High-added Value Research Articles

Industrial-level Paired Electrosynthesis of Valuable Chemicals over a High-performance Heterostructural Electrode.

Paired electrosynthetic technology is of significance to realize the co-production of high-added value chemicals. However, exploiting efficient bifunctional electrocatalyst of the concurrent electrocatalysis to achieve the industrial-level performance is still challenging. Herein, an amorphous Co2P@MoOx heterostructure is rationally designed by in-situ electrodeposition strategy, which is acted as excellent bifunctional catalysts for the electrocatalytic nitrite reduction reaction (NO2RR) and glycerol oxidation reaction (GOR). The membrane-electrode assembly (MEA) electrolyzer realizes a low voltage of 1.30 V, robust stability over 200 h at 100 mA cm-2, high Faraday efficiencies and yield of NH3 (above 95%, 49.7 mg h-1 cm-2) and formate (above 95%, 152.3 mg h-1 cm-2) at industrial-level current density of 500 mA cm-2. In-situ spectroscopy studies have shown that high-valence CoOOH is the main active material of GOR, and the main catalytic conversion pathway of NO2RR involves key *NH2OH reaction intermediates. In addition, theoretical calculations confirm that the Co2P@MoOx heterostructure has strong interfacial electronic interaction and optimized reaction energy barriers, which endows its intrinsically high electrocatalytic activity for the co-electrosynthesis of NH3 and formate.

Advances of the past 12 years in decarboxylation of biomass carboxylic acids to biofuels and high-value chemicals via photo- or electrocatalysis

Recent advances in the decarboxylative transformation of biomass-derived carboxylic acids to produce biofuels and high-added value chemicals via photo- or electrocatalysis strategies are reviewed.

Стратегічні імперативи виробництва багатоцільових продуктів харчування та забезпечення продовольчої безпеки в умовах геополітичної нестабільності

The article examines the current problem of ensuring food security in Ukraine in the context of geopolitical instability, which affects the agro-food market and food industry. Particular attention is paid to the challenges associated with the instability of international trade relations, economic sanctions, and the growing demand for functional food products. The authors analyze the current state of food security in Ukraine, considering the impact of market conditions and state policy on the availability and quality of food products. The paper highlights key strategic areas for ensuring food security, including the introduction of innovative technologies, the development of production based on the domestic raw material base, the creation of products with improved physiological properties, as well as the modernization of production facilities to increase their efficiency and environmental sustainability. Special emphasis is placed on developing environmentally safe production, which is focused on forming competitive products with high-added value for domestic consumption and export. The authors emphasize the importance of integrating national strategies into the context of global challenges ensuring food security, sustainable development, and adaptation to climate change. The article emphasizes the role of state policy in forming an effective system of access to quality food, which is the basis of social stability and economic development. The prospects for the development of functional food products in the market are also considered, as they can satisfy the growing consumer demand for healthy food and contribute to improving the population’s standard of living. The study offers specific recommendations for improving food policy, focusing on the need for state regulation, supporting low-income groups, stimulating local production, and reducing dependence on imports. The presented results are the basis for further scientific research in ensuring food security in Ukraine in the face of global challenges and crises. Keywords: food security, agri-food market, functional products, sustainable development, innovative technologies, competitiveness.

Techno-functional, physicochemical and thermal characteristics of black chickpeas aquafaba under ultrasound pre-processing

Aquafaba is the liquid that remains from the cooking of beans in the canning industry, generally discarded as wastewater. This research aimed to optimize ultrasound pretreatment to enhance this by-product and introduce it as a high-added value product (known as liquid gold) in the food industry. The results showed that with the increase in the sonication time and amplitude, the extraction efficiency, soluble protein content, the density, and dry matter content of black chickpeas aquafaba increased significantly (p < 0.05). The results also demonstrated that foaming ability (in short ultrasonication times) and foam stability significantly increased with higher amplitude. The results of numerical optimization showed that ultrasound pre-treatment for 30 min with an amplitude of 72 % on black chickpeas before the cooking process created the best conditions for aquafaba extraction. Under these optimized conditions, the results yielded the highest values so that extraction efficiency, protein content, density, dry matter, foaming ability, and foam stability were 212.07 %, 3546.7 mg/kg, 1.038 g/mL, 4.76 %, 243.57 %, and 44.50 % respectively. Thermogravimetric and FT-IR analysis showed that the pre-sonication process not only makes aquafaba thermally stable, but also does not cause any structural changes in its chemical components. According to the favorable physicochemical characteristics of aquafaba, this product can benefit the food industry. It can be a material with high added value, profitable for the canning industry.

