Search Results (160)

Brewer’s spent grain (BSG), the main by-product of the brewing industry, is an abundant lignocellulosic residue that remains underused. In this study, antioxidant-rich extracts were obtained from BSG using pressurized liquid extraction (PLE) and subsequently incorporated into thermoplastic starch (TPS) films for sustainable food packaging applications. The phenolic profile analysis revealed 13 compounds, with caffeic acid and its hexoside as the most abundant. Extraction conditions were optimized using response surface methodology (RSM) to maximize yield and total phenolic content, showing that temperature had a significant positive effect. The selected extract had a total phenolic content of 3.19 mg/g dw and exhibited notable antioxidant activity. It was then incorporated into the polymer matrix, and the resulting films were analyzed for their structural, thermal, and antioxidant properties. The incorporation of BSG extracts improved the film antioxidant activity. Additionally, the release of phenolic compounds was evaluated and successfully described using a diffusion model based on Fick’s law, which allowed the calculation of a diffusion coefficient D = 2.63 × 10⁻⁸ cm²/s. Overall, the findings indicate that BSG-based extracts may represent promising functional additives for biodegradable polymer films, and the developed TPS films serve as proof-of-concept active packaging materials from renewable agro-industrial residues. Full article

Babassu (Attalea speciosa) is one of the most abundant palm species in the Brazilian Amazon and an important unconventional crop, playing a key socioeconomic role due to the commercial exploitation of its oil-rich almonds. However, approximately 90–93% of the fruit biomass—mainly mesocarp, epicarp, and endocarp—is generated as underutilized residue. This systematic review aims to analyze extraction methods, phytochemical composition, and antioxidant capacity of bioactive compounds derived from different babassu fractions. Following PRISMA guidelines, searches of five databases (Embase, ScienceDirect, Scopus, PubMed, and Web of Science) retrieved 410 records, of which 23 met the inclusion criteria. The results show that, although research has predominantly focused on the almond fraction, non-edible parts contain significant levels of phenolic compounds, flavonoids, phytosterols, and other bioactive metabolites with antioxidant properties. Green and non-thermal extraction technologies, such as ultrasound-assisted extraction (UAE), supercritical CO₂ extraction (SC-CO₂), and pressurized liquid extraction (PLE), demonstrated advantages in improving extraction efficiency while reducing solvent consumption and thermal degradation. Overall, the available evidence indicates that babassu residues represent a promising and still underexplored source of bioactive compounds. Their valorization may contribute to sustainable extraction strategies, waste reduction, and the development of value-added products within agricultural and bioeconomic systems. Full article

Rapeseed press cake (RPC), the protein-rich residue from edible oil production, is currently underutilized and is primarily used as animal feed. This study aimed to investigate pressurized liquid extraction (PLE) for protein recovery from RPC using response surface methodology (RSM) with precipitation yield (PY) as the response variable. Following alkaline extraction, proteins were precipitated at their isoelectric point, and solid residues were freeze-dried to obtain protein powders. Conventional extraction (CE) under magnetic stirring at room temperature was used as a reference. The results demonstrated that increasing pH from 8 to 11 significantly enhanced protein extraction efficiency for both methods. PLE exhibited superior performance, achieving higher PY compared to CE while drastically reducing extraction time from 120 min (CE) to 6 min (PLE). Optimal conditions were identified at a solid-to-liquid ratio of 0.10 g/mL, 150 °C, and 6 min, yielding a PY of 14.9%, protein recovery in extract (PR_E) of 43.8%, and protein recovery in precipitated mass (PR_P) of 20.0%, with a protein content (PC_P) of 647.2 mg albumin eq./g. RSM analysis identified extraction temperature as the most critical parameter for PLE, highlighting its dominant role in mass transfer. Finally, amino acid (AA) analysis revealed that protein powders were rich in essential AAs, with glutamic and aspartic acids being the most abundant. Additionally, PLE-derived protein powders exhibited enhanced solubility. This study confirms PLE as a highly promising and time-efficient technique for protein recovery from RPC, supporting the potential of sustainable valorization of agro-industrial by-products and promoting a circular economy model within the food industry. Full article

