Search Results (171)

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

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 valorization of olive oil production residues represents an innovative and sustainable strategy aligned with circular economy principles and the United Nations Sustainable Development Goals. In this study, we aimed to explore the phytochemical composition and neuroprotective potential of organic extracts obtained from olive pomace of the Arbequina and Arbosana cultivars. Extracts were prepared through solid–liquid extraction and analyzed by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS), enabling the comprehensive identification of bioactive metabolites. The analysis revealed a diverse profile of phenolic compounds, including hydroxytyrosol, tyrosol, and multiple oleuropein derivatives, as well as triterpenic acids such as oleanolic and maslinic acids. These compounds are widely recognized for their antioxidant, anti-inflammatory, and neuroprotective activities. The antioxidant potential of the extracts was evaluated in vitro using DPPH and ABTS radical scavenging assays, showing significant activity comparable to that of standard antioxidants. Moreover, cholinesterase inhibitory assays demonstrated moderate to strong inhibition of acetylcholinesterase, an enzyme implicated in neurodegenerative diseases such as Alzheimer’s disease. To further elucidate the molecular basis of these effects, in silico molecular docking studies were performed on the most abundant compounds, revealing favorable binding affinities and interactions with key active site residues of acetylcholinesterase. Overall, these findings highlight olive pomace as a promising, underutilized source of bioactive compounds with potential applications in the development of functional foods, nutraceuticals, and neuroprotective therapeutic agents. The integration of in vitro and in silico approaches strengthens the evidence supporting the use of these extracts in future biomedical and industrial applications. Full article

This study explores the development of bigels (BGs) combining a hydrophilic hydrogel (HG) and a lipophilic oleogel (OG) for co-delivery of two carob fruit extracts (CFEs): I-CFE (inositols) and P-CFE (phenolics). The BGs were formulated in HG:OG ratios of 70:30 and 30:70, using a sodium alginate-based HG and an OG composed of olive pomace oil (OPO) and microcrystalline wax (MW). CFEs were loaded in three modes: I-CFE in HG, P-CFE in OG, and both in their respective phases. Rheological, thermal, physicochemical, and microstructural properties were assessed. All the BGs exhibited solid-like viscoelastic behavior, with greater rigidity in 30:70 formulations. The OG phase enhanced the structural BG network, especially when loaded with P-CFE. At 70:30, I-CFE conferred pseudoplasticity and conformational flexibility, particularly in the absence of P-CFE. At 30:70, both extracts acted synergistically, increasing mechanical strength and network organization. Thermal analysis confirmed MW’s role in structuration, with the BGs showing melting peaks between 40–50 °C. The effects studied affected color and stability. Polarized light microscopy confirmed organized microstructures. This is the first work demonstrating the structuring potential and interactive effects of dual carob extracts (I-CFE and P-CFE) within BGs. All the BGs showed suitable fat-replacer properties, remaining self-standing for 21 days, except the 70:30 I-CFE-free formulation. The findings highlight the potential of CFE-loaded BGs as multifunctional fat replacers in healthier meat products. Full article

The increasing demand for sustainable substrates in agriculture and urban greening calls for alternatives to peat, whose extraction poses significant environmental risks. This study assesses the potential of olive pomace biochar (OB), wood biochar (WB), and green compost (GC), alone or in combination, to partially replace peat in growing media and improve substrate properties and plant development. Ten different substrates were formulated by substituting 10–20% of a commercial peat-based substrate with these organic amendments, using the commercial substrate alone as a control. The effects of such replacements were evaluated in the following experiments: a germination test conducted in Petri dishes using four forage species (Medicago polymorpha, Lolium perenne, Festuca arundinacea, and Lolium rigidum); and two parallel pot experiments lasting 100 days each (one with M. polymorpha and L. perenne, and another with young Olea Europaea var. Arbequina saplings). This study evaluated the impact on plant development, as well as the physical properties and composition of the substrates during the incubation process. Germination and survival of forage species were comparable or improved in most treatments, except those including 20% OB, which consistently reduced germination—likely due to high electrical conductivity (>10dS/m). In the pot experiments, substrate pH and total carbon content increased significantly with biochar addition, particularly with 20% WB, which doubled total C relative to control. Both forage species (Medicago polymorpha and Lolium perenne) and the olive saplings (Olea Europaea) exhibited normal growth, with no significant differences in biomass, water content, or physiological stress indicators when compared to the control group. Nutrient uptake was found to be stable across treatments, although magnesium levels were below sufficiency thresholds without triggering visible deficiency symptoms. Overall, combining compost and biochar—particularly WB and GC—proved to be a viable strategy to reduce peat use while maintaining substrate quality and supporting robust plant growth. This approach proved effective across the different plant varieties tested, including Medicago polymorpha, Lolium perenne, and young olive plants, which together encompass a wide spectrum of agronomic and horticultural applications as well as contrasting growth and nutrient requirements. Adverse effects on early plant development can be avoided by carefully selecting and characterizing biochars, with specific attention to salinity and C/N ratio. This finding is crucial for the successful large-scale implementation of sustainable alternatives to peat. Full article

