Current trends and possibilities for exploitation of Grape pomace as a potential source for value addition

Antioxidant Ready-to-Use Grape Pomace Extracts Recovered with Natural Eutectic Mixtures for Formulation of Color-Rich Gummies

The growing consumer demand for natural and eco-friendly food products motivates the development and evaluation of new and natural inputs for the food industry. So, this work explores the potential of grape pomace (GP) from winemaking, a food production residue, to obtain an anthocyanin-rich, ready-to-use extract with antioxidant activity that can confer improved color-rich gummy candies. The anthocyanins' chemical nature and the predictive COSMO-SAC model was considered for screening the best natural eutectic mixture for anthocyanin extraction. The eutectic mixtures composed of choline chloride as a hydrogen bond acceptor and acetic and citric acids as hydrogen bond donors were selected as solvents. The extraction was performed using a high-shear disperser (Ultra-Turrax®) at 45 °C and was stirred at 5000 rpm for 10 min. The extracts presented high total anthocyanin content (TAC), up to 60 µg equivalent of cyaniding-3-glucoside/g of dry GP, and high antioxidant activity as determined by DPPH and FRAP assays. The phenolic profile was also determined by high-performance liquid chromatography (HPLC) and the results corroborated with the antioxidant activity of the extracts. The results also demonstrate that eutectic mixtures enhance the extraction efficiency of anthocyanins and improve their stability, making them suitable for incorporation into functional food products such as gummies, acting as natural colorants.

Wild Vitis Species as Stilbenes Sources: Cane Extracts and Their Antibacterial Activity against Listeria monocytogenes

Grapevines (Vitis spp.) produce several valuable polyphenol-type secondary metabolites including various stilbenoids. Although the potential application of stilbenes may offer alternative solutions to food safety or health challenges, only little information is available on their antibacterial activity against foodborne pathogens. In this work, high-performance liquid chromatography was used to analyze the stilbenoid profile of various wild Vitis species, including V. amurensis, V. davidii, V. pentagona, and V. romanetii, selected from the gene bank for grapes at the University of Pécs, Hungary. We found that the stilbene profile of cane extracts is strongly genotype-dependent, showing the predominant presence of ε-viniferin with a wide concentration range ≈ 320-3870 µg/g dry weight. A novel yet simple and efficient extraction procedure was developed and applied for the first time on grape canes, resulting in ε-viniferin-rich crude extracts that were tested against Listeria monocytogenes, an important foodborne pathogen. After 24 h exposure, V. pentagona and V. amurensis crude extracts completely eliminated the bacteria at a minimum bactericidal concentration of 42.3 µg/mL and 39.2 µg/mL of ε-viniferin, respectively. On the other hand, V. romanetii extract with 7.8 µg/mL of ε-viniferin resulted in 4 log reduction in the viable bacterial cells, while V. davidii extract with 1.4 µg/mL of ε-viniferin did not show significant antibacterial activity. These findings indicate that the ε-viniferin content was directly responsible for the antibacterial effect of cane extract. However, pure ε-viniferin (purity > 95%) required a higher concentration (188 µg/mL) to eradicate the bacteria under the same conditions, suggesting the presence of other antibacterial compounds in the cane extracts. Investigating the onset time of the bactericidal action was conducted through a kinetic experiment, and results showed that the reduction in living bacterial number started after 2 h; however, the bactericidal action demanded 24 h of exposure. Our results revealed that the canes of V. pentagona and V. amurensis species are a crucial bio-source of an important stilbene with antimicrobial activity and health benefits.

Current trends and possibilities of typical microbial protein production approaches: a review

Global population growth and demographic restructuring are driving the food and agriculture sectors to provide greater quantities and varieties of food, of which protein resources are particularly important. Traditional animal-source proteins are becoming increasingly difficult to meet the demand of the current consumer market, and the search for alternative protein sources is urgent. Microbial proteins are biomass obtained from nonpathogenic single-celled organisms, such as bacteria, fungi, and microalgae. They contain large amounts of proteins and essential amino acids as well as a variety of other nutritive substances, which are considered to be promising sustainable alternatives to traditional proteins. In this review, typical approaches to microbial protein synthesis processes were highlighted and the characteristics and applications of different types of microbial proteins were described. Bacteria, fungi, and microalgae can be individually or co-cultured to obtain protein-rich biomass using starch-based raw materials, organic wastes, and one-carbon compounds as fermentation substrates. Microbial proteins have been gradually used in practical applications as foods, nutritional supplements, flavor modifiers, and animal feeds. However, further development and application of microbial proteins require more advanced biotechnological support, screening of good strains, and safety considerations. This review contributes to accelerating the practical application of microbial proteins as a promising alternative protein resource and provides a sustainable solution to the food crisis facing the world.

Grape Pomace-Advances in Its Bioactivity, Health Benefits, and Food Applications

From a circular economy perspective, the appropriate management and valorization of winery wastes and by-products are crucial for sustainable development. Nowadays, grape pomace (GP) has attracted increasing interest within the food field due to its valuable content, comprising nutritional and bioactive compounds (e.g., polyphenols, organic and fatty acids, vitamins, etc.). Particularly, GP polyphenols have been recognized as exhibiting technological and health-promoting effects in different food and biological systems. Hence, GP valorization is a step toward offering new functional foods and contributing to solving waste management problems in the wine industry. On this basis, the use of GP as a food additive/ingredient in the development of novel products with technological and functional advantages has recently been proposed. In this review, we summarize the current knowledge on the bioactivity and health-promoting effects of polyphenolic-rich extracts from GP samples. Advances in GP incorporation into food formulations (enhancement of physicochemical, sensory, and nutritional quality) and information supporting the intellectual property related to GP potential applications in the food industry are also discussed.

Organosolv Treatment of Red Grape Pomace for Effective Recovery of Antioxidant Polyphenols and Pigments Using a Ternary Glycerol/Ethanol/Water System under Mild Acidic Conditions

The purpose of this investigation was (i) the development of a novel, green tertiary solvent system, composed of water, ethanol and glycerol, and (ii) the implementation of an organosolv treatment of red grape pomace (RGP) for the efficient production of polyphenol-containing extracts with enhanced antioxidant properties. The treatment developed was performed under mild acidic conditions, imparted by the addition of citric acid, and it was first evaluated on the basis of severity, establishing linear models that described the correlation between treatment performance and combined severity factors. To solicit treatment optimization, response surface methodology was implemented, considering solvent acidity and residence time as the treatment variables. The optimized treatment afforded maximum total polyphenol (166 ± 6 mg GAE g-1 DM), total pigment (4.4 ± 0.2 mg MvE g-1 DM) and total flavanol (31.5 mg CtE g-1 DM) yields and extracts with particularly enhanced antioxidant activity. This might be attributed to specific constituents with high antioxidant potency, such as catechin, determined in the extract using high-performance liquid chromatography. Thus, the treatment developed is proposed as a highly efficient process to generate RGP extracts enriched in polyphenolic compounds, with enhanced antioxidant activity. Such extracts might then be valorized as food additives, to provide antioxidant protection and/or pigmentation.

