Subcritical solvent extraction (SSE) is an efficient and versatile technology for the recovery of bioactive compounds from food by-products. The present work aims to study the SSE efficiency and ...kinetics for the extraction of grape marc polyphenols. Water, ethanol, and a 50% water-ethanol mixture (EtOH 50%) were used as green solvents. The higher polyphenol content (4.05 ± 0.23 gGAE/100 gd. m.) and antioxidant activity (42.30 ± 0.68 mg α-toc/mL) were obtained with subcritical EtOH 50% at 120 °C and 10.3 MPa, respectively, 1.5- and 3-fold higher than the conventional extraction. According to kinetic modeling, SSE was four-fold faster and a degradation phenomenon of polyphenols was highlighted for times longer than 10 min. The two-site kinetic model and a second order exponential decay function suitably described the extraction kinetics and degradation phase, respectively (R2 > 0.97). A remarkable effect was highlighted on the polymerization degree and galloylation percentage of proanthocyanidins by SSE, and an increase in their antioxidant activity was observed.
•Subcritical solvent extraction (SSE) is more efficient and faster than conventional.•The subcritical 50% water-ethanol mixture is more effective than pure components.•SSE is constituted by two process steps: polyphenol extraction and degradation.•Two-site kinetic model well described the SSE extraction phase.•Subcritical fluids affect the proanthocyanidins properties and bioactivities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Extracts rich in monomeric anthocyanins (MAC) and total phenolic compounds (TPC) were obtained from grape marc by Pressurized Liquid Extraction (PLE). PLE was performed using ethanol and water ...mixtures (acidified or not) (50% w/w), pure ethanol and acidified water at temperatures from 40 to 100 °C. The best PLE conditions for MAC extraction (ethanol-water pH 2.0 50% w/w) resulted in 10.21 mg of malvidin-3-O-glucoside/g of dried grape marc (dr). Fifteen anthocyanins were identified and quantified in PLE extracts by UHPLC-UV-Vis. PLE with ethanol-water (50% w/w) as solvent at 100 °C achieved the highest TPC content (65.68 mg GAE/g dr) and antioxidant capacity by ORAC (772.11 μmol TE/g dr) and FRAP (1452 mg TE/g dr) among the evaluated conditions. Based on the results for extraction of monomeric anthocyanins and phenolics compounds, a sequential PLE process was performed and proved to be viable for the recovery of two different extract fractions.
•PLE presented great potential to recover bioactive compounds from grape marc.•High correlation was found between phenolic content and antioxidant capacity.•Two mathematical models were applied to describe the PLE kinetic curves.•Sequential PLE proved to be feasible for the recovery of bioactive compounds.•Grape marc extracts can be applied in food, cosmetics and nutraceuticals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this report, cost-effective nitrogen (N) -doped porous biocarbon was fabricated from grape marcs, and it demonstrated excellent capacitance, cyclic stability and rate performance as an electrode ...material for supercapacitors. By using urea as N-doping agent and KOH as activator, the as-prepared carbon material possessed suitable N-doping content (2.04 at%), well-developed porous structure and large specific surface area (2221.4 m2 g−1). As is clearly evidenced by the experimental results, the introduced N-containing functional groups could not only boost the electric double-layer capacitance (EDLC), but endow the material with considerable pseudo-capacitance under acidic conditions, thus resulting in distinct capacitances of the material under different electrolytes (446.0, 345.5 and 310.0 F g−1 at 0.5 A g−1 in 1 M H2SO4, 6 M KOH and 1 M Na2SO4, respectively). Moreover, the symmetrical supercapacitor device assembled based on this material also showed excellent performance by reaching an energy density of 16.3 Wh kg−1 with the power density of 348.3 W kg−1. All the results ensure that the biomass carbon derived from grape marcs can be used as a low cost, renewable and high-performance electrode material for supercapacitors.
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•N-doped porous carbon is prepared from grape marc for supercapacitors.•As-prepared porous carbon has a higher specific surface area of 2221.4 m2 g−1.•The carbon electrode has excellent capacitances of 446.0 F g−1 at 0.5 A g−1.•The symmetric supercapacitor delivers an energy density of 16.3 Wh kg−1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Supercritical carbon dioxide (SC-CO2) extraction of policosanol (PC) from grape marc was investigated for the first time. Employing the broken plus intact cells (BIC) model (Sovová's model) the ...investigation focused on analyzing the SC-CO2 process to extract the nonpolar fraction from grape marc efficiently. Operating conditions for SC-CO2 extraction—280 bar pressure, 70 °C temperature, and a flow rate of 10 kgCO2/h—yielded the highest policosanol content. The extracted policosanol ranged between 3922 and 4083 mg/kgDM, constituting approximately 8 % of the total extraction yield. Surprisingly, this amount of PC was of the same order of magnitude found in beeswax yellow, a well-known rich natural source of PC. The primary aliphatic alcohols found in the PC from grape marc were hexacosanol, octacosanol, and triacontanol. These findings were consistent with grape marc samples from other Italian regions. Furthermore, a comparative analysis between SC-CO2 and Soxhlet extraction methods for PC was carried out.
