Vinification Byproducts Research Articles

Gut Microbiota Modulators Based on Polyphenols Extracted from Winery By-Products and Their Applications in the Nutraceutical Industry.

Vine-growing for the production of wine is one of the oldest and most important agricultural activities worldwide, but the winemaking process leads to vast amounts of waste. Viticulture and vinification by-products have many bioactive molecules, including polyphenols, prebiotic fibers, organic acids, and minerals. While research on the specific human health effects of grapevine residues (pomace, seeds, barks, stalks, canes, and leaves) is still ongoing, the available data suggest the potential to positively modulate the normal and dysbiotic gut microbiota (GM) using polyphenol-rich extracts obtained from winery by-products. This review provides an updated summary of the in vitro and in vivo evidence in animal models and humans concerning the ability of polyphenol-rich winery residue to be used as a GM modulator that supports their nutraceutical applications as a functional ingredient. Additionally, this review aims to enhance interest in viticulture waste (grapevine stems and leaves), as the levels of polyphenols are similar to those found in red grapes or seeds. However, more research is still needed to obtain innovative products. The valorization of winery residues is not only environmentally friendly; it can also be economically beneficial, creating added-value nutraceuticals that modulate microbiota and a new revenue stream for wine producers.

Utilization of Agro-Industrial By-Products for Sustainable Poultry Production

Agro-industrial by-products (AIBPs) that are not intended for human consumption can be used as alternatives to conventional feedstuffs in animal nutrition to produce animal products without competing for land or triggering the food-feed competition, thus leading to environmental, social, and economic sustainability. These by-products are also known to contain several bioactive compounds and have a potential to become nutraceuticals that can promote the health and well-being of poultry. The potentials of some AIBPs (e.g., fruit juice industry leftovers, oilseed industrial by-products, distillers’ grain by-products, vinification by-products, olive oil industry by-products, pomegranate by-products, tomato processing by-products) and their derivative products as functional feeds for poultry, but also potential limitations of utilizing AIBPs in poultry nutrition are elaborated in the present review. The possible mechanisms through which AIBPs may improve the health status and productivity of poultry are also discussed. We suggest that nutrient variability across countries should be stabilized and potential hazards such as mycotoxins and pesticides should be eliminated, and the potential hazards present in AIBPs (e.g., mycotoxins) should be better controlled through appropriate legislation and proper application of control measures. Modern processing methods, new types/classifications, and proper developmental strategies foster the utilization of AIBPs in animal nutrition. This review focuses on the AIBPs as feeds, not only for their nutritional value but also for their contribution to sustainable practices.

New technology for large preparation of a series of bioactive polyphenols from by-products of vinification

Grape pomaces or vinification by-products are abundant and rich in polyphenols, particularly proanthocyanidins. During the last three decades, grape and wine polyphenols, particularly catechins (CATs) and oligomeric proanthocyanidins (OPCs) have attracted considerable attention of the international scientific community, due essentially to their potential health-beneficial effects, related to their protective action towards cardiovascular disease and the oxygen free radical scavenger capacity. Such phenolic compounds have been proved to be the key components responsible for the health-beneficial effects of red wine. Furthermore, although the most widely recognized antioxidants are Vitamins A, C, and E, scientific research has shown that OPCs are likely the most powerful antioxidants known. Although various OPCs have been available in the market, they are generally very expensive due to the high cost of their production. As a consequence, the development of efficient methods for large-scale preparation of these bioactive compounds have still a challenging task for scientists. In this communication, we will present a new and efficient technology for large preparation of bioactive polyphenols from vinification by-products (grape seed and grape skin). On one hand, polymeric proanthocyanidins were transformed into a series of low- molecule-weight bioactive compounds using various degradation methods. On the other hand, High-Speed Countcurrent Chromatography (HSCCC), as a relative new separation technology for natural product preparation, was applied to large and efficient isolation of these bioactive compounds.

