to identify the winery by-product from the Região Demarcada do Douro and its corresponding extraction solvents that yields the most favorable results in (poly)phenols content and antioxidant capacity. To achieve this, five different ratios of ethanol: water, namely 0:100, 25:75, 50:50, 75:25, and 100:0 (v/v), for extracting the phenolic compounds were employed. Afterwards, the determination of total phenolic content (TPC), ortho-diphenols content (ODC), and flavonoid content (FC) as well as the antioxidant capacity of the obtained extracts using three different methods was performed. Since the best results of the spectrophotometric assays were obtained mostly with hydroethanolic extracts of stems (50:50, v/v), identification by HPLC-DAD has carried out. It was possible to conclude that the Tinta Roriz variety displayed the highest number of identified (poly)phenols.

The Potential of Wine Lees as a Fat Substitute for Muffin Formulations

The current study evaluates the prospect of wine lees (WL), a costless by-product from Amarone winemaking, as a fat replacer in muffin formulation. WL have elsewhere replaced sunflower oil, allowing the creation of 0, 25, 50, 75, and 100% fat-substituted muffins named ML0, ML25, ML50, ML75, and ML100, respectively. Batter rheology, in addition to the textural and colorimetric characteristics, the pore dimension, and the sensory aspect of the different formulations were evaluated. The batter consistency (K) of fat-replaced muffins was lower than that of the control, while the hardness and chewiness of the end products were higher. ML25 and ML50 samples reached the highest volume, while the baking loss decreased due to WL's fiber components. ML25, ML50, ML75, and ML100 accounted for caloric reductions of 9, 18, 22, and 26%, respectively, compared to full-fat muffins. Muffins with WL showed a darker crust and crumb as lightness (L*) decreased. Moreover, a* parameter increased with the increment of WL in the formulation, leading to a redder and less yellow-hued fat-replaced muffin. In conclusion, WL could effectively replace fat in the 25-50% range in muffins, achieving a final product with reduced calories, a higher dietary fiber content, higher volume, and promising sensory aspects.

Preparative Fractionation of Phenolic Compounds and Isolation of an Enriched Flavonol Fraction from Winemaking Industry By-Products by High-Performance Counter-Current Chromatography

High-performance counter-current chromatography (HPCCC) was used as a tool for the isolation and fractionation of phenolic compounds (PCs) in extracts from wine lees (WL) and grape pomace (GP). The biphasic solvent systems applied for HPCCC separation were n-butanol:methyl tert-butyl ether:acetonitrile:water (3:1:1:5) with 0.1% trifluoroacetic acid (TFA) and n-hexane:ethyl acetate:methanol:water (1:5:1:5). After refining the ethanol:water extracts of GP and WL by-products by ethyl acetate extraction, the latter system yielded an enriched fraction of the minor family of flavonols. Recoveries of 112.9 and 105.9 mg of purified flavonols (myricetin, quercetin, isorhamnetin, and kaempferol) in GP and WL, respectively, from 500 mg of ethyl acetate extract (equivalent to 10 g of by-product) were obtained. The HPCCC fractionation and concentration capabilities were also exploited for the characterization and tentative identification of constitutive PCs by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). In addition to the isolation of the enriched flavonol fraction, a total of 57 PCs in both matrixes were identified, 12 of which were reported for the first time in WL and/or GP. The application of HPCCC to GP and WL extracts may be a powerful approach to isolate large amounts of minor PCs. The composition of the isolated fraction demonstrated quantitative differences in the individual compound composition of GP and WL, supporting the potential exploitation of these matrixes as sources of specific flavonols for technological applications.

