Search Results (107)

The olive industry is experiencing significant growth, which is only held back by the environmental and management issues that its by-products can cause. The two most polluting effluents produced are a new aqueous phase, or ‘alpechín ’, obtained from alperujo, which is the most important waste generated in the olive oil industry, and brine in the table olive industry. The high organic and phytotoxic loads of both, together with the conductivity of the brines, make their reuse difficult and pose a real technological challenge owing to the environmental problems they cause. This study demonstrates that the application of thermo-malaxation (45–65 °C, 60–90 min) followed by three-phase centrifugation (>3500× g) allows the removal of the most active phenolics, including hydroxytyrosol, 3,4-dihydroxyphenylglycol, and tyrosol from the alperujo in a 30% solution, yielding a partially detoxified solid phase and a liquid phase rich in the most active phenolics. Furthermore, the application of an industrial chromatographic process (0.6 mm diameter rigid strong-cationic resins) enables the removal of between 50% and 75% of the phenolic load from the liquid fraction of the aforementioned system and from the brines of the table olive industry. The high antioxidant activity of the extracted phenolics was verified using in vitro assays. Full article

Agricultural residues, municipal organic waste, animal manure, and food-processing residues represent promising resources for sustainable waste-based bioenergy production. In addition to serving as renewable energy sources, these biomass resources can contribute to improved waste management, rural development, and environmental protection. In the context of global efforts to accelerate the transition toward sustainable energy systems, biomass and bioenergy are increasingly being investigated alongside other renewable energy technologies. Jordan faces significant challenges related to its dependence on imported fossil fuels and the associated economic and environmental impacts. Fluctuations in international oil prices, energy security concerns, and the need to reduce greenhouse gas emissions have encouraged Jordan to explore alternative and renewable energy options. Bioenergy offers a potential pathway to diversify the national energy mix while also addressing organic waste management and supporting rural and agricultural sectors. This study assesses the current status of bioenergy in Jordan and reviews the potential of available biomass resources, including agricultural residues, municipal organic waste, animal manure, olive-industry residues, sewage sludge, and food-processing waste. It matches these resources with suitable conversion technologies and provides a qualitative, literature-based discussion of their environmental and socioeconomic implications and the principal conditions affecting implementation. The study also identifies the main technical, logistical, financial, institutional, and regulatory barriers to bioenergy deployment and proposes practical recommendations for policy development, pilot projects, financing mechanisms, and local capacity building. The harmonized results indicate a combined energy potential of approximately 25.3 PJ/year for animal manure and agricultural residues reported on a comparable basis, with animal manure contributing approximately 73% of this total. A screening-level recoverability assessment estimates that approximately 2.55 Mt/year of biomass could potentially be recoverable under the central scenario, compared with 1.94 and 3.17 Mt/year under the low and high scenarios, respectively, excluding sewage sludge. A published theoretical estimate indicates a biogas-derived electricity potential of approximately 960.9 GWh/year, equivalent to about 5.1% of Jordan’s electricity consumption in 2019. The results identify animal manure, source-separated organic municipal waste, sewage sludge, and concentrated food-processing residues as the most relevant near-term resources. These findings can support policymakers, researchers, and industry stakeholders in prioritizing locally appropriate waste-based bioenergy pathways. Full article