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•First study on policosanol content and composition from grape marc extracted using SC-CO2.•Investigated fundamental mechanisms of SC-CO2 extraction.•Unexpected richness in policosanol content of grape marc.•Consistency of policosanol findings extended to grape marc samples from diverse Italian regions.•Identification of key aliphatic alcohols: hexacosanol, octacosanol, and triacontanol.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This research demonstrates the conversion of grape marc into highly carbonaceous and oxygen functionalized porous activated biocarbons (PABs) with a high specific area for CO2 capture. The materials ...are synthesized using KOH activation at 800 °C and show a high content of micropores and high specific surface areas which can be easily manipulated by varying the amount of KOH. The optimized material PAB3 obtained using KOH/grape marc biochar ratio of 3 displays the highest specific surface area (2473 m2 g−1), high micropore volume (0.72 cm3 g−1) and a pore diameter of 0.74 nm. Owing to its highly developed porosity and excellent textural parameters, PAB3 exhibits a high CO2 adsorption of 6.2 mmol g−1 at 0 °C/1 bar and 26.8 mmol g−1 at 0 °C/30 bar. It is often considered challenging to synthesize a CO2 adsorbent with all-round performance for CO2 capture under diverse conditions of temperature and pressure. The optimized material PAB3 is also found to be thermally stable which when coupled with its superior CO2 capture performance presents a promising candidature in the field of carbon capture. Furthermore, the excellent features of the synthesized material suggest that these materials could be extended to several other adsorption related fields.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Chardonnay marc (pomace), an agricultural waste product, has demonstrated significant potential health benefits in previous studies. This study represents the first comprehensive chemical ...characterization of chardonnay marc, its seed and seedless fractions, and a seed extract to uncover the bioactive compounds inducing their observed health benefits. Chardonnay marc and its processing fractions' gross composition (i.e. protein, lignin, fat, carbohydrates, polysaccharides), phenolic contents, and oligosaccharide profiles were determined. The chardonnay seeds contained higher quantities of protein, fat, and polysaccharides than the seedless marc while the seedless marc contained more total carbohydrates and sugars. All samples had abundant phenolics with the seed extract being the most concentrated (34.72 ± 0.13 mg/g). (−)-Gallocatechin was the most abundant phenolic in the marc (1.4905 ± 0.0393 mg/g) and seedless marc (0.94 ± 0.04 mg/g), and (−)-epicatechin was the most concentrated phenolic in the seeds (9.4093 ± 0.1018 mg/g) and seed extract (14.22 ± 0.09 mg/g). Thirty-six distinct oligosaccharides were discovered between the four samples with three to nine degrees of polymerization and eleven distinct monosaccharide subunits. Overlap existed between the samples’ oligosaccharides with six of the same hexose and hexose-pentose oligosaccharides present in all. Each sample, however, had a distinct oligosaccharide profile such as with eight oligosaccharides unique to the seed extract.
•Composition analysis of chardonnay marc and its seed and seedless components.•Phenolics and oligosaccharides differ between chardonnay seeds and seedless marc.•All chardonnay marc fractions contain multiple, diverse oligosaccharides.•Seedless chardonnay marc oligosaccharides are built from eleven monosaccharides.•Subcritical water extraction increases phenolic content and oligosaccharide diversity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The wine industry represents an important economic sector in the Mediterranean countries. Currently, grape marc is valorized for ethanol production by distillation process generating a second residue ...called exhausted grape marc (EGM) that should be properly managed in order to avoid any related negative impacts onto the environment. In the present investigation, an innovative strategy was proposed to convert EGM into biofuels and biofertilizers through thermochemical conversion process such as carbonization/pyrolysis technique. In order to select the appropriate operating parameters, the impact of the slow pyrolysis temperatures of EGM (from 300 to 700 °C) on biochar production yields as well as their physico-chemical characteristics were assessed. The experimental results showed that the biochars yields production decrease with increasing the pyrolysis temperature and reach a plateau above 500 °C. The biochar yield at 500 °C is around 33%, which is amongst the highest values obtained for food processing residues. The biochar physico-chemical characterization showed a higher surface area (253.4 m2/g) was obtained for the char prepared at 600 °C. However, the maximum nutrients contents, namely potassium, nitrogen and phosphorus were registered at 500 °C. Based on the biochar yields and characteristics, it seems that EGM biochar produced through slow pyrolysis at 500 °C could be considered as a promising biofertilizer for agricultural purposes.
