Search Results (1,817)

The valorization of food industry by-products is a promising strategy for developing natural additives to increase food quality. This study examined the efficiency of tomato processing industry waste (TPIW), which is a significant agro-industrial by-product, in enhancing the oxidative stability of three common edible vegetable seed oils (i.e., sunflower, soybean, and corn oils) under accelerated storage conditions. A custom response surface methodology (RSM) approach was employed to design and optimize the experiments, also using butylated hydroxytoluene (BHT), a potent synthetic antioxidant (i.e., oil type, TPIW and/or BHT enrichment). Oils were incubated under controlled conditions at 60 °C for 28 d (Schall oven test), wherein both darkness and light exposure were employed. Untreated (control), TPIW-enriched, and BHT-fortified (positive control) oils were examined in this study. The oxidative stability and shelf-life of oils was thoroughly evaluated using standard oxidative indices for both primary and secondary oxidation by-products, antioxidant capacity (DPPH radical scavenging activity), total carotenoid content, chromatic coordinates (CIE 1976 L*a*b*), and Fourier-Transform Infrared spectroscopy to monitor structural changes. The results revealed that enrichment with TPIW significantly (p < 0.05) reduced both primary and secondary oxidation products compared to untreated oils, approaching the protective efficiency of BHT in some assays. Specifically, it was observed that the combination of soybean oil enriched with both BHT and TPIW was the most preferable to enhance oxidation stability. Results from FT-IR supported these findings; slower formation of oxidative derivatives was revealed. Light exposure did not show a significant impact on the oxidation process regardless of the oil sample when compared to the temperature parameter. The results of this study confirm that TPIW could assist shelf-life prolongation of edible vegetable oils and promote a circular economy strategy by valorizing food by-products as a viable alternative to synthetic antioxidants. Full article

Arachidonic acid (AA) is a high-value long-chain polyunsaturated fatty acid commonly produced by submerged fermentation of oleaginous fungi. Solid-state fermentation (SSF) using low-cost agro-industrial by-products represents a promising alternative approach for sustainable microbial lipid production. In this study, spent malt, a by-product of the brewing industry, was evaluated as a solid substrate for AA production by Mortierella alpina under SSF conditions. Four M. alpina strains were screened for growth, lipid accumulation, and AA production, and M. alpina 959 was selected as the most promising strain. The effects of nitrogen supplementation and oil incorporation on biomass formation, lipid accumulation, and AA productivity were subsequently investigated. Sunflower oil incorporation into spent malt-based substrates improved AA productivity under the most favorable conditions, resulting in an AA proportion of 38.6% of total fatty acids and 102.5 mg AA g⁻¹ of final dry mass of the SSF system (FDW-SC). Comparison of selected vegetable oils further demonstrated that the lipid source affected AA production, while having only a limited effect on fungal growth and total lipid accumulation. Overall, this study demonstrates the feasibility of spent malt-based SSF for AA production by M. alpina and highlights the valorization of brewery spent malt as a low-cost agro-industrial by-product for the production of value-added microbial lipids. Full article

The valorization of agro-industrial by-products has gained increasing attention as a sustainable strategy to support circular economy principles and reduce environmental impacts. Spain, the world’s largest olive oil producer, generates substantial amounts of olive pomace (OP), which can represent up to 80% of the processed olive mass. Due to their hydrophilic nature, approximately 98% of olive phenolic compounds remain in OP after oil extraction, making this by-product a valuable source of bioactive compounds with antioxidant, anti-inflammatory, antimicrobial, and cardioprotective properties. Numerous extraction strategies have been investigated to maximize phenolic recovery while reducing processing costs and environmental impacts. Conventional solvent-based techniques, such as solid–liquid extraction (SLE) and liquid–liquid extraction (LLE), remain widely used, while greener approaches, including microwave-, ultrasound-, supercritical fluid-, pressurized liquid-, and high-pressure-assisted extraction, among others, have gained increasing attention. In addition, deep eutectic solvents (DES) have been applied either alone or in combination with green extraction technologies to enhance extraction efficiency. This review provides a comprehensive overview of extraction techniques for OP valorization and the analytical methodologies used to characterize OP extracts, including spectrophotometric and chromatographic approaches. The biological activities of OP-derived phenolics and their food applications are also discussed, highlighting their valorization potential. Full article

