Search Results (51)

The valorization of agri-food residues is crucial for advancing circular bioeconomy strategies and mitigating environmental impacts. Turnip greens (Brassica rapa subsp. sylvestris) are a traditional vegetable cultivated in southern Italy. While the edible portions include flower sprouts, buds, and young leaves, the more leathery leaves and stems are typically discarded. These wastes represent valuable sources of compounds with antioxidant and antimicrobial potential. This study aims to develop the extraction of phenolic compounds from turnip green residues using two techniques: silent maceration and ultrasound-assisted extraction (UAE). Ethanol was selected over methanol as a food-safe alternative solvent, with preliminary tests confirming equivalent efficiency. A Design of Experiments (DoE) approach was applied to both leaves and stems to assess the effects of solvent composition, solvent-to-matrix ratio, and extraction time on Total Phenolic Content and Trolox Equivalent Antioxidant Capacity. DoE results identified UAE as the most effective method for stems, while for leaves, the solvent-to-dry-mass ratio was the key parameter. HPLC-DAD analysis was performed to identify and quantify the phenolic acids in selected extracts. The antibacterial activity of these extracts against biofilms of six pathogenic strains was evaluated using crystal violet and MTT assays, confirming efficacy in both biofilm formation and mature stages. Full article

The winemaking industry represents one of the most important sectors of the Mediterranean agrifood economy, generating large amounts of solid residues, especially grape pomace. The study aimed to evaluate during two consecutive harvest years the influence of the production system (conventional vs. organic) and cultivar on the mineral, chemical, and antioxidant composition, as well as the colorimetric properties, of grape pomaces obtained from four Vitis vinifera L. cultivars in Alentejo-Portugal. The results showed that mineral composition was significantly affected by both production system and cultivar, with organic grape pomace showing higher K and Mn contents, whereas Ca and Cu showed consistently higher content under conventional. Protein content tended to increase under organic production, while fiber and fat were overall higher in conventional, particularly in the first year. Sugars displayed strong cultivar specificity, with Arinto showing the highest concentrations (30 to 40%), and considering all cultivars, total phenolic content ranged between 4000 ando 9000 mg GAE/100 g, while antioxidant capacity varied among cultivars and years. Colorimetric parameters were essentially influenced by cultivar and harvest year rather than production system. The PCA revealed that PC1 (44.06%) represented a gradient associated with mineral and antioxidant composition, while PC2 (21.26%) reflected minor variation in color and sugars, and the hierarchical clustering distinguished Syrah and Alicante Bouschet as the cultivars most responsive to production system, whereas Aragonez and Arinto exhibited greater compositional stability across years. Overall, the findings indicate that both cultivar and management practices (organic and conventional) influence the compositional profile of grape pomace, with organic showing a tendency to enhance K, Mn, protein, and antioxidant parameters, whereas conventional practices favored higher levels of Ca, Cu, and fiber. The results provide valuable insights for the valorization of grape pomace and the development of sustainable viticultural strategies in Mediterranean environments. Full article

This study investigates the valorization of two agri-food residues, specifically olive pomace (alperujo, A) and banana peel (B), into efficient N-doped carbon-based catalysts for polluted wastewater treatment. The residues were converted into hydrochar (HA and HB), which were subsequently N-doped using polyethylenimine (PEI) in combination with cross-linkers (glutaraldehyde (GTA) or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)) to optimize their catalytic properties. The enhanced hydrochars were utilized as catalysts for the removal of organic pollutants from water by activation of peroxymonosulfate (PMS). Characterization techniques, including CHNS, FTIR, XPS, SEM and electrochemical analysis, were employed to understand the physicochemical properties of the materials. The catalytic activity was evaluated using Reactive Black 5 (RB5) as a model pollutant, with the N-doped alperujo-derived hydrochar cross-linked with EDC (N-HA-EDC) showing the best performance, achieving 80% removal in 60 min and an adsorption capacity of 97 mg/g. The versatility of this functionalization approach was assessed through tests with three pharmaceuticals, corroborating the adaptability and efficacy of the catalyst and demonstrating its potential for wastewater treatment applications. This study provides insights into the development of sustainable, cost-effective carbocatalysts, aligning with circular economy and zero waste principles. Full article