Agroindustrial and food processing residues valorization for solid-state fermentation processes: A case for optimizing the co-production of hydrolytic enzymes

In the pursuit of sustainability, managing agro-industrial and food processing residues (AFR) efficiently is crucial. This study proposes a systematic approach to convert AFR into valuable products via solid-state fermentation (SSF). Using fungal enzyme production as a case study, this adaptable methodology suits any SSF bioprocess. Initially, AFR's physicochemical properties were evaluated to assess their feasible use as carbon sources and solid matrices for SSF. Then, five strains were screened for their capability to produce enzymes (Xylanase, X; pectinase, P; cellulase, C). Apple pomace (AP) and brewery spent grain (BSG) with Aspergillus sp. (strain G5) were selected. Subsequent steps involved a two-phase statistical approach, identifying critical factors and optimizing them. Process conditions were screened using a Plackett-Burman design, narrowing critical variables to three (BSG/AP, pH, humidity). Response Surface Methodology (Central Composite Design) further optimized these factors for co-synthesis of X, P, and C. The humidity had the most significant effect on the three responses. The optimum conditions depended on each enzyme and were further validated to maximize either X, P or C. The obtained extracts were used for pectin extraction from orange peels. The extract containing primarily xylanase (X = 582.39, P = 22.86, C = 26.10 U mL-1) showed major pectin yield recovery (12.33 ± 0.53%) and it was obtained using the optimal settings of BSG/AP (81/19), humidity (50.40%), and pH (4.58). The findings will enable adjusting process conditions to obtain enzymatic cocktails with a tailored composition for specific applications.

Biological Activity and Metabolomics of Griffonia simplicifolia Seeds Extracted with Different Methodologies

Griffonia simplicifolia, a tropical plant endemic to West Africa, is highly regarded for its significant pharmacological potential. The objective of this study was to evaluate the metabolomic profile and to explore the antioxidant properties, antiproliferative activity, and antimicrobial potential of G. simplicifolia seed extracts obtained through either maceration, microwave-assisted extraction (MAE), or Soxhlet extraction using water, acetone, methanol and ethanol as solvents. Overall, methanol possessed superior total extraction efficiency. HPLC analyses confirmed the efficacy of acetone and ethanol as optimal solvents for the extraction of flavonoids and flavan-3-ols, whereas MAE exhibited enhanced effectiveness in extracting N-containing compounds, including 5-hydroxytryptophan (5-HTP). HPLC-MS analyses identified forty-three compounds, including thirty-four phenolic compounds and nine N-containing molecules. Isomyricitrin, taxifolin and a flavonol glucuronide were the main polyphenols, whereas 5-HTP was the main N-containing compound. Hydroalcoholic G. simplicifolia extracts showed the highest radical scavenging and metal-reducing antioxidant power, suggesting that most of the contribution to antioxidant activity depends on the more polar bioactive compounds. G. simplicifolia extracts showed dose-dependent antiproliferative activity against three distinct cancer cell lines (HeLa, HepG2, and MCF-7), with notable variations observed among both the different extracts and cell lines and divergent GI50 values, emphasizing substantial discrepancies in cell sensitivity to the various extracts. Furthermore, G. simplicifolia extracts revealed antibiotic activity against Staphylococcus aureus. Our results highlight the potential of G. simplicifolia phytochemicals in the development of functional foods, nutraceuticals, and dietary supplements.

Strategies to Formulate Value-Added Pastry Products from Composite Flours Based on Spelt Flour and Grape Pomace Powder

In recent years, sustainability has promoted new research to develop reformulation strategies for value-added food products by exploiting grape pomace. Grape pomace powder (GP) was used to substitute spelt flour (SF) at 0, 5, 10, 15, 20 and 25% to obtain three types of fortified pastry products: biscuits and cakes involving a chemical leavening agent, and rolls leavened by yeast. Proximate composition, total phenolic content (TPC), total flavonoids content (TFC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric-reducing antioxidant power (FRAP) along with physical characteristics and sensory analysis of the enriched products were considered. The retention rate of the functional attributes of formulations in response to baking was also evaluated. Significant improvements in TPC, TFC and both antioxidant tests were achieved in the fortified products by the incremental incorporation of GP. With a substitution of 25% SF by GP, the following increases were recorded in biscuits, cakes and rolls over the control samples: 7.198-, 7.733- and 8.117-fold for TPC; 8.414-, 7.000- and 8.661-fold for TFC; 16.334-, 17.915- and 18.659-fold for FRAP and 16.384-, 17.908- and 18.775-fold for DPPH. The retention rates of TPC, TFC, FRAP and DPPH relative to the corresponding dough were 41-63%, 37-65%, 48-70% and 45-70%. The formulas leavened by yeast revealed higher functionality than those produced with a chemical raising agent. With the increase in GP, the elasticity and porosity gradually decreased for cakes and rolls, while the spread ratio of biscuits increased. Regarding sensory evaluation, all formulations with incorporated GP up to 10% were rated at an extremely pleasant acceptability level. The solutions derived from this study have great practical applicability for the development of new pastry formulations with improved functionality from GP valorisation.

Enhanced Polyphenols Recovery from Grape Pomace: A Comparison of Pressurized and Atmospheric Extractions with Deep Eutectic Solvent Aqueous Mixtures

Deep eutectic solvents (DES) are emerging as potent polyphenol extractors under normal atmospheric conditions. Yet, their effectiveness in hot pressurized liquid extraction (HPLE) must be studied more. We explored the ability of various water/DES and water/hydrogen bond donors (HBDs) mixtures in both atmospheric solid liquid extraction (ASLE) and HPLE (50%, 90 °C) for isolating specific polyphenol families from Carménère grape pomace. We assessed extraction yields based on total polyphenols, antioxidant capacity, and recovery of targeted polyphenols. The HBDs ethylene glycol and glycerol outperformed DES in atmospheric and pressurized extractions. Ethylene glycol exhibited a higher affinity for phenolic acids and flavonols, while flavanols preferred glycerol. Quantum chemical computations indicated that a high-water content in DES mixtures led to the formation of new hydrogen bonds, thereby reducing polyphenol-solvent interactions. HPLE was found to be superior to ASLE across all tested solvents. The elevated pressure in HPLE has caused significant improvement in the recovery of flavanols (17-89%), phenolic acids (17-1000%), and flavonols (81-258%). Scanning electron microscopy analysis of post-extraction residues suggested that high pressures collapse the plant matrix, thus easing polyphenol release.

