Search Results (1,568)

Background: This study proposes a cascade strategy for the comprehensive valorization of Rosa canina L. leaves, considered an underutilized agricultural by-product. Methods: The approach is based on a combination of optimized Ultrasound-assisted extraction (UAE) followed by High-pressure homogenization (HPH) of the residual biomass from both whole and ground leaves. UAE parameters (temperature, process duration, and ethanol concentration) were optimized to maximize the yield of total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (DPPH, FRAP). Results: The optimal conditions (55.5 °C, 69.7 min, 40.8% ethanol) yielded extracts with a high TPC (289.55 mg GAE/g) and TFC (177.88 mg CE/g), reducing the processing time by 22% while increasing the TPC yield by 31% compared to the conventional solid–liquid extraction (SLE). It was found that primary extraction from whole leaves is more efficient than extraction from ground leaves, suggesting that the energy-intensive preliminary grinding step could be eliminated. The application of HPH to the residual biomass provided a significant secondary release of bioactive compounds, exceeding high-shear mixing (HSM) by up to 1.5 times for whole leaves. Kinetic analysis showed a higher release of bioactive compounds from whole leaves compared to ground leaves. Conclusions: The proposed UAE + HPH cascade process is a sustainable approach, ensuring rational use of resources and a significant increase in the total yield of antioxidants from Rosa canina L. leaves. Overall, the study may contribute to the circular economy by promoting valorization of agricultural by-products through an energy-efficient, sustainable cascade approach. Full article

Mango (Mangifera indica L.) processing generates peel and seed by-products with high potential for valorization as sources of phenolic-rich ingredients. In this study, peel and seed from four Ecuadorian cultivars were extracted by ultrasound-assisted hydroalcoholic extraction and characterized for total phenolics, phenolic profile by HPLC-ESI-QTOF, antioxidant capacity (DPPH and ABTS), and antimicrobial activity against food-relevant bacteria. A dynamic in vitro gastrointestinal digestion model was also applied to evaluate digestion-driven changes in phenolic-related measurements and antioxidant response, and to assess colonic fermentation outputs, including short-chain fatty acids and viable microbial populations. The results showed a strong dependence on cultivar and by-product type, with total phenolics ranging from 2562.35 to 6304.35 mg GAE/100 g in peels and 212.69 to 3006.48 mg GAE/100 g in seeds. LC–MS profiles were dominated by gallotannin-related compounds and phenolic acids. Extracts displayed antioxidant activity (DPPH: 221.97–456.31 mg Trolox/100 g in peels; 43.71–530.46 mg Trolox/100 g in seeds) and dose-dependent antibacterial effects, with inhibition at 700 mg/L reaching 87.57–94.75%. Digestion markedly modulated phenolic-related indices and fermentation-associated metabolites, with peel phenolics decreasing from 284.27 to 73.95 mg GAE/L and seed extracts increasing propionic acid production up to 55.46 mM. Overall, mango peel and seed are differentiated, cultivar-sensitive sources of bioactive extracts with antioxidant and antimicrobial functionality and measurable impacts on colonic fermentation, supporting their use as sustainable ingredients for circular-economy food and nutraceutical applications. Full article

Astaxanthin (AST) is a carotenoid with powerful antioxidant and anti-inflammatory properties and increasing interest in dermatological and nutraceutical applications. In this study, AST-rich extracts were obtained from by-products of the blue crab Callinectes sapidus and chemically characterized using HPLC-DAD analysis. The antioxidant activity of the extracts was assessed through complementary spectrophotometric assays (DPPH and FRAP). Comparable AST contents were detected in the two extracts, with values of 1.269 ± 0.006 and 1.219 ± 0.015 mg/100 g dry weight for EtOH and IPrOH, respectively. However, the EtOH extract exhibited higher antioxidant activity, reaching 0.10 ± 0.01 mg Trolox equivalents (TE)/g in the DPPH assay and 0.27 ± 0.02 mg TE/g in the FRAP assay, compared with 0.08 ± 0.01 and 0.11 ± 0.03 mg TE/g for the IPrOH extract. The biological activity of AST extracts was further evaluated against the opportunistic pathogen Staphylococcus aureus and beneficial lactic acid bacteria. AST exhibited moderate antibacterial activity against S. aureus, with an MIC value of 50 μg/mL and inhibition zones up to 14 mm at 200 μg/disc, while promoting the proliferation of Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus reuteri. These findings highlight the prospective valorization of blue crab by-products as a sustainable supply of antioxidant and microbiota-modulating compounds with possible applications in skin health and cosmetic formulations. Full article

