Grape Pomace Research Articles

Grape pomace in diets for European sea bass: influence on oxidative status, intestinal microbiota, and fillet quality

Grape pomace in diets for European sea bass: influence on oxidative status, intestinal microbiota, and fillet quality

Novel foods, food enzymes, and food additives derived from food by-products of plant or animal origin: principles and overview of the EFSA safety assessment

The European Union (EU) is committed to transitioning toward a circular economy model, with food waste being one of the areas to be targeted. To close the loop of food waste generated during food processing and discarded at the retail or consumption phases, research and innovation parties proposed to valorize agro-food by-products to produce novel foods and food improvement agents (food additives, food enzymes, and food flavorings). In the EU, the authorization of such novel foods and food improvement agents is governed by different regulatory frameworks. A centralized safety assessment by the European Food Safety Authority (EFSA) is the prerequisite for their authorization through the so-called Union Lists. Up to December 2023, EFSA published 45 scientific opinions on the safety of novel foods, food enzymes, and food additives derived from by-products of plant and animal origin. The current study illustrates examples of these by-products for the production of novel foods or food improvement agents and the data requirements behind their respective safety assessments conducted by EFSA. In this review, applications on novel foods, food enzymes, and food additives received by EFSA were screened and analyzed to find the common scientific requirements and differences in terms of the safety evaluation of such products. Various by-products (i.e., corncobs, coffee husks, spent grains of barley and rice, grape pomace, pumpkin peels, bovine whey, eggshells, shrimp heads, and animal organs or tissues) were described in the applications as being processed (extraction, physical treatments, and chemical and enzymatic reactions) to obtain novel foods and food improvement agents. The heterogeneity and complexity of these products emphasize the challenge of their safety assessment, depending on the characteristics of each product. However, as this study shows, the scientific requirements underpinning their safety do not differ substantially in the different regulated product areas considered, with similar information needed to assess their safety in terms of identity, production process, compositional characterization, proposed/intended uses and exposure assessment, toxicological information, and allergenicity data. Additional nutritional information and data on the history of use are required in the case of novel foods.

Optimizing, characterizing, and unveiling of functional properties and structure of grape pomace pectin obtained by a sequential ultrasound-microwave extraction

Optimizing, characterizing, and unveiling of functional properties and structure of grape pomace pectin obtained by a sequential ultrasound-microwave extraction

Transformation of agricultural wastes into functional oligosaccharides using enzymes and emerging technologies.

Pectin-oligosaccharides (POS) serve diverse purposes as a food ingredient, antimicrobial and biostimulant in plants, and their functionality is linked to the degree of esterification. Grape and broccoli wastes emerge as environmentally friendly alternatives to obtaining pectin, serving as a sustainable source to producing POS. For example, microwaves have proven to be an effective and sustainable method to extract polysaccharides from plant matrices. This work aims to use grape and broccoli wastes as alternative sources for obtaining pectin by microwave-assisted extraction and biotransformation into POS, which possess biological properties. The extraction conditions were identified at a power of 400 W, 300 s for the extraction of pectin from grape pomace and broccoli waste. Biotransformation of pectins into POS, using commercial enzyme preparations (Viscozyme L and Pectinase). Characterisation was carried out by Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Physicochemical analysis indicated grape pomace and broccoli waste pectins had galacturonic acid content of 63.81 ± 1.67 and 40.83 ± 2.85 mg 100 mg-1, low degree of esterification of 34.89% and 16.22%, respectively. Biotransformation of pectins into POS resulted in a 20% hydrolysis rate. The main enzymatic activity was polygalacturonase for the degradation of the main structure of the pectin. Production of POS from agro-industrial wastes by emerging technologies, such as the combined use of microwave-assisted extraction and enzymatic processes, represents an alternative method for the generation of bioactive compounds with distinctive properties suitable for different applications of interest.