Olive pomace (OP) has been widely reported as a rich source of phenolic compounds with potential application as food additives with health-promoting properties. The aim of this work was to evaluate pressurized liquid extraction (PLE) as a strategy to obtain antioxidant and antimicrobial extracts from OP. Extractions were carried out in laboratory-scale equipment following a combined static/dynamic procedure. The extraction temperature (100, 120 and 140 °C) and the composition of solvent (50, 75 and 100% ethanol in water) were studied as independent variables of the process using a Face Centered Central Composite Design (α = 1). According to the fitted quadratic model (p < 0.05), the maximum Total Phenol Content (TPC) and Trolox Equivalent Antioxidant Capacity (TEAC) values were obtained at 120 °C using ethanol concentrations between 60 and 80%. Chemical characterization by RP/HPLC-Q-TOF MS/MS allowed the tentative identification of 37 compounds, with quinic acid being the most abundant compound under all extraction conditions, followed by elenolic acid, dimethyl-hydroxy-verbascoside, maslinic acid, hydroxy-verbascoside and oleuropein aglycone. Other secoiridoids, secoridoid derivatives, flavonoids, simple phenols and triterpenic acids were also identified. The extract obtained at 120 °C with 75% ethanol was able to protect purified sunflower oil in an accelerated oxidative stability test (Rancimat), increasing its induction period by 2.4-fold when added at 1000 mg/kg. This extract also exhibited antimicrobial activity against S. aureus, B. cereus, S. enterica and S. sonnei with a Minimum Inhibitory Concentration (MIC) of 3.6 mg/mL. These results highlight the potential of PLE olive pomace extracts as natural preservatives for food applications. Full article

Artichoke by-products (ABP) represent valuable sources of bioactive compounds with relevant health benefits. In this study, a green extraction strategy based on pressurized liquid extraction (PLE) was optimized to enhance the recovery of phenolic and flavonoid compounds from ABP using a response surface methodology. Extraction temperature and solvent composition were identified as the key factors driving extraction performance. Optimal conditions using a mixture of ethyl acetate and ethanol (90/10, v/v) at 180 °C significantly enhanced extraction yield, total phenolic and flavonoid content, and antioxidant activities, as measured by ORAC and DPPH assays. Chemical characterization via HPLC-C18-Q-TOF-MS/MS revealed a diverse profile of phenolic and flavonoid compounds, including caffeoylquinic acid derivatives and related transformation products. The neuroprotective potential of the optimized extract was further evaluated through in vitro inhibition assays targeting acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and lipoxygenase (LOX), alongside a permeability assessment using an in vitro blood–brain barrier (BBB) model. Molecular docking simulations were performed to explore the interactions of apigenin—the most representative flavonoid in the optimal extract—with the three target enzymes. Overall, these findings support the valorization of ABP as a source of bioactive compounds and highlight the potential of PLE as an efficient and sustainable extraction approach. Full article

Pterospartum tridentatum (L.) Willk. (carqueja) is widely used in traditional medicine and culinary practices in the Iberian Peninsula; however, most studies have focused on its flowers, while its stems remain largely unexplored, despite representing a significant proportion of the plant biomass. This study aimed to evaluate the potential of P. tridentatum stems as a source of bioactive compounds using different extraction methodologies. Aqueous, hydroethanolic, ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were applied, and the resulting extracts were characterized in terms of their extraction yield, protein and carbohydrate content, phenolic composition, antioxidant capacity, antimicrobial activity, and cytotoxicity in HaCaT and Caco-2 cell lines. Phenolic profiling by LC-ESI-QqTOF-HRMS tentatively identified 37 compounds, mainly corresponding to flavonoid and isoflavonoid glycosides, with genistein derivatives representing the dominant constituents across all extracts. Although extraction yields differed among methods, phenolic profiles were broadly similar. UAE and PLE extracts showed slightly higher antioxidant activity, while antimicrobial activity was limited, with only moderate inhibition observed against Staphylococcus epidermidis and Malassezia furfur. Additionally, cytotoxicity assays indicated low toxicity. Overall, the results demonstrate that P. tridentatum stems represent a promising yet underutilized biomass source of phenolic compounds with antioxidant potential and low cytotoxicity under the tested in vitro conditions. Full article