Abundant non-medicinal byproducts of Polygonatum sibiricum and Gentiana scabra are severely underutilized, resulting in resource waste and environmental burden. A previous study confirmed that triple-microbial co-fermentation enhances their antibacterial activity, yet the temporal metabolic mechanism and optimal process parameters remain unclear due to endpoint-only metabolomics limitations. This study aimed to optimize the staged solid-state fermentation (SSF) system for maximum antibacterial activity, verify the triple-microbial consortium’s synergistic enhancement effect, and elucidate the dynamic metabolic mechanism via time-series metabolomics. A staged SSF strategy was established: Aspergillus niger monoculture (0–48 h) followed by Bacillus subtilis and Saccharomyces cerevisiae co-culture (48–72 h). Key parameters were optimized via single-factor experiments and a Box–Behnken design. Under optimal conditions, inhibition zones against Staphylococcus aureus and Escherichia coli reached 20.8 ± 0.3 mm and 17.6 ± 0.2 mm, respectively, with a 17.5% increase in S. aureus inhibition and markedly improved E. coli inter-batch consistency. Time-series untargeted LC-MS/MS metabolomics (2681 identified metabolites) revealed a three-stage metabolic relay model driving antibacterial enhancement: 0–48 h shikimate pathway activation for phenolic precursor accumulation; 48–60 h dipeptide conversion and ABC transporter enrichment initiating antibacterial synthesis; 60–72 h metabolic flux redirected to indole alkaloid biosynthesis for complex antibacterial compound accumulation. This work provides a mechanistic paradigm for the high-value valorization of herbal byproducts, with applications in natural antibacterial agents and functional feed additives. Full article

Pistachio hull (PH) is the largest by-product of the pistachio industry. It contains high levels of phenolic compounds, which have antioxidant properties and promote health. However, PH can accumulate during harvesting, potentially resulting in environmental pollution. This study aimed to optimize the operational conditions for conventional solvent extraction (CSE) and accelerated solvent extraction (ASE) of phenolic compounds from PH using response surface methodology (RSM). The extracts obtained under optimal conditions for the two extraction techniques were compared. The highest values of phenolic recovery (9.92 ± 0.09 g gallic acid equivalent (GAE)/100 g dried matter (DM)) and radical-scavenging activity for α,α-diphenyl-β-picrylhydrazyl (DPPH) (IC50 = 0.16 ± 0.00 mg/mL) were achieved by the extract obtained by ASE (23% ethanol in water, 180 °C, 15 min). Regarding individual phenolic compounds, gallic acid accounted for 35.7–48.1% of the total phenolic compounds contained in the PH extracts, followed by 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic and 2,5-dihydroxybenzoic acid. The findings of this study demonstrate for the first time that PH can be valorized by ASE using eco-friendly solvents, obtaining extracts with a high phenolic content, reducing waste and promoting the bioeconomy development. Full article

