Search Results (236)

Fish processing by-products represent an abundant source of valuable biomolecules that can be valorized through sustainable extraction approaches. In this work, cod backbone hydrolysates obtained by subcritical water hydrolysis were incorporated into chitosan-based films for potential food packaging applications. The hydrolysis residue, rich in minerals, particularly hydroxyapatite (HAp residue), was also incorporated into the films to maximize the utilization of all hydrolysis-derived fractions. The effects of hydrolysate and HAp residue incorporation on the properties of the films were evaluated. The hydrolysate incorporation significantly improved the tensile strength of the films (from 11.56 to 24.39 MPa) and reduced water vapor permeability (from 4.93 to 2.89 (×10⁻¹¹) mol.m.m⁻².s⁻¹.Pa⁻¹), suggesting the formation of a denser and cohesive polymer network. However, the films also exhibited increased swelling and solubility (22–29% and 231–561%, respectively). When adding HAp residue, the films showed lower visible light transmittance and higher opacity, demonstrating improved light barrier properties. The addition of HAp residue also reduced swelling capacity but increased water vapor permeability and decreased tensile strength, suggesting the formation of a more heterogeneous film structure. Overall, the results demonstrate that cod backbone hydrolysates can be an alternative additive to chitosan films to tailor their functional properties for food packaging applications. The incorporation of hydroxyapatite-rich residues contributes to the full valorization of fish processing by-products, supporting the development of sustainable and biodegradable functional materials within a circular economy approach. Full article

Seed mucilage is a natural hydrophilic polysaccharide gel secreted by seed coat epidermal cells comprising xylan, pectin, glucomannan, and cellulose alongside minor proteins, minerals, and lipids, with its composition varying substantially across plant species. This review critically compares conventional and green extraction technologies, including ultrasound-, microwave-, enzyme-, and subcritical water-assisted extraction, on a seed-mass-normalized yield basis together with their solvent-to-seed ratios and processing times, showing that green technologies can reduce solvent consumption, energy use, and processing time relative to matched conventional controls, though the magnitude of these gains is method and species-specific rather than uniform. We synthesize how molecular weight, uronic acid content, branching pattern, and microfibril organization govern seed mucilage hydration, rheological, emulsifying, and foaming behavior, and link these structure–function relationships to its antioxidant, prebiotic, anti-inflammatory, and antimicrobial bioactivities. Beyond functional characterization, this review evaluates the translational barriers, extraction standardization, safety and regulatory status, and clinical validation that currently limit seed mucilage adoption in food, pharmaceutical, and cosmetic industries. Unlike previous reviews focused on ecological function or application cataloging, this review uniquely reframes seed mucilage as a structurally programmable bioactive polysaccharide, integrating molecular architecture, green process intensification, and structure–function–application relationships to bridge fundamental chemistry with industrial translation. Full article

Valorizing agro-industrial by-products within a circular bioeconomy provides sustainable alternatives to synthetic pesticides. This study evaluated a coffee production waste (CPW) aqueous extract, obtained via subcritical water extraction, as a multifunctional biopesticide. We assessed its chemical profile, antifungal and insecticidal efficacy, ecotoxicology, allelopathy, and biochemical phytotoxicity. HPLC-DAD-MS revealed high levels of caffeine (12.9 mg/g DM), trigonelline (10.8 mg/g DM), and chlorogenic acids (~8.5 mg/g DM). It demonstrated broad in vitro antifungal activity, inhibiting Botrytis cinerea mycelial growth (84.0%) and conidial germination (98.1%). In vivo, CPW reduced apple gray mold severity to 34.9%, though in planta protection on tomato was partial. The extract reduced Halyomorpha halys egg hatching to 33.0% and increased nymphal mortality to 49.0% via symbiotic disruption, without harming its parasitoid Trissolcus japonicus. However, high acute mortality in the pollinator Osmia bicornis highlights the need for risk mitigation. Crucially, CPW showed negligible phytotoxicity on crops but selectively reduced weed germination by up to 25%, supported biochemically by its non-inhibition of plant defense CYP74 enzymes. In conclusion, CPW extract is a promising bioactive candidate for sustainable crop protection, requiring formulation optimization to enhance field safety and performance. Full article