Evironmentally friendly comprehensive utilization of retired waste electrolytes of aluminum electrolysis by calcification leaching

Low energy consumption and environmentally friendly recycling methods can extract high-added value and high-demand elements from retired waste fluorinated aluminum electrolytes (RWE-Al), which is crucial for alleviating resource shortages and environmental hazards. This study aims to develop a method for recovering fluorine and aluminum from RWE-Al through calcium leaching transformation combined with acid leaching. Compared to the traditional high-temperature roasting transformation and high-concentration alkali-metal-salt leaching process, this new process only involves one step of low-temperature leaching, purification of fluorine, carbonization of excess calcium, and evaporation extraction of aluminum, avoiding the generation of high energy consumption and secondary hazardous waste (F-containing liquid/ residue). Fluorine and aluminum are effectively separated and purified with extraction rates exceeding 96%. The effects of leaching temperature, CaO addition coefficient, liquid–solid ratio, and leaching time on the leaching process were systematically studied. The effects of acid concentration, liquid–solid ratio, time, and temperature on the acid-leaching process were also investigated. In summary, the comprehensive utilization of RWE-Al by this new process has proved to be feasible.

Valorization of phosphate mine waste rock as alternative aggregates for high-performance concrete

Natural aggregate quarrying significantly impacts the environment while phosphate mine waste rock (PMWR) offers alternative aggregates for use in high-added value construction materials. This study was the first to investigate the application of three aggregate types from PMWR as a complete substitute to natural aggregate to produce high-performance concrete (HPC). For this aim, three coarse aggregate (CA) types: Flint (F), Phosflint (PF), and Dolomite (D) from PMWR in Morocco were selected and compared with a natural Reference CA (R). Two mixtures were tested: HPC-0.40 and HPC-0.36 with a w/c ratio equal to 0.40 and 0.36. D-HPC and PF-HPC achieved a slump exceeding 20 cm and a 28-d compressive strength (CS) equal to 55 MPa ± 5 MPa on average, similar to the R-HPC, while F-HPC did not meet the requirement for HPC (i.e. a 28-d CS superior to 55 MPa). Scanning electron microscope observations showed that D-HPC exhibited a very dense and indistinguishable interfacial transition zone (ITZ), while F-HPC showed a debonding of F-CA and a larger ITZ size which explain its lower CS. Life ycle assessment revealed a major positive environmental impact on ecosystem quality that reduced land occupation and land transformation by up to 32 %. A secondary evaluation of the valorization of PMWR as alternative fine aggregate (FA) in high-strength mortar (HSM) was investigated and showed that the 28-d CS is equal to 93 MPa for PF-HSM and equal to 81 MPa for D-HSM, superior to RS-HSM which is equal to 61 MPa. Dolomite and Phosflint FA offered a better alternative to natural River sand to overcome the ceiling effect. These findings encourage the construction sector to adopt a sustainable consumption of aggregates by using PMWR as alternative CAs and FAs to produce high-strength construction materials.

Xylose, glucose and acetate as feedstock for three microalgal species cultivated in heterotrophy