Therapeutic potential of grape pomace extracts: a review of scientific evidence

Therapeutic potential of grape pomace extracts: a review of scientific evidence

Inclusion of by-products of the brewing and wine industry in dairy goats

The aim of the following work was to evaluate a diet formulated with byproducts from the brewing and wine industry for lactating goats and quantify its potential in terms of nutritional quality and quantity. Twelve multiparous Nubian x Saanen goats, 2.75 years old (+ 1,24) during an experimental period of 12 weeks: 2 weeks of habituation and 10 weeks of testing. In both diets the goats grazed 6 hours on natural grass. Diet T0 (n = 6): Commercial feed: 500 g/day/goat (16% CP and 2.6 Mcal ME/kg DM) and diet T1 (n = 6): non-traditional balanced feed: 500 g/day/goat (16% CP and 2.6 Mcal ME/kg DM). Productive performance and health parameters were evaluated in goats fed with both diets during a period of 5 weeks starting 35 days postpartum. Total dry matter intake (DMI), milk production and corrected (MY and MYC), live weight (BW), body condition score (BCS), degree of FAMACHA© and quantitative coproparasitological diagnosis (EPG and OPG) were measured. A greater DMI was observed at T0 compared to T1 (p < 0.05). MY, MYC, BW, BCS, FAMACHA©, EPG and OPG did not show significant differences (p > 0.05) between both diets (T0 vs T1) throughout the experimental period evaluated. Goat health parameters throughout the study were within the physiological range during the production cycle and did not interfere with dietary treatments. The formulation of the diet with barley bagasse and grape pomace in dairy goats had a productive behaviour and health parameters like those of the commercial diet evaluated, without affecting milk production.

Characterization of Grape Pomace Extract Microcapsules: The Influence of Carbohydrate Co-Coating on the Stabilization of Goat Whey Protein as a Primary Coating

Both grape pomace and whey are waste products from the food industry that are rich in valuable ingredients. The utilization of these two by-products is becoming increasingly possible as consumer awareness of upcycling increases. The biological activities of grape pomace extract (GPE) are diverse and depend on its bioavailability, which is influenced by processes in the digestive system. In this work, goat whey protein (GW) was used as the primary coating to protect the phenolic compounds of GPE during the spray drying process. In addition, trehalose (T), sucrose (S), xylose (X), and maltodextrin (MD) were added to the goat whey proteins as co-coatings and protein stabilizers. All spray drying experiments resulted in microcapsules (MC) with a high encapsulation efficiency (77.6–95.5%) and yield (91.5–99.0%) and almost 100% recovery of phenolic compounds during the release test. For o-coumaric acid, the GW-coated microcapsules (MC) showed a bioavailability index of up to 731.23%. A semi-crystalline structure and hydrophilicity were characteristics of the MC coated with 10% T, S, X, or 5% MD. GW alone or in combination with T, S, MD, or X proved to be a promising carrier for polyphenols from grape pomace extract and ensured good bioavailability of these natural antioxidants.

Characterization of Oil-in-Water Emulsions Prepared with Triblock Copolymer Poloxamer 407 and Low-Molecular-Mass Surfactant Mixtures as Carriers of Grape Pomace Waste Polyphenols

Background: Natural antioxidants, such as grape pomace polyphenols, can be extracted by a surfactant-based green technology and incorporated into various emulsions. Therefore, this work aimed to investigate the physical stability and rheological characteristics of oil-in-water emulsions stabilized with poloxamer 407 (P407) and its mixtures with the low-molecular-mass surfactants Brij S20 (BS20) and Tween 60 (T60). Also, the influence of polyphenolic grape pomace extracts on the physical stability and rheological characteristics of the emulsions was examined. Methods: Grape pomace polyphenols were extracted by aqueous solutions of P407 and BS20/P407 and T60/P407 mixtures. Two different types of oil-in-water emulsions were examined: emulsions prepared with pure surfactants and emulsions prepared with surfactant-based polyphenol extracts of grape pomace. Both types contained 20% sunflower oil. Characterization of the emulsions comprised droplet size evaluation, rheology characteristics and creaming stability. Results: All the emulsions showed shear-thinning flow, while the rheological characteristics and creaming instability depended on the proportion of P407 in the emulsifier mixtures. Incorporation of grape pomace extracts had no effect on the investigated properties of the emulsions. Conclusion: The presence of extracted polyphenols in emulsifier mixtures had no significant effects on the emulsions’ physico-chemical characteristics and stability. Therefore, the investigated emulsions can be considered suitable carriers for polyphenol-rich extracts.

