Search Results (378)

A portable electronic nose based on modern digital metal oxide (MOX) gas sensors and programmable temperature modulation was developed and validated. The system integrates four modern commercially available MOX sensors capable of generating temperature-dependent odor fingerprints and multidimensional sensor responses compared with conventional fixed-temperature operation. The performance of the device was assessed in terms of sensor stability, repeatability, and pattern-recognition capability under long-term operation. As a proof of concept, the electronic nose was applied to the discrimination of Extra Virgin Olive Oil and pomace oil. Repeatability analysis using the Root Mean Squared Error (RMSE) demonstrated stable responses across one month of measurements. Temperature-modulated signals were processed using Principal Component Analysis (PCA) and classified with k-Nearest Neighbors (KNNs) and Multilayer Perceptrons (MLPs), achieving 100% accuracy after selecting the most repeatable sensor. These results highlight the robustness and analytical potential of temperature-modulated digital MOX sensors and demonstrate the feasibility of a compact and highly reproducible electronic-nose platform suitable for complex odor-analysis tasks in real-world applications. Full article

Olive pomace is an abundant agro-industrial residue whose recalcitrant composition limits its efficient valorisation, highlighting the need for sustainable recovery strategies. This study investigated the use of Hermetia illucens larvae for the bioconversion of olive pomace and its integration with anaerobic digestion to evaluate the simultaneous recovery of biomass and energy. Larvae were initially reared on olive pomace, goat manure, and their mixture to assess growth performance, survival, and substrate suitability. Subsequently, olive pomace was subjected to thermal pre-treatment and anaerobic digestion with goat manure, and the resulting digestates were reused as substrates for larval rearing. Their phytotoxicity was also evaluated through germination tests on alfalfa. Larval performance was higher on non-digested substrates, confirming the suitability of raw mixtures for insect rearing. Thermal pre-treatment did not result in a significant increase in methane production. In contrast, digestates, particularly those obtained under more severe thermal treatments, resulted in reduced larval growth and survival under the tested conditions and showed variable phytotoxic effects. Overall, although anaerobic digestion enabled energy recovery, its integration with insect-based bioconversion resulted in reduced larval performance under the tested conditions. These findings highlight the importance of optimising substrate treatment to ensure effective integration of insect rearing within circular bioeconomy systems. 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

Sandy calcareous soils in arid regions suffer from low phosphorus (P) availability due to high fixation rates, limiting crop productivity. This study investigates a novel hybrid smart fertilizer (BN) composed of olive pomace biochar (BC) and nano-hydroxyapatite (nHAP). BN was synthesized and characterized using XRD, FTIR, SEM/TEM, and zeta potential analysis. Its P release kinetics were modeled, and its agronomic performance was assessed on faba bean (Vicia faba L.) in a pot experiment under sandy soil conditions with and without wood vinegar (WV). The 1:1 BC:nHAP formulation showed a two-stage release profile: a rapid initial burst (Higuchi model, R² = 0.86) followed by sustained zero-order release (R² = 0.80). In the pot experiment, BN combined with WV significantly increased plant height by 36%, shoot fresh weight by 232%, and available soil P by 39% compared to conventional SSP (p < 0.05). This synergistic treatment also improved root nodulation and nutrient (N, P, K) uptake. The BC-nHAP hybrid coupled with WV acts as an efficient P delivery system, improving soil fertility in arid environments based on circular economy principles, aligning with SDGs 2, 12, and 15. Full article

This research focuses on the synthesis of a novel baking powder enriched with bioactive molecules recovered from olive pomace via ultrasound-assisted extraction using a hydro-ethanolic mixture. The functional ingredient was engineered by anchoring the extracted phytocompounds onto a starch backbone through a sustainable grafting technique. Biscuits formulated with the innovative ingredient showed an increased concentration of phenolic compounds (2.162 mg GAE/g), encompassing both phenolic acids (0.372 mg GAE/g) and flavonoids (0.360 mg CTE/g). Enhanced antioxidant efficacy was recorded, mostly in aqueous media (IC₅₀ = 0.554 mg mL⁻¹ against ABTS radical) compared to organic environments (IC₅₀ = 0.132 mg mL⁻¹ against DPPH radical). Furthermore, Oxitest and oxidation stability reactor analyses revealed exceptional antioxidant capacity (induction period = 37 ± 2 h). By an accelerated shelf-life test, a marked instrumental color difference was observed with the fortified sample showing a darker, redder/brown color (ΔE > 16), as also confirmed by trained panelists. On the contrary, similar scores were achieved for the olfactory, textural and tasting attributes of the two samples, as well as values of the friability index (<1 mm⁻¹) evaluated by instrumental techniques. This approach represents a sustainable strategy, transforming a high-polluting agri-food by-product into a source of bioactive compounds for nutritional and technological improvement of baked foods. Full article