Redefining the Use of Vinification Waste By-Products in Broiler Diets

In this study, the use of vinification by-products in broiler diets, as a sustainable and promising way of exploiting them, was examined. In particular, the potential use of ground grape pomace (GGP), wine lees extract (WYC) and grape stem extract (PE) in broiler diets was examined. Growth performance parameters, the weight of selected internal organs, meat quality traits, fatty acid profiles of breast meat and selected haematological parameters were determined. Two hundred and forty one-day-old broilers were assigned to four treatments with four replicate pens of fifteen broilers. There was one control treatment (CON), fed a basal diet, and the GGP, WYC and PE treatments, fed a basal diet supplemented with 25 g/kg GGP, 2 g/kg WYC and 1 g starch including 100 mg pure stem extract/kg PE, respectively. The duration of the experiment was 42 days. The average body weight gain during the starter, grower and finisher stages did not differ among treatments. Similarly, the feed intake, FCR and carcass yield did not show a significant difference. The weight of the internal organs was also similar among treatments. Some positive differences were observed in colour traits of meat and in haematological parameters. In the GGP group, saturated (SFAs) and unsaturated fatty acids (USFAs) were lower and higher, respectively, compared to the CON, WYC and PE groups. Vinification by-products seem to be a promising feed additive in broiler diets providing a sustainable approach to grape waste management without affecting broiler performance.

Immune-Related Gene Expression Profiling of Broiler Chickens Fed Diets Supplemented with Vinification Byproducts: A Valorization Approach II.

Simple SummaryThe valorization of grape byproducts appears to be a sustainable bioeconomic strategy that could promote the substitution of synthetic with natural antioxidant compounds in the food and feed industry. The nutritional physiology of broiler chickens requires special attention to the interactions between nutrients and antioxidant mechanisms since the stressor signals of factory farming could impair the immune status, resulting in detrimental effects on broilers’ performance. The objective of this study was to assess the inclusion of grape byproducts (grape pomace, wine lees, and stem extract) on the transcriptional profiling of genes regulating the immune system in the liver, bursa of Fabricius, and spleen. The dietary supplementation of grape byproducts rich in polyphenolic compounds decreased the mRNA levels of the predominant pro-inflammatory receptor in the liver, while in the spleen, the stem extract diet upregulated the aforementioned receptor. Upregulation of interleukin 8 was observed in the bursa of Fabricius and spleen of the stems extract-fed broilers. Although grape byproducts depicting a sustainable source of bioactive compounds with vast antioxidant potential, there were unveiled preliminary insights for immune stimulation at the transcriptional level.The valorization of vinification byproducts portrays a promising bioprocess for the enrichment of animals’ diet with bioactive compounds, such as polyphenols, which could regulate the immune response. Therefore, the impact of dietary grounded grape pomace (GGP), wine lees extract (WYC), and grape stem extract (PE) on the relative transcript level of immune related genes of broiler chickens were examined. Two hundred forty, one-day-old as hatched (male/female) chicks (Ross 308) were allocated to four dietary groups, with four replicate pens each with 15 birds. Birds were fed either a basal diet (CON) or the basal diet supplemented with 2.5% GGP, or 0.2% WYC, or 0.1% PE for 42 d. The relative expression of immune-related genes was investigated using a real-time PCR platform. The mRNA levels of Toll-like Receptor 4 (TLR4) were downregulated (p = 0.039) in the liver of broilers fed the GGP-containing diet compared to the CON, while in the spleen of PE-fed broilers, TLR4 was significantly upregulated (p = 0.043). The mRNA levels of interleukin 8 (IL8) tended to upregulate (p = 0.099) in the bursa of Fabricius and were significantly increased (p = 0.036) in the spleen of broilers fed the PE diet. Vinification byproducts depict a promising sustainable source of polyphenols for the poultry feed industry, but more research is needed under field conditions.

Antioxidant Status of Broiler Chickens Fed Diets Supplemented with Vinification By-Products: A Valorization Approach.