Techno-Economic analysis of an efficient anthocyanin extraction process from grape pomace using eutectic solvents ─ A critical panorama regarding drying techniques and reusability of solvents

A techno-economic analysis of a novel eutectic solvent-based platform useful to recover anthocyanins from grape pomace was performed. The study addressed the economic impact of conventional drying methods and explored the economic implications of purification strategies to separate the extract from the eutectic solvent. This was exemplified by employing solid-phase extraction (SPE) with C18-based adsorbent material. An alternative low-energy demanding approach using SiO2 particles was also assessed for profitability as a freeze-drying replacement strategy. The results highlighted challenges in the economic feasibility of eutectic solvent reusability when conventional SPE is applied, highlighting the need to obtain new and inexpensive bio-based adsorbents. Moreover, it was uncovered that the SiO2-based drying strategy presents itself as a financially viable alternative, effectively addressing the elevated energy requirements associated with conventional drying methods. The findings highlight the potential of alternative solvents-based processes, particularly towards challenges related to the circularity of raw materials.

The proteomic evidence on protein oxidation in pea protein concentrate-based low-moisture extrudates and its inhibition by antioxidants derived from plant extracts

This study aimed to assess the antioxidant activity of golden chlorella (GoC) and grape pomace (GrP) extracts both in vitro and in pea protein-based extrudates. We hypothesized that GoC/GrP would limit oxidation of proteins in the extrudates compared with commercial antioxidants. The results showed that GoC extract was effective in metal chelation and GrP extract possessed excellent radical scavenging activity and reducing power. Protein oxidation inevitably occurred after low-moisture extrusion in terms of elevated level of protein carbonyls and the gradual loss of thiols. LC-MS/MS revealed that the monoxidation and 4-hydroxynonenal adduction were the major oxidative modifications, and legumin was the most susceptible globulin for oxidation. The GoC/GrP extracts effectively retarded the oxidation progress in extrudates by lower intensity of oxidized peptides, whereas protein electrophoretic profiles remained unaffected. This study highlighted the great potential of GoC/GrP as natural antioxidants in plant-based foods.

Effects of turning aeration and the initial carbon/nitrogen ratio on the biodegradation of polylactic acid under controlled conditions

Plastic pollution is primarily caused by the accumulation of petroleum-derived plastics, as they tend to degrade slowly. Sustainable alternatives to these materials are bio-based and biodegradable plastics, such as polylactic acid (PLA). In this study, we assessed how turning aeration and the initial carbon/nitrogen (C/N) ratio impact PLA biodegradation. The study was carried out under controlled composting conditions, over 180 days, with the aim of decreasing the biodegradation time of the PLA. Apple pomace, rice husk, grape pomace compost, and PLA were used as substrates in the composting process. The experiments were conducted using three types of turning aeration: without turning, one turn per week, and two turns per week. Three initial C/N ratios were used: 20, 30, and 40. A stepwise temperature ramp was designed and implemented to simulate industrial composting conditions, which influence microbial activity and thus the rate of decomposition of substrates, including PLA. The data showed behavior; hence, a nonlinear regression model based on the logistic growth equation was used to predict the PLA biodegradation at the end of the composting process. The results showed that two turns per week with an initial C/N ratio of 30 or 40 led to a 90 % biodegradation of the PLA in 130 days. This degradation was verified by Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM).

Development of a New Kombucha from Grape Pomace: The Impact of Fermentation Conditions on Composition and Biological Activities

Development of a New Kombucha from Grape Pomace: The Impact of Fermentation Conditions on Composition and Biological Activities

Improving Soluble Phenolic Profile and Antioxidant Activity of Grape Pomace Seeds through Fungal Solid-State Fermentation.

Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with Aspergillus niger, Monascus anka, and Eurotium cristatum at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with M. anka increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during M. anka SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.