Innovative Use of Olive, Winery and Cheese Waste By-Products as Novel Ingredients in Weaned Pigs Nutrition

New sustainable sources of feeds, which can enhance the health and welfare of farm animals, lower feeding costs, and lead to safer products, are of high priority in modern animal production systems. In the present study, a novel silage created from Greek olive, winery, and feta cheese waste by-products, was evaluated as a feed ingredient at different inclusion rates (0%, 5% or 10%) in 34-day-old weaned pigs. The potential beneficial effects on performance, health and intestinal digesta microflora balance of the pigs were evaluated. Additionally, chemical, microbiological and quality analysis of the meat was carried out. Results showed no detrimental effects (p > 0.05) on the pigs' performance and no significant changes (p > 0.05) in meat pH, color and chemical analysis. Ileum and cecum microflora populations (total anaerobes, Lactobacillaceae) were positively affected (p ≤ 0.05) by the dietary usage of the silage. The microbial populations (Clostridium spp.) of belly meat cuts were positively modified (p ≤ 0.01). The concentration of total phenols in the meat cuts were increased (p ≤ 0.05) and their resistance to oxidation was improved (p ≤ 0.05). In addition, the fatty acid profile of the meat lipids (polyunsaturated and n-3 fatty acids) was positively modified (p ≤ 0.001).

Valorisation of fresh waste grape through fermentation with different exogenous probiotic inoculants

The disposal of fresh waste grape berries restraining the sustainable development of vineyards. The aims of this study were to evaluate the effects of different exogenous probiotic inoculants on the fermentation of fresh waste grape berries. In the fermentation process, the variations of pH and EC value, chemical characteristics of the fermentation products, as well as the microbial communities' composition were simultaneously observed. In addition, the feasibility of using the fermentation products as chemical fertilizer substitute in agricultural production also has been verified in this study. The results indicated that the different probiotic inoculants has shown clear impacts on the variation trends of pH and EC value in the grape waste fermentation. Lactobacillus casei and Zygosaccharomyces rouxii are ideal probiotics for the fermentation of waste grape, which enhanced the contents of free Aa and other nutrients in fermentation products. Compared with Fn treatment (without exogenous inoculants), the total free Aa contents in Fs (inoculation with Z. rouxii) and Fm (inoculation with L. casei and Z. rouxii mixture) treatments have improved by 199.1% and 325.5%, respectively. The microbial communities' composition during the fermentation process also been greatly influenced by the different inoculants. At the genus level, Lactobacillus and Pseudomonas were the dominant bacteria, while Saccharomyces and Candida were the dominant fungi in the fermentation. Using the fermentation products as chemical fertilizer substitute has enhanced the quality of Kyoho grape. Compared with traditional chemical fertilization treatment (T1), application with fermented grape waste (T2) has significantly improved VC and soluble solid contents in grape berries by 16.89% and 20.12%, respectively. In conclusion, fermentation with suitable probiotics was an efficient approach for the disposal and recycling of fresh waste grape in vineyards.

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.

Functional Foods Acceptability: A Consumers' Survey on Bread Enriched with Oenological By-Products

In recent years, consumers have shown considerable attention to functional foods that can provide various benefits. At the same time, the awareness of the problem of waste generation from the agri-food supply chains has increased; thus, scholars and practitioners are devoting great attention to sustainable food waste management. Within the wine processing, the production phase generates by-products such as marc, grape seeds, stems, and wine lees. In most cases, these by-products are treated as waste rather than as a resource, creating environmental, economic, and social impacts related to their disposal. By contrast, the reuse of oenological by-products in food production can have several health benefits, since they are rich in functional molecules such as fibres, polyphenols, and vitamin E, and can also trigger a circular economy model. The aim of this research is to investigate the acceptance of consumers towards bread enriched with oenological by-products through the application of k-means clustering, providing insights on the characterisation of groups of consumers based on their specific features and declared attitudes. The results showed three different consumers' clusters, highlighting that the acceptance of this enriched bread is not influenced by the consumers' socio-economic features, but it is related to consumers' sensitivity. Therefore, target strategies should be put in place to inform consumers about the benefits associated with the consumption of bread enriched with oenological by-products.

Basic constituents, bioactive compounds and health-promoting benefits of wine skin pomace: A comprehensive review

Wine pomace (WP) is a major byproduct generated during winemaking, and skin pomace (SKP) comprises one of the most valuable components of WP. Since SKP differs in composition and properties from seed pomace (SDP), precise knowledge of SKP will aid the wine industry in the development of novel, high-value products. The current review summarizes recent advances in research relating to SKP presents a comprehensive description of the generation, composition, and bioactive components, primarily focusing on the biological activities of SKP, including antioxidant, gastrointestinal health promotion, antibacterial, anti-inflammatory, anticancer, and metabolic disease alleviation properties. Currently, the separation and recovery of skins and seeds is an important trend in the wine industry for the disposal of winemaking byproducts. In comparison to SDP, SKP is rich in polyphenols including anthocyanins, flavonols, phenolic acids, stilbenes, and some proanthocyanidins, as well as dietary fiber (DF). These distinctive benefits afford SKP the opportunity for further development and application. Accordingly, the health-promoting mechanism and appropriate application of SKP will be further elucidated in terms of physiological activity, with the progress of biochemical technology and the deepening of related research.

Effect of Grape Pomace Flour in Savory Crackers: Technological, Nutritional and Sensory Properties

The wine industry generates large amounts of by-products that are usually destined as waste. Grape pomace is the residue of the winemaking process and is rich in compounds with functional properties, such as dietary fiber and phenolic compounds. The aim of this research was to study the influence of white and red grape pomace flour (GPF) addition in the enhancement of functional properties of savory crackers. Different levels of incorporation were tested (5%, 10% and 15% (w/w)). Analysis of physical properties, nutritional composition and sensory acceptability were conducted to evaluate the effect of GPF incorporation. GPF cracker stability throughout a four-week period was achieved with regard to firmness and color. These products presented distinctive and appealing colors, ranging from a violet (GPF of Touriga Nacional variety) to a brown hue (GPF of Arinto variety). Concerning nutritional composition, both crackers incorporated with 10% GPF of Arinto or Touriga Nacional varieties could be considered “high in fiber”, as per the Regulation (EC) No. 1924/2006, suggesting a functional food. GPF crackers demonstrated an overall great acceptance of this kind of innovative foods, with the majority indicating that they would certainly/probably buy them. Moreover, the cracker with 10% Arinto GPF achieved the most balanced and overall preference.

Enhanced Recovery of Natural Antioxidants from Grape Waste Using Natural Eutectic Solvents-Based Microwave-Assisted Extraction

The evaluation of sustainable solvents as alternatives to more harmful conventional solvents combined with intensification techniques to recover phenolic compounds from agri-food waste is in the spotlight. The wine industry generates large amounts of waste as a consequence of grape processing operations, which can be revalued by solvent extraction of valuable antioxidants for food and fine chemical applications. Therefore, the present study focuses on the use of natural eutectic solvents (NAESs) with benign environmental, health, and safety profiles, for valorization of grape waste in the context of a circular economy. Herein, up to 15 NAESs consisting of combinations of three hydrogen bond acceptors (choline chloride, L-proline, and betaine) and four hydrogen bond donors (1,2-propanediol, glycerol, and 1,2- and 1,3-butanediol) were evaluated for antioxidant recovery. After an initial screening of the performance of NAESs by conventional extraction, the process was intensified by microwave-assisted extraction (MAE). The extracts were analyzed by UV/VIS spectrophotometric and HPLC methods. Promising results were obtained with the solvent betaine, 1,2-butanediol [1:4], using MAE at 100 °C for 3 min. Overall, the proposed NAESs-based MAE method was successfully applied to recover target compounds from grape waste, with great prospects for the antioxidants market and sustainable development for the winery sector.