Natural resources play a fundamental role in ensuring global food security, while agricultural production itself strongly influences their demand, extraction, and availability. This article discusses natural strategies for increasing crop productivity within the framework of sustainable intensification, focusing on the integrated role of plant biostimulants and micronutrients. Both groups of substances are analyzed from a resource-oriented perspective, highlighting their potential to be derived from renewable sources, particularly agro-industrial by-products and plant biomass. Plant extracts obtained from fruit, vegetable, and cereal processing residues contain numerous bioactive compounds, including phenolics, amino acids, peptides, and organic acids, which can stimulate plant growth, improve nutrient uptake, and enhance tolerance to abiotic stress. Micronutrients such as Fe, Zn, Mn, Cu, and B are also strategic resources in crop production because they regulate key metabolic processes and influence the efficiency of macronutrient utilization. Their effectiveness, however, depends strongly on chemical form and bioavailability in soil–plant systems. The novelty of this work lies in integrating perspectives from plant physiology, coordination chemistry, and resource management to propose a conceptual framework in which plant-derived extracts and micronutrient complexes act as complementary tools supporting circular and resource-efficient agricultural systems. Full article

Growing municipal solid wastes, environmental deterioration, and the world’s increasing energy demand highlight the urgent need for effective, sustainable energy recovery solutions. Uncontrolled municipal solid wastes contribute explicitly to the global crises of climate change, pollution, and biodiversity loss. Food and organic waste are converted into value-added products using biochemical and thermochemical techniques. Anaerobic digestion (AD) is a versatile, multi-phase waste-to-energy technology that transforms organic waste into renewable energy in an oxygen-free environment. AD uses microorganisms to break down waste, yielding biogas (mostly methane and carbon dioxide) and digestate, a nutrient-fortified by-product. Compared with traditional Single-Stage Anaerobic Digesters (SSAD), Two-Stage Anaerobic Digesters (TSAD) offer notable benefits by separating hydrolysis–acidogenesis from acetogenesis–methanogenesis. These include increased methane yield, improved process control, increased microbial stability, and resistance to inhibitory substances. According to the literature, TSAD systems have been shown to increase methane yield by about 10–30% compared to SSAD. This article covers the dynamics of the microbial population at various stages, the impact of operational factors (HRT, OLR, pH, and temperature), and novel reactor designs with modular and multi-state functions. In line with Oman’s Vision 2040, this study discusses the continuous operation of a two-phase AD co-digestion process and the in-depth techno-economic feasibility of decentralized waste management through optimized biogas production. Optimizing the carbon-to-nitrogen (C/N) ratio within the range of 20–30 in co-digestion systems significantly enhances microbial activity and methane production. The potential of recent developments, such as microbial immobilization, biogas generation techniques, and hybrid integration with photobioreactors or electrochemical systems, to enhance the scalability and efficiency of bioconversion is addressed in a TSAD system. In addition to encouraging circular economy principles through efficient organic waste valorization, this review identifies TSAD as a promising approach to achieving the SDGs related to sustainable cities, clean energy, and responsible consumption. Full article

Palm kernel cake (PKC), a byproduct of palm kernel oil extraction, is processed into palm kernel meal (PKM), which contains hemicellulose rich in mannose, a versatile sugar with applications in the pharmaceutical and food industries. However, its association within the lignin–cellulose matrix is a challenge for industrial extraction. This study proposes an optimized enzymatic hydrolysis method utilizing mannanase to maximize the mannose content from PKM powder to produce palm kernel mannose syrup. A 3³ Box–Behnken design within a response surface methodology coupled with a desirability function method was used to optimize hydrolysis parameters to maximize mannose and solids content while minimizing enzyme concentration and hydrolysis time. The optimal conditions for enzymatic hydrolysis were established as a reaction time of 16 h, 5% (w/v) solids, and 5% (w/w) enzyme, resulting in 4.325 g/L of mannose and a mannose yield of 24.33 ± 0.5%. The palm kernel mannose syrup was evaluated, resulting in a moisture content of 15.85 ± 0.07%, water activity of 0.6918 ± 0.003, and a pH of 4.05 ± 0.282, demonstrating shelf-life stability. These findings demonstrate the technical feasibility of valorizing PKC and PKM into a stable, mannose-rich syrup, offering a sustainable and scalable pathway for converting agro-industrial waste into high-value ingredients for multiple value-added applications. Full article

