Grape Pomace Extract Research Articles

Biotransformed grape pomace as a potential source of anti-inflammatory polyphenolics: Effects in Caco-2 cells

Grape pomace is rich in polymeric phenolic compounds and glycosides. Enzymatic treatments may change grape pomace’s phenolic composition, producing monomers and aglycones. The aims of this study were to evaluate if tannase-biotransformed grape pomace extracts have improved intestinal anti-inflammatory activity using an in vitro colon model and to analyze significant differences between white grape pomace, and mixed grape pomace varieties, due to the absence of a pomace fermentation process during white wine production. No differences were observed in the cytotoxicity caused by different extracts. All extracts, before and after biotransformation at 100 and 200 μg/mL (dry extract w/v) had comparable efficacy in reducing reactive oxygen species production in Caco-2 cells. After treatment and induction of inflammation using an interleukin 1β (IL-1β) challenge, tannase-treated white grape pomace extract at 200 μg/mL was the most efficient treatment in down-regulating nuclear factor kappa B activation by 40%, compared to control. On the other hand, tannase-treated mixed grape pomace extract significantly decreased prostaglandin E2 production by 81% and interleukin-8 by 61%, being more effective than white grape pomace extract. Overall, both grape pomace extracts after biotransformation were more potent in the amelioration of IL-1β-induced inflammation in Caco-2 cells. White grape pomace extract did not show higher anti-inflammatory activity than mixed grape pomace. In general, the biotransformation improved the anti-inflammatory effect in Caco-2 cells, indicating that the application of a bioprocess in grape residues may contribute to the development of new ingredients and nutraceuticals with anti-inflammatory potential.

Polyphenols from grape pomace induce osteogenic differentiation in mesenchymal stem cells.

Polyphenols are increasingly investigated for the treatment of periodontitis and research on their use in dental biomaterials is currently being conducted. Grape pomace extracts are a rich source of polyphenols. In the present study, the polyphenols of two different types of grape pomace were characterized and identified by high-performance liquid chromatography-diode array detector, and the effect of polyphenol-rich grape pomace extracts on mesenchymal stem cell (MSC) osteogenic differentiation was investigated. Solid-liquid extraction was used to recover polyphenols from red and white grape pomace. The two extracts have been characterized through the phenolic content and antioxidant power. Human MSCs (hMSCs) from the bone marrow were cultured both with and without given amounts (10 or 20 µg/ml) of the obtained pomace extracts. Their effects on cell differentiation were evaluated by reverse transcription-quantitative polymerase chain reaction, compared with relevant controls. Results showed that both pomace extracts, albeit different in phenolic composition and concentration, induced multiple effects on hMSC gene expression, such as a decreased receptor activator of nuclear factor κ-B ligand/osteoprotegerin ratio and an enhanced expression of genes involved in osteoblast differentiation, thus suggesting a shift of hMSCs towards osteoblast differentiation. The obtained results provided data in favor of the exploitation of polyphenol properties from grape pomace extracts as complementary active molecules for dental materials and devices for bone regeneration in periodontal defects.

Microencapsulation and controlled release of bioactive compounds from grape pomace

The grape pomace extract obtained by microwave-assisted extraction (1000 W × 10 min) was encapsulated by spray drying and freeze drying using dispersions with mixtures of whey protein isolate (WPI), gum Arabic (GA) and pectin as wall materials. Fourier transform infrared spectra analysis revealed that the microencapsulation occured, however without chemical reaction between the wall materials and the bioactive compounds from grape pomace. Thermogravimetric analysis indicated that the interactions between the wall materials resulted in powders with suitable thermal stability. The powders obtained by spray drying and freeze drying containing mixtures of WPI and GA presented the highest phenolic compounds retention (2.66 and 2.42 mg g−1 of GAE), total monomeric anthocyanins (0.346 and 0.353 mg g−1 of malvidin-3,5-diglycoside equivalent), antioxidant activity by ABTS (8.23 and 8.32 μmol g−1 of TE) and DPPH (12.64 and 10.92 μmol g−1 of TE). However, accelerated storage stability tests (at 35 and 55 °C; 75 and 90% HR), indicated that powders containing WPI, GA and pectin were more stable. Simulated gastrointestinal digestion assays demonstrated that the powders containing WPI and GA as wall materials had higher releases of anthocyanins in the intestinal phase.