Microalgae are known as good producers of high-added value bioproducts useful in many applications such as pharmaceuticals, nutrition or biofuel production. In contrast to phototrophy, heterotrophy emerges as a promising strategy for algal biomass production due to high cell densities, controlled conditions and reduced space requirement. Hemicellulose is the second most abundant material in land plants. Its hydrolysis liberates xylose, glucose, acetate. Our study focuses on three microalgal species, Galdieria sulphuraria, Euglena gracilis, and Auxenochlorella protothecoides, cultivated under heterotrophy with the above-mentioned carbon sources, supplemented alone or in combination. Growth parameters and biomass analysis revealed distinctive characteristics. G. sulphuraria, despite a modest fatty acid content (5–15 % w/w), displayed potential for hemicellulose valorization, demonstrating high biomass yield using xylose as a sole carbon source (approx. 0.5 gDW gxylose−1) and high saturated fatty acid (SFA) content (45–63 %). In our cultivation conditions, E. gracilis only assimilated acetate with low fatty acid content (approx. 6 % w/w), but high SFA content (60–77 %) and high paramylon content (47 % w/w), convertible to wax-esters under anaerobiosis. A. protothecoides exhibited biomass yields of 0.42–0.54 gDW gsubstrate−1 depending on the carbon substrate supplied but maintained constant fatty acid content (16–18 % w/w) in the presence of all substrates except xylose. Surprisingly, despite an inability to grow with xylose alone, sugar depletion analysis indicated decreasing xylose concentration when other carbon sources were present in the cultivation medium for this alga. This comparative study discusses the strengths and weaknesses of each strain, providing insights into their potential when grown on hemicellulose carbon sources.

Photochemical Aerobic Upcycling of Polystyrene Plastics via Synergistic Indirect HAT Catalysis.

Plastic pollution constitutes an evergrowing urgent environmental problem, since overaccumulation of plastic waste, arising from the immense increase of the production of disposable plastic products, overcame planet's capacity to properly handle them. Chemical upcycling of polystyrene constitutes a convenient method for the conversion of plastic waste into high-added value chemicals, suggesting an attractive perspective in dealing with the environmental crisis. We demonstrate herein a novel, easy-to-perform organocatalytic photoinduced aerobic protocol, which proceeds via synergistic indirect hydrogen atom transfer (HAT) catalysis under LED 390 nm Kessil lamps as the irradiation source. The developed method employs a BrCH2CN-thioxanthone photocatalytic system and was successfully applied to a variety of everyday-life plastic products, leading to the isolation of benzoic acid after simple base-acid work up in yields varying from 23-49 %, while a large-scale experiment was successfully performed, suggesting that the photocatalytic step is susceptible to industrial application.

Replacing oxygen evolution reaction in water splitting process by electrochemical energy-efficient production of high-added value chemicals with co-generation of green hydrogen

The utilization of biomass represents a promising alternative to the use of fossil fuels in facing both the energy problem and environmental pollution. Using the electrochemical oxidation of organic pollutants instead of the oxygen evolution reaction at the anode and the hydrogen evolution reaction at the cathode of an electrolyzer, it is possible to make high-value chemicals, break down pollutants, and produce hydrogen efficiently at the same time. In this study, the scale-up of the electrochemical treatment was investigated by treating technical cashew nutshell liquid effluent using a photovoltaic-driven electrochemical reactor with two compartments and equipped with a boron-doped diamond electrode as the anode and a Ni stainless-steel mesh as the cathode. Tests were carried out varying the anode current densities (40, 70, and 100 mA cm-2), the nature of the electrolyte solution (NaOH and Na2SO4), and the concentration of technical cashew nutshell liquid (0.01, 0.05, or 0.10 %). The results clearly shown that it is possible to successfully scale up a divided electrochemical reactor (passing from the batch approach of previous works to the flow approach of this study), favoring a selective accumulation of acetate (600 mg L-1) in the anodic compartment. In addition, the simultaneous production of green hydrogen (0.182 L h-1) was achieved when electrolyzing a biomass effluent containing 0.10 % technical cashew nutshell liquid in 1 mol L-1 NaOH and applying a current density of 40 mA cm-2. In conclusion, the sustainable electrochemical transformation of the waste (from technical cashew nutshell liquid into valuable products and energy carriers) was successfully achieved. We believe that the results will help the energy transition towards zero carbon emission and a cost-effective production of hydrogen through an integrated-hybrid process.