This study compared the physicochemical properties, nutritional composition, and flavor characteristics of broccoli stalk and floret juices fermented with Limosilactobacillus reuteri 18 (Lr18) to enhance the valorization of broccoli processing by-products. Four sample groups were analyzed: non-fermented stalks, fermented stalks, non-fermented florets, and fermented florets. After 48 h of fermentation, total viable counts and total phenolic content were slightly higher in florets than in stalks. Total titratable acids, total sugars, total soluble solids (TSS), total flavonoids, and vitamin C were initially higher in florets but decreased after fermentation in both groups. Organic acid analysis revealed that fermentation increased citric acid, reduced oxalic acid, and promoted the conversion of malic acid to lactic acid. Stalks contained higher levels of lactic and malic acids but lower citric acid than florets. Tryptophan content was higher in florets and was partially converted to indole derivatives after fermentation. Volatile compound analysis and sensory evaluation indicated that fermentation reduced fruity notes in florets while increasing acidic and sulfurous notes. In contrast, fermentation enhanced fruity and rounded notes in stalks while reducing pungency. These findings provide a scientific basis for developing fermented vegetable products with improved functional and sensory properties, particularly using broccoli stalks as a valuable by-product. Full article

The co-pyrolysis of Chlorella vulgaris (CV) and Eucalyptus branches (EP) offers a promising strategy to enhance bio-oil yield, improve resource utilization efficiency, and alleviate environmental pressures. In this study, the microwave-assisted co-pyrolysis of CV and EP at a mass ratio of 2:1 was investigated, focusing on the catalytic performance of Ni-X (X = Mg, Cu, Fe) bimetallic modified HZSM-5 zeolites. The effects of these catalysts on pyrolysis characteristics, product distribution, and bio-oil composition were systematically evaluated. Experimental results showed that the 15% Ni-Cu/HZSM-5 catalyst exhibited the best catalytic performance, achieving the highest bio-oil yield of 16.83%; it also elevated the R_m to 0.0687 wt.%/s and reduced T_s to 2084 s. Composition analysis revealed that Ni-Cu/HZSM-5 significantly promoted the formation of hydrocarbons, increasing their relative content from 11.59% (C2E1 Group) to 28.92%, while effectively suppressing the formation of nitrogen-containing compounds, reducing their content by 5.05%. Based on these results, a possible reaction pathway is proposed in which the Ni-Cu/HZSM-5 catalyst may enhance heteroatom removal through hydrodeoxygenation (HDO) at the Ni-Cu sites, followed by cracking and aromatization at the HZSM-5 acid sites. This effect may be complemented by preferential adsorption of oxygenated intermediates over nitrogen-containing species, which could help suppress the formation of nitrogenous heterocycles. This work provides theoretical guidance for the application of bimetallic zeolite catalysts in microalgae/lignocellulose co-pyrolysis, alongside a viable pathway for valorizing Eucalyptus by-products to produce high-quality bio-oil. Full article

Despite its rich bioactive composition, orange peel dust (OPD), a fine industrial by-product generated during citrus processing in the filter tea industry, has not received much attention as a valuable matrix. Using antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP)), α-amylase inhibitory activity, antimicrobial potential, and sugar composition as function-oriented indicators, this study aimed to compare four green extraction technologies: subcritical water extraction (SWE), pressurized ethanol extraction (PEE), ultrasound-assisted extraction (UAE), and sequential supercritical CO₂–UAE (Sc-CO₂–UAE) applied to OPD derived from Citrus sinensis L. Among thermally driven techniques, PEE at 220 °C had the highest radical-scavenging activity, while UAE showed the broadest antifungal activity against Fusarium spp. and Alternaria alternata, along with selective antibacterial activity against Bacillus cereus. Sequential Sc-CO₂ pretreatment at 300 bar followed by UAE resulted in the highest α-amylase inhibitory activity. Sugar analysis indicated that thermal conditions enhanced carbohydrate hydrolysis, while UAE and Sc-CO₂-UAE maintained structural sugars under mild conditions. All green extraction approaches outperformed conventional maceration. These findings validate OPD as a valuable industrial by-product suitable for sustainable valorization, supporting circular economy concepts in the citrus processing sector. Full article