Nano-encapsulation of grape and apple pomace phenolic extract in chitosan and soy protein via nanoemulsification

Enhancement of lipid solubility and antioxidant activity besides maintenance of the stability for phenolics extract of grape and apple pomace could be achieved by their encapsulation. This work aims mainly to optimize nanocapsules (NCs) of total polyphenols extracted from golden apple (APP) and red grape (GPP) pomace in chitosan (polysaccharide) and soy protein. Nanoemulsification method was adopted with high encapsulation efficiency in case of soy protein, about 95%, and slightly lower efficiency for chitosan, about 75%. The NCs characteristics were confirmed by FTIR spectra, TEM, fluorescence spectra and spectrophotometric analysis. Good lipid NCs of oil/water emulsion type with diameter range of about 5˗300 nm were obtained in presence of Tween20 surfactant according to TEM images. FTIR spectra indicated that the most extracted polyphenolic compounds were encapsulated successfully. The NCs have enhanced the antioxidant activity of phenolic extract, apple juice and pineapple juice indicating their potential as food edible materials.

Use of agro‐industrial residues as potent antioxidant, antiglycation agents, and α‐amylase and pancreatic lipase inhibitory activity

Agro‐industrial residues are a potential source of bioactive compounds. This research is focused on the extraction of phenolic compounds from agro‐industrial residues produced in large scale in Brazil (peanut and grape marc), as well as to evaluate their antioxidant activity and ability to inhibit glycation reactions and digestive enzymes. As glycation is the main spontaneous cause of protein damage and is involved in the progression of diseases such as diabetes and obesity. The results showed that the major polyphenolics found in the residues were catechin and procyanidin B2. All extracts significantly inhibited the in vitro formation of advanced glycation end products and digestive enzymes (α‐amylase and lipase). This is the first study that compares the effects of peanut skin and grape pomace extracts against glycation. The results corroborate the understanding that using these phenolic extracts may have beneficial effects on preventing diseases related to glycation and suggest their use as a high value‐added agro‐industrial residue. PRACTICAL APPLICATIONS: The glycation process causes oxidative stress, inflammatory responses in the human body, and is related to the progression of diabetes mellitus and obesity. This study showed that the selected industrial residues presented new results in their biological activities, mainly in relation to the high capacity to inhibit glycation and their high activity against alpha‐amylase and lipase enzymes. These residues can then be used for sustainable production of high added value products for both the food industry and the pharmaceutical industry.

Quercetin attenuates adipose hypertrophy, in part through activation of adipogenesis in rats fed a high-fat diet

An impaired capacity of adipose tissue expansion leads to adipocyte hypertrophy, inflammation and insulin resistance (IR) under positive energy balance. We previously showed that a grape pomace extract, rich in flavonoids including quercetin (Q), attenuates adipose hypertrophy. This study investigated whether dietary Q supplementation promotes adipogenesis in the epididymal white adipose tissue (eWAT) of rats consuming a high-fat diet, characterizing key adipogenic regulators in 3T3-L1 pre-adipocytes. Consumption of a high-fat diet for 6 weeks caused IR, increased plasma TNFα concentrations, eWAT weight, adipocyte size and the eWAT/brown adipose tissue (BAT) ratio. These changes were accompanied by decreased levels of proteins involved in angiogenesis, VEGF-A and its receptor 2 (VEGF-R2), and of two central adipogenic regulators, i.e. PPARγ and C/EBPα, and proteins involved in mature adipocyte formation, i.e. fatty acid synthase (FAS) and adiponectin. Q significantly reduced adipocyte size and enhanced angiogenesis and adipogenesis without changes in eWAT weight and attenuated systemic IR and inflammation. In addition, high-fat diet consumption increased eWAT hypoxia inducible factor-1 alpha (HIF-1α) levels and those of proteins involved in adipose inflammation (TLR-4, CD68, MCP-1, JNK) and activation of endoplasmic reticulum (ER) stress, i.e. ATF-6 and XBP-1. Q mitigated all these events. Q and quercetin 3-glucoronide prevented TNFα-mediated downregulation of adipogenesis during 3T3-L1 pre-adipocytes early differentiation. Together, Q capacity to promote a healthy adipose expansion enhancing angiogenesis and adipogenesis may contribute to reduced adipose hypertrophy, inflammation and IR. Consumption of diets rich in Q could be useful to counteract the adverse effects of high-fat diet-induced adipose dysfunction.