Wood vinegar (WV), also known as pyroligneous acid, is the aqueous condensate produced during lignocellulosic biomass pyrolysis, generated alongside biochar and non-condensable gases. In forest biorefineries, it represents a promising value-added coproduct capable of transforming forestry and agroforestry residues into a multifunctional bioproduct. Its composition, dominated by water, organic acids, phenolic compounds, aldehydes, and ketones, confers antimicrobial, antioxidant, biostimulant, herbicidal, and preservative properties. This review critically examines WV production, chemical composition, purification strategies, mechanisms of action, and applications, explicitly distinguishing evidence-based uses from prospective ones. Current evidence supports applications in agriculture, wood preservation, environmental management, and forestry, including forest nursery production and clonal propagation of Eucalyptus and Pinus. However, the literature remains fragmented by compositional variability, non-standardized terminology, limited mechanistic understanding, and scarce long-term toxicological and techno-economic assessments. WV holds significant potential for sustainable biomass valorization and circular bioeconomy strategies. Realizing this potential requires harmonized analytical protocols, standardized formulations, rigorous mechanistic studies, life-cycle assessments, and regulatory frameworks that support the transition of this heterogeneous pyrolysis byproduct into a reliable commodity within integrated forest biorefineries. Full article

This work reviews the strategic valorization of industrial by-products as sustainable sources of biopolymers and bioactive compounds, promoting a circular economy through the efficient use of renewable resources and reducing waste generation. These strategies contribute to lowering the carbon footprint of conventional packaging and plasticulture while supporting more resilient and diverse agriculture systems. Special emphasis is placed on processing roots and tubers as renewable raw materials for the production of biodegradable films for agronomic applications as eco-friendly alternatives to petroleum-based plastics and contributing to soil and ecosystem protection. Additionally, the incorporation of by-products from yerba mate (Ilex paraguariensis) demonstrate significant potential as both matrix-forming and filler materials in biodegradable composites while also providing antioxidant activity and pH-sensing capacity. This sustainable framework is further expanded through the utilization of non-traditional species like rosehip (Rosa rubiginosa), Aloe vera (Aloe barbadensis), and topinambur (Helianthus tuberosus), which provide versatile functional matrices and bioactive compounds. Finally, the development of active and intelligent food packaging is addressed. Extracting natural pH-sensitive pigments from red cabbage and topinambur flowers enables the formulation of eco-friendly inks for real-time freshness monitoring. Ultimately, integrating these waste streams drives technological disruption, scaling sustainable, tailored solutions for global industry needs. Full article

The use of non-traditional oilseeds for food purposes has increased significantly in recent years. Due to the high content of unsaturated fatty acids, the production of cold-pressed oils from pumpkin and hemp seeds is growing at a steady pace. This results in the accumulation of a by-product (oilseed press cake), from which high-quality proteins can be derived. Protein hydrolysates based on these raw materials offer further potential for valorization. This review summarizes classical and modern methods for obtaining protein isolates from pumpkin and industrial hemp oilseed cakes, as well as possible approaches for their modification to enhance their nutritional and functional properties. Furthermore, it provides an overview of the methods for producing protein hydrolysates rich in bioactive peptides. The presence of peptides with antioxidant, antihypertensive, or hypoglycemic properties makes hydrolysates a valuable source of nutraceutical components with potential applications in the development of functional foods or dietary supplements. However, most studies to date have been conducted using in vitro systems. Further research involving animal models or clinical observations is required to determine dosage regimens and applications of these hydrolysates. Regarding protein isolates, the challenges for their broader use in the food industry are related to increasing solubility, removing anti-nutritional factors, and improving techno-functional properties. Full article

Fungal cellulases are key biocatalysts for lignocellulosic biomass valorization and the development of sustainable biorefineries. This review examines recent advances in the production of endoglucanase (EGL), exoglucanase (EXG), and β-glucosidase (BGL) by fungi of the genera Trichoderma, Aspergillus, and Penicillium under solid-state fermentation (SSF) and submerged fermentation (SmF). Emphasis is placed on fermentation strategies, substrate selection, process optimization, and emerging chemometric and artificial intelligence-based approaches. The literature reveals a predominance of SSF systems, especially when agri-food residues such as wheat bran, sugarcane bagasse, rice-derived residues, fruit-processing wastes, and cocoa by-products are employed as low-cost substrates. Among the evaluated genera, Aspergillus was among the most frequently investigated genera and exhibited broad substrate versatility, whereas Trichoderma reesei remains the principal industrial production host for cellulase-rich enzyme preparations used mainly in the saccharification of lignocellulosic biomass for cellulosic ethanol and other biorefinery applications. In contrast, Penicillium stands out as an important source of BGL, complementing cellulase systems derived from other fungi. Temperature, pH, moisture content, and fermentation time were consistently identified as the main factors affecting cellulase biosynthesis, with optimal production generally occurring under mildly acidic conditions and mesophilic temperatures. CCD and BBD were the predominant optimization strategies, while artificial neural network-based models are emerging as promising alternatives. The complementary characteristics of these fungi genera support their application in integrated biomass conversion and future lignocellulosic biorefineries. Full article