The exponential growth of the fruit-processing industry generates significant quantities of organic by-products, such as peels, seeds, and pomace, which represent a rich but underutilized source of bioactive polyphenols. Valorizing these residues is critical for the transition toward a circular bioeconomy, yet conventional extraction methods remain solvent-intensive and kinetically inefficient. This review provides a comprehensive analysis of emerging green extraction technologies, specifically Ultrasound-Assisted (UAE), Microwave-Assisted (MAE), Enzyme-Assisted (EAE), Pressurized Liquid (PLE), and Supercritical Fluid Extraction (SFE), and Pulsed Electric Field (PEF), applied to key industrial matrices including apple, citrus, grape, olive, and coffee. Comparative data demonstrate that intensification technologies significantly outperform conventional maceration, with UAE and MAE reducing processing times by up to 90% while enhancing polyphenol yields by 20–55% through mechanisms such as acoustic cavitation and dipole rotation. Furthermore, high-pressure methods exhibit tunable selectivity, enabling the specific recovery of heat-sensitive anthocyanins and bound phenolics without the use of toxic organic solvents. The study concludes that the future of industrial valorization lies in the adoption of hybrid technologies and sequential biorefinery strategies to achieve high-purity isolates with minimal environmental impact. Full article

Soybean husk (SH), a major processing by-product, is a rich source of fiber and antioxidants. This study characterized SH and optimized bioactive compound recovery using green technologies: ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE). Raw SH contained high fiber (67.98%) and moderate protein (10.56%). Experimental designs evaluated temperature, power, and solvent composition (EtOH/H₂O). In UAE, yield increased with longer time and 50% ethanol. However, PLE significantly outperformed UAE; optimal conditions (140 °C, 50% EtOH) yielded 19.97% extract, with 17.1 mg GAE/g total phenolics and 167.6 µmol TE/g antioxidant capacity. Isoflavone profiling identified daidzin, genistin, and their malonyl/acetyl derivatives as predominant. The optimal extract and raw SH were incorporated into scone formulations to evaluate functional potential. Results showed that scones containing extract (alone or with SH) exhibited significantly higher phenolic content and antioxidant activity (≈36 µmol Trolox/g) than controls. SH addition increased dietary fiber, qualifying the product as a “source of fiber” under current regulations. This research demonstrates that SH valorization through PLE enhances the nutritional and functional quality of bakery products. Full article

This study used high-pressure extraction to obtain antioxidant-rich fractions from Desmodium canadense leaves harvested at five vegetation phases (intensive growing to end of blooming) and to evaluate their antioxidant activity and phytochemical profile. Supercritical CO₂ extraction recovered lipophilic compounds, with the highest yield at massive flowering. The remaining plant material was fractionated by pressurized liquid extraction (PLE) using acetone, ethanol, and water; the highest PLE yield was achieved with water (16.54 g/100 g DW) at the bud formation stage. Antioxidant capacity was measured using total phenolic content (TPC) and ABTS^•+, CUPRAC, and ORAC assays. Overall, ethanol PLE extracts showed the strongest antioxidant properties: maximum TPC (282.1 mg GAE/gE) and ABTS^•+ (1010 mg TE/gE) at massive flowering, and highest CUPRAC (853.3 mg TE/gE) and ORAC (1882 mg TE/gE) at bud formation. UPLC-Q-TOF-MS/MS profiling identified 37 compounds, mainly C-glycosyl flavones, flavonol O-glycosides, hydroxycinnamic acid derivatives, and low molecular weight organic acids. Water extracts were rich in low molecular weight organic acids, while acetone and ethanol extracts contained the highest flavonoid levels. Citric acid and vitexin were the most abundant compounds. The findings indicate that D. canadense leaves, especially harvested at budding through massive flowering, are a promising source of flavonoid-rich antioxidant extracts for nutraceutical and functional food applications. Full article