Vinification by-products display great potential for utilization as feed additives rich in antioxidant compounds. Thus, the effect of dietary ground grape pomace (GGP), wine lees extract rich in yeast cell walls (WYC), and grape stem extracts (PE) on the relative expression of several genes involved in liver oxidative mechanisms and the oxidative status of the blood and breast muscle of broiler chickens was investigated. In total, 240 one-day-old as hatched chicks (Ross 308) were assigned to four treatments, with four replicate pens and 15 birds in each pen. Birds were fed either a basal diet (CON) or a basal diet supplemented with 25 g/kg GGP, or 2 g/kg WYC, or 1 g starch including 100 mg pure stem extract/kg (PE) for 42 days. The polyphenolic content of vinification by-products was determined using an LC-MS/MS library indicating as prevailing compounds procyanidin B1 and B2, gallic acid, caftaric acid, (+)-catechin, quercetin, and trans-resveratrol. Body weight and feed consumption were not significantly affected. The relative transcript level of GPX1 and SOD1 tended to increase in the liver of WYC-fed broilers, while NOX2 tended to decrease in the PE group. SOD activity in blood plasma was significantly increased in WYC and PE compared to the CON group. The total antioxidant capacity measured with FRAP assay showed significantly higher values in the breast muscle of PE-fed broilers, while the malondialdehyde concentration was significantly decreased in both WYC- and PE-fed broilers compared to the CON group. The exploitation of vinification by-products as feed additives appears to be a promising strategy to improve waste valorization and supply animals with bioactive molecules capable of improving animals’ oxidative status and products’ oxidative stability.

High-Throughput Quantification of 32 Bioactive Antioxidant Phenolic Compounds in Grapes, Wines and Vinification Byproducts by LC-MS/MS.

The well-established, health-benefitting effects of grapevines and derivatives (wines and vinification byproducts) are attributed to their antioxidant phenolic content. The dearth of an efficient method for the simultaneous quantitation of antioxidant phenolics prompted us to develop a novel method utilizing triple quadrupole LC–MS/MS for the accurate, fast, simultaneous quantitation of the 32 most abundant grapevine phenolics. The fully validated, novel method is capable to simultaneously record the quantitative presence of 12 phenolic acids, 19 polyphenols and coniferyl aldehyde (a phenolic compound extracted from cork stoppers into wines) and is applicable for the determination of antioxidant phenolics content of grape berries, pomace, stems and wines. Its utility was demonstrated for three native Greek grapevine varieties, two red (Mandilaria and Aidani mavro) and one white (Monemvassia). Results herein highlighted the stems of the Monemvassia white variety as particularly rich in antioxidant phenolics such as the flavonol monomer (+)-catechin (387 mg/kg) and the dimer procyanidin B1 (400 mg/kg) along with stilbene phytoalexin trans-resveratrol (24 mg/kg). These results are in line with the TPC, TFC and TTC content of stems and the determined antioxidant capacities, highlighting the stems of this Vitis vinifera variety as potentially exploitable source of antioxidant phenolics.

Strategies for Reuse of Skins Separated From Grape Pomace as Ingredient of Functional Beverages.

Wine grape pomace, the by-product of wine making, is a source of polyphenols, metals, and organic acids, and may be exploited for the production of functional beverages. Among red wines, Primitivo and Negramaro varieties possess an interesting amount of polyphenolic compounds and other chemicals. Consequently, study of the biological activity of Primitivo and Negramaro vinification by-products is of great interest as well as optimizing the extraction of its bioactive components. In order to stabilize the grape pomace, different methods of drying grape pomace were tested. After stabilization of the pomace, the grape skins were manually separated from the seeds and any woody parts. The chemical characterizations of acidified alcoholic (methanol/ethanol) and water extracts and either microwave-assisted or ultrasound-assisted extractions of separated grape skins were compared. Besides that, the in vitro antioxidant activity of wine pomace skin extracts was also investigated as Trolox equivalents antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC). Overall, the alcoholic extractions were found to be the most effective for recovering phenolic compounds, when compared with those in water. Ultrasound- and microwave-assisted extraction of pomace skin using acidified water allowed the highest TEAC value. Taking into account the water extraction result, in order to reuse grape pomace skins to produce a functional beverage, we utilized them in combination with black tea, karkadè (Hibiscus sabdariffa L.), or rooibos (Aspalathus linearis Burm.) to produce an infusion. The combination of grape skins and black tea showed the highest ratio of total phenol content to antioxidant activity. Moreover, skin isolated from pomace, with or without black tea infusions, were shown to have anti-inflammatory capacity in human cell culture. Our results raise the value of grape skin pomace as a rich source of bioactive compounds with antioxidant and anti-inflammatory activity and suggest its exploitation as an ingredient for functional beverages.