Lignocellulosic fruit peel waste represents an abundant, carbon-neutral feedstock for green biohydrogen production via dark fermentation, yet its rigid compact structure and high cellulose crystallinity severely restrict saccharification and fermentative hydrogen yield. In this study, a hydrothermal acidification pretreatment strategy was proposed to boost dark fermentative biohydrogen generation from navel orange peel waste, and systematic investigations were conducted to reveal the regulating mechanisms of key pretreatment parameters (hydrochloric acid concentration, pretreatment temperature, duration) on reducing sugar release and hydrogen-producing performance. Multiscale characterizations including SEM, XRD, FTIR, and TG were integrated to unravel the microstructural and chemical compositional evolution of raw and pretreated substrates. The results demonstrated that hydrothermal acidification effectively disrupted the dense lignocellulosic network of navel orange peel, lowered cellulose crystallinity, and greatly improved substrate accessibility for hydrolytic reactions and microbial adhesion. Under the optimal pretreatment condition (1.0 mol/L HCl, 120 °C, 1 h), the concentration of released reducing sugars reached 10.2 g/L, which was 67.2% higher than that of untreated raw peel. The corresponding maximum cumulative hydrogen yield attained 36.5 mL H₂/g TS, representing a 67.4% improvement relative to the untreated control group. Pearson correlation analysis verified that pretreatment temperature, acid concentration, and duration exhibited strong positive correlations with hemicellulose and cellulose removal efficiencies, while excessive pretreatment (HCl > 1.0 mol/L, temperature > 120 °C, duration > 1 h) generated inhibitory by-products that suppressed microbial hydrogen evolution. This study comprehensively clarifies the structural modification and biohydrogen promotion mechanism of hydrothermal acidification pretreatment on pectin-rich biomass, and delivers a cost-effective, facile technical route for high-value energy valorization and harmless disposal of fruit processing solid wastes. Full article

Agri-food by-products and residues are increasingly being studied as raw materials for three-dimensional (3D) printing, especially to convert secondary streams into useful, more sustainable products. This review discusses recent advances in the use of these materials, focusing on how their origins, compositions, pretreatments, processing behaviors, and final applications are interconnected. Plant-, animal-, industrial-, and post-consumer-derived residues are considered, particularly when they provide fibers, proteins, polysaccharides, lipids, bioactive compounds, or biopolymers with technological value. The review also examines the main printing approaches used in this field, including extrusion-based printing, inkjet printing, sintering, and direct ink writing. Particular attention is given to factors that determine successful printing, including rheological behavior, viscosity, particle size, moisture content, structural stability after deposition, interlayer adhesion, and shape fidelity. Current applications range from functional foods and biodegradable or active packaging to biomaterials, controlled-release systems, biocomposites, construction materials, energy-related devices, textiles, and agricultural products. Although the reviewed studies show clear potential, most developments still face important barriers, including raw material variability, safety requirements, sensory acceptance, mechanical performance, scale-up, and regulatory uncertainty. Future progress will depend on moving beyond printable prototypes toward reproducible formulations, real-use validation, and clearer comparison criteria, in line with Sustainable Development Goal 12 and the transition toward higher-value circular production chains. Full article