Agro-industrial wastewaters contain substantial organic and lipid loads that pose environmental challenges but may also provide potentially low-cost substrates for microbial bioprocessing. This scoping review evaluated the use of agro-industrial wastewaters as fermentation feedstocks for microbial lipase production and their potential integration with wastewater treatment and resource recovery. Previous reviews have largely treated microbial lipase production, waste-derived fermentation substrates, and lipase-based wastewater treatment as separate topics. This review bridges these areas by focusing on liquid agro-industrial wastewaters as fermentation feedstocks and jointly evaluating lipase production, changes in wastewater quality, process conditions, analytical comparability, and technological readiness. Following PRISMA-ScR guidance, Scopus and the Web of Science were searched for studies published from 2016 to 2026, yielding 20 eligible articles. The evidence was heavily concentrated on olive mill wastewater and palm oil mill effluent, whereas other agro-industrial effluents were scarcely investigated. Yeasts, bacteria, filamentous fungi, mixed cultures, and recombinant whole-cell systems were employed, although cultivation strategies, wastewater conditioning, supplementation, and lipase assays varied substantially. Several studies combined lipase production with reductions in chemical oxygen demand, oil and grease, phenolic compounds, or other wastewater constituents. However, most processes remained at the shake-flask scale, while downstream recovery, detailed enzyme characterization, storage stability, catalyst reuse, and controlled scale-up were infrequently investigated. Wastewater-based lipase production therefore represents a promising circular-bioeconomy strategy, but further development requires standardized performance reporting, minimal-input cultivation, integrated final-effluent assessment, scale-up, and formal techno-economic and life-cycle assessment. Full article

Circular economy is today a key driver of every transformation process aimed at reducing and optimizing the use of energy and materials. The production of solid biofuel from waste is a typical route to lower the potential impact of greenhouse-gas emissions. In this context, olive pomace is a relevant feedstock, as 4 million tonnes are generated worldwide each year alongside olive oil production. However, only a small fraction of olive pomace is currently valorized. Fresh olive pomace must first be quickly dried to a low, controlled moisture. This step is performed poorly and at a high energy cost. This paper presents an automation-based approach to enhance biomass production from olive pomace, thereby advancing circular-economy practices in olive oil production. The work is focused on four aspects. In the first part, a review of the state of automation in agricultural engineering with a focus on biomass and olive pomace is proposed. Then, the design and construction of an innovative drying system that integrates an infrared solution directly into the transporting screw conveyor is described, integrating real-time online microwave moisture sensing and PLC control. After that, a cloud-based service is presented for remote monitoring, data analysis, and optimization. The innovative and automated drying system was validated during a preliminary field campaign at an olive mill. After about sixteen hours of continuous, cloud-monitored operation, the resulting olive pomace moisture fell below the 5% threshold across a wide range of inlet-moisture conditions, with a stable electrical power demand of approximately 1.85 kW. Finally, an environmental analysis is provided to evaluate the environmental aspects related to the proposed system. The preliminary analysis confirms a significant avoided-carbon potential if the resulting olive pomace is reused as biomass for energy production. The impact associated with 1 kWh_-eq produced from olive pomace is in the range of 0.006–0.033 kg CO_2-eq. Full article

Olive pomace is a major side stream originating from olive processing for the production of olive oil. This waste material bears a load of polyphenolic antioxidants, and thus it might serve as a source of precious phytochemicals. This work had as its objective the development of an extraction process for the efficacious recovery of polyphenols from dried olive pomace (dOP), employing eco-friendly extraction media. To this end, environmentally benign solvents were first compared for their efficiency in obtaining increased yields in total polyphenols, and 40% aqueous isopropanol was selected as the best-performing mixture. Further examination of the role of acidification showed that mineral acid addition (sulfuric, hydrochloric) had a rather negative effect on polyphenol yield. To the contrary, incorporation of oxalic acid into the solvent at a 10% level provided significantly higher extraction yield (p < 0.05), which reached 27.1 ± 1.1 mg caffeic acid equivalents (CAE) per g dOP. This solvent system (40% isopropanol/10% oxalic acid) was additionally scrutinized for its effectiveness by studying the role of process severity and response surface optimization. Out of both approaches, it was demonstrated that polyphenol extraction yield, but also antiradical activity, was directly correlated with residence time and temperature, within the limits tested. Moreover, a high correlation between polyphenol concentration and antiradical activity was also revealed. Liquid chromatography-tandem mass spectrometry analyses showed that the extract obtained with the solvent system used (40% isopropanol/10% oxalic acid) was characterized by the presence of both hydroxytyrosol and the flavone luteolin (242.1 and 178.6 μg g⁻¹ dOP, respectively), but, in the absence of isopropanol, the extract produced was largely dominated by hydroxytyrosol (4629.7 μg g⁻¹ dOP). Thus, it was concluded that the solvent system could fundamentally diversify extract composition. It is proposed that, when combined with integrated biorefinery technologies, this approach could effectively contribute to reducing environmental impacts while enabling the production of valuable natural antioxidants or platform chemicals that are vital for the food, pharmaceutical, and cosmetic industries. Within the broader context of sustainable food waste management, such strategies might be key elements of a circular economy framework. Full article