Polyphenols are natural compounds with antioxidant properties that help prevent chronic diseases. Red onion (Allium cepa) peels are an underutilized source of polyphenols, offering a sustainable opportunity for the valorization of agricultural by-products. Polyphenol-rich extracts were obtained from red onion peels using subcritical water extraction and adsorption resin chromatography. Their biological effects were evaluated in Caenorhabditis elegans under oxidative stress conditions. A multi-omics approach integrating transcriptomics, metabolomics, and lipidomics was applied to assess molecular responses. The extract exhibited a high total phenolic content (>400 mg GAE/g) and strong antioxidant capacity, supporting a highly enriched polyphenolic profile. Survival assays confirmed the absence of toxicity at 100 µg/mL GAE. Transcriptomic analysis revealed 158 differentially expressed genes associated with stress response and metabolic regulation. Metabolomic profiling indicated a systematic reduction in amino acid levels alongside an increase in betaine in treated worms, suggesting adaptive metabolic reprogramming. Lipidomic analysis revealed significant lipid remodeling, characterized by decreased triglycerides, increased diacylglycerols, and changes in membrane phospholipids, indicating alterations in membrane composition and cellular responses associated with oxidative stress adaptation. Together, these results support a model in which red onion peel extracts induce coordinated transcriptional and metabolic adaptations associated with cellular resilience and stress adaptation. This study highlights the potential of agro-industrial by-products as functional bioactive ingredients and demonstrates the value of multi-omics approaches for uncovering system-level responses. Full article

Grape pomace (GP) is the main residue of the winemaking process; it is rich in phenolics with great bioactive potential. This study applied subcritical water extraction (SWE) to GP at 120, 140, and 160 °C to fractionate it into value-added products. The extraction performed at 120 °C and 1.3 bar (E-120) was the most efficient, resulting in the highest soluble fraction yield (61 g/100 g GP) with high phenolic content (4.1 g GAE (gallic acid equivalent)/100 g extract solids) and strong antioxidant capacity (EC₅₀: 0.79 mg extract/mg DPPH (2,2-Diphenyl-1-picrylhydrazyl)), while it inhibited the growth of Listeria innocua at 325 mg/mL. The insoluble extraction residue (38 g/100 g GP) also retained substantial phenolic content (10 g GAE/100 g), with high antioxidant activity (EC₅₀: 1.5 mg residue/mg DPPH) and a fibre-rich composition, supporting its value as a functional ingredient. To improve handling and stability, the E-120 extract was encapsulated in maltodextrin or pectin. For both polymers, a 40% polymer ratio with respect to the extract solids yielded a stable, single-phase, glassy powder (T_g ~50 °C), with thermal stability extending up to 200 °C. Therefore, SWE constitutes an efficient and sustainable technique for obtaining functional ingredients from GP, allowing for its valorisation. Full article

This study investigates subcritical water extraction (SWE) as an alternative to hydroalcoholic extraction for the production of Echinacea purpurea root extracts standardized to hydroxycinnamic acids (cichoric and caftaric acids). Extractions were performed at 100 °C, 125 °C, 150 °C, and 170 °C for 10–30 min. The recovery of cichoric and caftaric acids was significantly (p < 0.05) influenced by extraction temperature, with the highest values obtained within the range of 100–125 °C. Further experiments identified 110 °C for 10 min as the optimal condition, yielding the highest cumulative recovery of cichoric and caftaric acids (1.87 ± 0.10% of dry material). In the resulting dry extracts, SWE at 100–125 °C produced hydroxycinnamic acid contents of 5.5–7.1%, whereas the total dry extract yield in-creased from 24–28% at 100 °C to 40–41% at 150–170 °C (p < 0.05). Higher temperatures, however, reduced cichoric and caftaric acid cumulative content to 0.6–1.7% (p < 0.05), indicating a degradation of the target compounds. In contrast, total polyphenol recovery in-creased continuously with temperature, reaching 4.86% at 170 °C for 30 min. This was accompanied by marked increases in rutin, gallic and caffeic acid, reaching 458.5 mg/100 g dry weight (DW), 175.5 mg/100 g DW and 945.7 mg/100 g DW (p < 0.05), respectively, suggesting the release of bound phenolics following partial disruption of plant cell wall structures. SWE also enhanced the extraction of carbohydrates, uronic acids, fructans, proteins and organic acids, demonstrating an extensive temperature-dependent modification of the root matrix. 5-HMF was not detected in extracts obtained below 125 °C, but increased progressively at higher temperatures, reaching 200 mg/100 g (p < 0.05) at 170 °C. Biological evaluation in the human colorectal adenocarcinoma cell line (HT29) showed favorable cytocompatibility of SWE extracts, confirmed by cell viability, morphological assessment and low DNA damage in the Comet Assay. Overall, SWE enables the production of cichoric and caftaric acid-standardized E. purpurea extracts without organic solvents, supporting its application in pharmaceutical, nutraceutical, food and cosmeceutical products. Full article