Production of phenolic enriched mushroom powder as affected by impregnation method and air drying temperature

This study aimed to develop a functional food ingredient by incorporating grape pomace extract into mushroom slices using both vacuum impregnation (VI) and simultaneous application of ultrasound assisted vacuum impregnation (VI+US) techniques with further air drying at 55, 65 and 75 °C. Drying kinetics of processes as well as bioactive compounds and physical properties of mushroom powders belonging to VI and VI+US treatments were assessed and compared with non-treated (N-T) samples. The activation energies of drying for VI (27.05 kJ mol−1) and VI+US (16.24 kJ mol−1) treatments were found significantly lower than N-T (43.42 kJ mol−1) samples, and VI+US samples exhibited highest total phenolic and total flavonoid contents with highest antioxidant capacity values. Physical properties of the mushroom powders were affected by both impregnation techniques and air-drying temperatures. Impregnation treatments increased D[3,2] values (surface area mean) of the samples dried at higher temperatures, and the ultrasound application resulted in the highest values. Both VI and VI+US treatments improved flowability (Carr index) compared to N-T samples. The highest oil and water holding capacity values were determined in VI+US samples while sole VI treatment revealed lowest water holding capacity.

Anti-platelet and anti-inflammatory properties of an ethanol-water red grape pomace extract

AbstractPrevious reports support that wine contains a mixture of micro-constituents in a proper quality and quantity that possess cardio-protective effect partly through Platelet-Activating Factor (PAF) inhibition. Grape pomace (GP) is a source of wine-like micro-constituents that may be a suitable alternative in food fortification. Limited data exist concerning their effects on thrombosis and inflammation. Therefore, the purpose of this study was to examine a grape pomace extract regarding its anti-platelet and anti-inflammatory properties. GP from four red grape varieties were extracted with 80% ethanol (GP:solvent 1:5w/v). The extract's total phenolic compounds were evaluated and the phenolic profile was performed by Ultrahigh-Performance-Liquid-Chromatography coupled to Mass-Spectrometry and the determination of fatty acids profile was performed by Gas-Chromatography. The extract's anti-platelet properties were tested in healthy volunteers’ platelet rich plasma by the light transmittance method, against three agonists: PAF, ADP and TRAP. The results expressed as IC50 values (μg of extract that cause 50% inhibition of aggregation) and EC50 values (agonist concentration that causes 50% of the maximum aggregation) in the extract's presence and absence. Concerning the extract's anti-inflammatory properties, peripheral blood mononuclear cells from healthy volunteers were pre-incubated with different extract concentrations, which were tested for their effect on cell viability, for 1 h and then stimulated with LPS for 4 h. Secretion of IL-1β and TNF-a was measured and normalized with the total cell protein. Phenolic compounds were calculated at 8.79 ± 1.17 mg gallic acid per g of GP. The most abundant ones were catechin, epicatechin and quercetin at 202.9 ± 6.9, 84.8 ± 1.5 and 83.7 ± 3.5μg per g of GP respectively. Out of the 18 fatty acids detected, the most abundant ones were palmitic, oleic, linoleic, and linolenic acid at 28.7 ± 0.1, 11.4 ± 0.01, 32.5 ± 0.07, 12.7 ± 0.005 g per 100 g of fat. The extract's IC50 was calculated at 162.1 ± 66.9, 181.2 ± 82.3 and 156.3 ± 97.5μg against PAF, ADP and TRAP, respectively. The EC50 values in the presence of 150μg extract were increased (lower platelet aggregation sensitivity) approximately at 100%, 45% and 13% against PAF, ADP and TRAP respectively, compared to EC50 values in the absence of extract. The presence of 500 and 1000μg/mL of extract reduced LPS-induced TNF-a secretion at approximately 38.2% (p = 0.04) and 6.0% (p < 0.000), respectively. Potent anti-platelet and anti-inflammatory properties are combined in a grape pomace extract. The use of its bioactive micro-constituents is likely to lead to the production of functional foods with cardioprotective properties.

Grape pomace extract supplementation activates FNDC5/irisin in muscle and promotes white adipose browning in rats fed a high-fat diet.