The olive tree (Olea europaea L.) has been cultivated for millennia, with olive oil representing both a cornerstone of the Mediterranean diet and a major agricultural commodity. Its composition, rich in monounsaturated fatty acids, polyphenols, tocopherols and squalene, supports well-documented cardioprotective, antioxidant and anti-inflammatory benefits. Olive oil production generates substantial secondary streams, including pomace, leaves, pits and mill wastewater, which are rich in phenols, triterpenes and fibers. This review consolidates recent advances in their phytochemical characterization, innovative extraction technologies and health-promoting effects, while highlighting the economic and regulatory prospects for industrial adoption. Comparative analysis shows that olive leaves can produce up to 16,674.0–50,594.3 mg/kg total phenolics; oleuropein 4570.0–27,547.7 mg/kg, pomace retains 2.24 g GAE/100 g dried matrix (DM)total phenolics; oil 13.66% DM; protein 6.64% DM, and wastewater contains high concentration of phenolics content of olives. Innovative extraction techniques, such as ultrasound and microwave-assisted methods, allow for a recovery, while reducing solvent use and energy input. The analysis highlights opportunities for integrating these by-products into circular bioeconomy models, supporting the development of functional foods, nutraceutical applications and sustainable waste management. Future research should address techno-economic feasibility, regulatory harmonization and large-scale clinical validation to accelerate market translation. Full article

Tomato processing residues—including peels, seeds, and pomace—are rich in bioactive compounds, such as lycopene, β-carotene, cutin, pectin, and antioxidants, yet are often underutilized. This study evaluates microwave-assisted extraction (MAE) and high-pressure-assisted extraction (HPAE) for the recovery of carotenoids from TP, compared to conventional extraction (CE) using ethyl acetate. Optimal MAE conditions (150 W, 50 °C, 20 min, solid/liquid ratio of 1:10 g/mL) yielded 592.5 mg carotenoids/kg dry weight (dw), exceeding CE yields (505.3 mg/kg dw), while significantly reducing extraction time (20 min vs. 120 min). By contrast, direct HPAE (650 MPa, ambient temperature, solid/liquid ratio of 1:10 g/mL) resulted in lower carotenoid yields (ca. 84 mg/kg dw), but when used as a pre-treatment followed by stirring for 24 h, HPAE enhanced carotenoids extractability to 277.0 mg/kg dw, recovering 55% of carotenoids extracted by CE. Bioaccessibility studies showed low lycopene bioaccessibility across all methods (3.9% for HPAE, 3.4% for MAE, and 1.6% for CE). Incorporation into oils significantly improved bioaccessibility, with olive pomace oil (OPO) achieving 28.1%, compared to 8.1% in corn oil (CO). Overall, MAE and HPAE (as pre-treatment) present efficient strategies that reduce solvent usage and processing time, though they still rely on organic solvents, while strategies to enhance bioaccessibility should further be explored for effective functional ingredient development. Full article

This review concentrates on the bioactive potential of two significant agri-food by-products: coffee by-products (coffee pulp and husk, spent coffee grounds, and silverskin) and olive by-products (olive mill wastewater, pomace, stones, and leaves). These residues are produced in substantial quantities, and despite their considerable application potential, they remain predominantly underutilized, thereby contributing to environmental burdens and economic losses. Their richness in bioactive compounds is unequivocal. Specifically, coffee by-products are abundant in caffeine and chlorogenic acids, whereas olive by-products serve as excellent sources of oleuropein, hydroxytyrosol, and tyrosol. Such compounds possess health-promoting properties and are promising active ingredients for cosmetic formulations, owing to their antioxidant, anti-aging, UV protective, antimicrobial, emollient, and moisturizing effects. This review not only compiles the bioactive compounds present in these by-products and explores their potential applications but also examines the extraction methods employed for their recovery. Both conventional techniques (solvent extraction) and green extraction technologies (ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction) are discussed. These innovative and environmentally friendly approaches enhance extraction efficiency and are aligned with sustainability objectives. In this context, the importance of incorporating natural ingredients into cosmetic products is emphasized, both to meet regulatory and environmental standards and to satisfy the increasing consumer demand for safer, more effective, and environmentally sustainable formulations. Full article