Vinification By-products and Their Phenolic Compounds

The waste production by grape industrialization has been growing because about 60% of the harvested fruits are used in vinification. Grape marc (skins and seeds) and lees (sediment solids) are the most abundant by-products of the winemaking process, because the former represents approximately 5% of the total grapes processed and the second, 4% of the total volume of wine produced. Some studies have shown that winery residues contain phenolic compounds, potent antioxidants that were not fully transferred to the wine during the winemaking process, thus have economic and functional interest.

Biological and Health-promoting Activity of Vinification Byproducts Produced in Spanish Vineyards

Several by-products are produced in the Spanish agricultural system. Among them, fresh and vinified grape skins represent an abundant source of phenols with a potential nutraceutical value. Fresh grape skin extracts (FGSE) and vinification of grape skin extracts (VGSE) obtained by a microwave-assisted method have been chemically and biologically characterised. Their role in the maintenance of genetic stability was stated by in vivo genotoxic and antigenotoxic evaluations (Drosophilla melanogaster wing spot test), as well as by their potential chemopreventive effect (in an HL60 in vitro model). Total phenolic, anthocyanin and resveratrol contents were chemically characterised in the two extracts, showing some qualitative differences. Both extracts and resveratrol were not mutagenic in the Drosophila somatic mutation and recombination tests, and exerted antigenotoxic activities against hydrogen peroxide. They also showed cytotoxic activity to HL60 leukaemia cells, with an IC 50 of 4.5µL/mL, 4.6µL/mL and 98µM respectively and induced apoptotic internucleosomic fragmentation in the HL60 cell line.

A comparative study on different extraction techniques to recover red grape pomace polyphenols from vinification byproducts

In this study, Agiorgitico red grape pomace byproducts were dehydrated by air drying and accelerated solar drying and sequentially extracted by three different extraction methods using water, water:ethanol (1:1) and ethanol as solvents. The methods include microwave assisted (MAE) and ultrasound assisted extraction (UAE) and the conventional Soxhlet extraction (SE). The efficiency and selectivity of drying and extraction processes were determined in terms of extraction yield, antiradical activity (AAR) and total phenolic content (TPC). UAE water:ethanol extracts were found to be rich in phenolic compounds (up to 438984±4034ppm GAE in dry extract) with high AAR (0.36±0.01 to 0.91±0.02mg/mL) and therefore were analysed using HPLC-DAD-ESI-MS/MS and DMACA assay. The profile of anthocyanins, flavonols and flavan-3-ols were significantly affected (p<0.05) by the drying procedure. Air dried grape pomace extracts exhibited the highest total flavan-3-ol (43469±1210ppm CE), total anthocyanin (34188±362ppm Mv-3-glc eq.) and total flavonol (4484±108ppm QE) content.

Biochemical and biological assessment of the inhibitory potency of extracts from vinification byproducts of Vitis vinifera extracts against glycogen phosphorylase

The inhibitory potency of thirteen polyphenolic extracts obtained from vinification byproducts of Greek varieties of Vitis vinifera against glycogen phosphorylase (GP) has been studied by kinetic experiments. GP is an enzyme involved in glucose homeostasis and a molecular target for the discovery of new hypoglycemic agents. Studies have shown that all extracts display significant inhibitory potency for GP in vitro with IC50 values in the range of low μg/mL. X-ray crystallographic analysis of GP crystals soaked with two of these extracts revealed that the most active ingredient is quercetin which binds at novel binding site, distinct from the other known sites of the enzyme. One of the most potent of the studied extracts had also a moderate effect on glycogenolysis in the cellular lever with an IC50 value of 17.35μg/mL. These results highlight the importance of natural resources in the quest for the discovery of new hypoglycemic agents, while at the same time they can serve as the starting point for their exploitation for antidiabetic usage and the development of novel biofunctional foods.