Inside Current Winemaking Challenges: Exploiting the Potential of Conventional and Unconventional Yeasts

Wine represents a complex matrix in which microbial interactions can strongly impact the quality of the final product. Numerous studies have focused on optimizing microbial approaches for addressing new challenges to enhance quality, typicity, and food safety. However, few studies have investigated yeasts of different genera as resources for obtaining wines with new, specific traits. Currently, based on the continuous changes in consumer demand, yeast selection within conventional Saccharomyces cerevisiae and unconventional non-Saccharomyces yeasts represents a suitable opportunity. Wine fermentation driven by indigenous yeasts, in the various stages, has achieved promising results in producing wines with desired characteristics, such as a reduced content of ethanol, SO₂, and toxins, as well as an increased aromatic complexity. Therefore, the increasing interest in organic, biodynamic, natural, or clean wine represents a new challenge for the wine sector. This review aims at exploring the main features of different oenological yeasts to obtain wines reflecting the needs of current consumers in a sustainability context, providing an overview, and pointing out the role of microorganisms as valuable sources and biological approaches to explore potential and future research opportunities.

Brewer's Spent Yeast Cell Wall Polysaccharides as Vegan and Clean Label Additives for Mayonnaise Formulation

Brewer's spent yeast (BSY) mannoproteins have been reported to possess thickening and emulsifying properties. The commercial interest in yeast mannoproteins might be boosted considering the consolidation of their properties supported by structure/function relationships. This work aimed to attest the use of extracted BSY mannoproteins as a clean label and vegan source of ingredients for the replacement of food additives and protein from animal sources. To achieve this, structure/function relationships were performed by isolating polysaccharides with distinct structural features from BSY, either by using alkaline extraction (mild treatment) or subcritical water extraction (SWE) using microwave technology (hard treatment), and assessment of their emulsifying properties. Alkaline extractions solubilized mostly highly branched mannoproteins (N-linked type; 75%) and glycogen (25%), while SWE solubilized mannoproteins with short mannan chains (O-linked type; 55%) and (1→4)- and (β1→3)-linked glucans, 33 and 12%, respectively. Extracts with high protein content yielded the most stable emulsions obtained by hand shaking, while the extracts composed of short chain mannans and β-glucans yielded the best emulsions by using ultraturrax stirring. β-Glucans and O-linked mannoproteins were found to contribute to emulsion stability by preventing Ostwald ripening. When applied in mayonnaise model emulsions, BSY extracts presented higher stability and yet similar texture properties as the reference emulsifiers. When used in a mayonnaise formulation, the BSY extracts were also able to replace egg yolk and modified starch (E1422) at 1/3 of their concentration. This shows that BSY alkali soluble mannoproteins and subcritical water extracted β-glucans can be used as replacers of animal protein and additives in sauces.

Evaluation of Physicochemical and Microbial Properties of Extracts from Wine Lees Waste of Matelica’s Verdicchio and Their Applications in Novel Cosmetic Products

Wine lees are sediments deposited on the walls and bottom of barrels resulting from wine fermentation and mainly consist of yeasts. Saccharomyces cerevisiae extracts, rich in beneficial components for the skin, have already been used in cosmesis, while wine lees have not been well exploited by the cosmetics industry yet. The aim of this work was the full characterization of the wine lees from Verdicchio’s wine, with the aim to exploit it as a beneficial ingredient in new cosmetic products. After mapping the microbial composition of the sample waste, the parameters for the sonication extraction process were optimized and the physicochemical properties of the extract were analyzed. The efficiency of the aqueous extraction—and in particular the yeast cell lysis necessary for the release of proteins from the cell—was assessed by evaluating cell shape and size, and protein release, under scanning electron microscopy (SEM), dynamic light scattering (DLS) and Bradford’s protein assays. Thus, the total phenol content and antioxidant capacity of the supernatant recovered from native and sonicated lees were determined by Folin–Ciocalteu’s and spectrophotometric assays, respectively. To quantify the heavy metals and highlight the presence of microelements beneficial for the skin, inductively coupled plasma-mass spectrometry (ICP-MS) was applied. In vitro metabolic activity and cytotoxicity were tested on both HaCat keratinocytes and human gingival fibroblasts, showing that wine lees are safe for skin’s cells. The results show that sonicated lees appear to be more interesting than native ones as a consequence of the release of the active ingredients from the cells. Due to the high antioxidant capacity, content of beneficial elements for skin and an appropriate microbiologic profile, wine lees were included in five new solid cosmetic products and tested for challenge test, compatibility with human skin, sensory analysis, trans epidermal water loss (TEWL) and sebometry.