Agro-industrial waste impacts populations worldwide. Food waste, in turn, is a major source of complex lipids, carbohydrates, and other substances. Therefore, it is crucial to convert food waste into products that reduce environmental problems. Enzymatic hydrolysis has advantages over chemical hydrolysis. Examples include the enzymatic hydrolysis of starch by α-amylase and the hydrolysis of inulin by inulinase, which occur under milder environmental and temperature conditions than acid hydrolysis of starch or inulin. Despite these milder temperature conditions, during substate hydrolysis, enzyme deactivation occurs under exposure to temperature. As temperature increases above $T_{opt}$ (which maximizes catalytic activity), enzyme deactivation becomes more pronounced, leading to a decrease in enzyme activity. Therefore, determining the rate constant of deactivation $k_d$, during biotransformation is an important aspect in understanding enzyme kinetics. Most experimental studies focus on changes in enzyme activity with time and temperature. However, enzyme deactivation also occurs during enzymatic reactions conducted at different temperatures, and this process is characterized by specific deactivation parameters. The study is to present the rate constants of deactivation $k_d$, for selected biotransformation processes. The selected biotransformation processes are hydrolysis of olive oil by lipase, hydrolysis of inulin by inulinase, and hydrolysis of starch by α-amylase. Given the widespread use of enzymes in industry, the information on enzyme deactivation presented in this study can be used by engineers involved in modeling and optimizing enzymatic processes. This knowledge is also essential for the effective and sustainable use of enzymes in industrial applications. It is important to emphasize that the deactivation parameters discussed in this study also carry significant economic, social, and environmental implications. Full article

Waste valorisation has become a key strategy for applying circular economy principles in the agro-industrial field. This study investigated the territorial implementation of the waste composting on a territorial scale. The wastes considered were the post-processing orange waste, spent olive oil pomace, and spent wine grape pomace. Their potential use as soil amendments across the provinces of Sicily was assessed through a GIS-based analysis, taking into account nitrogen (N) application constraints. Moreover, a cascade valorisation scheme was also evaluated: post-processing orange waste was first used as animal feed, and the remaining fraction was directed to composting; olive pomace was first sent to pomace oil extraction mills, and the residual material was subsequently used for composting. Results indicate that N inputs derived from composted residues remain below legal thresholds in all provinces, with relative contributions ranging from 38% to 92% of the regulatory limits. Spatial variability in nitrogen availability reflects the territorial distribution of agro-industrial activities, highlighting the importance of localised management strategies. These findings demonstrate that composting, combined with cascade valorisation, is an effective pathway to close nutrient cycles, reduce waste generation, and support sustainable biomass management in regional agri-food systems. Full article

The Olea europaea L., commonly known as the European olive, has been recognized for centuries as one of the most valuable species among useful plants. In contemporary applications, the olive tree provides a wide array of raw materials utilized in the food, pharmaceutical, and nutraceutical industries. Extracts derived from the leaves, bark, and fruits of O. europaea have also gained significant relevance in dermatological and cosmetic formulations. The aim of this paper was to review scientific studies published between 2019 and 2025 concerning the application of olive oil and other derivatives of the European olive in the care of skin, hair, and nails. The analysis underscores the role of olive-derived bioactives in wound healing, stretch mark management, and skin regeneration, highlighting compounds such as oleocanthal and oleuropein in hydration, elasticity, wrinkle reduction, and photoprotection relevant to skin aging. The evidence for olive oil in hair and nail care mainly highlights their moisturizing and strengthening effects, though studies remain limited. O. europaea derivatives show a favorable safety profile with low allergenic potential, and their availability and minimal sensitization risk support use in home cosmetics. The importance of the European olive and its products is expected to grow in the coming years. However, the availability of technologies for processing waste materials obtained from this plant, as well as the associated technological costs, remain significant limitations. Full article