Tunable Production of Diesel Bio-Blendstock by Rhenium-Catalyzed Hydrogenation of Crude Hexanoic Acid from Grape Pomace Fermentation

The transition from fossil resources to renewable ones represents a pressing need. The acidogenic fermentation of biomass-derived ethanol to carboxylic acids represents a novel and smart possibility, opening the way for the production of further value-added bio-products through cascade chemical approaches. In this work, the hydrogenation of commercial hexanoic acid to give 1-hexanol/hexyl hexanoate mixtures was preliminary studied in the presence of commercial rhenium catalysts (Re2O7 and 5 wt% Re/C), which resulted as mainly active and selective towards 1-hexanol. On the other hand, the use of niobium phosphate as the acid co-catalyst markedly shifted the selectivity towards hexyl hexanoate. Moreover, 5 wt% Re/C and physical mixtures of (5 wt% Re/C + niobium phosphate) were further tested for the hydrogenation of crude hexanoic acid obtained through fermentation of white grape pomace, confirming the promising performance of these catalytic systems and their recyclability. For the first time, the employment of 1-hexanol/hexyl hexanoate mixtures as a diesel blendstock was evaluated, highlighting a significant reduction of soot and CO emissions, without any significant change in the engine performance. The promising properties of these oxygenated additives are favorable for the partial replacement of traditional fossil fuels, in accordance with the short-term goals of EU countries.

Antioxidative and immunostimulant potential of fruit derived biomolecules in aquaculture

Huge amounts of non-edible by-products could be generated from fruit industrial processes. They consist mainly of peels together with low amounts of pulp and seeds. These by-products pose an environmental hazard due to soil, air, and water pollution. Moreover, treating these by-products is very expensive and under strict governmental regulations. Nevertheless, they are an excellent source of bioactive constituents, such as phenols, flavonoids, terpenes, and glucans. Based on their constituents, these by-products can significantly enhance the antioxidant defense, immune response, and modulation of gut microbiota and host resistance against various diseases. Therefore, sustainable valorization of fruits by-products can efficiently obtain value-added products that improve the well-being of organisms and reduce environmental stress, in addition to earning an additional industrial income. Since aquaculture is a vital economic sector, there is urgent to look for inexpensive natural food additives that improve health and maintain high nutritional quality for farming organisms without harming the environment and human health. Therefore, using fruit wastes as feed additives represents a striking alternative for fruitful aquaculture. In order to make use of these value-added products, it is a dire need to determine their biological effects on aquaculture organisms by understanding their mechanism of action. In this context, this review will holistically address a comprehensive focus on utilizing fruits by-products and their immunostimulant and antioxidative action.

Reducing Emissions from Combustion of Grape Residues in Mixtures with Herbaceous Biomass

The use of grape residues as a renewable energy source for combustion presents various problems. One of these is the excessive production of carbon monoxide and nitrogen oxides. Analyses and combustion tests were performed on white and red grape pomace as well as grape stems. To verify the possibility of a reduction in emissions, straw of Miscanthus sinensis was added to mixtures with red grape pomace. Emission concentrations of carbon monoxide and nitrogen oxides were determined on a grate combustion device with a nominal thermal output of 8 kW under steady-state conditions. In addition to these emission concentrations, the excess air factor and the flue gas temperature were monitored. The results show a high energy content in grape residues. In red grape pomace, the gross calorific value of dry matter reached 22.17 MJ kg^-1. Unfavourable properties included high ash and nitrogen contents. During combustion tests on all types of grape residue, the emission concentrations of carbon monoxide were above the legal limit for the combustion of solid fuels. The addition of Miscanthus straw improved the behaviour during combustion. The maximum content of grape pomace in the mixture capable of meeting legislative emission requirements was 50% wt.

Revitalizing Unfermented Cabernet Sauvignon Pomace Using an Eco-Friendly, Two-Stage Countercurrent Process: Role of pH on the Extractability of Bioactive Phenolics

As the major byproduct of the winemaking industry, grape pomace remains an untapped source of valuable bioactive phenolic compounds. This study elucidated the optimal aqueous extraction parameters for maximizing phenolic extractability, while avoiding the use of harsh conventional solvents and limiting water usage, from Cabernet Sauvignon grape pomace in which the red grape was processed for white wine. In the single-stage aqueous extraction process (AEP), the concurrent impact of pH (2.64–9.36), solids-to-liquid ratio (SLR, g pomace/mL water) (1:50–1:5), and temperature (41.6–58.4 °C) on the total phenolic content (TPC) of Cabernet Sauvignon pomace was evaluated alongside a kinetic study (15–90 min). Optimal single-stage extraction conditions (pH 9.36, 1:50 SLR, 50 °C, 75 min) guided the development of a two-stage countercurrent extraction process (pH 9.36, 1:10 SLR, 50 °C, 75 min) to further reduce water consumption without compromising overall extractability. The countercurrent process reduced fresh water usage by 80%, increased the TPC of the extracts by 18%, and improved the in vitro antioxidant activities (ABTS and ORAC) of the extracts. Untargeted metabolomics enabled the identification of a diverse pool of phenolics, especially flavonol glycosides, associated with grape pomace, while further phenolic quantitation detected improvements in the release of commonly bound phenolics such as ferulic acid, p-coumaric acid, syringic acid, and protocatechuic acid in alkaline extracts compared to the ethanolic extract. This investigation provides an efficient, eco-friendly extraction strategy suitable for applications in functional food, beverage, nutraceutical, and cosmetic industries.

The Wine Industry By-Products: Applications for Food Industry and Health Benefits

Each year, 20 million tons of wine by-products are generated, corresponding to 30% of the total quantity of vinified grapes. Wine by-products are a source of healthy bioactive molecules, such as polyphenols and other molecules (pigments, fibers, minerals, etc.). The abundance of bioactive compounds assures a promising future for nutritional foodstuff production. Wine by-products can be used to fortify aromatized waters and infusions, bread, pasta, dairy products, alcohol, sugary beverages, and processed foods. These innovative products are part of the Mediterranean diet and are of great interest to both human and environmental health. Pre-clinical studies show that consumption of food produced with wine by-products or with their extracts attenuates the inflammatory state and increases antioxidant status. As such, wine by-products provide protective effects against the underlying pathophysiological hallmarks of some chronic diseases such as atherosclerosis, diabetes, hypertension, obesity, and cancer. However, the poor bioavailability warrants further investigation on how to optimize the efficacy of wine by-products, and more clinical trials are also needed. The scientific evidence has validated the uses of the dietary nature of wine by-products and has helped to promote their use as a functional food to prevent chronic human diseases.