The (Poly)phenolic Profile of Separate Winery By-Products Reveals Potential Antioxidant Synergies

The by-products of grapes (Vitis vinifera L.) in the winemaking process present a diverse phytochemical profile of (poly)phenols, essentially represented by phenolic acids, flavonoids, and stilbenes, which have health benefits. In winemaking, solid (grape stems and pomace) and semisolid (wine lees) by-products are generated, negatively impacting the sustainability of the agro-food activity and the local environment. Although information on the phytochemical profile of grape stems and pomace has been reported, especially information concerning (poly)phenols, research on wine lees is necessary to take advantage of the compositional traits of this residue. So, in the present work, an updated, in-depth comparison of the (poly)phenolic profiles of these three resulting matrices in the agro-food industry has been carried out to provide new knowledge and interesting data on the action of yeast and lactic acid bacteria (LAB) metabolism in the diversification of phenolic composition; additionally, we extract complementarities for the possible joint application of the three residues. The phytochemical analysis of the extracts was carried out using HPLC-PDA-ESI-MSn. The (poly)phenolic profiles of the residues showed significant discrepancies. The results obtained showed that the greatest diversity of (poly)phenols was found in the stems of the grapes, followed closely by the lees. Through technological insights, it has been suggested that yeasts and LAB, responsible for the fermentation of must, might play a key role in the transformation of phenolic compounds. This would provide new molecules with specific bioavailability and bioactivity features, which might interact with different molecular targets and, consequently, improve the biological potential of these underexploited residues.

Sustainable Soil Management: Effects of Clinoptilolite and Organic Compost Soil Application on Eco-Physiology, Quercitin, and Hydroxylated, Methoxylated Anthocyanins on Vitis vinifera

Climate change and compostinS1g methods have an important junction on the phenological and ripening grapevine phases. Moreover, the optimization of these composting methods in closed-loop corporate chains can skillfully address the waste problem (pomace, stalks, and pruning residues) in viticultural areas. Owing to the ongoing global warming, in many wine-growing regions, there has been unbalanced ripening, with tricky harvests. Excessive temperatures in fact impoverish the anthocyanin amount of the must while the serious water deficits do not allow a correct development of the berry, stopping its growth processes. This experiment was created to improve the soil management and the quality of the grapes, through the application of a new land conditioner (Zeowine) to the soil, derived from the compost processes of industrial wine, waste, and zeolite. Three treatments on a Sangiovese vineyard were conducted: Zeowine (ZW) (30 tons per ha), Zeolite (Z) (10 tons per ha), and Compost (C) (20 tons per ha). During the two seasons (2021-2022), measurements were made of single-leaf gas exchange and leaf midday water potential, as well as chlorophyll fluorescence. In addition, the parameters of plant yield, yeast assimilable nitrogen, technological maturity, fractionation of anthocyanins (Cyanidin-3-glucoside, Delphinidin-3-glucoside, Malvidin-3-acetylglucoside, Malvidin-3-cumarylglucoside, Malvidin-3-glucoside, Peonidin-3-acetylglucoside, Peonidin-3-cumarylglucoside, Peonidin-3-glucoside, and Petunidin-3-glucoside), Caffeic Acid, Coumaric Acid, Gallic Acid, Ferulic Acid, Kaempferol-3-O-glucoside, Quercetin-3-O-rutinoside, Quercetin-3-O-glucoside, Quercetin-3-O-galactoside, and Quercetin-3-O-glucuronide were analyzed. The Zeowine and zeolite showed less negative water potential, higher photosynthesis, and lower leaf temperature. Furthermore, they showed higher levels of anthocyanin accumulation and a lower level of quercetin. Finally, the interaction of the beneficial results of Zeowine (soil and grapevines) was evidenced by the embellishment of the nutritional and water efficiency, the minimizing of the need for fertilizers, the closure of the production cycle of waste material from the supply chain, and the improvement of the quality of the wines.