The agrifood sector produces considerable waste, offering opportunities for sustainable innovation. In the coffee industry, spent coffee grounds (SCG) can be valorized to generate eco-friendly nanomaterials such as nano zerovalent iron (nZVI), widely applied in soil and water remediation. In this study, green nZVIs were synthesized using SCG hydromethanolic extracts and FeCl₃, subsequently characterized, and assessed for cytotoxicity. High-performance liquid chromatography with diode-array detection (HPLC-DAD) was employed to identify hydroxycinnamic acids, caffeine, and trigonelline in the SCG extracts. Preliminary remediation assays were conducted with seven contaminants, with venlafaxine selected for detailed pH and kinetic studies. Characterization of nZVIs included SEM and EDS analyses, which revealed spherical nZVI particles (72–83 nm) composed of carbon (47%), oxygen (34%), and iron (16%). Dynamic light scattering (DLS) measurements indicated the presence of smaller particles (15–23 nm). Thermogravimetric analysis (TG) confirmed a residual mass of about 20% at 1400 °C. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed phenolic compound incorporation, while X-ray diffraction (XRD) revealed an amorphous structure. The particles exhibited magnetic behavior and showed no cytotoxicity toward MRC-5 and U87 cell lines. Among the tested contaminants, venlafaxine displayed the highest removal efficiency in remediation tests. Compared with chemically synthesized nZVI, the green version exhibited enhanced stability, attributed to the presence of surface-bounded organic matter. Overall, this sustainable and cost-effective approach to produce nZVI from SCG provides an innovative method for waste valorization and environmental remediation. 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

The Special Issue “Unlocking the Potential of Agri-Food Waste for Innovative Applications and Bio-Based Materials” brings together recent advances and emerging strategies for the valorization of agri-food residues. This Editorial provides an overview of the contributions included in the Special Issue, highlighting innovative approaches that convert waste streams into valuable bio-based materials, chemicals, and products. The collected works demonstrate how hydrodynamic, chemical, biological, and catalytic processes can be integrated to achieve sustainable waste management and circular resource recovery. By summarizing the main findings and perspectives, this Editorial emphasizes the growing relevance of agri-food waste valorization within the framework of the circular bioeconomy and encourages further interdisciplinary collaboration to accelerate the transition toward sustainable production systems. Full article

Valorizing agri-food waste through black soldier fly larvae (BSFL) bioconversion offers a promising path to enhance circular and sustainable food systems. This study used attributional Life Cycle Assessment (LCA) to evaluate the environmental performance of BSFL reared on six agro-industrial residue diets: tomato, pea, onion, chickpea, wheat, and liquid digestate. The Environmental Footprint 3.1 method was used to assess multiple impact categories. The rearing trials were conducted in a dedicated pilot plant (13.5 m × 2.5 m × 2.7 m) that can treat about 1.58 t of residue per cycle. From the results, BSFL biomass yields were similar across diets, with 12–15% bioconversion and 70–85% substrate reduction. BSFL protein had higher impacts than fishmeal and pea protein but was comparable to soybean meal. BSFL lipids had greater impacts than rapeseed, palm, and sunflower oils yet were similar to soybean oil for bioenergy from fat. Electricity use for climate control was the main hotspot (~85%). Scenario analysis showed that using residual heat for climate control and scaling up via optimization could cut impacts by over 80%. The findings demonstrate the potential for producing BSFL on a medium-to-large scale to enhance circularity in the agri-food sector. Full article

Plant-based residues generated within the agri-food system represent an abundant resource with significant potential for sustainable valorization. However, they are still underutilized and place a substantial burden on the environment and climate. This review discusses research trends over the past decade, combining bibliometric analysis with an overview of emerging technologies applied to the processing of residues generated from conventional crops and medicinal and aromatic plants. The bibliometric analysis reveals main valorization pathways, ranging from energy production to recovery of high-value bioactive compounds. Recent advances in this field are discussed in detail, with emphasis on low-energy and non-thermal processing (ultrasound, microwave, cold plasma), green solvents (natural deep eutectic solvents, bio-based solvents), biological pretreatments (with ligninolytic microorganisms and enzymes), thermochemical technologies (hydrothermal carbonization, pyrolysis), and emerging cascade strategies applied for multi-product recovery. Published research proves that these approaches have a great potential for sustainable valorization, while process optimization and economic feasibility remain a challenge at industrial scales for wider adoption. By providing an integrated perspective on diverse types of plant-based residues, this review highlights the importance of developing cascade and circular processing strategies, which align with global sustainability goals and encourage innovation in bio-based industries. New knowledge and advances in this field are highly required and will further help the transition of the current agri-food system towards greater circularity and sustainability. Full article