Landmark epidemiological studies and clinical trials, such as the Seven Countries Study, the Lyon Diet Heart Study, the PREDIMED Study and the CORDIOPREV Study, have shown significant reductions in cardiovascular events in those following the Mediterranean diet (MD). The aim of the present work is to summarize the most robust available evidence and the major biological pathways underlying the protective effects of the MD, with particular emphasis on the role of PAF inhibitors. Mechanistically, MD functions through a complex synergy of antioxidant, anti-inflammatory, and antithrombotic effects that collectively improve lipid profiles, enhance endothelial function, optimize postprandial metabolism and cell membrane signaling, making it a functional model for human longevity. The PAF-Implicated Atherosclerosis Theory has emerged as a key unifying framework, proposing that Platelet-Activating Factor (PAF)—a highly potent lipid inflammatory mediator—plays a central role in the initiation and progression of atherosclerosis. Oxidized LDL promotes the production of PAF and PAF-like lipids, leading to endothelial dysfunction, vascular inflammation, and atherosclerotic plaque formation. Traditional Mediterranean foods are rich in natural PAF inhibitors, particularly the polar lipid fractions of extra virgin olive oil, as well as wine, fish, vegetables, onions, and garlic. Animal studies demonstrate that these compounds can reduce or even regress atherosclerotic lesions, independently of serum cholesterol levels. Human dietary interventions have further shown that MD-based meals and functional foods enriched with PAF inhibitors reduce PAF activity and improve thrombosis-related biomarkers. This mechanistic framework helps explain phenomena such as the “French Paradox” and the cardio-protective effects associated with fish consumption. Moreover, the extraction of PAF inhibitors from Mediterranean food by-products, such as olive pomace, offers promising ecological and economic advantages. Collectively, targeting PAF and increasing dietary intake of PAF inhibitors represent promising strategies for the prevention and management of atherosclerosis and other inflammatory diseases, supporting the view that PAF may function as a major, modifiable risk factor in these conditions. Full article

The growing environmental impacts associated with conventional plastics and textiles have intensified interest in bio-based and circular material alternatives. This study presents a qualitative and structured literature review of the valorization of fruit and nut agricultural residues as sustainable feedstocks for biomaterials and biotextiles, with a strategic focus on Greece. Drawing on international literature, regional agricultural production data, and validated processing technologies, the review synthesizes existing evidence on residue availability, conversion routes, environmental performance, and market trends. The reviewed literature indicates that residues such as grape pomace, olive by-products, citrus peels, and nut shells have been widely reported as suitable sources of cellulose, lignin, and pectin for the development of fibers, films, and composite materials. Findings from published life cycle assessment (LCA) studies suggest potential reductions in water use, greenhouse gas emissions, and land-use intensity compared with conventional cotton and synthetic textiles, although results vary depending on system boundaries and processing conditions. The review further highlights enabling factors, technical limitations, and policy considerations relevant to the Greek context. This study provides a qualitative integrative perspective on the opportunities and constraints associated with agricultural residue valorization, identifying key research gaps and strategic directions for future development within Greece and similar Mediterranean regions. 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

This study evaluated the sustainability of removing phenolic compounds from olive mill effluents using a nanobiochar synthesized from olive pomace. Catechol, tyrosol, hydroxytyrosol, and homovanillic alcohol were chosen as model pollutants due to their presence in agro-industrial wastewater. The surface morphology, elemental composition, crystallographic structure, functional groups, porosity, and thermal stability of the nanobiochar were investigated by SEM, EDX, XRD, FTIR, BET analysis, and TGA/DTA. The developed nanobiochar exhibited a predominantly amorphous carbon structure, enriched in carbon (85.6%), with localized graphitic domains. Its mesoporous architecture (S_BET = 15.478 m² g⁻¹; Dp = 2.14 nm) promotes accessibility to active sites, while its thermal stability confirmed its suitability for adsorption applications. In this batch adsorption study, the technological aspect considered is the influence of operating parameters on adsorption efficiency, using kinetic and equilibrium models. Pseudo-first-order and pseudo-second-order kinetic models, as well as Freundlich and Langmuir isotherms, were used to analyze the experimental data. The pseudo-second-order model proved to be the most suitable for describing adsorption, suggesting that the process is primarily dominated by chemisorption. Similarly, the Langmuir model gave the least satisfactory results regarding equilibrium data, indicating monolayer adsorption on homogeneous active sites. The adsorption capacity of phenolic compounds was variable. The highest adsorption capacities were observed for catechol (250 mg g⁻¹), tyrosol (19.23 mg g⁻¹), homovanillic alcohol (15.38 mg g⁻¹), and hydroxytyrosol (13.16 mg g⁻¹). The results of this research indicate that adsorption affinity depends on molecular structure and electronic properties. Furthermore, computer modeling based on molecular simulations and electronic descriptors was performed to explain the adsorption mechanism. Linear regression, principal component analysis, and elastic regression revealed strong correlations between adsorption parameters and molecular descriptors. These results demonstrate that olive pomace-based nanobiochar is an environmentally friendly adsorbent for the treatment of phenolic effluents, with adsorption primarily controlled by surface interactions. Full article