Hydrodynamic cavitation is assessed as a conditional process-intensification platform for the sustainable recovery and transformation of bioactive and functional fractions from agri-food residues, food-processing by-products, and plant-derived matrices. The analysis focuses on fractions enriched in polyphenols, flavonoids, pectins, carotenoids, proteins, pigments, essential oils, and other value-added compounds with potential relevance for food, nutraceutical, formulation-oriented, and related high-value applications. Rather than being considered an inherently green or universally superior technology, hydrodynamic cavitation is evaluated according to the specific process functions it can provide, including matrix disruption, mass-transfer enhancement, solvent-use reduction, recovery of pectin-associated fractions, protein extraction, macromolecular restructuring, dispersion, and process integration. Quantitative and scale-relevant indicators are considered where available, including recovery yield, target-compound content, solvent use, operating conditions, treated volume, energy input, fraction quality, and reporting limits. Comparison with ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric fields, subcritical water extraction, natural deep eutectic solvents, and enzyme-assisted extraction indicates that its advantage is most defensible when hydrodynamic effects address a clearly identified matrix or process limitation. The available evidence supports substantial potential for wet matrices, plant by-products, aqueous suspensions, and liquid food systems. However, critical gaps remain in energy reporting, selectivity, recovered-fraction stability, scale-up, downstream processing, and application-oriented validation. Recovered fractions should therefore be regarded as candidate ingredients or functional intermediates, rather than as direct evidence of efficacy in final products. Full article

Grape bagasse is an abundant agro-industrial by-product and an important source of phenolic compounds with antioxidant properties. This study evaluated Soxhlet extraction, supercritical fluid extraction (SFE), pressurized liquid extraction (PLE), subcritical water extraction (SWE), and sequential extraction strategies for recovering bioactive compounds from grape bagasse. Box–Behnken designs were applied to SFE and PLE to evaluate process effects on extraction yield, while total phenolic content (TPC), total anthocyanin content (TAC), and antioxidant activity (ABTS) were additionally determined for PLE extracts. Hydroethanolic extractions showed greater selectivity toward phenolic compounds, whereas water-based extractions promoted higher yields associated with additional polar constituents. In SWE, increasing temperature enhanced extraction yield and phenolic recovery, although anthocyanin contents decreased under more severe thermal conditions. SWE provided higher extraction yields than PLE with comparable phenolic content and antioxidant activity, suggesting the recovery of additional highly polar non-phenolic compounds, whereas PLE resulted in higher extraction yields than SFE. Sequential extraction demonstrated that the first step accounted for most of the phenolic recovery and antioxidant activity, while the second aqueous step increased overall extraction yield. The sequential PLE–SWE route resulted in the highest TPC (198.0 mg GAE g⁻¹) and antioxidant activity (2321 μmol TE g⁻¹), demonstrating the potential of sequential extraction for grape bagasse fractionation and valorization. Full article

The introduction of sustainable practices into waste management can have a favorable environmental impact, increase resource value, and yield economic gains. Hydrothermal technologies have strong potential for the production of up-cycled ingredients from biowaste (amino acids, sugars, phenols, pharmacologically active compounds, etc.), enabling high energy recovery (50–80%) from biowaste with net-negative carbon emissions. This review discusses the use of subcritical and supercritical water technologies for sustainable valorization of biowaste and conversion of biomass into high-value chemicals and biofuels. The potential for the extraction/generation of bioactive compounds from plant and animal waste is presented, emphasizing the efficiency, compound stability, and bioactivity of the fractions obtained. The possibilities of simultaneous extraction of added-value compounds and hydrolysis of feedstock biopolymers by these technologies are elaborated. The review further addresses the production of biofuels through hydrothermal carbonization for solid fuels, hydrothermal waste liquefaction for liquid fuels, and supercritical water gasification for gaseous fuels. The paper highlights the environmental and economic advantages of technologies based on sub- and supercritical water over conventional chemical and fermentative routes, emphasizing their contribution to a circular bioeconomy by converting biowaste into value-added products and sustainable energy sources. Full article