Irisin is a myokine regulated by peroxisome proliferator-activated receptor gamma co-activator-1α (PGC-1α) in the exercising skeletal muscle and released into the bloodstream after cleavage of FNDC5. Circulating irisin can up-regulate UCP-1 expression in white adipose tissue (WAT) promoting the formation of brown-like adipocytes. The aim of this study was to evaluate if supplementation with a grape pomace extract (GPE) could activate the FNDC5/irisin pathway via PGC-1α in rats fed a high fat diet (HFD). For this purpose we characterized the activation of: i. the FNDC5/irisin pathway and AMPK in skeletal muscle and ii. proteins involved in the formation of brown-like cells in epididymal WAT (eWAT). Consumption of the GPE activated the FNDC5/irisin pathway, increased AMPK phosphorylation in skeletal muscle and enhanced irisin plasma levels. In eWAT, the GPE increased the level of proteins involved in WAT browning, i.e. PGC-1α, PPARγ, PRDM16 and UCP-1. The GPE also prevented HFD-induced adipocyte hypertrophy and systemic insulin resistance. Consistently, in L6 myotubes, (-)-epicatechin (EC), a flavonoid abundant in the GPE, prevented palmitate-mediated downregulation of FNDC5/irisin protein expression and secretion, in part via PGC-1α activation. Consumption of the GPE, a winemaking residue rich in bioactive compounds, could be a beneficial strategy to counteract the adverse effects of Western style diets through the promotion of WAT browning.

Valorization of Food Waste to Produce Eco‐Friendly Means of Corrosion Protection and “Green” Synthesis of Nanoparticles

Agrifood by‐products are a key element within Europe’s sustainable strategies. Valorization and reuse of zero‐waste technologies are becoming more popular, and they are commonly named as “second‐generation food waste management.” The present study is directed to the valuable extracts of “green” organic compounds from the by‐products of fruit and berry/vegetable crops, which can be revalorized in sustainable chemical technology and engineering, namely, in the production of “green” synthesis of nanoparticles and for the inhibition of corrosion and scaling of metals in corrosive media. Numerous types of agrifood by‐products (rapeseed pomace, sugar beet pulp, fodder radish cake, grape pomace, and pomegranate peels) were investigated. The waste extracts for corrosion and scale inhibitors of mild steel in tap water were prepared by the conventional extraction method that uses 2‐propanol and characterized by gas chromatography‐mass spectroscopy (GC‐MS). Inhibition of scaling and corrosion was investigated in thermal scaling conditions on the surface of the electrode manufactured from mild steel. The LPR technique was applied to measure the corrosion rate, and the scaling rate was determined gravimetrically. The extracts were found to inhibit the corrosion rate 2‐3 times, while only radish cake extract inhibited both the corrosion and scaling rates. The waste extracts to produce nanoparticles were prepared by the ultrasound‐assisted water extraction with subsequent oxidation by oxygen purge and characterized by liquid chromatography‐mass spectroscopy (LC‐MS). The aqueous grape pomace and pomegranate peel extracts were screened for total phenolic content (TPC) and total flavonoid content (TFC). The reduction capacity of the extracts was assessed using ferric reducing power (FRAP) and phosphomolybdenum (PM) assays. AgNPs were characterized by UV‐Vis spectroscopy, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscope (SEM), and energy‐dispersive X‐ray spectroscopy (EDX) analysis. The particle size of AgNPs ranged between 40 and 50 nm. The antimicrobial activity of AgNPs was tested against Escherichia coli using the agar diffusion method and optical density.

Lyophilized and microencapsulated extracts of grape pomace from winemaking industry to prevent lipid oxidation in chicken pâté

Abstract The aim of this study was to characterize spray-dried and lyophilized powders made from winery by-products and to evaluate their effect on the oxidative stability of chicken pâté. Phenolic profile, antioxidant activity, and microencapsulation efficiency were evaluated in the extracts. Two pâté formulations containing grape pomace lyophilized (GPWL) and grape pomace microencapsulated (GPWM) were produced. In addition, a sodium erythorbate and a control batch were used to compare the effects. The pâtés were evaluated by thiobarbituric acid reactive substances (TBARS) assay during refrigerated storage (4 °C/42 days). Although the microencapsulation efficiency was 90.03%, the GPWL was statistically more effective in the lipid oxidation inhibition in chicken pâté than GPWM. However, the addition of both natural antioxidants in chicken pâté resulted in lower TBARS values than pâté treated with synthetic antioxidant due to the presence of gallic acid, caffeic acid, vanillic acid, ferulic acid, coumaric acid and trans-resveratrol with high antioxidant activity. Thus, the bioactive compounds with antioxidant activity detected in the GPWL and GPWM opened possibilities for use as a potential ingredient in chicken pâté and other meat products.