Mineral oil hydrocarbons (MOH), comprising saturated (MOSH) and aromatic (MOAH) compounds, are ubiquitous lipophilic contaminants. This review critically examines their occurrence, toxicology, analysis, contamination sources, and mitigation strategies in the olive oil sector. Emphasis is placed on analytical evolution, highlighting online LC-GC-FID and the EN ISO 20122:2024 standard, including advances in saponification and epoxidation to minimize biogenic interferences. Monitoring data reveal that virgin olive oils from the market can sometimes exceed the 2.0 mg/kg limit for the MOAH. Ten times higher levels are usually found in olive pomace oils (OPOs). In OPO, solvent extraction causes a significant reconcentration of hydrocarbons remaining on the solid matter after physical extraction and accumulating during the open-air storage of pomace. Conversely, for virgin oils, contamination can occur at multiple points along the supply chain, but harvesting emerged as the most important critical step, often due to accidental contact with lubricants, greases, or hydraulic fluids. Post-milling operations may also contribute to contamination. Mitigation strategies rely on Good Agricultural and Manufacturing Practices, focusing on the systematic replacement of technical-grade lubricants with food-grade alternatives. Additionally, olive washing can reduce initial MOSH content, while refining further lowers levels, particularly in lighter fractions. Full article

The large-scale use of compost in arable cropping systems is often limited by the large quantities required to meet the crop’s nutritional needs. Palletization can increase the nutrient density of organic fertilizers and improve their logistical feasibility by reducing storage, transport and application costs. This study evaluated the agronomic and environmental performance of compost pellets derived from pig slurry solids and olive pomace, using them as an alternative nitrogen source for wheat (Triticum aestivum L.) cultivated under Mediterranean conditions. A field experiment was conducted during the 2022–2023 growing season, with four treatments arranged in 24 m² replicated plots: an unfertilized control (C); pelletized compost (PSCOP); fresh pig slurry (PS); and mineral fertilization based on monoammonium phosphate and urea (IN). Excluding the control treatment, all fertilized plots received a uniform nitrogen rate of 150 kg N ha⁻¹. Soil chemical properties and nutrient availability (Pext, NH₄⁺-N and NO₃⁻-N) were evaluated at the beginning and end of the experiment, while wheat yield and grain quality were assessed at harvest. Greenhouse gas (GHG) emissions were monitored throughout the cropping season to evaluate environmental impacts. The results showed that the wheat yields achieved with PSCOP were comparable to those obtained with PS, although they remained lower than those achieved with mineral fertilization. Grain quality was not adversely affected by the application of PSCOP. Furthermore, PSCOP resulted in lower GHG emissions than mineral fertilization, with values closer to those observed in the unfertilized control. These findings suggest that pelletized organic fertilizers such as PSCOP may be a promising way to enhance nutrient circularity and reduce reliance on synthetic fertilizers and maintain crop productivity and limit environmental impact in Mediterranean agricultural systems. Full article

This study evaluated olive leaves from three cultivars (Hojiblanca, Picual, and Arbequina) and olive pomace as complementary sources of bioactive compounds, comparing ultrasound-assisted extraction using organic solvents (UAE) with supercritical CO₂ extraction (SFE). The aim was to determine how the plant matrix and extraction method influence phytochemical composition and functional properties, including antioxidant and antimicrobial activity. The results showed that both factors strongly affected extract composition and bioactivity. UAE favored the recovery of phenolic compounds associated with antioxidant activity, particularly in leaf extracts, while SFE promoted a distinct compositional profile enriched in flavonoids and lipophilic constituents, especially in olive pomace. Multivariate analysis confirmed a clear differentiation between matrices and extraction methods. Leaf extracts from Picual and Arbequina were mainly associated with phenolic compounds linked to antioxidant activity, including luteolin, ethyl vanillin, tyrosol, and isorhamnetin-3-O-glucoside. In contrast, olive pomace extracts were more strongly associated with flavonoids and lipophilic metabolites, such as triterpenes (oleanolic, maslinic, and ursolic acids) and lipid derivatives (oleic acid and lauric isopropanolamide). These compositional differences were reflected in biological activity: UAE extracts showed higher antioxidant activity, whereas SFE extracts, enriched in lipophilic and triterpenic compounds, exhibited stronger antimicrobial effects against Pseudomonas savastanoi and Hanseniaspora sp. Overall, these findings demonstrate that extraction-driven selectivity enables the production of olive-derived extracts with targeted functionalities, with UAE favoring antioxidant-oriented extracts and SFE promoting extracts enriched in lipophilic compounds with antimicrobial potential, particularly from olive pomace. Full article