Anti-Proliferative and Pro-Apoptotic Effects of Digested Aglianico Grape Pomace Extract in Human Colorectal Cancer Cells

Grape pomace (GP)—the major by-product of winemaking processes—still contains bioactive molecules with known beneficial properties for human health, such as an antiradical scavenging activity or an antiproliferative activity of tumors. In vitro studies have demonstrated that GP polyphenols specifically influence colon cancer cell proliferation. In addition to previously published work, we tested the phenolic compounds of Aglianico GP following an in vitro simulated gastrointestinal digestion on colorectal cancer cell lines at different degrees of differentiation. Our experiments, using HT29 and SW480 cells, confirmed the anti-proliferative effect of GP gastrointestinal digested extract and provided intriguing insights on the way it influences the cancer cell features (i.e., viability, proliferation, and apoptosis). We observed that Aglianico GP extract showed a great ability to affect cell proliferation and apoptosis. Interestingly, both HT29 and SW480 cells produced a significant increase in Bax, and a significant increase in the Bax/Bcl-2 ratio and caspase-3. The gastrointestinal digested GP extract was previously characterized both for antioxidant activity and phenolic composition. As a result, the TPC and the antioxidant activity reached high values in the Aglianico GP digested extract, and the main compounds assessed by UHPLC-DAD were anthocyanins, phenolic acids, and flavonoids. This work shed light on the use of digested GP extract as a dietary ingredient, a very sustainable source of nutritional compounds with potential health benefits for colon cancer cell proliferation.

Influence of earthworms on the microbial properties and extracellular enzyme activities during vermicomposting of raw and distilled grape marc

The treatment of winery wastes by using appropriate management technologies is of utmost need in order to reduce to a minimum their disposal and avoid negative environmental impacts. This is of particular interest for grape marc, the main solid by-product of the winery industry. However, comparative studies on a pilot-scale dealing with the impact of earthworms on marc derived from both red and white grape varieties during vermicomposting are still scarce. The present study sought to evaluate the changes in the biochemical and microbiological properties of red and white raw marc in the presence and the absence of the earthworm species Eisenia andrei. The distilled marc obtained through distillation of the red grape marc was also considered under this scenario. Samples were taken after 14, 28, 42, and 63 days of vermicomposting. On day 14 earthworms led to a pronounced increase in most of the enzymatic activities, but only in those vermireactors fed with raw marc from the red grape variety. Alfa- and beta-glucosidase as well as chitinase and leucine-aminopeptidase activities were between 3 to 5-times higher relative to the control, while alkaline phosphomonoesterase was even up to 14-fold higher with earthworm presence. From day 28 onwards the magnitude of earthworms' effect on the studied enzymes was also dependent on the type of grape marc. Reduced values of basal respiration, ranging between 200 and 350 mg CO₂ kg OM h^-1 and indicative of stabilized materials were found in the resulting vermicomposts. Moreover, the content of macro- and micronutrients in the end products matched with those considered to have the quality criteria of a good vermicompost. Altogether, these findings reinforce the effectiveness of vermicomposting for the biological stabilization of grape marc with the dual purpose of fertilizer production and environmental protection.

Improved Sustainability in Wine Industry Byproducts: A Scale-up and Economical Feasibility Study for High-Value Compounds Extraction Using Modified SC-CO2

The objective of the present work was to optimize the operating conditions (P, T cosolvent %) and to study the scale-up and the feasibility of the supercritical fluid extraction (SFE) process for polyphenols from grape pomace, the main solid byproduct of the wine industry. Pilot-scale equipment (1 L extraction vessel) was used to study the scale-up prediction for extraction vessels of 50, 100, 500, and 1000 L capacity. The adopted scale-up criteria consisted of maintaining and keeping constant the solvent mass-to-feed mass ratio and the bed geometry dimension. The results indicated an excellent predictive level obtained by Sovová's model and success of the adopted scale-up criteria. At industrial scale, yields were close to 2.3 g_GAE/100 g_DM, a value obtained using the pilot-scale equipment. High concentrations of high-added-value phenols such as cis-resveratrol glucoside, cis-coutaric acid, trans-p-coumaric acid, quercetin, and proanthocyanidins were found in the extract. An economic evaluation of the process indicated the feasibility of an industrial SFE plant with a capacity of 500 L for producing in 60 min an extract with an expected phenolics' concentration of approximately 133 g_GAE/kg _extract at an estimated 67€ /kg_extract cost of manufacturing. Notably, all values are better than those currently reported in the literature.

Studies on antioxidant activities of grape pomace using in vitro, ex vivo, and in vivo models

Grape pomace (GP) is a by-product resulting from the wine industry and can be considered raw material for animal nutrition, mainly due to its richness in polyphenolic substances. The present study, determined the antioxidant activity of GP by different in vitro assays including 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, and hydroxyl radical and hydrogen peroxide scavenging activity and the inhibitory effect on iron-induced lipid peroxidation system. The estimated IC50 value (the concentration required to scavenge 50% of the radicals) of GP methanolic extract was 53.49 mg/L for DPPH; 57.37 mg/L for hydroxyl radical; 29.06 mg/L for superoxide radical and 102.15 mg/L for hydrogen peroxide. The effect of grape pomace supplements in broiler diets on oxidative stability of meat was tested in an experiment on 80 broiler chicks, 1-day-old Cobb 500, divided into 2 groups (C and E) reared on permanent wood shaves litter (10–12 cm thick). Compared to the control diet C, during the grower (14–28 days) and finisher (29–42 days) stages, the experimental diet (E) was supplemented with 6% GP. At the end of the experiment, 6 chicks aged 42 days from each group were slaughtered and samples of thigh meat were collected for further analysis. When the iron-induced lipid peroxidation system was applied, no significant differences were noticed between ex vivo groups’ lipid peroxidation inhibition percentage (24.71% inhibition when GP was added to meat samples and 24.10% inhibition when GP was ingested by animals) and in vivo data (26.92% inhibition) obtained.

Comparing the Effects of Concord Grape (Vitis labrusca L.) Puree, Juice, and Pomace on Intestinal Morphology, Functionality, and Bacterial Populations In Vivo (Gallus gallus)

This is a preliminary study evaluating the effect of different fractions of Concord grapes (Vitis labrusca L.) on the brush border membrane (BBM) morphology, duodenal gene expression, and specific gut bacterial populations. For this study, we utilized a unique intraamniotic approach, wherein, the test substances are administered into the amnion of the Gallus gallus egg (on day 17). The embryo orally consumes the amniotic fluid along with the injected test substance before the hatch. We randomly divided ~50 fertilized eggs into 5 groups including 6% grape (juice, puree, and pomace) along with controls (no injection and diluent—H2O). The grape juice was prepared by crushing the grapes; the grape residues were used as pomace. The grape puree included the grape skin, endocarp, mesocarp, and juice but not the seeds. On day 21, the hatch day, the blood, pectoral muscle, liver, duodenum, and large intestine were harvested. Our results showed no significant differences in blood glucose, pectoral glycogen level, or body weight. However, significant (p < 0.05) differences in duodenal and liver gene expression were observed between the treatment groups. The grape puree treatment resulted in higher Clostridium numbers and lower Bifidobacterium numbers when compared to all other groups. In summary, the dietary consumption of grape polyphenols has the potential to beneficially modulate aspects of intestinal health provided their concentration is limited.