Grape stems are undervalued winemaking by-products that constitute a promising source of bioactive phenolics with notable antioxidant potential and diverse industrial applications, including food preservation, cosmetics, and pharmaceuticals. Effective valorisation of this resource requires not only efficient extraction strategies, but also the strategic selection of grape stem varieties to tailor phenolic profiles for specific high-value uses. In this study, a comparative assessment of three extraction techniques, pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), and conventional solid–liquid extraction (SLE), across six grape stem varieties was conducted. By integrating spectrophotometric analyses of total phenolics and antioxidant capacity with HPLC-DAD profiling of individual phenolic compounds, the combined influence of extraction method and varietal composition on phenolic recovery was demonstrated. PLE and UAE significantly enhanced both yield and antioxidant capacity relative to SLE, with PLE providing the broadest spectrum of phenolic compounds. Varietal differences were also pronounced; e.g., Cabernet Sauvignon stems yielded higher antioxidant phenolic compound content, particularly under UAE, reinforcing the importance of aligning extraction technique and stem variety with the intended functional application. Full article

Inonotus obliquus (Chaga) is a medicinal basidiomycete fungus with diverse bioactive compounds and pharmacological properties. This study systematically compared green extraction techniques: maceration, ultrasound-assisted extraction (UAE), and combined supercritical CO₂-pressurized liquid extraction (ScCO₂-PLE), using solvents of varying polarity (water, 50%, and 70% ethanol). Chaga extracts were analyzed for phytochemical composition (HPLC-Orbitrap Exploris 120) and antioxidant activity toward DPPH and hydroxyl (^•OH) radicals using EPR spectroscopy. The results revealed that both solvent polarity and extraction technique significantly influenced extraction efficiency and antioxidant potential. The UAE extraction method achieved the highest overall recovery of phenolic and triterpenoid compounds, with extracts obtained using 50% and 70% ethanol exhibiting the most pronounced and well-balanced radical scavenging activity (>98% toward DPPH, >91% toward ^•OH). Correlation and PCA analyses identified phenolic and triterpenoid compounds, including fungal-specific polyphenols such as hispidin and hispolon, as key contributors to antioxidant activity. Among the extracts obtained using different solvents, the extracts with the highest overall antioxidant potential were encapsulated into liposomes and evaluated for their DPPH and ^•OH radical scavenging. Encapsulation effectively preserved the antioxidant activity of ethanol-derived extracts, demonstrating that Chaga liposomes can maintain bioactivity while offering the advantages of controlled delivery. Combining optimized extraction with liposomal encapsulation thus represents a promising strategy to enhance the stability and practical applicability of Chaga antioxidants in nutraceutical or therapeutic contexts. Full article

Isabella grape pomace (IGP) the primary by-product of Colombia’s winemaking industry, represents a promising source of nutraceuticals with potential uses in the food industry. This study developed a sequential green extraction process to recover nutraceutical from IGP. The approach integrated supercritical fluid extraction with CO₂ (SFE-CO₂) to obtain lipophilic compounds, followed by SFE with ethanol/water as co-solvent (SFE-CO₂/EtOH:H₂O) for medium-polarity phenolics, and pressurized liquid extraction (PLE) with EtOH:H₂O to recover the polar phenolic-rich fraction. The extraction parameters were optimized using response surface methodology, and optimal conditions were identified: SFE-CO₂ at 31.7 MPa/58.9 °C yielded 6.95% extract rich in linoleic acid (65.5%) and α-tocopherol (107.2 mg/kg); SFE-CO₂/EtOH:H₂O with 15% of co-solvent produced extracts with high phenolic content (105.35 mg GAE/g) and antioxidant activity (0.18 mmol TE/g); while PLE at 58.91% of EtOH/107.98 °C achieved notable recovery of flavonoids (757.18 mg QE/g), anthocyanins(1508 μg MAE/g) and condensed tannins (258.39 mg ECE/g), with potent antioxidant capacity (130.40 mmol TE/g). The sequential process demonstrated synergistic effects, with a total cumulative yield of 41.08% and phenolic recovery of 349.89 mg GAE/g extract. This approach offers a sustainable biorefinery approach for transforming IGP into high-value nutraceutical ingredients. Full article