This study aims to develop and characterize novel dermatocosmetic formulations designed to hydrate the skin, improve its appearance, reduce wrinkles, and provide antioxidant, anti-ageing, antimicrobial, and anti-inflammatory benefits, along with potential protection against UVA and UVB radiation. The formulations contain the following ingredients: xanthan gum (0.5%), Calendula officinalis oil (5%), Argania spinosa oil (5%), Helianthus annuus oil (5%), liposomes containing a hydroalcoholic extract of pomace from local red or white grapes (2%), an olive oil-based emulsifier (6%), vitamin E (0.5%), cetearyl alcohol (3%), propylene glycol (8%), and purified water (up to 100%). The natural ingredients used in these formulations, i.e., the red or white grape pomace extract from the aforementioned Romanian varieties, the oils of Calendula officinalis, Argania spinosa, and Helianthus annuus, xanthan gum, and the olive oil-based emulsifier (Olliva), promote the concept of ‘green cosmetics’. The use of liposomes to deliver bioactive substances from hydroalcoholic extracts allows the gradual release of active ingredients into the skin. An alternative for incorporating grape pomace extract into a cream-type matrix involves the use of liposomes. Liposomes loaded with red or white grape pomace extract were prepared using the thin-film hydration technique, followed by ultrasonication and extrusion. The obtained formulations were characterized using bio-physico-chemical analysis procedures in terms of consistency, colour, homogeneity, aroma, pH, stretch, texture, stability, and antioxidant activity/free radical scavenging capacity, as well as in vitro polyphenol release behaviour. These newly developed dermatocosmetic formulations were the subject of a patent application in Romania. Full article

The persistence of pesticide residues in food and water poses a significant challenge to global food safety, particularly under the pressures of intensive agriculture and climate variability. Despite significant progress in developing adsorbent materials for pesticide remediation, most approaches remain chemically optimized but geographically blind. This review introduces the concept of geo-adaptive design of carbon-based adsorbents, emphasizing that remediation materials should be tailored to the regional profiles of pesticide use, environmental conditions, and available biomass precursors. Pesticide contamination patterns vary widely across climates and agricultural systems, resulting in distinct chemical signatures that determine adsorption behavior. Simultaneously, locally abundant agro-industrial byproducts, such as walnut shells, rice husks, olive stones, or fruit pomace, offer sustainable carbon sources for region-specific materials. By correlating pesticide structure, adsorbent surface chemistry, and environmental parameters, geo-adaptive materials can be designed to maximize efficiency, selectivity, and sustainability in environmental remediation contexts, including the treatment of pesticide-contaminated soils and water streams. In addition, these materials may be integrated into food processing and packaging systems, where they can function as localized, low-cost mitigation strategies aligned with circular economy principles. The review highlights how regionally optimized carbon materials could connect advances in environmental remediation with the practical needs of food technology, leading toward food safety strategies that are both globally relevant and locally adaptable. Full article

Olive pomace biochar, obtained through the pyrolysis of lignocellulosic biomass, has emerged as a sustainable and multifunctional additive for polymer composites. Its physicochemical properties, including porosity, surface area, and electrical conductivity, can be tailored by controlling feedstock type and pyrolysis conditions. Although mechanical reinforcement and thermal stability improvements are well documented, the influence of biochar on surface-related properties such as wettability and contact angle remains insufficiently explored for environmentally relevant composite systems. In this study, epoxy-based composites containing biochar synthesized at 750 °C were evaluated in terms of their water interaction behavior by monitoring the evaporation dynamics of ultra-pure water droplets (10 μL, 0.055 mS/cm conductivity) at eight time intervals between 20 and 580 s using high-resolution digital microscopy. Image enhancement and segmentation were performed prior to Discrete Cosine Transform (DCT) analysis to describe droplet geometry in the frequency domain. Time-dependent variations in the standard deviations of DCT coefficients were optimized using the Bat Algorithm, resulting in mathematical models capable of accurately representing droplet evolution and surface–fluid interactions. The primary novelty of this study lies in the development of a hybrid experimental–computational framework that integrates droplet-based wettability measurements with signal-domain analysis and metaheuristic optimization. Unlike conventional studies focusing solely on material characterization, this approach establishes quantitative relationships between surface behavior and numerical descriptors derived from DCT and the Bat Algorithm. The proposed methodology provides a data-driven tool for predicting wettability trends in biochar-reinforced composites and supports the development of moisture-resistant materials for coatings, packaging, and thermal insulation applications within the context of sustainable composite design. Full article