Grape Pomace (Vitis vinifera L.) Waste Valorization: Assessing Its Potential as a Sustainable Natural Dye for Textiles Applications

The present study aimed to explore the textile dyeing capability using dyes derived from grape pomace. Extractions were conducted with water at different pH levels and with a water/ethanol solution. Cotton (natural and cationized) and wool were employed in the dyeing process for varying durations (100 and 200 min). The colorimetric and fastness properties, in terms of washing (with hot and cold water) and exposure to natural light, were evaluated. The final color evaluation was performed using ΔE*, a parameter quantifying the magnitude of a color difference by comparing the L*a*b* color coordinates of the CIELAB system of the dyed samples with those of the control. The hues obtained on the fabrics resulted in uniform and earthy colors. However, the cationized cotton substrate showed the highest ΔE* values for all conditions used in obtaining grape pomace extracts, in the range of 33.91 to 37.98. This suggests that the surface treatment enhanced dye uptake, while organic cotton achieved a lighter earthy color. Natural dyeing using grape pomace presents a sustainable, ecological, and non-toxic alternative for textile dyeing, resulting in unique and earthy tones with commercial potential while promoting the sustainable use of natural resources and environmental preservation. The key to achieving sustainable development lies in waste reduction and valorization, along with the adoption of conscious consumption.

Green Approach for Synthesis of Silver Nanoparticles with Antimicrobial and Antioxidant Properties from Grapevine Waste Extracts.

The present work aims to study the possibilities of developing silver nanoparticles using natural extracts of grape pomace wastes originating from the native variety of Fetească Neagră 6 Șt. This study focused on investigating the influence of grape pomace extract obtained by two different extraction methods (classical temperature extraction and microwave-assisted extraction) in the phytosynthesis process of metal nanoparticles. The total phenolic content of the extracts was assessed using the spectrophotometric method with the Folin-Ciocâlteu reagent, while the identification and quantification of specific components were conducted through high-performance liquid chromatography with a diode array detector (HPLC-DAD). The obtained nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM), along with assessing their antioxidant and antimicrobial properties against Gram-positive bacteria. The data collected from the experiments indicated that the nanoparticles were formed in a relatively short period of time (96 h) and, for the experimental variant involving the use of a 1:1 ratio (v/v, grape pomace extract: silver nitrate) for the nanoparticle phytosynthesis, the smallest crystallite sizes (from X-ray diffraction-4.58 nm and 5.14 nm) as well as spherical or semispherical nanoparticles with the lowest average diameters were obtained (19.99-23 nm, from TEM analysis). The phytosynthesis process was shown to enhance the antioxidant properties (determined using the DPPH assay) and the antimicrobial potential (tested against Gram-positive strains) of the nanoparticles, as evidenced by comparing their properties with those of the parent extracts; at the same time, the nanoparticles exhibited a selectivity in action, being active against the Staphylococcus aureus strain while presenting no antimicrobial potential against the Enterococcus faecalis strain.

Evaluation of Benzene Adsorption onto Grass-Derived Biochar and Comparison of Adsorption Capacity via RSM (Response Surface Methodology)

The present study reports the effective removal of benzene in aqueous phase onto biochar. The adsorption capacity of benzene onto biochars made at different pyrolytic temperatures (e.g., 350, 550, and 750 °C) and from various feedstocks (e.g., grape pomace, rice husk, and Kentucky bluegrass) were investigated. The adsorption capacity of Kentucky bluegrass-derived biochar (KB-BC) prepared at 550 °C for benzene was better than other biochars, owing to the higher surface area and functional groups. The adsorption isotherms and kinetics model for benzene by KB-BC550 fitted the Freundlich and pseudo-first order, respectively. In addition, the results of response surface methodology (RSM) designed with biochar dose, reaction time, and benzene concentration showed the maximum adsorption capacity (ca. 136 mg BZ/g BC) similar to that from kinetic study. KB-BCs obtained as waste grass biomass may be a valuable adsorbent, and RSM may be a useful tool for the investigation of optimal conditions and results.