Impact of wine grape pomace on humification performance and microbial dynamics during pig manure composting

The polyphenol humification pathway is essential for soil-forming and compost maturing processes. This study explored the effects of adding different proportions of polyphenol-rich wine grape pomace (WGP) on humification performance and microbial dynamics during pig manure (PM) composting. The results demonstrated that WGP effectively prolonged the duration of the thermophilic period, and improved humification production and compost maturity by enhancing beneficial interactions among microorganisms. Moreover, adding 40% WGP was optimal for nitrogen conservation, and the corresponding germination index (GI) reached 95%. Excitation-emission matrix (EEM) fluorescence spectroscopy analysis suggested that optimizing the WGP content was conducive to the conversion of protein-like substances, which improved the humification of organic matter. In addition, structural equation modelling (SEM) demonstrated that polyphenol content and temperature were the key parameters affecting the humification products. The results showed that WGP holds great promise to improve composting progress and fertilizer quality for biowaste utilization.

Grape stalk valorization for fermentation purposes

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Integrated valorization of grape stalks generated lignin, fermentable sugars and nanocellulose.

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For the first time, xylose was recover from grape stalk.

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First cellulose nanocrystals recovered from grape stalk.

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First proof of concept of use of a generated stream from an integrated valorization process.

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Grape stalks fermentable sugars are consumed to produce bioethanol.

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Biorefinery is a sustainable way for the processing of grape stalk.

White and red grape stalks biomass were fractioned to maximize its economic value by the production of fermentable sugars, as other value streams. High yields of extractives and lignin were first obtained, originating a biomass rich in cellulose and hemicellulose, which was subject to acid and enzymatic hydrolysis for production of fermentable sugars. Higher concentrations of sugars were obtained by enzymatic than by dilute acid hydrolysis. These biosugars were used for fermentation processes with Pichia stipitis and Saccharomyces cerevisiae. The presence of higher quantities of xylose favoured P. stipitis to produce higher ethanol yields than S. cerevisiae which is glucose lover. Cellulose nanocrystals were produced from the resulting biomass without monosaccharides. For the first time an integrated valorization of grape stalks followed by an application of one of the valorized streams is presented.

Valorization of Grape Pomace and Berries as a New and Sustainable Dietary Supplement: Development, Characterization, and Antioxidant Activity Testing

Grape pomace and berries represent natural sources of phytochemicals that can increase the quality of life of consumers by contributing to the prevention of chronic diseases; thus, the development of a dietary supplement was necessary. The raw material (r.m.) used for the development of the dietary supplement consisted of dried and powdered bilberries (Vaccinium myrtillus L.), red currants (Ribes rubrum L.), and red fermented pomaces (Vitis vinifera L.) from Feteasca Neagra and Cabernet Sauvignon cultivars. The particle size distribution, powder flow, total phenolic content (TPC), HPLC-DAD phenolic profile assessment, and radical scavenging assay (RSA) were employed for the analysis of the raw material. After encapsulation, the average mass and uniformity of mass, the disintegration, and the uniformity of content for the obtained capsules were performed to obtain a high-quality dietary supplement. All the assays performed complied to the compendial requirements and the TPC was determined at 9.07 ± 0.25 mg gallic acid equivalents/g r.m. and RSA at 48.32 ± 0.74%. The highest quantities of phenolic compounds determined were 333.7 ± 0.50 µg/g r.m. for chlorogenic acid, followed by rutin, ferulic acid, and (+)-catechin with 198.9 ± 1.60 µg/g r.m., 179.8 ± 0.90 µg/g r.m. and 118.7 ± 0.75 µg/g r.m., respectively. The results of this study can be used for the manufacturing and assessing of pilot scale-up capsule batches and thinking of quality assurance, we recommend that the industrial batch extracts should be standardized in polyphenols, and the manufacturing process should be validated.

Functional and chemical qualities of Vitis labrusca grape seed oil extracted by supercritical CO2

Grape seed oil, which is extracted with highly toxic organic solvents that are harmful to human health, is produced from tons of grape pomace waste, generated during winemaking. Sometimes, this waste is used to make compost or is burnt, which causes environmental contamination. The functional qualities, antioxidant capacity (AC), α-tocopherol and total phenolic compounds content (TPC) of Black Borgoña (Vitis labrusca) grape seed oil, extracted by supercritical CO2, were evaluated. The high content of linoleic acid (w-6) and monounsaturated fatty acids contributed to the beneficial effect on ​​the functional quality indices, which were 0.20, 0.23, 11.80 for IA, IT and H:H, respectively. In addition, a POV of 6.23 ± 0.08 milliequivalents of peroxide/kg oil and an anisidine index of 2.70 ± 0.05 indicated a good quality oil. Also, a high concentration of α-tocopherol (9.82 ± 0.02 mg/100 g oil) and a high TPC (114.14 ± 3.24 mg GAE/kg oil) were obtained. This study demonstrated that supercritical CO2 extraction is a suitable method for the delivery of a high-quality grape seed oil.  

A Comparative Study of the Influence of Various Fungal-Based Pretreatments of Grape Pomace on Phenolic Compounds Recovery

Wineries produce considerable amounts of grape pomace, which is a readily available natural source of bioactive phenolic compounds. In this study, grape pomace was used as a substrate for the cultivation of eleven filamentous fungi (Trametes versicolor TV6, Trametes versicolor TV8, Trametes versicolor AG613, Trametes gibbosa, Phanerochaete chrysosporium, Ceriporiopsis subvermispora, Pleurotus eryngii, Ganoderma lucidum, Ganoderma resinaceum, Humicola grisea, and Rhizopus oryzae) under solid-state conditions (SSF) for 15 days with the aim of improving the recovery of the individual phenolic compounds. Twenty-one phenolic compounds were quantified and the recovery of seventeen of them (gallic acid, ellagic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, 3,4-dihydroxybenzoic acid, ferulic acid, o-coumaric acid, p-coumaric acid, epicatechin gallate, galocatechin gallate, quercetin, kaempferol, procyanidin B1, procyanidin B2, resveratrol, and ε-viniferin) were positively affected by SSF. Ellagic acid is the most recovered compound, whose content increased 8.8-fold after 15 days of biological treatment with Ceriporiopsis subvermispora compared to the untreated initial sample. Among the microorganisms tested, the fungi Pleurotus eryngii and Rhizopus oryzae proved to be the most effective in increasing the recovery of most phenolic compounds (1.1–4.5-fold). In addition, the nutrient composition (proteins, ash, fats) of grape pomace was positively affected by the biological treatments.