Agrivoltaics (APV) mitigates land-use competition between photovoltaic installations and agricultural activities, thereby supporting multifaceted policy objectives in energy transition and sustainability. The availability of organic residuals from agrifood practices may also open the way to their energy valorization. This paper examines a small-scale farm in the Basilicata Region, southern Italy, to investigate the potential installation of an APV plant or a combined APV and bioenergy system to meet the electrical needs of the existing processing machinery. A dynamic numerical analysis is performed over an annual cycle to properly size the storage system under three distinct APV configurations. The panel shadowing effects on the underlying crops are quantified by evaluating the reduction in incident solar irradiance during daylight and the consequent agricultural yield differentials over the life period of each crop. The integration of APV and a biomass-powered cogenerator is then considered to explore the possible off-grid farm operation. In the sole APV case, the single-axis tracking configuration achieves the highest performance, with 45.83% self-consumption, a land equivalent ratio (LER) of 1.7, and a payback period of 2.77 years. For APV and bioenergy, integration with a 20 kW cogeneration unit achieves over 99% grid independence by utilizing a 97.57 kWh storage system. The CO₂ emission reduction is 49.6% for APV alone and 100% with biomass integration. Full article

The valorization of agri-food by-products represents a promising approach to advancing sustainable agriculture while contributing to climate resilience efforts. Leguminous crops, cultivated extensively across diverse agroecological zones, play a central role in global food systems and soil fertility dynamics. Waste from leguminous crops can contribute essential nutrients to the soil, such as nitrogen, helping the growth of associated or subsequent crops, thereby reducing the need for inorganic fertilizers. Additionally, they can help improve soil biological activity, physical soil properties, and increase nutrient availability. As nitrogen-fixing crops, the waste obtained after threshing pulses probably still contains large amounts of nutrients, which can replenish part of the nutrient needs required for other crops. However, there is little information available about the amount of nutrients these residues may contain, as well as their decomposition rate and release. In this review, we explore the role of agri-food waste, particularly leguminous residues, in promoting sustainable agricultural practices, identifying main knowledge gaps in legume crop residue characterization (i.e., nutrient content and decomposition rates). We also identify potential risks in using leguminous waste and discuss mitigation strategies for using these residues safely. Additionally, we propose new strategies to promote more sustainable agricultural practices and highlight future research directions. Full article

The growing demand for sustainable biorefinery approaches calls for efficient, environmentally benign strategies to valorize agricultural residues and ensure their complete utilization. This study explores the combination of deep eutectic solvents (DESs) and microwave heating technology as a greener process for the selective fractionation of agri-food waste residues in a zero-waste perspective. Within this framework, five representative biomasses were thoroughly investigated, namely brewer’s spent grain, raw and parboiled rice husks, rapeseed cakes, and hemp hurds. DES formulation was selected for its ability to solubilize and separate lignocellulosic components, enabling the recovery of a polysaccharide-rich fraction, lignin, and bioactive compounds. DES extraction was performed using both microwave heating and conventional batch heating, enabling a direct comparison of the two methods, the optimization of a more sustainable fractionation process, and the maximization of yields while preserving the functional integrity of the recovered fractions. A comprehensive characterization of the separated fractions was carried out, revealing that the two fractionation methods do not yield significant differences in the composition of the primary components. Moreover, a ¹³C CP-MAS NMR analysis of the recovered lignins demonstrates how this analytical technique is a real fingerprint for the biomass source. The results demonstrate the great potential of microwave DES-mediated fractionation as a mild, tunable, and sustainable alternative to conventional methods, aligning with green chemistry principles and opening new approaches for the full valorization of waste byproducts Full article

The genera Parageobacillus and Geobacillus comprise thermophilic, spore-forming bacteria. The extraordinary heat resistance of their spores, together with their ability to form biofilms and produce thermostable enzymes, makes them a relevant cause of spoilage in shelf-stable, heat-treated products like dairy and canned foods. However, these same biological traits offer valuable opportunities for the food industry. In this context, the purpose of this review is to describe the challenges posed by (Para)Geobacillus spp. as food spoilage agents, while also highlighting their existing and prospective applications in the food industry. In terms of food safety, G. stearothermophilus spores are used as biological indicators in commercially available tests to detect antibiotic residues in food within a few hours. Additionally, (Para)Geobacillus can be exploited for the fermentation of agri-food residues to produce high-value compounds such as biofuels, food ingredients and technological adjuvants, and compost. Their thermostable enzymes—such as amylases, xylanases, L-arabinose isomerases, β-galactosidases, lipases, proteases, and L-asparaginases—have potential applications in food processing and ingredient production. However, several challenges persist, including limited knowledge on genetic diversity, physiology, and metabolism, as well as low yields of biomass and target compounds. These issues reinforce the need for further studies to unlock their full potential. Full article