Rice straw is a highly produced agricultural waste with a high cellulose content, which can be used as a cellulose source. Nevertheless, more sustainable extraction and purification strategies are needed to reduce the consumption of chemicals during the production of cellulose-derived materials. In this way, an integrated method based on subcritical water extraction and bleaching with hydrogen peroxide was used for isolating cellulose from rice straw. The cellulose fibres obtained were converted into microcrystalline cellulose (MCC) by applying acid hydrolysis with HCl 2N at 60 °C to reduce the fibre amorphous fraction. High cellulose purity (86%) and crystallinity (67%) were obtained in the isolated fibres. The influence of high-shear homogenisation (12,000 rpm) during hydrolysis was analysed, compared to mild stirring (350 rpm) at different times (30 and 60 min). High-shear homogenisation greatly accelerated the hydrolysis process of the amorphous fraction of the fibres, contributing to the reduction in particle size (to about 10 µm), defibration, increased crystallinity (70–72%), and shorter cellulose chains (92,400–61,600 g/mol) for a given treatment time. After 30–60 min of treatment, the resulting MCCs exhibited properties within the range reported for commercial AVICEL, with greater reinforcing performance in PHBV films. These MCCs resulted in lower water vapour permeability, while improved oxygen barrier properties were mainly observed for those obtained under high-shear hydrolysis conditions. Full article

Subcritical water extraction (SWE) is an eco-friendly and efficient technique for isolating bioactive ingredients from natural products. To improve the extraction yield of Artemisia argyi leaf polysaccharides (AAPs), a three-stage hybrid optimization strategy combining single-factor experiments, response surface methodology (RSM), neural network (NN), and direct search algorithm (DSA) was proposed. Single-factor experiments were used to screen key parameters. A Box–Behnken design (BBD)-based RSM was applied for preliminary optimization. A {3, 5, 1} structured NN was trained using 63 datasets from RSM, and DSA was used to determine the globally optimal process parameters. The optimal conditions were obtained as follows: extraction time 17.72 min, liquid-to-solid ratio 92.83 mL/g, extraction temperature 123.35 °C, stirring speed 1800 r/min, and natural pH. Under these conditions, the experimental AAP extraction yield reached 6.99%, with a relative error of only 1.16% compared with the predicted value of 6.91%. Fourier transform infrared (FT-IR) spectroscopy confirmed that the product exhibited typical polysaccharide structural characteristics. The integrated RSM–NN–DSA framework provides a reliable and high-precision approach for optimizing SWE of plant polysaccharides, showing good potential for industrial applications. Full article

Globe artichoke (Cynara scolymus) processing generates large amounts of agro-industrial waste, including stems, leaves, and bracts. These by-products represent a valuable and underexplored source of bioactive compounds, particularly phenolic acids, flavonoids, pectin, and inulin, which exhibit significant nutritional, health-promoting, and functional properties. This review provides a comprehensive overview of green extraction strategies applied to the recovery of bioactive compounds from globe artichoke waste, with emphasis on green extraction techniques such as deep eutectic solvent, ultrasound-assisted, microwave-assisted, enzyme-assisted, subcritical water, supercritical CO₂, and the use of green solvents. Nutritional composition and biological activities, including antioxidant, antimicrobial, anti-inflammatory, hypolipidemic, and hepatoprotective effects of artichoke waste extracts, are critically discussed. Given the inherent instability and limited bioavailability of many phenolic compounds, recent advances in encapsulation and stabilisation approaches, alginate-based systems, spray-drying, and nano and microencapsulation technologies are highlighted as effective strategies to enhance shelf life and controlled release. The valorisation of globe artichoke waste through green extraction and encapsulation of bioactive compounds contributes to circular economy principles by reducing environmental impact while adding value. Overall, the promising role of artichoke by-products as sustainable resources for functional food development is discussed. Full article