Modeling the dehydration kinetic of grape pomace

Three mathematical models have been used to predict the dehydration kinetics of grape pomace. To the aim, three different temperatures have been set to determine the different desorption kinetics. All the dehydration kinetic data have been fitted to verify the predictive ability of the proposed models. The fitting goodness were assessed by using four coefficients: E‾%, RMSE, χ2, and R2. Results show that all the proposed models can adequately fit the experimental data. In particular, the Dual-Stage Type B model is the best one, whereas the Fick model is the worst. The soundness of the mathematical approach adopted was tested by assessing the dependence of the model's parameters on the testing temperature: only some parameters followed the expected trend. The computational complexity referred to each model was considered evaluating the suitability of the proposed models to describe the desorption kinetics. To sum up, the Dual-Stage Type B model is the most complex, whereas the simplest one is the Dual-Stage Type A model. Considering both suitability and complexity, the Dual-Stage Type A is the best model to predict the dehydration kinetic of grape pomace.

Effects of Grape Pomace on Growth Performance, Nitrogen Metabolism, Antioxidants, and Microbial Diversity in Angus Bulls.

Polyphenol-rich grape pomace (GP) represents a valuable processing by-product with considerable potential as sustainable livestock feed. This study aimed to investigate the effects of different levels of GP on the growth performance and nitrogen utilization efficiency, antioxidant activity, and rumen and rectum microbiota of Angus bulls. Thirty Angus bulls were allocated three dietary treatments according to a completely randomized design: 0% (G0), 10% (G10), and 20% (G20) corn silage dry matter replaced with dried GP dry matter. The results showed that the average daily gain (ADG) of the G0 group and G10 group was higher than that of the G20 group (p < 0.05); urinary nitrogen levels decreased linearly with the addition of GP (linear, p < 0.05). In terms of antioxidants, the levels of catalase (CAT) in the G10 group were higher than in the G0 and G20 groups (p < 0.05), and the total antioxidative capacity (T-AOC) was significantly higher than that in the G20 group (p < 0.05). In addition, in the analysis of a microbial network diagram, the G10 group had better microbial community complexity and stability. Overall, these findings offer valuable insights into the potential benefits of incorporating GP into the diet of ruminants.

Evaluation of black grape pomace, a fruit juice by‐product, in shalgam juice production: Effect on phenolic compounds, anthocyanins, resveratrol, tannin, and in vitro antioxidant activity

AbstractThe aims of this research were to investigate the usability of black grape pomace in the production of shalgam juice, which is a traditional fermented Turkish beverage, to transform the pomace into the high value‐added product and to enrich the shalgam juice with phenolic compounds. Black grape pomace and black carrot were used as the sources of polyphenols and five different formulations were obtained according to the amounts of black carrot and black grape pomace. During the fermentation, the samples were taken at different periods and analyzed for anthocyanins, phenolic compounds, antioxidant activity, and tannin content. Gentisic, caffeic, ferulic, coumaric, and chlorogenic acids, catechin, glucosides of kaemferol and isorhamnetin, resveratrol, rutin, cyanidin‐3‐xylosylglucosylgalactoside, cyanidin‐3‐xylosylgalactoside, cyanidin‐3‐xylosylglucosylgalactoside acylated with sinapic acid, ferulic acid, or coumaric acid, and glucosides of cyanidin, petunidin, and malvidin were identified in the shalgam juices that contained both black grape pomace and black carrot in their formulation. Some of these polyphenols were not detected detect in the shalgam juices that were produced from only the black carrot or black grape pomace. During the fermentation, a decrease in the amount of anthocyanins originated from black carrots and an increase in the amount of anthocyanins orginated from black grape pomace were determined. Black grape pomace addition to the formulation before the fermentation caused an increase in the amount of tannin in the shalgam juice samples. Consequently, it is thought that black grape pomace can be fruitfully evaluated in shalgam juice production and can be enhanced by polyphenolic profile of shalgam juice.

Using grape pomace powder as a pectin replacer to prepare low water activity bake-stable fruit filling

Using grape pomace powder as a pectin replacer to prepare low water activity bake-stable fruit filling