Agri-food residues have accumulated globally at unprecedented scales, generating environmental pressures and resource inefficiencies, a core problem addressed in this review, while simultaneously representing rich, underutilized reservoirs of health-promoting phytochemicals. This review synthesizes recent advances (2016–2025) in the green extraction, characterization, and biological validation of phytochemicals from plant-based residues, including polyphenols, flavonoids, carotenoids, alkaloids, and dietary fibers from key sources such as grape pomace, citrus peels, coffee silverskin, pomegranate peel, cereal brans, and tropical fruit by-products. Emphasis is placed on sustainable extraction methods: ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), pressurized liquid extraction (PLE), supercritical CO₂ extraction (SFE), and natural deep eutectic solvents (NADES), which enable efficient recovery while minimizing environmental impact. In vitro, in vivo, and clinical studies demonstrate that residue-derived compounds exert antioxidant, anti-inflammatory, metabolic-regulating, and prebiotic effects, contributing to health in general and gut microbiota modulation. Integrating these bioactives into functional foods and nutraceuticals supports sustainable nutrition and circular bioeconomy goals by reducing food waste and promoting health-oriented valorization. Regulatory advances, including approvals from the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA) for ingredients such as olive phenolics, citrus flavanones, and coffee cascara, further illustrate increasing translational readiness. The convergence of green chemistry, biorefinery design, and nutritional science positions agri-food residues as pivotal resources for future health-promoting and environmentally responsible diets. Remaining challenges include scaling cost-effective green processes, harmonizing life cycle assessment protocols, expanding toxicological datasets, and conducting longer-term clinical trials to support safe and evidence-based commercialization. Full article

While numerous extraction methods have been applied to the brown algae Saccharina latissima, a systematic evaluation of how individual extraction parameters influence the extraction of each target polysaccharide has not previously been reported. Accordingly, this study compared conventional and advanced techniques for extracting fucoidan, laminarin, and alginate from pre-treated biomass. Conventional methods employed diluted acid (0.01 M and 0.1 M HCl), diluted alkali (0.01 M and 0.1 M NaOH), and hot water (121 °C for 30/60 min) for extraction. Advanced techniques involved pressurized liquid extraction (PLE) using water and moderate electric field (MEF) extraction with conditions optimized by statistical experimental design. Pre-treatment with aqueous ethanol removed 30% ash and eliminated mannitol, improving extraction selectivity. The results demonstrated fucoidan yields of 31% with 0.01 M HCl and 46% with 0.1 M NaOH, while 0.01 M NaOH facilitated laminarin co-extraction (45%). Alginate, as a mannuronic acid polymer, was obtained at 9% yield with 0.1 M HCl, 42% yield with 0.1 M NaOH, and 27% with pressurized hot water for 30 min. High-temperature, short-duration PLE further improved alginate yield, while MEF showed limited gains due to high ionic content but demonstrated potential under optimized settings. The results support a cascading biorefinery approach in which different polysaccharide fractions can be sequentially obtained, contributing to more sustainable seaweed valorization. Full article

The rising amount of food industry waste has sparked interest in its valorization as a source of bioactive compounds. This study combines bibliometric analysis and a systematic review to map the scientific literature on the recovery of bioactive compounds from food byproducts, focusing on green extraction strategies and their alignment with the principles of the circular economy. A total of 176 documents, published between 2015 and 2025, were analyzed. The analysis shows significant growth after 2020 and highlights bioactive compounds, extraction, and the circular economy as the primary research themes. Italy, Spain, and Brazil emerged as the leading countries in scientific production. The systematic review covers green extraction techniques, including ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), pressurized liquid extraction (PLE), supercritical fluid extraction (SFE), enzyme-assisted extraction (EAE), and natural deep eutectic solvent extraction (NADES). UAE- and NADES-based processes were the most frequently applied extraction techniques, mainly targeting phenolic compounds and flavonoids. Significant progress has been observed, particularly in the advancement of extraction technologies, in the recovery of key bioactive compounds, and in their industrial applications. These methods recover phenolics, flavonoids, anthocyanins, and other compounds with antioxidant, antimicrobial, and cardioprotective properties, which have potential applications in functional foods, nutraceuticals, pharmaceuticals, cosmetics, and biodegradable packaging. Nutraceuticals and functional foods represent the main application areas, followed by cosmetics and pharmaceuticals. Despite progress, challenges remain, including scalability, equipment costs, solvent recovery, and process standardization. The green extraction of bioactive compounds from food byproducts shows promise and can support the goals of the 2030 Agenda. Full article