On the Perspective of Solid-State Fermented Olive Leaves for High-Added Value Applications

PurposeThe effect of solid-state fermentation (SSF), employing different microbial strains (single or co-cultured), to the chemical composition of olive leaves (OL) and the possible perspectives of the derived material for high added-value applications was explored.MethodsEmphasis was given on bioactives (oleuropein, OLE, hydroxytyrosol, HT, elenolic acid (EA) related compounds, maslinic (MA) and oleanolic (OA) acids). In parallel, the levels of other chemical components with nutritional/antinutritional interest for feed application and certain minerals were also measured.ResultsA gradual decrease in OLE and an EA derivative till their complete loss was found. HT progressively increased and then consumed reaching low levels. MA and OA were unaffected. A. niger resulted in the highest formation of HT (1 mg/g dw), and the lowest loss of OL antioxidant potential (13.8% at 72 h). Varying levels of protein production were observed potentially improving their nutritional value.ConclusionThe study demonstrated that fermented OL significantly altered phenolic compounds, particularly OLE and HT, and maintained triterpenic acids such as MA and OA. Despite reductions in certain phenolics, fermented OL showed improved nutritional profiles, particularly in protein content and antioxidant potential, suggesting their potential for added-value applications in various industrial sectors, including animal feed. To our knowledge this is the first time that the co-cultures selected in the present study were employed for OL SSF and that under all conditions examined the triterpentic acids MA and OA were the dominant bioactives despite some improvements in HT formationGraphical

Photochemical Aerobic Upcycling of Polystyrene Plastics.

Although the introduction of plastics has improved humanity's everyday life, the fast accumulation of plastic waste, including microplastics and nanoplastics, have created numerous problems with recent studies highlighting their involvement in various aspects of our lives. Upcycling of plastics, the conversion of plastic waste to high-added value chemicals, is a way to combat plastic waste that is receiving increased attention. Herein, we describe a novel aerobic photochemical process for the upcycling of real-life polystyrene-based plastics into benzoic acid. A new process employing a thioxanthone-derivative, in combination with N-bromosuccinimide, under ambient air and 390 nm irradiation is capable of upcycling real-life polystyrene-derived products in benzoic acid in yields varying from 24-54%.

Design, motion-planning, and manufacturing of custom-shaped tools for five-axis super abrasive machining of a turbomachinery blade type component

Free-form surfaces generated by non-uniform rational B-splines (NURBS) are evolving to face turbomachinery component requirements, such as turbine blades to enhanced efficiency. Super abrasive machining (SAM) is presented as a potential process for high-added value components using custom-shaped tools to be adapted to any surface. The adaptability and flexibility of these tool concepts are specifically designed to fit these complex surfaces. This paper presents an innovative manufacturing approach for blade type components using a custom-shaped tool designed through an optimization process that simultaneously optimizes both the shape of the tool and its motion. The proposed method with SAM finishing using a custom-shaped tool is compared against a standard tool and traditional machining process. The result obtained on the blade test case shows that the custom-shaped tools need fewer paths, yet produce more accurate surface finish.

Oregano and thyme by-products of olive oil aromatization process with microwave assisted extraction as a rich source of bio-active constituents.

Processing of Medicinal Aromatic Plants (MAPs) results in the production of a significant amount of by-products, which are not commercially exploitable. Towards this direction, we studied extensively the by-products of oregano and thyme, remaining after the aromatization of olive oils with microwave assisted extraction (MAE). The purpose of the study was the exploitation of the "wastes" of these two economically significant herbs of Greece, for the potential development of innovative bioactive products. Hence, superior and inferior quality plant material from Origanum vulgare subsp. hirtum and Thymus vulgaris, were extracted with extra virgin olive oil using MAE. For the evaluation of raw plant material, beside the characterization of the essential oils (EOs), the hydroalcoholic extracts of superior and inferior plant material were afforded by ultrasound assistant extraction (UAE). In addition, the remaining plant material after the flavoring of olive oil by MAE, was extracted with c-Hex, MeOH, H2O:MeOH using UAE. All the extracts were evaluated for their DPPH free radical scavenging activity and total phenolic content (TPC) as well as their chemical profile was investigated by HPTLC. In parallel, the EOs, the olive oils and the c-Hex extracts were analyzed by GC-MS and Headspace Solid Phase Microextraction (HS-SPME)-GC-MS. The results showed that the composition of the EOs and the volatile fraction of the olive oil extracts were similar for the superior quality material whereas for the inferior the composition of the volatile fraction of olive oil extracts was not analogous to the respective EOs. GC-MS analyses of oregano and thyme by-products revealed the presence of carvacrol, thymol, γ-terpinene and p-cymene among the major constituents. Moreover, the hydroalcoholic extracts obtained from the plant material remaining after olive oil flavoring with MAE showed similar phenolic content and scavenging activity with the hydroalcoholic extracts of the corresponding raw plant materials underlying their potent use in the preparation of high-added value products such as nutraceuticals and cosmeceuticals as well as enriched animal nutrition products.