Hydrogen sulfide (H₂S), a high-volume by-product of the hydrodesulfurization of fossil fuels, can be valorized by thermolysis to recover both molecular hydrogen and elemental sulfur, rather than being oxidized as in the conventional Claus process. The viability of this route depends on quantitative knowledge of the reaction mechanism and of the energy costs of dissociation, which are difficult to obtain experimentally at the temperatures involved. Here we study H₂S thermolysis by reactive molecular dynamics (RMD) with the ReaxFF potential for systems of 1000 H₂S molecules at 1 atm, addressing three coupled questions: the simulation parameters required for dilute gases, the energetics of dissociation, and the elementary reaction mechanism. The interaction cutoff radius proved critical: the original 10 Å value, parametrized for condensed systems, misses about 23 eV of attractive non-bonded interaction energy in the gaseous system at 298.15 K (≈0.023 eV per molecule) and fails to capture dissociation at 3000 K within 20 ns, whereas radii of 30–40 Å converge. Using a 40 Å cutoff at 2500, 3000 and 3500 K, atom-resolved species-transition records reveal a free-radical chain mechanism built from the same set of elementary steps at the three temperatures, whose relative contributions shift with temperature: S–H homolysis initiates the chain, hydrogen abstraction (H• + H₂S → H₂ + HS•) is essentially the exclusive source of H₂ (persistent H• + H• recombination contributed only 1, 13 and 17 events, below 0.5% of the abstraction count), and a slow sulfur-condensation stage (S₂ → S₃ → S₄) limits the net conversion, which reached 9.3 ± 0.9%, 26.3 ± 1.4% and 46.7 ± 1.6% within the simulated windows (single-trajectory counting resolution)—kinetically limited values, not equilibrium conversions. The enthalpy of the system rises linearly with the number of H₂S molecules consumed (R² ≥ 0.99), defining energy costs of 2.46 ± 0.04, 3.10 ± 0.08 and 3.95 ± 0.18 eV per molecule that increase with temperature by ≈1.48 eV per 1000 K; at 3500 K the cost lies between the 0 K complete-dissociation limit D₀ = 3.90 eV derived from the experimental H–SH bond energy and the Kirchhoff-corrected complete-dissociation enthalpy at that temperature (4.11–4.12 eV), statistically indistinguishable from the latter (a 0.9σ difference). These results provide a thermochemically validated, molecular-level basis for engineering the valorization of residual H₂S as a source of green hydrogen. Full article

The transition towards a circular economy of agri-food wastes requires innovative strategies for transforming them into value-added products. This study evaluates the environmental and economic sustainability of a laboratory-scale process that converts 100 g of pomegranate waste, experimentally processed and defined as functional unit (FU), into a cosmetic emulsion. Primary data were collected from laboratory activities carried out in an Italian university, including material and reagent consumption, equipment operating times and energy use. A cradle-to-gate Life Cycle Assessment was performed in SimaPro according to ISO 14040 and 14044 using the Environmental Footprint 3.1 method, while Life Cycle Costing was developed in Microsoft Excel using the same system boundaries. The process valorized the three main pomegranate fractions (arils, mesocarp and exocarp) to obtain a cosmetic emulsion. The exocarp treatment was identified as the main impactful phase. The overall climate change impact reached 328 g CO₂ eq/FU, while fossil resource use amounted to 5.3 MJ/FU. The total production cost was estimated at 189 €/FU, mainly due to labor, reagents, enzymes and equipment costs. Although laboratory-scale operation results in relatively high impacts and costs, the study identifies the main hotspots and provides a baseline for future process optimization and industrial scale-up. Full article

Alkali-activated mortars (AAMs) have emerged as sustainable alternatives to conventional hydraulic cement (HC) matrices produced with natural sand. In this context, interest in the valorization of industrial by-products to develop eco-efficient construction materials has gained crucial academic and industrial attention. This study investigates the feasibility of producing AAMs incorporating copper slag (CS) as an artificial fine aggregate (AFA) to partially or completely replace natural sand. Moreover, the binder matrix was formulated using 80% CS and 20% HC as precursors, activated with different alkaline solutions (Na₂SiO₃ + NaOH) at activator-to-precursor mass ratios ranging from 0.15 to 0.35. Concurrently, CS was incorporated as AFA at volumetric replacement levels of 0%, 25%, 50%, 75%, and 100%. The AAMs were evaluated in terms of workability, physical performance (i.e., bulk density, water absorption, and void content), and mechanical performance. The results demonstrate that the workability of the AAMs increased with higher AFA dosages, reaching a maximum improvement of 23.8% compared with the AAM without AFA. The bulk density of the AAMs increased monotonically with increasing AFA content (consistent with the higher density of AFA with respect to natural sand), whereas water absorption and void content decreased progressively. Although all AAMs exhibited significantly lower compressive strengths than M1 at 7 and 28 days, the differences progressively decreased with curing age. At 56 and 90 days, M5 and M6, incorporating 75% and 100% AFA, respectively, achieved mean compressive strengths that were not statistically different from those of M1, indicating that the mixtures with the highest AFA contents maintained later-age mechanical performance within the variability of the conventional reference mortar. The study demonstrates the feasibility of the synergistic utilization of CS as both precursor and AFA in AAMs. This dual-pathway valorization closes materials loops and advances circular economy principles within the construction sector. Full article