This study presents the fabrication and characterization of sustainable polylactic acid (PLA)-based biocomposites reinforced with bio-origin fillers derived from food waste: seashells, eggshells, walnut shells, and spent coffee grounds. All fillers were introduced at 15 wt% into a commercial PLA matrix modified with a compatibilizer to improve interfacial adhesion. Mechanical properties (tensile, flexural, and impact strength), morphological characteristics (via SEM), and hydrolytic aging behavior were evaluated. Among the tested systems, PLA reinforced with seashells (PLA15S) and coffee grounds (PLA15C) demonstrated the most balanced mechanical performance, with PLA15S achieving a tensile strength increase of 72% compared to neat PLA. Notably, PLA15C exhibited the highest stability after 28 days of hydrothermal aging, retaining ~36% of its initial tensile strength, outperforming other systems. In contrast, walnut-shell-filled composites showed the most severe degradation, losing over 98% of their mechanical strength after aging. The results indicate that both the physicochemical nature and morphology of the biofiller play critical roles in determining mechanical reinforcement and degradation resistance. This research underlines the feasibility of valorizing agri-food residues into biodegradable, semi-structural PLA composites for potential use in sustainable packaging or non-load-bearing structural applications. Full article

The olive oil industry, a key component of Southern Europe’s agricultural sector, generates large amounts of by-products during processing, including olive leaves, branches, stones, and seeds. In the context of growing environmental concerns and limited natural resources—particularly in the Mediterranean regions—there is increasing interest in circular economy approaches that promote the valorization of agricultural residues. These by-products are rich in bioactive compounds, particularly phenolics such as oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities. This study aimed to evaluate the phenolic content and antioxidant capacity of by-products from three olive cultivars using high-performance liquid chromatography with photodiode array detection (HPLC–PDA) and mass spectrometry (MS). The leaves and seeds, particularly from the “Cobrança” and a non-identified variety, presented the highest antioxidant activity, as well as the highest concentration of phenolic compounds, demonstrating once again the direct relationship between these two parameters. The identification of the compounds present demonstrated that the leaves and branches have a high diversity of phenolic compounds, particularly secoiridoids, flavonoids, phenylpropanoids, phenylethanoids, and lignans. An inverse relationship was observed between the chlorophyll and carotenoid content and the antioxidant activity, suggesting that phenolic compounds, rather than pigments, are the major contributors to antioxidant properties. Therefore, the by-products of the olive oil industry are a valuable source of sustainable bioactive compounds for distinct industrial sectors, such as the food, nutraceutical, and pharmaceutical industries, aligning with the European strategies for resource efficiency and waste reduction in the agri-food industries. Full article

Membrane processes are extensively employed in a range of industrial and food applications. Due to growing environmental concerns and the introduction of regulatory measures, it is imperative to develop innovative membrane materials that can effectively replace petrochemical-based polymers, in line with the principles of a circular economy. The focus of this review is the use of polysaccharides for obtaining films/membranes for food and industrial applications using selected case studies. Besides the polysaccharides extracted from biomass, the valorization of agrifood residues and the use of plants adapted to arid lands (i.e., cactus) to produce polysaccharide films for food packaging is addressed. Moreover, microbial polysaccharides produced using renewable resources present a significant alternative to commercial hydrophilic membranes for gases and ethanol dehydration. To meet industry requirements, the mechanical and barrier properties of the films can be improved by the inclusion of inert impermeable fillers and/or the chemical modification of the polysaccharides. The adsorption of proteins, dyes, and pharmaceutical compounds using a cellulose-based polymer is discussed. Despite their unique characteristics, polysaccharide production costs are still higher than most synthetic polymers. This is a challenge that can be overcome by scaling up the production and by valorizing agro-industrial wastes and by-products to make the application of polysaccharide membranes/films in the food and industry sectors more widespread. Full article