Smart self-healing polymer materials are breaking open new pathways in industry, minimizing waste, and enhancing the long-term reliability of applications. Moreover, when they possess anti-corrosive properties, they effectively protect surfaces from wear and corrosion, leading to improved and more robust products. In the present work, we develop a series of new self-healing polyurethane coatings activated by temperature, through the encapsulation of vegetable oils (VO), namely olive, soybean, and castor oil, in the core of polyurea microcapsules (VO-MCs). Using a green method, water-dispersible microcapsules were embedded in water-based polyurethane matrices. Both the self-healing ability and the anti-corrosive properties of the respective films were evaluated after mechanical damage. Encapsulation allowed for the direct release of VOs into the damaged area; subsequently, the temperature increase reduced the viscosity of the oils, facilitating their flow and diffusion into the damaged area and accelerating the healing process. Soybean oil and olive oil showed remarkable performance in terms of self-healing and high anti-corrosion ability for the polyurethane coatings, while castor oil showed a limited anti-corrosion effect but quite satisfactory effectiveness in terms of self-healing. Overall, the study highlights the potential of using encapsulated oils in environmentally friendly, active coatings with dual action: corrosion protection and self-repair of damage. Full article

The valorization of waste materials is essential for sustainability, with used cooking oils (UCOs) offering potential for transformation into valuable functional products. The study investigates the oxidative stability of sunflower and olive oils subjected to high temperatures (160–200 °C) and frying on their physico-chemical properties (acidity, peroxide and iodine value, total polar compounds). Significant deterioration occurred above 180 °C, with increased peroxide and polar compounds and reduced iodine values. A technological process for the purification and saponification of UCOs (sunflower, olive, and palm oils) was developed, demonstrating the potential to transform pollutant waste into a valuable and sustainable product—soap. The incorporation of oregano and thyme essential oils (EOs), identified by GC-FID as rich sources of carvacrol, thymol, p-cymene, and limonene, improved the functional properties of the soaps. The antimicrobial activity of soaps largely relates to their alkaline pH, while the incorporation of EOs contributes to additional antimicrobial effects, obtaining zones of inhibition of up to 10.8 mm against Staphylococcus aureus and up to 7.6 mm against Escherichia coli for palm oil. The study highlights a sustainable approach that transforms waste oils into functional soaps with EOs for added antimicrobial benefits. Full article

Bio-based polymeric composites were prepared by dispersing different amounts of olive pit (OP) powder within an acrylate epoxidized soybean oil (AESO) photocurable resin using tetrahydrofurfuryl acrylate (THFA) as diluent and (2,4,6-trimethylbenzoyl), phosphine oxide (BAPO) as photo-initiator, and they were photocured by Vat Photopolymerization (VP) using a Liquid Crystal Display (LCD) 3D printer. Formulation viscosity was studied because of its important role in a VP process able to influence the printability of the final parts. Different 3D printed architectures were successfully realized with good resolution and accuracy, high level of detail, and flexibility. The effect of OP addition was investigated by thermal (TGA and DSC), morphological (SEM and PSD), viscoelastic (DMA), and mechanical (tensile testing) characterization. The filler led to an increase in the T_g, storage modulus, and tensile properties, underlining the stiffening effect induced by the OP particles onto the polymeric starting resin. This underlines the possibility to apply these bio-based composites in many application fields by valorizing agro-wastes, developing more sustainable materials, and taking advantages of VP 3D printing, such as low costs, minimal wastage, and customized geometry. Biocompatibility tests were also successfully carried out. The results clearly indicate that the AESO-based composites promote cell adhesion and viability. Full article