Enhancement of the anti-inflammatory properties of grape pomace treated by Trametes versicolor.

The application of solid-state fermentation for the production of value-added products from the agro- and food-industry residues has been recently investigated greatly. The white-rot basidiomycete Trametes versicolor is a widely used fungi for the degradation lignocellulosic material in solid-state conditions. Grape pomace constitutes the major by-product of Vitis vinifera L. and is a source of compounds with recognized health benefits. In this study, a process for treating grape pomace with Trametes versicolor for 15 days under solid-state conditions was developed, and the phenolic profile and anti-inflammatory potential of the grape pomace extracts before and after treatment was studied. The anti-inflammatory potential of the grape pomace extracts was studied via tests based on the inhibition of 5-lipoxygenase and hyaluronidase, two key enzymes in inflammatory processes. A total of 24 phenolic compounds were identified and quantified by HPLC methods. With the exception of anthocyanins, an increase in phenolic acids, flavan-3-ols and the flavonol rutin was observed after a treatment period of 1-4 days with T. versicolor. Moreover, the increase in the phenolic content was accompanied by an enhancement in the anti-inflammatory activity of the grape pomace extracts, which was confirmed by the strong correlation between them. This is the first study providing evidence of the benefits of the application of fungal-based solid-state fermentation as an environmentally friendly process for the enhancement of the phenolic composition and anti-inflammatory potential of grape pomace, increasing the possibility of profiting from the great waste produced by the grape-processing industry.

Antibacterial activity of grape (Vitis vinifera) pomace fatty extracts against Xanthomonas citri subsp. citri in lemons

The objective of this investigation was the identification of compounds present in grape pomace, seed and skin extracts and the evaluation of their antibacterial activity against Xanthomonas citri in vitro and in vivo using preventive and curative methods. β-sitosterol and stigmasterol were detected in grape pomace extracts. The screening of the antibacterial activity demonstrated that all extracts have antibacterial activities against X. citri The MIC and MBC values of tested extracts were between 350 and 700 μg/mL. The in vivo test showed that the preventive method was more effective than curative method. No viable cells of X. citri were detected at 7 d in lemons treated with 1000 μg of grape pomace, seed and skin extracts/mL, 500 μg of β-sitosterol/mL or 750 μg of stigmasterol/mL, using preventive method. Grape pomace extracts could be reuse by applying as natural antibacterial agent against Xanthomonas citri, etiologic agent of citrus canker in lemons.

Paradoxical Effect of Grape Pomace Extract on Cisplatin-Induced Acute Kidney Injury in Rats.

Cisplatin is one of the most used drugs in the therapy of different types of cancer. However, its use is limited by nephrotoxicity. This study investigated the effects of a commercially available grape pomace extract (GE) from Vitis vinifera on cisplatin-induced kidney toxicity in rats. Sixty-four male Wistar albino rats were randomly divided into eight groups. Groups 1–3 were controls, receiving 0.9% saline and doses 1 and 2 of GE respectively. Cisplatin was given to groups 4–8. Two groups received pretreatment with GE, while another two groups received pre- and post-treatment with GE. Blood samples were collected and all animals sacrificed. Kidneys were harvested for histopathological analysis. GE significantly increased blood creatinine and urea levels, the severity of kidney histopathological damage, and mortality in all cisplatin groups, except for group 7 which received pre- and post-treatment with a low dose of GE. Renal toxicity was determined by mortality and severe histopathological renal lesions. Additionally, the serum total antioxidant capacity (TAC) was not significantly modified in the treated groups compared to the control. These results indicate that the GE did not have a protective effect on cisplatin-induced nephrotoxicity; on the contrary, GE accentuated the toxic effect of cisplatin.