Corn processing waste represents an abundant, renewable, and low-cost lignocellulosic resource with considerable potential for environmental remediation applications. Large quantities of residues generated during corn processing, including cobs, husks, bran, and other by-products, are produced annually and can be utilized directly as native biomass or converted through thermochemical processes into hydrochars and biochars. This systematic review provides a comparative analysis of native corn processing biomass, hydrochars produced via hydrothermal carbonization, and biochars obtained through pyrolysis, with a focus on their potential as adsorbents for the removal of organic and inorganic pollutants from soil and water systems. Particular attention is given to the influence of thermochemical conversion processes on the physicochemical properties of the materials, including surface chemistry, porosity, functional groups, and structural characteristics, which govern adsorption mechanisms such as ion exchange, electrostatic interactions, surface complexation, hydrogen bonding, and π–π interactions. Furthermore, the advantages and limitations of each material type are discussed, together with key environmental and techno-economic considerations related to their production and practical application, including indicative production costs (USD per kg of adsorbent) and cost–performance relationships in terms of adsorption capacity. By linking biomass conversion processes, material properties, and adsorption performance, this review aims to provide a comprehensive overview of corn processing waste valorization and to support the development of sustainable adsorbent materials for soil and water remediation. A total of 36 studies were included in the qualitative synthesis following PRISMA guidelines. 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

Solid-state fermentation (SSF) is a pivotal biotechnology in the circular economy, leveraging agri-food industrial waste and byproducts to produce high-value bioproducts while minimizing organic waste. By aligning with sustainability goals and zero-waste principles, SSF enables the production of enzymes, bioactive compounds, and secondary metabolites for food, agriculture, and biomedical applications. Recent advancements have optimized critical parameters, including substrate selection, culture conditions, and scalable bioreactor designs, enhancing process efficiency and reducing environmental impact. Despite progress, challenges persist in maximizing production yields and fostering industrial adoption. Addressing these hurdles, particularly through integrated environmental and techno-economic analyses, is essential to solidify SSF’s role as a sustainable and competitive bioprocessing method. This review analyzes the latest advances in SSF, including the valorization of food and agro-industrial wastes, innovative bioreactor designs, microbial engineering for more efficient strains, bioenergy production and its integration into biorefineries, and contributions to the circular bioeconomy. Thus, SSF emerges as a key technology in sustainable industrial biotechnology, offering eco-friendly alternatives and promoting a more efficient production model. Full article

Industrial zinc borate is commonly produced through a hydrothermal process using boric acid and zinc oxide as raw materials. In this study, zinc borate was synthesized by replacing boric acid with borax ore and fresh water with borax plant wastewater in order to improve resource efficiency and water sustainability within an industrial symbiosis framework. Due to side reactions originating from borax, the reaction medium exhibited high ionic strength, and the synthesis was completed at 90 °C in approximately 5 h, slightly longer than conventional industrial processes. An additional washing step was applied to reduce impurities, resulting in a final impurity level of 2966 mg/kg, comparable to that of commercial zinc borate. The use of borax plant wastewater significantly reduced fresh water consumption. However, the formation of a by-product stream containing approximately 16% Na₂SO₄ may limit direct industrial applicability. If this sodium sulfate stream is valorized within an industrial symbiosis framework, zinc borate production from borax and wastewater could represent a cost-effective and sustainable alternative to conventional processes. Full article