Bioactive Compound Extraction of Hemp (Cannabis sativa L.) Leaves through Response Surface Methodology Optimization

Hemp, commonly known as Cannabis sativa L., is a medicinal plant species of the Cannabaceae family. For the efficient extraction of C. sativa leaves using the conventional stirring process with water as the solvent, three crucial extraction parameters (i.e., extraction duration, liquid–solid ratio, and temperature) were investigated through the response surface methodology (RSM). The concentrations of the extracted bioactive compounds (polyphenols, ascorbic acid, and carotenoids) showed significant variations in the RSM design points, suggesting the importance of finding the optimal extraction conditions in which liquid–solid ratio and extraction temperature were found to have the highest impact. Further analysis was conducted on the optimal extract employing several assays to determine their polyphenol content, total carotenoid content, color evaluation, anti-inflammatory activity, and antioxidant capacity through FRAP, DPPH, and H2O2 assays. A low extraction time (30 min) at 50 °C and a high liquid–solid ratio (50:1) were required for the highest possible yield of polyphenols. The total polyphenol content was determined to be 9.76 mg gallic acid equivalents/g under optimum conditions, with pelargonin being the most abundant polyphenol (1.51 mg/g) in C. sativa extracts. Ascorbic acid was measured at 282.23 μg/g and total carotenoids at 356.98 μg/g. Correlation analyses revealed that anti-inflammatory activity was negatively correlated with specific polyphenols. As determined by DPPH (27.43 μmol ascorbic acid equivalents (AAE)/g), FRAP (49.79 μmol AAE/g), and H2O2 (230.95 μmol AAE/g) assays, the optimized aqueous extract showed a high antioxidant capacity. Furthermore, it demonstrated considerable anti-inflammatory activity at 17.89%, with the potential to increase to 75.12% under particular extraction conditions. Given the high added-value of the aqueous extracts, the results of this study highlight the potential utility of C. sativa leaves as a source of health-improving antioxidant compounds in the pharmaceutical and food industries.

The Impact of Deficit Irrigation on the Agronomic Performance and Chemical Composition of Scolymus hispanicus L.

In the current study, the effects of drought stress on the growth and phytochemical profile of Scolymus hispanicus L. (a.k.a. golden thistle) were evaluated. Plants were treated with three irrigation regimes, e.g., plants that received only rainwater (Control; C), deficit irrigation (I1; 50% of field capacity (FC)), and full irrigation (Ι2; 100% of FC). The fresh weight of the rosette of leaves was not negatively impacted by deficit irrigation, whereas root development was severely restrained compared to control and I2 treatments. Drought stress conditions had a positive effect on the nutritional properties of the golden thistle since the treatments of control and deficit irrigation showed the highest content of macronutrients and energy. Oxalic acid was the richest organic acid, especially under the I1 regime. Similarly, α-tocopherol was the only identified vitamin E isoform, whose content was also doubled in I1 treatment. Raffinose, glucose, and sucrose were the most abundant free sugars in amounts that varied among the irrigation treatments, while the total and distinct free sugar content was the highest for the I1 treatment. The most abundant detected fatty acid compounds were α-linolenic acid, followed by palmitic and linoleic acid, with the highest amount being detected in C, I1, and I2 treatments, respectively. Flavonoids were the only class of polyphenols detected in golden thistle leaves, including mostly kaempferol and quercetin derivatives. The greatest antioxidant potency was shown for the control and I1 treatments (for OxHLIA and TBARS methods, respectively). The evaluated leaf samples recorded a varied antimicrobial effect for the different bacterial strains and fungi, whereas no cytotoxic, hepatotoxic, and anti-inflammatory effects against the tested cell lines were recorded. Finally, the mineral content of leaves was significantly affected by the irrigation regime, with Ca, Mg, Cu, and Zn being the highest for the I1 treatment, while the I2 treatment had the highest content of K, Fe, and Mn and the lowest Na content. In conclusion, deficit irrigation showed promising results since it improved the phytochemical content without compromising the fresh weight of leaves, and thus it could be suggested as a sustainable agronomic practice for producing high-added value products without significant constraints in growth development and yield parameters of golden thistle.