Due to its high content of bioactive constituents and associated health benefits, Aronia melanocarpa is considered a superfood, and its consumption has increased substantially in recent years. This growing demand has led to the generation of large quantities of processed by-products, which remain rich in valuable phytochemicals and require sustainable utilization. In this study, four extraction techniques—conventional solvent extraction (CSE), pressurized liquid extraction (PLE), pulsed electric field extraction (PEF), and ultrasound-assisted extraction (UAE)—were comparatively evaluated and optimized for the recovery of bioactive compounds from aronia pomace. A second-order polynomial model (Fit Least Squares) was applied to determine the optimal conditions for each technique. The optimized extracts exhibited distinct phytochemical profiles: total polyphenol content reached 71.5 (UAE), 70.0 (CSE), 67.0 (PLE), and 48.0 (PEF) mg GAE/g dw, while total anthocyanins were 15.5 (UAE), 13.0 (CSE), 11.0 (PEF), and 3.5 (PLE) mg CyE/g dw. Antioxidant capacity ranged from 538.0 to 800.0 µmol AAE/g dw (FRAP) and 17.0 to 39.0 mmol AAE/g dw (DPPH). HPLC analysis confirmed cyanidin-3-O-glucoside as the predominant compound, with concentrations of 5.0 (UAE), 4.6 (CSE), 3.2 (PEF), and 0.8 mg/g dw (PLE). Overall, ultrasound-assisted extraction under optimal conditions provided the highest recovery of bioactive constituents, highlighting its suitability for the valorization of aronia by-products. Full article

The growing demand for clean-label and low-sulphite wines has increased interest in alternative preservation strategies capable of reducing sulphur dioxide (SO₂) usage while maintaining wine quality and stability. In this study, the effectiveness of Vitis vinifera leaf extract as a natural alternative to sulphur dioxide was evaluated in High Hydrostatic Pressure (HHP)-treated Fiano wines. Three experimental wines were produced: CW (control wine), SW (sulphited wine), and LW (leaf-extract wine). Following alcoholic fermentation, all wines were subjected to HHP treatment (600 MPa for 5 min) and stored at 4 °C for 60 days. Physicochemical parameters, volatile organic compounds (VOCs), and sensory characteristics were evaluated immediately after alcoholic fermentation and after HHP treatment followed by refrigerated storage. Compared with the control wine, LW exhibited approximately 20% higher total polyphenol concentrations, whereas SW showed the greatest preservation of fermentation-derived esters. HHP treatment induced only moderate changes in the volatile fraction, confirming the suitability of this non-thermal technology for wine stabilization. LW wines were characterized by higher abundances of terpene-related compounds, C6 alcohols, medium-chain fatty acids, and phenolic-associated volatiles, resulting in more pronounced floral, balsamic, herbaceous, and vegetal sensory attributes. Principal Component Analysis (PCA) explained 79.0% of the total VOC variability and clearly differentiated LW wines from CW and SW according to their volatile profiles, while sensory analysis confirmed the development of a distinctive aromatic identity associated with grapevine leaf extract. Overall, the results indicate that the combined application of V. vinifera leaf extract and HHP represents a promising strategy for the partial replacement of sulphur dioxide in white winemaking. This integrated approach contributes to wine stabilization while promoting the valorization of grapevine leaves as a sustainable winery by-product within a circular economy framework. Full article

The valorization of food by-products represents a key strategy for sustainable food systems and the circular bioeconomy. Pomegranate peels from two selected Italian cultivars were subjected to environmentally friendly extraction processes aimed at optimizing ellagitannins’ recovery and exploiting their biological activity. Punicalagin (PU) was the predominant compound, and the extracts exhibited high antioxidant capacity in both DPPH and FRAP assays. The Granato cultivar was selected for in vivo evaluation on the Caenorhabditis elegans (C. elegans) nematode model, where it extended lifespan and improved key healthspan markers. Locomotion, feeding activity, muscle integrity, and intestinal barrier function were improved through the activation of conserved stress-response pathways, particularly the SKN-1/NRF2 axis. The results were associated with improved mitochondrial function and reduced age-related oxidative stress, consistent with a hormetic mechanism. The extract also exhibited antibacterial activity, mainly against Gram-positive bacteria. Overall, the results highlight pomegranate peel as a sustainable source of high-value bioactive compounds with potential applications in nutrition, dietary supplements, and dermo-cosmetics. Full article