Protective ability of phenolics from white grape vinification by-products against structural damage of bovine serum albumin induced by glycation

Grape skins recovered from white grape vinification processes were studied as possible anti-glycation agents. Total phenolics were characterised by the Folin Ciocalteu assay, proanthocyanidins by depolymerisation with n-butanol/HCl, flavonols by HPLC-DAD, reducing capacity by ferric ion reducing antioxidant power assay (FRAP) and anti-glycation activity by a bovine serum albumin (BSA)/fructose model system. Structural modifications of BSA were investigated by 2D isoelectric focusing sodium dodecyl sulfate polyacrylamide gel electrophoresis (IEF/SDS–PAGE) and fluorescence measurements. Both pI and Mr. of BSA were modified upon glycation reaction. These changes attributable to the involvement of free amino groups in Maillard-type reactions were inhibited by the white grape skin extracts. The anti-glycation activity ranged between 250 and 711mmol aminoguanidine Eq/kg. These results raise the interest in the potential health benefits of by-products of white grape vinification that could have a secondary use as an ingredient for new functional foods targeting wellbeing of diabetic and elderly people.

Effect of spray drying on the physicochemical properties and color stability of the powdered pigment obtained from vinification byproducts of the Bordo grape (Vitis labrusca)

The aim of this work was to produce and evaluate powdered pigments obtained from vinification byproducts of Bordo red grapes (Vitis labrusca). The concentrated extract obtained from the byproducts was spray dried under different conditions of inlet air temperatures (130–170°C) and carrier concentration (10–30%) in a total of 9 treatments. Besides, one sample of freeze-dried extract was obtained to comparison. The samples were analyzed by: moisture content, anthocyanin retention, hygroscopicity, water solubility, moisture sorption isotherms, infrared spectroscopy (FTIR), and changes in color during storage. Moisture content and anthocyanin retention were influenced by the drying temperature and carrier agent concentration, whereas hygroscopicity was more influenced by the carrier concentration. The moisture sorption isotherms were also influenced by the maltodextrin concentration. Infrared spectroscopy indicated that the extract was covered or encapsulated by the carrier agent. During storage, samples containing maltodextrin preserved the color more intensely than the freeze-dried sample and the liquid extract. Results suggested that spray drying of Bordo grape extracts using maltodextrin produces powders with low moisture content, low hygroscopicity, high solubility, and stable color. These results evidence that this byproduct of wine production may be used as a natural source of pigments.

Grape stem extracts: Polyphenolic content and assessment of their in vitro antioxidant properties

Grape stems constitute a scarcely investigated class of vinification byproducts with limited reports on their bioactive polyphenol content and/or industrial applications. Herein we present the outcome of our investigation on various grape stems extracts from native Greek grape varieties, concerning the assessment of their total polyphenolic content (TPC), the quantification of the individual bioactive polyphenols and the detailed evaluation of their antioxidant properties. Results obtained indicate that grape stems are particularly rich in flavonoids and stilbenes, with trans-resveratrol and ɛ-viniferin present in considerably high concentrations. They also exhibit significant antioxidant properties, which were determined by DPPH• radical scavenging and FRAP assays (modified to fit into a high throughput approach). Additional experiments concerning the inhibition of CuSO4-induced LDL oxidation and the reduction of intracellular reactive oxygen species (ROS) indicated that most extracts tested display an extreme capability to prevent the oxidation of LDL−lipoprotein at very low concentrations and to reduce the intracellular ROS levels, exhibiting IC75 values between 10.4 μg and 49.1 μg per gram of extract. Results herein reveal that grape stems represent a rich source of high added value natural antioxidants, particularly stilbenes such as trans-resveratrol, which may be used by pharmaceutical, food and cosmetic industries.