Extraction and In Vitro Skincare Effect Assessment of Polysaccharides Extract from the Roots of Abelmoschus manihot (L.).

Obtaining high-added value compounds from agricultural waste receives increasing attention, as it can both improve resource utilization efficiency and reduce waste generation. In this study, polysaccharides are extracted from the discarded roots of Abelmoschus manihot (L.) by the high-efficiency ultrasound-assisted extraction (UAE). The optimized condition was determined as solid-liquid ratio SL ratio = 1:20, temperature T = 30 °C and time T = 40 min, achieving an extraction yield of 13.41%. Composition analysis revealed that glucose (Glc, 44.65%), rhamnose (Rha, 26.30%), galacturonic acid (GalA, 12.50%) and galactose (Gal, 9.86%) are the major monosaccharides of the extract. The extract showed a low degree of esterification (DE) value of 40.95%, and its Fourier-transform infrared (FT-IR) spectrum exhibited several characteristic peaks of polysaccharides. Inspired by the wide cosmetic applications of polysaccharides, the skincare effect of the extract was evaluated via the moisture retention, total phenolic content (TPC) quantification, 2,2-Diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activity, anti-hyaluronidase and anti-elastase activity experiments. The extract solutions demonstrated a 48 h moisture retention rate of 10.75%, which is superior to that of commercially available moisturizer hyaluronic acid (HA). Moreover, both the TPC value of 16.16 mg GAE/g (dw) and DPPH-free radical scavenging activity of 89.20% at the concentration of 2 mg/mL indicated the strong anti-oxidant properties of the extract. Furthermore, the anti-hyaluronidase activity and moderate anti-elastase activity were determined as 72.16% and 42.02%, respectively. In general, in vitro skincare effect experiments suggest moisturizing, anti-oxidant, anti-radical and anti-aging activities of the A. manihot root extract, indicating its potential applications in the cosmetic industry.

Selective extraction of high-added value carboxylic acids from aqueous fermentative effluents with new hydrophobic eutectic solvents (HES)

SummaryRecovering these carboxylic acids from the fermentative streams in a sustainable, green, and economical way is a significant challenge. This work assessed hydrophobic eutectic solvents (HES) – water-immiscible – for the selective recovery of carboxylic acids via liquid–liquid extraction. Different trioctylphosphine oxide (TOPO) mixtures with menthol and thymol were studied and deeply characterized by 1H and 31P NMR to yield stable eutectic solvents, including a novel experiment of 31P NMR at variable temperatures for the first time. Those stable eutectic solvents were tested in the liquid extraction of complex aqueous mixtures containing C2–C6 carboxylic acids and simple sugars (glucose and xylose). The back-extraction of the carboxylic acids for the recovery of the HES was optimized, being necessary in three stages for the complete cleaning of the eutectic solvent using NaOH 0.1 M. The eutectic mixture of TOPO and thymol in a molar ratio of 1:2 exhibited an overall recovery of C5 and C6 carboxylic acids over 70 %, allowing its selective extraction from the rest of the compounds in the complex mixture. Likewise, this HES (after back extraction) was successfully reused in a second extraction cycle, keeping the performance of the fresh one. Therefore, this study demonstrated that HES can have a high extraction selectivity for carboxylic acids of ≥C5. Moreover, these solvents were stable and allowed reusability, reducing the environmental impact and process costs.