Nɛ-(carboxymethyl)lysine, Available Lysine, and Volatile Compound Profile of Biscuits Enriched with Grape by-Product During Storage

We investigated the changes in Nɛ-(carboxymethyl)lysine (CML) and available lysine content, antioxidant properties, volatiles, and oxidation products of biscuits enriched with grape by-product (GP), stored for six months under a modified atmosphere of 0%/30%/70% O₂/CO₂/N₂ and in air. Fresh GP-formulated biscuits showed lower concentrations of CML (89%), available lysine (40%), and pyrazines (75%), but higher antioxidant capacities (~ sixfold), furans (12-fold), and lipid-derived compounds (three-fold) than the control. Although ~ 15% higher losses of Maillard-type volatiles were identified in the air atmosphere during storage, lipid oxidation was ~ 30% less pronounced in the modified atmosphere. A significant correlation of 0.994 between the reduction in CML and the available lysine suggest further CML reactions with the ɛ-NH₂ group of amino acids. Significant correlations (of -0.550 to -0.980) between oxidation products, antioxidant capacities, and changes in CML content during storage suggest that these parameters might be involved in the CML elimination mechanism.

The “End Life” of the Grape Pomace Waste Become the New Beginning: The Development of a Virtuous Cycle for the Green Synthesis of Gold Nanoparticles and Removal of Emerging Contaminants from Water

During the last decades, the demand for processes developed according to the Circular Economy Principles has increased, searching for an alternative life for wastes. For this purpose, a one-pot green approach is exploited during this work to synthesize gold nanoparticles (AuNPs) by using grape pomace waste from Vitis vinifera. A raw aqueous extract of grape seeds, skin, and stems is used for AuNPs synthesis. UV-Vis, XPS, SEM, and ATR-FTIR spectroscopies demonstrate the main role of the extract’s polyphenolic components in stabilizing nanoparticles. XRD, DLS, and Zeta Potential analyses were used to characterize AuNPs. Moreover, the ionic strength, pH, and temperature role was investigated through the Surface Plasmon Resonance (SPR) band observation to assess AuNPs’ stability and photostability. For foreseeing the as-synthesized AuNPs’ potential use in cosmetic and biomedical fields as multifunctional platforms, their antioxidant, and skin-lightening properties were tested, together with their sunscreen ability. A preliminary in-vitro evaluation is reported about the AuNPs’ cytoprotective effects against H₂O₂ oxidative stress-induced in normal human dermal fibroblasts. Briefly, the possibility of reusing the grape pomace waste after the AuNPs synthesis as an adsorbent for the efficient removal of emergent contaminants is preliminarily discussed in the paper, further valorizing the use of waste according to a bio circular approach.

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.

Optimization of Pulsed Electric Fields-Assisted Extraction of Phenolic Compounds From White Grape Pomace Using Response Surface Methodology

This study was focused on the optimization of the pulsed electric fields (PEF)-assisted extraction process using central composite design for response surface methodology from response surface methodology (RSM) with the aim to sustainably intensify the extractability of phenolic compounds from white grape pomace. The cell disintegration index (Zp) was used as response variable to identify the optimal PEF pre-treatment conditions of grape pomace in terms of field strength (E = 0.5–5 kV/cm) and energy input (WT = 1–20 kJ/kg), to be applied prior to the subsequent solid-liquid extraction (SLE) process. for both untreated and PEF-treated samples SLE process was optimized to determine the most effective combination of extraction temperature (20–50°C), extraction time (30–300 min), and solvent concentration (0–100% ethanol in water). Total phenolic content (TPC), flavonoid content (FC), and antioxidant activity (FRAP) of the obtained extracts were determined. The extracted compounds from untreated and PEF-treated samples at the optimal conditions were analyzed via HPLC-PDA analysis. Results revealed that, at a fixed extraction temperature (50°C), the application of PEF at optimal processing conditions (E = 3.8 kV/cm, WT = 10 kJ/kg) prior to SLE has the potential to reduce the solvent consumption (3–12%) and shorten the extraction time (23–103 min) to obtain the same recovery yield of phenolic compounds. Under optimized conditions, the extracts derived from PEF-treated samples showed significantly higher TPC (8%), FC (31%), and FRAP (36%) values, as compared to the control extraction. HPLC analyses revealed that epicatechin, p-coumaric acid, and quercetin were among the main phenolic compounds extracted, and no degradation phenomena occurred due to PEF application.

Sustainable biochar: A facile strategy for soil and environmental restoration, energy generation, mitigation of global climate change and circular bioeconomy

The increasing agro-demands with the burgeoning population lead to the accumulation of lignocellulosic residues. The practice of burning agri-residues has consequences viz. Release of soot and smoke, nutrient depletion, loss of soil microbial diversity, air pollution and hazardous effects on human health. The utilization of agricultural waste as biomass to synthesize biochar and biofuels, is the pertinent approach for attaining sustainable development goals. Biochar contributes in the improvement of soil properties, carbon sequestration, reducing greenhouse gases (GHG) emission, removal of organic and heavy metal pollutants, production of biofuels, synthesis of useful chemicals and building cementitious materials. The biochar characteristics including surface area, porosity and functional groups vary with the type of biomass consumed in pyrolysis and the control of parameters during the process. The major adsorption mechanisms of biochar involve physical-adsorption, ion-exchange interactions, electrostatic attraction, surface complexation and precipitation. The recent trend of engineered biochar can enhance its surface properties, pH buffering capacity and presence of desired functional groups. This review focuses on the contribution of biochar in attaining sustainable development goals. Hence, it provides a thorough understanding of biochar's importance in enhancing soil productivity, bioremediation of environmental pollutants, carbon negative concretes, mitigation of climate change and generation of bioenergy that amplifies circular bioeconomy, and concomitantly facilitates the fulfilment of the United Nation Sustainable Development Goals. The application of biochar as seen is primarily targeting four important SDGs including clean water and sanitation (SGD6), affordable and clean energy (SDG7), responsible consumption and production (SDG12) and climate action (SDG13).

Effects of Grape Pomace Polyphenols and In Vitro Gastrointestinal Digestion on Antimicrobial Activity: Recovery of Bioactive Compounds

Grape pomace (GP), a major byproduct obtained from the winemaking process, is characterized by a high amount of phenolic compounds and secondary plant metabolites, with potential beneficial effects on human health. Therefore, GP is a source of bioactive compounds with antioxidant, antimicrobial, and anti-inflammatory activity. As people are paying more attention to sustainability, in this work, we evaluate two different extractions (aqueous and hydroalcoholic) of GP bioactive compounds. In vitro simulated gastrointestinal digestion of the GP extracts was performed to improve the bioavailability and bioaccessibility of polyphenols. The antioxidant activity (ABTS and DPPH assays) and the phenolic characterization of the extracts by UHPLC-DAD were evaluated. The antimicrobial effects of GP antioxidants in combination with a probiotic (Lactiplantibacillus plantarum) on the growth of pathogenic microorganisms (Escherichia coli, Bacillus megaterium, and Listeria monocytogenes) were evaluated. As a result, an increase of antioxidant activity of aqueous GP extracts during the gastrointestinal digestion, and a contextual decrease of hydroalcoholic extracts, were detected. The main compounds assessed by UHPLC-DAD were anthocyanins, phenolic acids, flavonoids, and stilbenes. Despite lower antioxidant activity, due to the presence of antimicrobial active compounds, the aqueous extracts inhibited the growth of pathogens.