Multi-feedstock biorefinery concept: Valorization of winery wastes by engineered yeast

The wine industry produces significant amounts of by-products and residues that are not properly managed, posing an environmental problem. Grape must surplus, vine shoots, and wine lees have the potential to be used as renewable resources for the production of energy and chemicals. Metabolic engineering efforts have established Saccharomyces cerevisiae as an efficient microbial cell factory for biorefineries. Current biorefineries designed for producing multiple products often rely on just one feedstock, but the bioeconomy would clearly benefit if these biorefineries could efficiently convert multiple feedstocks. Moreover, to reduce the environmental impact of fossil fuel consumption and maximize production economics, a biorefinery should be capable to supplement the manufacture of biofuel with the production of high-value products. This study proposes an integrated approach for the valorization of diverse wastes resulting from winemaking processes through the biosynthesis of xylitol and ethanol. Using genetically modified S. cerevisiae strains, the xylose-rich hemicellulosic fraction of hydrothermally pretreated vine shoots was converted into xylitol, and the cellulosic fraction was used to produce bioethanol. In addition, grape must, enriched in sugars, was efficiently used as a low-cost source for yeast propagation. The production of xylitol was optimized, in a Simultaneous Saccharification and Fermentation process configuration, by adjusting the inoculum size and enzyme loading. Furthermore, a yeast strain displaying cellulases in the cell surface was applied for the production of bioethanol from the glucan-rich cellulosic. With the addition of grape must and/or wine lees, high ethanol concentrations were reached, which are crucial for the economic feasibility of distillation. This integrated multi-feedstock valorization provides a synergistic alternative for converting a range of winery wastes and by-products into biofuel and an added-value chemical while decreasing waste released to the environment.

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.

Mediterranean Food Industry By-Products as a Novel Source of Phytochemicals with a Promising Role in Cancer Prevention

The Mediterranean diet is recognized as a sustainable dietary approach with beneficial health effects. This is highly relevant, although the production of typical Mediterranean food, i.e., olive oil or wine, processed tomatoes and pomegranate products, generates significant amounts of waste. Ideally, this waste should be disposed in an appropriate, eco-friendly way. A number of scientific papers were published recently showing that these by-products can be exploited as a valuable source of biologically active components with health benefits, including anticancer effects. In this review, accordingly, we elaborate on such phytochemicals recovered from the food waste generated during the processing of vegetables and fruits, typical of the Mediterranean diet, with a focus on substances with anticancer activity. The molecular mechanisms of these phytochemicals, which might be included in supporting treatment and prevention of various types of cancer, are presented. The use of bioactive components from food waste may improve the economic feasibility and sustainability of the food processing industry in the Mediterranean region and can provide a new strategy to approach prevention of cancer.

Potential Prebiotic Effect of Cava Lees: Changes in Gut Microbiota

Lees are a winery by-product with a fiber-rich composition that could have a potential prebiotic effect on gut microbiota. Prebiotics cannot be digested by humans but can be used by bacteria found in the large intestine. To evaluate the potential prebiotic effect of lees, they were administered to Wistar rats for 14 days. Feces were collected daily, and DNA was extracted and analyzed by shot gun sequencing. The supplementation with lees did not affect weight, food intake, or water consumption of the studied rats. It was found that lees promoted the increase of relative abundance of probiotic bacteria belonging to the Lactobacillaceae family, as well as other potentially probiotic species such as Blautia hansenii, Roseburia intestinalis, and Ruminococcus obeum. Moreover, lees supplementation also reduced the abundance of certain pathogenic bacteria. In conclusion, lees can improve the presence of beneficial bacteria in the gastrointestinal tract and can be re-valorized as a new ingredient in food formulation.