Bioactive non-coloured polyphenols content of grapes, wines and vinification by-products: Evaluation of the antioxidant activities of their extracts

Abstract The comparative quantization of main non-coloured polyphenols, the assessment of total polyphenolic content (TPC) and the detailed evaluation of the antioxidant activities of various grape-based products – from the harvest stage up to the production of the corresponding wines – are presented. The material studied consisted of grape tissues (berries, seeds and skins) of native Greek Vitis vinifera cultivars, which provided polyphenol-rich extracts via an optimized ultrasound extraction procedure, while the respective wine samples were condensed by a novel extraction procedure using XAD-4 adsorption resin column. The extraction methods accuracies were thoroughly validated and the polyphenolic content of extracts was assessed by HPLC–DAD and photometric methods. Their antioxidant properties were evaluated by following assays, modified to fit into a high throughput approach: DPPH radical scavenging, FRAP, inhibition of CuSO4-induced LDL oxidation and the reduction of intracellular reactive oxygen species (ROS) in smooth muscle cell cultures. Seed samples exhibited the highest TPC values, which are well correlated with their significant antioxidant properties in all assays performed. Of special interest is the significant capability of the tested extracts to prevent the LDL oxidation at very low concentrations. Furthermore, the good correlation between the antioxidant activities assessed for the LDL oxidation inhibition and the intracellular ROS assays is indicative of the possible in vivo antioxidant properties of the extracts. Results herein reveal the considerable antioxidant potential of the Greek grapevine production and exploits their vinification by-products as a potential inexpensive source of high added value antioxidants.

Antilisterial Activities of Polyphenol-Rich Extracts of Grapes and Vinification Byproducts

The quantitation of the main polyphenols and the assessment of the total polyphenolic content (TPC) in polyphenol-rich extracts of grape berries and vinification byproducts, obtained from Vitis vinifera cultivars of the Greek islands, are presented. The results indicated that seed extracts contain high concentrations of flavan-3-ols and their derivatives, whereas pomace and stem extracts consist of significant amounts of flavonoids, stilbenes, and phenolic acids. In particular, stemsa scarcely studied class of grape byproductwere also characterized by high trans-resveratrol and epsilon-viniferin content. The evaluation of their in vitro antilisterial activities revealed as most potent the seed and stem extracts of the red variety Mandilaria. Their minimum inhibitory concentrations (MICs) were assessed using a Malthus apparatus by two methods, a plate count technique and an automated technique that combines the conductance measurements with the common dilution method. The results revealed the usefulness of the conductance method as an alternative rapid means for the MIC estimation, whereas the respective values (0.26 and 0.34 for seeds and stems) indicated that both extracts represent an inexpensive source of potent natural antilisterial mixtures, which may be incorporated in food systems to prevent the growth of Listeria monocytogenes .

Determination and quantitative analysis of the principal polyphenolic compounds present in stem extracts of native Greek islands grape varieties-assessment of their antioxidant activity in Vitro

Grape stems are vinification byproducts with no economic interest which are being discarded. In this work we have studied the principal native grape varieties (Vitis vinifera) that are cultivated in Greek islands, in respect to their content in major soluble polyphenols and the assessment of their antioxidant properties. In this regard, their respective extracts were obtained by an optimized ultrasound extraction procedure and their main polyphenolic substances were determined by HPLC-DAD. In addition, their total polyphenolic content (TPC) was estimated pohotometrically. All extracts were found to contain polyphenols as 46–54% w/w, with flavonoids and stilbenes being the most abundant. It must also be noted that trans-resveratrol and ε-viniferin were assayed in considerably highest concentrations as compared to those reported in respective grape skins (considered as the principal source of trans-resveratrol in grapes). In addition, various resveratrol glucosides were also detected (but not quantified) by LC/MS/MS.

Quantitation of polyphenolic content and determination of antilisterial activities of grapes and vinification byproducts

Four grape varieties (two red and two white) –cultivated in the Greek islands– were studied in respect to their total polyphenolic content (TPC) and quantization of their main polyphenols. More specifically, berries, seeds, stems and pomace samples were examined, indicating that seeds contain high concentration of flavan-3-ols and respective derivatives, while pomace and stems contain considerable amounts of flavonoids. stilbenes and phenolic acids. In particular, stems were found to possess high trans-resveratrol and ε-viniferin content. Subsequently, the in vitro antilisterial activities of these extracts were evaluated.

Determination of biologically interesting polyphenols from grapes, wines and vinification byproducts of Greek origin-assessment of their in vitro antioxidant activity

Determination of biologically interesting polyphenols from grapes, wines and vinification byproducts of Greek origin-assessment of their in vitro antioxidant activity