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.

Grapevine Wastes: A Rich Source of Antioxidants and Other Biologically Active Compounds

Wine production is one of the most critical agro-industrial sectors worldwide, generating large amounts of waste with negative environmental impacts, but also with high economic value and several potential applications. From wine shoots to grape pomace or seeds, all of the wastes are rich sources of bioactive compounds with beneficial effects for human health, with these compounds being raw materials for other industries such as the pharmaceutical, cosmetic or food industries. Furthermore, these compounds present health benefits such as being antioxidants, supporting the immune system, anti-tumoral, or preventing cardiovascular and neural diseases. The present work aims to be a critical discussion of the extraction methods used for bioactive compounds from grapevine waste and their beneficial effects on human health.

White Grape Pomace Valorization for Remediating Purposes

The present investigation focuses on a possible alternative to reduce grape pomace’s negative impact on the environment by exploiting its capacities for wastewater remediation. Therefore, three directions are followed: (1) the characterization of white grape byproducts’ antioxidant and antiradical properties; (2) the determination of organophosphorus compound concentration that might be present in the samples; and (3) the evaluation of the possible use for wastewater remediation. The grape pomace was used for obtaining different extracts considering different extraction conditions. The hydroalcoholic extracts have an increased amount of total phenolic content. The lyophilized hydroalcoholic extract showed high total phenolic content (159.52 mg/100 g) and low organophosphorus content (0.257 ± 0.015 nmol). The lowest DPPH antiradical-scavenging activities were obtained for the extracts in ethanol obtained from refrigerated pomace (0.055) and for dried pomace (0.045).

A Potential Valorization Strategy of Wine Industry by-Products and Their Application in Cosmetics-Case Study: Grape Pomace and Grapeseed

Grape pomace and grapeseed are agro-industrial by-products, whose inadequate treatment generates socioeconomic and environmental concerns. Nevertheless, it is possible to valorize them by extracting their bioactive compounds, such as antioxidants (phenolic compounds), vitamin E and fatty acids. The bioactive compounds were extracted using solid-liquid extraction. The yields for phenolic compounds were 18.4 ± 0.4% for grape pomace, and 17.4 ± 0.4%, for grapeseed. For the oil, the yields were 13.3 ± 0.2% and 14.5 ± 0.3% for grape pomace and grapeseed. Antioxidant capacity was assessed by the assay with 2,2-diphenyl-1-picrylhydrazyl (DPPH), and showed that phenolic extract has higher antioxidant capacity than the oils. Grape pomace and grapeseed extracts exhibit, correspondingly, values of 90.8 ± 0.8 and 87.5 ± 0.5 of DPPH inhibition and IC₅₀ of 48.9 ± 0.5 and 55.9 ± 0.7 μg_extract·mL_DPPH⁻¹. The antimicrobial capacity was assessed by the disk diffusion test, and revealed that, phenolic extracts inhibit the growth of Staphylococcus aureus and Staphylococcus epidermidis. The obtained extracts were incorporated in 10 face cream formulations, with slight modifications in quantities of formulation stabilizers. Their stability was studied for 35 days, and this revealed the possibility of incorporating extracts and oils obtained from by-products as antioxidants in cosmetics, and replacing synthetic ones. As a future recommendation, microencapsulation of the extracts should be performed, in order to increase their stability.

Advances in solid-state fermentation for bioconversion of agricultural wastes to value-added products: Opportunities and challenges

The increase in solid waste has become a common problem and causes environmental pollution worldwide. A green approach to valorise solid waste for sustainable development is required. Agricultural residues are considered suitable for conversion into profitable products through solid-state fermentation (SSF). Agricultural wastes have high organic content that is used as potential substrates to produce value-added products through SSF. The importance of process variables used in solid-phase fermentation is described. The applications of SSF developed products in the food industry as flavouring agents, acidifiers, preservatives and flavour enhancers. SSF produces secondary metabolites and essential enzymes. Wastes from agricultural residues are used as bioremediation agents, biofuels and biocontrol agents through microbial processing. In this review paper, the value addition of agricultural wastes by SSF through green processing is discussed with the current knowledge on the scenarios, sustainability opportunities and future directions of a circular economy for solid waste utilisation.

Liposomes loaded with polyphenol-rich grape pomace extracts protect from neurodegeneration in a rotenone-based in vitro model of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease with no satisfactory therapy options. Similar to other neurodegenerative conditions, such as Alzheimer's and Huntington's diseases, oxidative stress plays a key factor in the neurodegeneration process. To counteract the uncontrolled increase of reactive oxygen species (ROS) and oxidative stress-dependent cell death, several preclinical and clinical tests exploit natural-derived organic antioxidants, such as polyphenols. Despite some promising results, free antioxidants show scarce brain accumulation and may exhaust their scavenging activity before reaching the brain. In this work, we developed an antioxidant therapeutic nanoplatform consisting of nano-sized functionalized liposomes loaded with selected polyphenol-rich vegetal extracts with high blood-brain barrier crossing capabilities. The antioxidant extracts were obtained from the grape seeds and skins as a byproduct of wine production (i.e., pomace), following a sustainable circular approach with reduced environmental impact. The antioxidant nanoplatform was successfully tested in a relevant in vitro model of PD, where it completely rescued the ROS levels, prevented the aggregation of α-synuclein fibrils, and restored cell viability, paving the way for preclinical translation of the approach.

Biotechnological Conversion of Grape Pomace to Poly(3-hydroxybutyrate) by Moderately Thermophilic Bacterium Tepidimonas taiwanensis

Polyhydroxyalkanoates (PHA) are microbial polyesters that have recently come to the forefront of interest due to their biodegradability and production from renewable sources. A potential increase in competitiveness of PHA production process comes with a combination of the use of thermophilic bacteria with the mutual use of waste substrates. In this work, the thermophilic bacterium Tepidimonas taiwanensis LMG 22826 was identified as a promising PHA producer. The ability to produce PHA in T. taiwanensis was studied both on genotype and phenotype levels. The gene encoding the Class I PHA synthase, a crucial enzyme in PHA synthesis, was detected both by genome database search and by PCR. The microbial culture of T. taiwanensis was capable of efficient utilization of glucose and fructose. When cultivated on glucose as the only carbon source at 50 °C, the PHA titers reached up to 3.55 g/L, and PHA content in cell dry mass was 65%. The preference of fructose and glucose opens the possibility to employ T. taiwanensis for PHA production on various food wastes rich in these abundant sugars. In this work, PHA production on grape pomace extracts was successfully tested.