•Exhausted grape marc (EGM) wastes were pyrolysed under various temperatures.•Biochar production decreases with temperature and the yield reaches 33% at 500 °C.•Physico-chemical, textural, structural properties of EGM biochars were determined.•The produced biochar at 500 °C (EGM-B500) has high nutrient contents and porosity.•The EGM-B500 is very attractive for agricultural and/or environmental applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this work, a valorisation of olive and wine industry co-products (olive pomace and grape marc, respectively) through different thermochemical processes is studied. The characterization of olive ...pomace and grape marc is made to evaluate which thermochemical process is more suitable for each type of biomass and a specific application. Then, a life cycle assessment (LCA) of olive pomace value chain is made to assess the environmental impacts. Several scenarios of biomass conversion process were considered: combustion, gasification and hydrothermal carbonization (HTC) followed by gasification to generate electricity; and pyrolysis to produce biochar, bio-oil and syngas. Finally, a techno-economic analysis was performed for each mentioned scenario to evaluate the feasibility and conclude which scenario is more economically advantageous. Results suggest that valorisation of olive pomace might be more suitable through the gasification process and grape marc through the pyrolysis process. From the LCA was possible to conclude that combustion scenario has the highest environmental impact. In comparison, gasification, HTC and pyrolysis presented a lower impact with a value of 69.45%, 50.96% and 40.97%, respectively, considering combustion as 100% impact. Regarding the techno-economic analysis, several scenarios have promising results with some scenarios with payback periods inferior to 5 years. The only exception is HTC followed by gasification which in current days is not competitive with other technologies. Overall gasification and pyrolysis are promising alternatives to the valorisation of olive pomace and grape marc. The drying process has an important role in terms of environmental impact and economic viability.
•Olive pomace and grape marc were found to have similar properties.•Olive pomace more suitable to be gasified and grape marc to HTC or pyrolysis.•Drying has a major impact in terms of environmental impact and economic viability.•Combustion has the higher environmental impact and HTC is not economically viable.•Gasification and pyrolysis are better to the valorisation of olive pomace.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The study of microbial communities or microbiotas in animals and environments is important because of their impact in a broad range of industrial applications, diseases and ecological roles. High ...throughput sequencing (HTS) is the best strategy to characterize microbial composition and function. Microbial profiles can be obtained either by shotgun sequencing of genomes, or through amplicon sequencing of target genes (e.g., 16S rRNA for bacteria and ITS for fungi). Here, we compared both HTS approaches at assessing taxonomic and functional diversity of bacterial and fungal communities during vermicomposting of white grape marc. We applied specific HTS workflows to the same 12 microcosms, with and without earthworms, sampled at two distinct phases of the vermicomposting process occurring at 21 and 63 days. Metataxonomic profiles were inferred in DADA2, with bacterial metabolic pathways predicted
PICRUSt2. Metagenomic taxonomic profiles were inferred in PathoScope, while bacterial functional profiles were inferred in Humann2. Microbial profiles inferred by metagenomics and metataxonomics showed similarities and differences in composition, structure, and metabolic function at different taxonomic levels. Microbial composition and abundance estimated by both HTS approaches agreed reasonably well at the phylum level, but larger discrepancies were observed at lower taxonomic ranks. Shotgun HTS identified ~1.8 times more bacterial genera than 16S rRNA HTS, while ITS HTS identified two times more fungal genera than shotgun HTS. This is mainly a consequence of the difference in resolution and reference richness between amplicon and genome sequencing approaches and databases, respectively. Our study also revealed great differences and even opposite trends in alpha- and beta-diversity between amplicon and shotgun HTS. Interestingly, amplicon PICRUSt2-imputed functional repertoires overlapped ~50% with shotgun Humann2 profiles. Finally, both approaches indicated that although bacteria and fungi are the main drivers of biochemical decomposition, earthworms also play a key role in plant vermicomposting. In summary, our study highlights the strengths and weaknesses of metagenomics and metataxonomics and provides new insights on the vermicomposting of white grape marc. Since both approaches may target different biological aspects of the communities, combining them will provide a better understanding of the microbiotas under study.
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•Microwave technology is a clean method for polyphenols extraction.•The optimal extraction conditions were 48% ethanol, 1.77 g extract, and 10 min.•Flavanols were the most abundant ...phenolic compounds in grape marc.•A DPPH· inhibition value of 87 ± 5% was obtained.
The aim of this work was to extract phenolic compounds from Chardonnay grape marc employing a microwave-assisted extraction (MAE). Firstly, the effect of solvent concentration (30–60%), solid mass (1.0–2.0 g) and extraction time (5–15 min) on the recovery of phenolic content and antioxidant capacity was evaluated using a response surface methodology (RSM). The optimal parameters found by RSM were 48% ethanol for the solvent content, 10 min for the extraction time, and 1.77 g for the solid mass. The extraction was carried out at room temperature to increase scaling-up opportunities at industrial level. It was found that the phenolic profile was mainly composed of flavanols, such as procyanidins, catechin and epicatechin. Furthermore, the polyphenols obtained by MAE showed a DPPH· inhibition value of 87 ± 5% and the total phenolic content was 1.21 ± 0.04 mg GAE/mL. Finally, it was observed that the degradation temperature of the extract (≈ 200 °C) was above the temperature commonly used for the manufacture of protein films by thermo-mechanical processes. This highlights the potential use of this extract as a bioactive additive in protein film forming formulations for food and pharmaceutical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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