Changes in the Volatile Profile of Wheat Sourdough Produced with the Addition of Cava Lees

The volatile fraction is of great importance for the organoleptic quality and consumer acceptance of bread. The use of sourdough improves the sensory profile of bread, as well as the addition of new ingredients to the fermentation. Cava lees are a sparkling wine by-product formed of dead microorganisms, tartaric acid, and other inorganic compounds, rich in antioxidant compounds as well as β-glucans and mannoproteins. The aim of this study was to evaluate the effect of different concentrations of Cava lees (0–2% w/w) on sourdough volatile compounds to re-valorize this by-product of the wine industry. Headspace solid-phase microextraction (HS-SPME) was optimized to study the volatile fractions of sourdoughs. The parameters selected were 60 °C, 15 min of equilibrium, and 30 min of extraction. It was found that the addition of Cava lees resulted in higher concentrations of volatile compounds (alcohols, acids, aldehydes, ketones and esters), with the highest values being reached with the 2% Cava lees. Moreover, Cava lees contributed to aroma due to the compounds usually found in sparkling wine, such as 1-butanol, octanoic acid, benzaldehyde and ethyl hexanoate.

By-Product Revalorization: Cava Lees Can Improve the Fermentation Process and Change the Volatile Profile of Bread

Wine lees are a by-product that represents a 25% of the total winery waste. Although lees are rich in antioxidant compounds and dietary fiber, they have no added value and are considered a residue. The aim of this study was to evaluate the effect of Cava lees (0 and 5% w/w) on microbial populations during sourdough and bread fermentation and the volatile fraction of the final bread. The results showed that 5% Cava lees promoted the growth of both lactic acid bacteria (LAB) and yeast in short fermentations (bread) but did not improve microbial growth in long fermentations (sourdough). Regarding volatile compounds, the addition of Cava lees increased the concentration of volatiles typically found in those products. Also, some compounds reported in sparkling wines were also identified in samples with Cava lees adsorbed on their surface. To sum up, the addition of Cava lees to sourdough and, especially, bread formulation may be a new strategy to revalorize such by-product.

Sequential Membrane Filtration to Recover Polyphenols and Organic Acids from Red Wine Lees: The Antioxidant Properties of the Spray-Dried Concentrate

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.

Membrane-based Operations for the Fractionation of Polyphenols and Polysaccharides From Winery Sludges

The present work investigated the impact of ultrafiltration (UF) and nanofiltration (NF) membranes on the recovery and fractionation of polyphenolic compounds and polysaccharides from Sangiovese and Cabernet Sauvignon wine lees. A laboratory-made flat-sheet membrane in cellulose acetate (CA400-38) was used in the UF treatment of Sangiovese wine lees; three laboratory-made flat-sheet membranes in cellulose acetate (CA316, CA316-70, CA400-22) and a polyamide commercial membrane (NF90) were used in the NF treatment of Cabernet Sauvignon wine lees. All membranes were characterized in terms of hydraulic permeability and rejection toward references solutes; the performances of the membranes were measured in terms of productivity, fouling index, cleaning efficiency and retention toward target compounds.

Experimental results indicated that all UF and NF membranes were effective in separating target compounds rejecting more than 92% of polysaccharides with polyphenols preferentially permeating through the membrane. The UF membrane rejected more than 40% of total polyphenols; rejections toward non-flavonoids and flavonoids were less than 25% and 12.5%, respectively.

The laboratory-made NF membranes exhibited higher permeate flux values (of the order of 11–12 L/m2h) in comparison with the commercial NF membrane, despite the observed differences in the retention of specific solutes. Among the prepared membranes the CA316 showed a total rejection toward most part of non-flavonoids and flavonoids.

The experimental results support the use of UF and NF processes in a sequential design to fractionate and refine phenolic compounds from winery sludge for the production of concentrated fractions with high antioxidant activities.