Annatto (Bixa orellana L.) seed by-products (ASBs), generated after industrial pigment extraction, remain a largely underexplored source of bioactive compounds, including residual carotenoids, phenolics, and proteins. This study compares three extraction strategies—maceration (ME), ultrasound-assisted extraction (UAE), and subcritical water extraction (SWE)—for the recovery of these compounds from ASB within a green processing framework. Extraction efficiency was assessed based on the yield, protein recovery, total carotenoid content (TCC), total phenolic content (TPC), antioxidant capacity (DPPH, ABTS, FRAP), and phenolic profile (HPLC-DAD). SWE at 140 °C (40 bar, 1:30 g/mL) achieved the highest extraction yields and compound recovery (proteins: 80.0 ± 3.22 mg/g extract; TCC expressed as bixin equivalents: 1.60 ± 0.07 mg/g extract; TPC: 17.96 ± 0.90 mg GAE/g extract). Phenolic profiling identified gallic and protocatechuic acids as major constituents, with significantly higher concentrations in SWE extracts. However, discrepancies between spectrophotometric and chromatographic data suggest the presence of unidentified phenolics. Cytotoxicity assays using Caco-2 cells indicated no significant effects at concentrations up to 10 µg/mL. While SWE demonstrates superior extraction performance, further studies on protein functionality, pigment stability, and bioavailability are required to validate food and nutraceutical applications. This work highlights ASB as a promising resource for circular bioeconomy strategies. Full article

In the context of the circular economy, the valorization of natural biomolecules from by-products has recently represented a major goal in health promotion. From this perspective, this study examined the antioxidant potential of Sicilian white grape pomace from the Pinot Gris variety, using subcritical water extraction as an eco-friendly and innovative method to recover bioactive compounds. Different extraction parameters allowed for comparing the potential of various fractions. Among these, the Subcritical Water Extract obtained after 5 min at 160 °C (SWE^160.1) was rich in gallic acid and protocatechuic acid, as evidenced by characterization with UHPLC-Q Exactive Orbitrap-HRMS system. SWE^160.1 showed efficacious antioxidant activity, as confirmed by DPPH assay and total polyphenol and flavonoid content. Interestingly, SWE^160.1 displayed cytotoxic activity in tumor cell lines, while preserving the viability of non-tumor bronchial epithelial cells. Specifically, SWE^160.1 protected these cells from exogenous oxidative stress, reducing the ROS levels and activating Nrf2-mediated antioxidant response. Surprisingly, upregulation of antioxidant enzymes (HO-1 and SOD-2) induced by SWE^160.1 was maintained in the presence of lipopolysaccharide, indicating a specific involvement of SWE^160.1 in the anti-inflammatory response. Finally, SWE^160.1 was also able to limit the formation of stress granules following acute stress, thereby supporting its potential to maintain cellular homeostasis. Overall, this study highlights the potential of grape pomace as a source of active molecules to prevent oxidative stress and inflammation. Full article

Grape pomace, the main solid by-product of winemaking, is a promising feedstock for the recovery of trans-resveratrol, a high-value stilbene of increasing interest for food, nutraceutical, and pharmaceutical applications. However, its efficient isolation remains challenging because of matrix complexity, the co-occurrence of structurally related stilbenes and polyphenols, and the chemical instability of trans-resveratrol. This review critically examines recent advances in the recovery of trans-resveratrol from grape pomace, while also incorporating relevant findings from other grapevine-derived matrices to distinguish matrix-specific recovery potential and to place grape pomace within the broader context of grapevine by-product valorization from extraction intensification and selective purification to analytical determination. Various extraction technologies, including ultrasound-, microwave-, and enzyme-assisted extraction, natural deep eutectic solvents, and subcritical water extraction, are assessed alongside conventional solvent extraction with emphasis on yield, selectivity, solvent compatibility, and process feasibility. Downstream separation methods such as liquid–liquid partitioning, solid-phase isolation, adsorbent resins, counter-current chromatography, molecularly imprinted polymers, and foam fractionation are compared in terms of selectivity, enrichment efficiency, solvent demand, and scale-up potential. Although significant progress has been achieved, major challenges remain regarding process integration, solvent sustainability, product stability, and industrial feasibility. Combining mild extraction with selective downstream purification is essential for producing stable, high-purity trans-resveratrol fractions suitable for future use in functional ingredients, natural preservation strategies, and other value-added applications within sustainable food systems. Full article