Green nanomaterial-based adsorbent for Cs and Pb removal: Synthesis from industrial waste producing high-value products

ABSTRACT The search for a sustainable society makes necessary the reuse of residues contributing to the producing high-value product. Producing new materials with high-added value increases technological development and builds up new applications. The present study aimed to use residue from the alumina industry and coal ash generated in thermal plants in energy production to synthesize zeolite for wastewater treatment to remove Cs and Pb. Two types of nanomaterials were synthesized: zeolite 4A (ZEA) and zeolite sodalite (ZSD). The Cs adsorption efficiency achieved 73% and 9.4% for ZEA and ZSD, respectively, fitting better for Lineweaver-Burk isotherm and both zeolites removed 100% of Pb from synthetic solutions. Results here reported may be used to design novel wastewater treatment systems from nuclear plants and other industrial processes. The present study can contribute to achieving Sustainable Development Goals 9, 11, and 12.

Improvement of agave bagasse hydrolysates processing under a biorefinery approach

SummaryThe economic viability of producing second-generation bioethanol from agave bagasse (AB) is influenced by the presence of phenolic compounds in the hydrolysates used during fermentation. These compounds substantially constrain the growth in yeasts that convert sugars into bioethanol, thus becoming a limitation for the process. In this study, it was proposed to select an effective adsorbent matrix to remove and recover phenolic compounds from AB hydrolysates. The related adsorption phenomena and processes were described and characterized. Four adsorbents were examined, including activated carbon (CA), as well as three polymeric matrices (MN-102, ADS-800EP, and SP825L). The adsorption parameters, such as maximum equilibrium adsorption capacity (qmax) and percent desorption, were determined through adsorption–desorption experiments in batch systems. Additionally, the impact of removing phenolic compounds on bioethanol yield was evaluated and the potential use of the recovered phenols as biopesticides against plant pathogens, such as fungi and nematodes, was explored. The results showed that activated carbon has a higher phenol adsorption capacity (qmax = 118.1 mg/g) but a lower desorption capacity (59.46 %), meanwhile, the MN-102 matrix displayed comparable adsorption characteristics and superior desorption capacity (95.81 %), rendering it the most appropriate for the process. Subsequently, the detoxification of the AB hydrolyzate, by phenolic compounds remotion, on bioethanol yield was assessed and resulted in a significant increase (3.5-fold). Finally, the fungicidal potential of the recovered phenolic compounds was evaluated on Fusarium oxysporum and Alternaria alternata, while the nematicidal activity was tested on Meloidogyne incognita. The phenolic compounds exhibited high antifungal activity against F. oxysporum (73.91 %) and moderate activity against A. alternata (40 %), in comparison to the positive control. Moreover, they showed very high nematicidal activity, causing 91.23 % mortality in M. incognita. These findings allow to conclude that incorporating the adsorption stage not only enhances bioethanol yields but also enables the efficient recovery of potentially valuable molecules.

Tisochrysis lutea as a source of omega-3 polar lipids and fucoxanthin: extraction and characterization using green solvents and advanced techniques

The marine microalga Tisochrysis lutea is a potential and sustainable source of bioactive compounds such as carotenoids and omega-3 fatty acids. In the present work, the extraction of fucoxanthin and docosahexaenoic acid (DHA), the most abundant omega-3 fatty acid which constitutes polar lipids particularly in the brain, was studied using advanced extraction techniques with green and bio-based solvents compared to traditional extraction techniques with hazardous organic solvents. The experimental design to maximize the lipid extraction yield by ultrasound-assisted extraction (UAE) was developed, choosing as experimental factors the percentage of solvent (0, 50 and 100% of 2-methyl-tetrahydrofuran or 2-methyloxolane (2-me-THF) in ethanol), the extraction time (20, 30 and 40 min) and temperature (40, 50 and 60 ºC). The highest lipid extraction yields were obtained using ethanol as solvent. Nevertheless, the most interesting extracts based on their chemical composition were obtained when the presence of 2-me-THF in the extraction mixture was greater than that of ethanol. Through analytical techniques such as HPLC-ELSD/DAD and GC-MS as well as spectrophotometric techniques, the contents of polar lipids, fatty acids, total carotenoids and fucoxanthin were quantified. In addition, the antioxidant capacity of different selected extracts was studied, being once again the most interesting those extracted with different amounts of 2-me-THF due to its selectivity and enriched composition in high-added value bioactives, mainly fucoxanthin and DHA. Therefore, it is shown the importance of choosing an advanced extraction technique together with the use of green solvents not only to develop procedures that are in agreement with Green Chemistry but also to preserve its bioactivity.