CHARACTERIZATION OF POLYPHENOL PROFILE OF EXTRACTS OBTAINED FROM GRAPE POMACE AND SYNERGISTIC EFFECT OF THESE EXTRACTS AND FUNGICIDES AGAINST Botrytis Cinerea

Botrytis cinerea is a phytopathogenic fungus that infects the aerial parts of approximately 250 plant species. Control of this fungus is based on synthetic fungicide application. However, it has been reported the detection of isolates of B. cinerea resistant to all fungicides. Due to the emergence of resistant isolates of phytopathogenic fungi to commercial fungicides and the concomitant reduction in the efficacy of fungicides, various strategies have been developed to prevent or delay this problem. One of them is the use of synergistic mixtures among fungicides and plant extracts. In this work, extracts obtained from grape pomace of Syrah, Cinsault, or Cabernet Sauvignon varieties were analyzed. The phenolic composition in the fractions was different. Quercetin and kaempferol were observed in all fractions, in exception of Cinsault/chloroform fraction. Interestingly, gallic acid was found only in Cinsault extracts. The flavan-3-ols catechin and (-)-epicatechin are only found in Cinsault/ethyl acetate fraction. The effect of mixtures among these extracts and the fungicides Tercel and Cantus on mycelial growth of B. cinerea was analyzed. Mixtures of chloroform and ethyl acetate fractions from Cinsault grape pomace extracts and the fungicide Tercel at 0.1 ppm showed a synergistic interaction.

The Synergistic Behavior of Antioxidant Phenolic Compounds Obtained from Winemaking Waste's Valorization, Increased the Efficacy of a Sunscreen System.

Grape pomace retains polyphenols in the peels and in the seeds after winemaking, which is indicative of the high valorization potential of this industrial waste. There is strong evidence that phenolics are robust antioxidants and confer photoprotection; thus, it is rational to apply these active compounds from winemaking waste to sunscreens, in order to increase UV protection. Despite the importance of this class of cosmetics to public health, more efficacious strategies are still needed to overcome the problems caused by the photoinstability of some UV filters. The hydroethanolic extract of Vitis vinifera L. grapes was obtained by percolation and then lyophilized. Six formulations were developed: Type I—cosmetic base and UV filters; Type II—cosmetic base and extract; and Type III—cosmetic base, extract and UV filters. Each formulation was prepared in the pHs 5 and 7. The antioxidant activities of the samples were measured by DPPH• and expressed in Trolox® equivalents (TE), and their photostability and in vitro sun protection factor (SPF) were analyzed by diffuse reflectance spectrophotometry. The anti-radical efficiencies observed in the formulations with grape extract were: (II) 590.12 ± 0.01 μmol TE g−1 at pH 5 and 424.51 ± 0.32 μmol TE g−1 at pH 7; (III) 550.88 ± 0.00 μmol TE g−1 at pH 5 and 429.66 ± 0.10 μmol TE g−1, at pH 7, demonstrating that the UV filters, butylmethoxydibenzoyl methane, ethylhexyl methoxycinnamate and ethylhexyl dimethyl 4-aminobenzoic acid had no influence on this effect. The photoprotective efficacy and the photostability of formulation III containing the extract and UV filters at pH 5 suggested that a synergism between the active molecules provided an 81% increase in SPF. Additionally, this was the only sample that maintained a broad spectrum of protection after irradiation. These results confirmed that the grape pomace extract has multifunctional potential for cosmetic use, mainly in sunscreens, granting them superior performance.

The Use of Candida pyralidae and Pichia kluyveri to Control Spoilage Microorganisms of Raw Fruits Used for Beverage Production.

Undesired fermentation of fruit-derived beverages by fungal, yeast and bacterial spoilage organisms are among the major contributors of product losses in the food industry. As an alternative to chemical preservatives, the use of Candida pyralidae and Pichia kluyveri was assessed for antimicrobial activity against several yeasts (Dekkera bruxellensis, Dekkera anomala, Zygosaccharomyces bailii) and fungi (Botrytis cinerea, Colletotrichum acutatum and Rhizopus stolonifer) associated with spoilage of fruit and fruit-derived beverages. The antagonistic properties of C. pyralidae and P. kluyveri were evaluated on cheap solidified medium (grape pomace extract) as well as on fruits (grapes and apples). Volatile organic compounds (VOCs) from C. pyralidae and P. kluyveri deemed to have antimicrobial activity were identified by gas chromatography-mass spectrometry (GC-MS). A cell suspension of C. pyralidae and P. kluyveri showed growth inhibition activity against all spoilage microorganisms studied. Direct contact and extracellular VOCs were two of the mechanisms of inhibition. Twenty-five VOCs belonging to the categories of alcohols, organic acids and esters were identified as potential sources for the biocontrol activity observed in this study. This study reports, for the first time, the ability of C. pyralidae to inhibit fungal growth and also for P. kluyveri to show growth inhibition activity against spoilage organisms (n = 6) in a single study.