Exhausted olive oil pomace (EOP), Fucus spiralis, and Limnospira sp. extracts—rich in bioactives, polysaccharides, or proteins—were incorporated into alginate-based edible coatings and applied to strawberries to evaluate their effects on postharvest quality parameters, including decay, weight loss, color, antioxidant activity, and microbial growth. Among the tested formulations, the EOP-based coating (0.25% bioactive rich-extract) was the most effective, reducing weight loss to approximately 18% after 10 days at 10 °C, compared with higher losses in the control and other coatings, while also better preserving color through higher hue and chroma retention. Antioxidant activity, measured by ABTS and DPPH assays, was consistently higher in EOP-coated strawberries, despite a general decline in total phenolic content across treatments. Specifically, ABTS values decreased from 21.43 ± 0.90 (day 0) to 12.88 ± 0.39 (day 10) mmol TE/100 mg DW, while DPPH values declined from 10.23 ± 1.39 (day 0) to 5.96 ± 1.03 (day 10) mmol TE/100 mg DW. Microbial analyses further showed that the EOP coating strongly inhibited spoilage fungi, yeasts, and bacteria, whereas coatings containing Fucus spiralis or Limnospira sp. extracts (0.25% bioactive rich-extract plus 0.5% polysaccharide- or protein-rich extract) offered only moderate protection and, in some cases, promoted microbial growth. Overall, the EOP coating demonstrated superior performance in maintaining freshness, delaying microbial spoilage, and extending the shelf life of strawberries, highlighting its potential as a sustainable and functional strategy for fruit preservation. Full article

The valorization of agro-industrial by-products is a key component of sustainability goals in food production. Olive pomace (OP), a major by-product of olive oil extraction, is characterized by a high content of dietary fiber and bioactive phenolic compounds with antioxidant activity, which contribute to its nutritional and functional potential. The present study investigated the effect of the fortification of sheep milk yogurt with freeze-dried OP (1% w/w), added either before pasteurization (YOPB) or after overnight refrigeration (YOPA). The OP showed considerable antioxidant capacity and was microbiologically safe. Its addition significantly increased the yogurt’s total phenolic content, with YOPB displaying the lowest syneresis and the highest water-holding capacity and apparent viscosity. Textural and scanning electron microscopy analyses revealed that the timing of OP addition affected the gel structure, with pre-pasteurization incorporation facilitating a superior integration into the protein network. The microbial viability was preserved, and the sensory evaluation showed no significant differences in consumer acceptance between the control and YOPB. These findings highlight OP’s potential as a functional ingredient for dairy fortification, contributing to waste reduction and improving gel structure. The findings obtained provide support for the development of sustainable and functional dairy products enriched with by-products derived from the olive oil industry. Full article

This study focuses on the design, development and quality assessment of an innovative shelf-stable olive paste dip, aiming at the valorization of by-products of tomato processing and olive oil production (Product 1: OPD). Bioactive compounds (BACs), i.e., total carotenoids and phenolic components, were extracted from tomato and olive pomace, respectively. For further enrichment, BACs were incorporated in olive paste dips into a second product (OPDEnr) in encapsulated form (Product 2: OPD_Enr). The total carotenoids (TC) of OPD and OPD_Enr were 20.0 ± 2.0 and 30.2 ± 1.0 mg/kg, respectively. Similarly, the total phenolic content (TPC) and the antioxidant activity (AA) were 1.62 ± 0.08 and 3.05 ± 0.10 mg GAE/g, and 0.801 ± 0.075 and 0.976 ± 0.032 mg Trolox/g, respectively. The quality of the developed olive paste dip product prototypes was assessed using the Accelerated Shelf Life Testing (ASLT) methodology at a temperature range of 20–40 °C. Both OPD_Enr and OPD were microbiologically stable during storage (i.e., not exceeding 4 logCFU/g for total mesophilic counts), and no lipid oxidation evolution was observed (Peroxide Value, PV did not exceed 4 meq O₂/kg), while TC, TPC and AA values remained stable. The shelf life of OPD_Enr and OPD was determined based on the overall sensory quality and was found to be 120 and 211 d at 25 °C, respectively. OPD_Enr and OPD were characterized by a high quality (color and texture), with an overall sensory score of 8.0/9.0 and 9.0/9.0, respectively, in the acceptability–hedonic scale 1 (dislike extremely)-9 (like extremely), and they could potentially be consumed as an antioxidant-enriched olive paste dip. Full article