Revalorization of Cava (Spanish Sparkling Wine) Lees on Sourdough Fermentation

Cava lees are a sparkling wine by-product formed of dead microorganisms, tartaric acid and other inorganic compounds, with a potential for enhancing microbial growth. Lees are rich in antioxidant compounds as well as β-glucans and mannoproteins. The aim of this study was to evaluate the effect of different concentrations of cava lees (0–2% w/w) on the microbiota (LAB and yeasts) responsible for sourdough fermentation (8 days) to revalorize this by-product of the wine industry. The results showed that 2% cava lees promoted microbial growth and survival in both wheat and rye sourdoughs, except for yeast growth in rye, which stopped at day 3 of fermentation. Moreover, sourdough with lees achieved lower pH values as well as higher concentrations of organic acids, especially lactic and acetic acids (p < 0.05). To sum up, the use of cava lees in sourdough formulation promotes the growth and survival of microorganisms, which, in consequence, promotes a lower pH and greater amounts of organic acids. This could lead to microbial stability as well as changes in bread flavor.

Techno-economic evaluation and life cycle assessment of a biorefinery using winery waste streams for the production of succinic acid and value-added co-products

This study presents techno-economic evaluation and life cycle assessment of a novel biorefinery using the three main waste streams generated by wineries for the production of bio-based succinic acid (SA), crude phenolic-rich extract, grape-seed oil, calcium tartrate and crude tannin-rich extract. Process design has been employed for the estimation of material and energy balances and the sizing of unit operations. The Minimum Selling Price of succinic acid production within a winery waste biorefinery ranges from $1.23-2.76/kg_SA depending on the market price and the potential end-uses of the extracted fractions. The Global Warming Potential and the Abiotic Depletion Potential of winery waste valorisation through the proposed biorefinery are 1.47 kg CO₂-eq per kg dry waste and 25.2 MJ per kg dry waste, respectively. Biorefining of winery waste could lead to the development of a sustainable and novel bioeconomy business model with new market opportunities and efficient waste management.

Discovering the Influence of Microorganisms on Wine Color

Flavor, composition and quality of wine are influenced by microorganisms present on the grapevine surface which are transferred to the must during vinification. The microbiota is highly variable with a prevalence of non-Saccharomyces yeasts, whereas Saccharomyces cerevisiae is present at low number. For wine production an essential step is the fermentation carried out by different starter cultures of S. cerevisiae alone or in mixed fermentation with non-Saccharomyces species that produce wines with significant differences in chemical composition. During vinification wine color can be influenced by yeasts interacting with anthocyanin. Yeasts can influence wine phenolic composition in different manners: direct interactions—cell wall adsorption or enzyme activities—and/or indirectly—production of primary and secondary metabolites and fermentation products. Some of these characteristics are heritable trait in yeast and/or can be strain dependent. For this reason, the stability, aroma, and color of wines depend on strain/strains used during must fermentation. Saccharomyces cerevisiae or non-Saccharomyces can produce metabolites reacting with anthocyanins and favor the formation of vitisin A and B type pyranoanthocyanins, contributing to color stability. In addition, yeasts affect the intensity and tonality of wine color by the action of β-glycosidase on anthocyanins or anthocyanidase enzymes or by the pigments adsorption on the yeast cell wall. These activities are strain dependent and are characterized by a great inter-species variability. Therefore, they should be considered a target for yeast strain selection and considered during the development of tailored mixed fermentations to improve wine production. In addition, some lactic acid bacteria seem to influence the color of red wines affecting anthocyanins’ profile. In fact, the increase of the pH or the ability to degrade pyruvic acid and acetaldehyde, as well as anthocyanin adsorption by bacterial cells are responsible for color loss during malolactic fermentation. Lactic acid bacteria show different adsorption capacity probably because of the variable composition of the cell walls. The aim of this review is to offer a critical overview of the roles played by wine microorganisms in the definition of intensity and tonality of wines’ color.