The Effects of Different Plant Extracts on Wine Phenolic Contents and Antioxidant Activities Used as an Alternatives of Sulphur Dioxide During Wine Production

Sulphur dioxide (SO2) is commonly used as an antioxidant and antimicrobial additive during wine production. Nowadays, consumers preferred foods treated with natural preservatives. The aims this study was to determine the effects of different natural plant extracts as an alternative of sulphur dioxide used in wines. Wine production was done according to the accepted conventional method of red wines (Cabernet sauvignon). The experimental design was achieved by using different plant extracts (grape pomace, rosemary and blueberry) at different concentrations. As control groups were used wine samples produced without addition of SO2. At the end of production basic oenological analyses (total acidity, volatile acidity, pH, dry matter, ash, free and total SO2) and specific wine analyses (total phenols, total flavanols, tartaric ester content and antioxidant activity) were performed. Results demonstrated that each used plant exact have different effects on wine quality parameters. The lowest concentrations of grape pomace extract caused reduction of SO2 and keeping the required wine properties. The highest value of antioxidant activities and total phenols were determined in the wine treated with 25 mg/L SO2 and 1 ml/L rosemary extract (in the 1st mount of storage) and 25 mg/L SO2 and 1 ml/L grape pomace extract (in the 2nd and 3rd mount of storage) as 89.92%, 5550.48 mg/l GAE; 88.51%, 5028.65 mg/l GAE; 88.42%, 4974.25 mg/l GAE, respectively. Results emphasized the importance of used plant extracts and their concentrations. The study demonstrated the possibilities of optimization of SO2 and wines phenols on the base of used natural plant extracts.

Green synthesis of silver nanoparticles using an extract of Ives cultivar (Vitis labrusca) pomace: Characterization and application in wastewater disinfection

Traditional methods for synthesizing metallic nanoparticles include the use of toxic chemicals, which can have negative impacts on the environment and human health. A safer alternative to produce these nanomaterials is based on the concept of Green Chemistry, which uses less harmful chemicals from renewable sources. In this work, we describe a specific approach for the green synthesis of silver nanoparticles (AgNPs) using the extract of Ives cultivar (Vitis labrusca) pomace, their characterization, and their immobilization in a polymer matrix of chitosan aiming the disinfection of a raw wastewater sample. The influence of some experimental parameters on synthesis such as pH, stabilization time as well as the temperature has been investigated. The grape pomace extract was initially characterized regarding its content of phenolic compounds and then used as stabilizing-reducing agent. The obtained AgNPs were analyzed by ultraviolet-visible spectroscopy, transmission electron microscopy, zeta potential, scanning electron microscopy coupled with energy dispersive spectroscopy, and raman spectroscopy. In general, the AgNPs were spherical in shape and very stable. Aiming to explain the reaction, we also proposed a mechanism of formation of AgNPs based on gallic acid molecule. Concerning the antimicrobial properties, the results demonstrated the synergistic activity of chitosan-AgNPs pellets against Gram-positive and Gram-negative bacteria. Additionally, these materials led to a reduction of 47% of the bacterial count of Escherichia coli on the disinfection of the wastewater. Finally, it was concluded that the extract of Ives cultivar pomace is capable of producing stable AgNPs that can be used as auxiliaries in wastewater disinfection.

Effect of different microencapsulating materials and relative humidities on storage stability of microencapsulated grape pomace extract

This work aims to prolong the storage stability of polyphenols, obtained from grape pomace, using a spray drying-based microencapsulation technique. The microcapsules obtained under optimal conditions were stored at two different relative humidities (33% and 52%) during 75 days. The analyses of total phenolic content, antioxidant activity, and individual phenolic compounds were carried out every 15 days, and the most stable microcapsules were achieved with maltodextrin DE4-7 prepared by adding gum Arabic to the wall material at a ratio of 8:2. The phenolic content loss rate was found to be in a range of 0.93–5.42 % depending on phenolic compound. The decrease in the content of rutin, chlorogenic acid, epicatechin, caffeic acid, gallic acid, caftaric acid and catechin was only 0.93, 2.09, 2.13, 2.27, 2.41, 3.40 and 5.42%, respectively. These results indicate more efficient storage conditions than those of previously reported studies.