This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which limit its direct reuse due to phytotoxicity. A native strain of Aspergillus sp., isolated from OP, was employed as the biological agent, while grape pomace (GP) was added as a co-substrate to enhance substrate structure. Fermentations were conducted at two scales, Petri dishes (20 g) and a fixed-bed bioreactor (FBR, 2 kg), under controlled conditions (25 °C, 7 days). Key parameters monitored included dry and wet weight loss, pH, color, phenolic content, and enzymatic activity. Significant reductions in color and polyphenol content were achieved, reaching 68% in Petri dishes and 88.1% in the FBR, respectively. In the FBR, simultaneous monitoring of dry and wet weight loss enabled the estimation of fungal biotransformation, revealing a hysteresis phenomenon not previously reported in SSF studies. Enzymes such as xylanase, endopolygalacturonase, cellulase, and tannase exhibited peak activities between 150 and 180 h, with maximum values of 424.6 U·g⁻¹, 153.6 U·g⁻¹, 67.43 U·g⁻¹, and 6.72 U·g⁻¹, respectively. The experimental data for weight loss, enzyme production, and phenolic reduction were accurately described by logistic and first-order models. These findings demonstrate the high metabolic efficiency of the fungal isolate under SSF conditions and support the feasibility of scaling up this process. The proposed strategy offers a low-cost and sustainable solution for OP valorization, aligning with circular economy principles by transforming agro-industrial residues into valuable bioproducts. Full article

The olive oil industry generates by-products like olive leaves and pomace, which are rich in bioactive compounds, especially polyphenols. This study applied a circular economy approach to valorize these residues using green ultrasound-assisted extraction (UAE) with GRAS solvents. Key parameters (solvent composition, ultrasound amplitude, and specific energy) were optimized via Response Surface Methodology (RSM) to enhance polyphenol recovery and yield. Ethanol concentration proved to be the most influential factor. Optimal conditions for olive pomace were 100% ethanol, 46 μm amplitude, and 25 J∙mL⁻¹ specific energy, while olive leaves required 72% ethanol with similar ultrasound settings. Under these conditions, extracts were prepared and analyzed using HPLC-ESI-QTOF-MS and DPPH assays. The optimized UAE process achieved yields of 15–20% in less than 5 min and under mild conditions. Optimal extracts showed high oleuropein content (6 mg/g in leaves, 5 mg/g in pomace), lower hydroxytyrosol levels, and minimal oxidized derivatives, suggesting reduced degradation compared to conventional methods. These findings demonstrate UAE’s effectiveness in recovering valuable phenolics from olive by-products, supporting sustainable and efficient resource use. 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

Background: Olive pomace, a byproduct of olive oil production, represents approximately 85% of the processed material and poses environmental risks when improperly discarded. Its composition is rich in polyphenols with potential for cosmetic use, especially in skin barrier care. Objective: To develop a natural extract rich in antioxidants from olive pomace using sustainable solvents (water and 1,3-propanediol) for skin barrier support. Methods: The phenolic composition and in vitro biological activities of the extracts were analyzed. Results: The extracts demonstrated a reducing capacity (15 to 33 mg GAE/g) and flavonoid content (4 to 5 mg QE/g). In addition, their antioxidant capacity was proven through the inhibition of the DPPH radical (7% to 91%) and ABTS (7% to 95%) and the reduction in oxidation in the beta-carotene/linoleic acid system (6% to 35%), presenting results superior to those of tocopherol acetate. The hydroxytyrosol and oleuropein compounds, ranging from 28 to 54 and 51 to 85 µg/mL, respectively, were quantified via HPLC. The extract with the highest levels of hydroxytyrosol and oleuropein was analyzed via UHPLC-QqTOF-MS, and 33 compounds were identified. This extract showed antiglycation activity (24% to 40%). The incorporation of this extract into a cosmetic emulsion resulted in sufficient antioxidant capacity to replace tocopherol acetate. Conclusions: The use of effective extraction techniques and nontoxic solvents ensures the sustainability and safety of the extract for application as a natural cosmetic ingredient, aiming to promote the health and integrity of the skin barrier. Full article