Revalorization of Cava Lees to Improve the Safety of Fermented Sausages

The revalorization of food processing by-products not only reduces the environmental impact of their disposal, but also generates added economic value. Cava lees consist of inactive cells of Saccharomyces cerevisiae, and though regarded as a valueless winery by-product, they are rich in fiber and phenolic compounds. In this study, a challenge test was performed to assess the effect of cava lees and a phenolic extract (LPE) derived therefrom on the behaviour of technological microbiota (lactic acid bacteria used as a starter culture) and the foodborne pathogens Salmonella spp. and Listeria monocytogenes during the fermentation and ripening of pork sausages. Ten batches of fermented sausages were prepared with and without cava lees or the LPE, and with or without different strains of Latilactobacillus sakei (CTC494 or BAP110). The addition of cava lees reduced the pH values of the meat batter throughout the fermentation and ripening process. No growth-promoting effect on spontaneous lactic acid bacteria (LAB) or the starter culture was observed. In contrast, the presence of cava lees prevented the growth of the tested pathogens (Salmonella and L. monocytogenes), as did the starter culture, resulting in significantly lower counts compared to the control batch. In addition, the combination of cava lees with L. sakei CTC494 had a bactericidal effect on Salmonella. LPE supplementation did not affect the pH values or LAB counts but reduced the mean counts of Salmonella, which were 0.71 log10 lower than the control values at the end of the ripening. The LPE did not exert any additional effect to that of the starters applied alone. The revalorization of cava lees as a natural ingredient to improve the microbiological safety of fermented sausages is a feasible strategy that would promote a circular economy and benefit the environment.

Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Characterization of Moravian Wines by Selected Chemical Parameters

Knowledge of analytical values in wines is essential to ensure product safety and compliance with legislation, and it is also essential to understand the various technologies in wine production. The aim of this work was to evaluate the analytical parameters of bottled Moravian wines from the Znojmo sub-region, from harvests 2015 and 2016. Basic oenological parameters and biologically active substances were evaluated. Moreover, we evaluated conditions during bottle aging in wines from harvest 2016. The results of the basic analytical values such as total phenolic acid (TPA), total sulfur dioxide (SO2), pH, actual alcohol content (EtOH), and titratable acidity (TA) were in accordance with generally known values in wines and met the legislative requirements within oenological practices. Biologically active substances, such as gallic acid, trans-caffeic acid (TCA), trans-p-coumaric acid (TPCA), rutin, ferulic acid (FA), myricetin, resveratrol, and quercetin were identified. Comparing the analytical values of individual types of wine leads to a better understanding of winemaking technology and the development of wine as such. The subject of the study was also the monitoring of produced grape pomace incurred during wine production harvest 2015 with the indication of possibilities of its further use.

Optimised Extraction and Preliminary Characterisation of Mannoproteins from Non-Saccharomyces Wine Yeasts

The exogenous application of yeast-derived mannoproteins presents many opportunities for the improvement of wine technological and oenological properties. Their isolation from the cell wall of Saccharomycescerevisiae has been well studied. However, investigations into the efficiency of extraction methods from non-Saccharomyces yeasts are necessary to explore the heterogeneity in structure and composition that varies between yeast species, which may influence wine properties such as clarity and mouthfeel. In this study, nine yeast strains were screened for cell wall mannoprotein content using fluorescence microscopy techniques. Four species were subsequently exposed to a combination of mechanical and enzymatic extraction methods to optimize mannoprotein yield. Yeast cells subjected to 4 min of ultrasound treatment applied at 80% of the maximum possible amplitude with a 50% duty cycle, followed by an enzymatic treatment of 4000 U lyticase per g dry cells weight, showed the highest mannoprotein-rich yield from all species. Furthermore, preliminary evaluation of the obtained extracts revealed differences in carbohydrate/protein ratios between species and with increased enzyme incubation time. The results obtained in this study form an important step towards further characterization of extraction treatment impact and yeast species effect on the isolated mannoproteins, and their subsequent influence on wine properties.