Recently, plastic and agricultural waste have gained attention as sustainable alternatives. Despite efforts to recycle these materials, much still ends up in landfills, raising environmental concerns. To optimize their potential, these wastes ought to be transformed into value-added products for diverse industrial applications. This work focused on producing thin composite material films using olive oil solid waste called JEFT and recycled plastic bottles. JEFT was cleaned, dried, and processed mechanically via ball milling to produce nano- and micron-sized particles. Composite films were produced via melt compounding and compression molding with a rapid cooling process for controlled crystallinity and enhanced flexibility. Their density, water absorption, tensile strength, thermal stability, water permeability, functional groups, and biodegradation were comprehensively analyzed. Results indicated that 50% JEFT in recycled plastic accelerated thermal deterioration (42.7%) and biodegradation (13.4% over 60 days), highlighting JEFT’s role in decomposition. Peak tensile strength (≈32 MPa) occurred at 5% JEFT, decreasing at higher concentrations due to agglomeration. Water absorption and permeability slightly increased with JEFT content, with only a 1% rise in water permeability for 50% JEFT composites after 60 days. JEFT maintained the recycled plastic’s surface chemistry, ensuring stability. The findings of this study suggest that JEFT/r-HDPE films show potential as greenhouse coverings, enhancing crop production and water efficiency while improving plastic biodegradation, offering a sustainable waste management solution. 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

The olive oil sector constitutes a fundamental pillar in the Mediterranean region from socio-economic and cultural perspectives. Nonetheless, it produces significant amounts of waste, leading to numerous environmental issues. These waste streams contain valuable compounds that can be recovered and utilized as inputs for various applications. This study introduces a novel value chain for olive wastes, focused on extracting lignin from olive pomace by ionic liquids and polyphenols from olive mill wastewater, which are then incorporated as hybrid nanoparticles in the formulation of an innovative starch-based biofertilizer. This biofertilizer, obtained by using residual wastewater as a source of soluble nitrogen, acting at the same time as a plasticizer for the biopolymer, was demonstrated to surpass traditional NPK biofertilizers’ efficiency, allowing for root growth and foliage in drought conditions. In order to recognize the environmental impact due to its production and align it with the technical output, the circularity and environmental performance of the proposed system were innovatively evaluated through a combination of Life Cycle Assessment (LCA) and the Material Circularity Indicator (MCI). LCA results indicated that the initial upcycling process was potentially characterized by significant hot spots, primarily related to energy consumption (>0.70 kWh/kg of water) during the early processing stages. As a result, the LCA score of this preliminary version of the biofertilizer may be higher than that of conventional commercial products, due to reliance on thermal processes for water removal and the substantial contribution (56%) of lignin/polyphenol precursors to the total LCA score. Replacing energy-intensive thermal treatments with more efficient alternatives represents a critical area for improvement. The MCI value of 0.84 indicates limited potential for further enhancement. Full article

The historical co-production of olive oil and wine has influenced the Mediterranean landscape and economy. Olive oil and wine production generates substantial organic waste, including olive pomace, grape pomace, and wastewater, which poses environmental challenges if untreated. These byproducts contain bioactive compounds, including polyphenols, such as hydroxytyrosol, resveratrol, and flavonoids, which possess antioxidant and anti-inflammatory properties, making them valuable for the development of functional foods and nutraceuticals. A combined waste valorization strategy can enhance bioactive compound recovery and align it with circular economic principles. The incorporation of olive oil and wine byproducts into food matrices, such as bread, pasta, dairy products, baked goods, chocolates, beverages, and processed items, has been explored to enhance antioxidant content, dietary fiber, and nutritional value. However, successful integration depends on maintaining acceptable sensory qualities and addressing the technical challenges in extraction, processing, and regulatory compliance. Realizing the potential benefits of dual valorization requires a systemic shift integrating scientific innovation, regulatory adaptability, and consumer engagement, guided by evidence, transparent communication, and inclusive governance to ensure that sustainability goals translate into environmental, economic, and public health outcomes. Full article