Enzyme-Assisted Extraction to Obtain Phenolic-Enriched Wine Lees with Enhanced Bioactivity in Hypertensive Rats

The antihypertensive effect of the soluble fraction of wine lees (WL) from Cabernet variety grapes was recently reported by our group. This blood pressure (BP)-lowering effect was attributed to the presence of flavanols and anthocyanins. In this context, phenolic-enriched wine lees (PWL) could potentially exhibit a stronger bioactivity. Therefore, the aim of this study was to obtain a soluble fraction of WL with increased phenolic content and evaluate its functionality. The PWL were obtained using an enzyme-assisted extraction based on the hydrolysis of WL proteins with Flavourzyme^®. They contained 57.20% more total phenolic compounds than WL, with anthocyanins and flavanols being the largest families present. In addition, PWL also showed greater angiotensin-converting enzyme inhibitory and antioxidant activities. Finally, the antihypertensive activity of the PWL was evaluated in spontaneously hypertensive rats. A single dose of 5 mL/kg body weight of PWL showed a greater BP-lowering effect than the one shown by WL. Moreover, this antihypertensive effect was more prolonged than the one produced by the antihypertensive drug Captopril. These results demonstrate that enzymatic protein hydrolysis is a useful method to maximize the extraction of phenolic compounds from WL and to obtain extracts with enhanced functionalities.

ACE Inhibitory and Antihypertensive Activities of Wine Lees and Relationship among Bioactivity and Phenolic Profile

Wine lees (WL) are by-products generated in the winemaking process. The aim of this study was to investigate the angiotensin-converting enzyme inhibitory (ACEi) activity, and the blood pressure (BP) lowering effect of WL from individual grape varieties. The relationship among their activities and phenolic profiles was also studied. Three WL, from Cabernet, Mazuela, and Garnacha grape varieties, were firstly selected based on their ACEi properties. Their phenolic profiles were fully characterized by UHPLC-ESI-Q-TOF-MS. Then, their potential antihypertensive effects were evaluated in spontaneously hypertensive rats (SHR). BP was recorded before and after their oral administrations (2, 4, 6, 8, 24, and 48 h) at a dose of 5 mL/kg bw. Cabernet WL (CWL) exhibited a potent antihypertensive activity, similar to that obtained with the drug Captopril. This BP-lowering effect was related to the high amount of anthocyanins and flavanols present in these lees. In addition, a potential hypotensive effect of CWL was discarded in normotensive Wistar-Kyoto rats. Finally, the ACEi and antihypertensive activities of CWL coming from a different harvest were confirmed. Our results suggest the potential of CWL for controlling arterial BP, opening the door to commercial use within the wine industry.

Biotechnological processes for regulating the quality and safety of wine products

The production of a competitive wine industry in Russia is an important task for the successful development of the country’s agro-industrial complex. The purpose of this research is to consider the ways of harmonious development of competitive Russian winemaking, based on the advanced bioecotechnologies of developed countries. This paper presents biotechnological processes and classes of enzymes or individual representatives. Established that both the enzymes of the grape and the enzyme systems of wine yeast are involved in the processes of wine production. During delivery of grapes for processing, means of inactivation of the activity of oxidative enzymes such as sulfur dioxide, liquid nitrogen, carbon dioxide should be used. Improvement and acceleration of clarification of grape must have to be done with the use of pectinesterases, polymethylgalacturonases, polygalacturonases, pectin transeliminases. In order to obtain wines stability to protein turbidity, the use of the technology of two-stage fermentation with deep protein transformation is recommended. Depending on the tasks of malolactic fermentation (MF) or its prevention, yeast strains that prevent the development of MF and strains that support the development of MF have been isolated. A relationship between the content of various groups of phenolic compounds and the activity of MF was established.