Search Results (47)

Background/Objectives: Citrus limon leaf essential oil (EO) is traditionally used for its calming and cognitive-enhancing properties. Although the chemical composition of C. limon leaf essential oils (EOs) obtained by means of hydrodistillation (HD) and solvent-free microwave extraction (SFME) has been previously characterized, the influence of the extraction method on their neuroprotective efficacy and dose–response effects remains insufficiently explored. In the present study, EOs obtained by means of HD (CEH) and SFME (CEM) were compared for their behavioral, biochemical, and in silico neuroprotective effects against scopolamine (SCOP)-induced cognitive and anxiety-like impairments in adult zebrafish. Methods: Adult Tübingen zebrafish were exposed to CEH or CEM via immersion at 10, 100, and 150 µL/L for 19 days prior to SCOP challenge (100 µM). Cognitive performance was evaluated using the Y-maze and novel object recognition (NOR) tests, while anxiety-like behavior was assessed using the novel tank test (NTT) and novel approach test (NAT). Brain acetylcholinesterase (AChE) activity and oxidative stress markers were quantified. Molecular docking analyses were conducted to investigate interactions between major EO constituents and AChE and monoamine oxidase A (MAO A). Results: Both CEH and CEM significantly attenuated SCOP-induced memory deficits, improved spontaneous alternation and NOR discrimination, and reduced anxiety-like behaviors. These effects were associated with AChE inhibition and restoration of redox balance. Notably, CEM generally exhibited stronger neurobehavioral and biochemical effects at comparable doses. In silico analyses supported these findings, revealing favorable binding affinities of key EO constituents toward cholinergic and monoaminergic targets. Conclusions: This study demonstrates that the extraction method influences the neuroprotective efficacy of C. limon leaf EOs. While both CEH and CEM exert antioxidant and cholinergic modulatory effects, CEM shows enhanced neuroprotective potential in a zebrafish model of SCOP-induced cognitive impairment, supporting the relevance of extraction-dependent biological profiling in EO-based neurotherapeutic research. Full article

This study focuses on the optimization of modern extraction techniques for selected by-product materials, including apple, lemon, and tangerine peels, and onion skins, using artificial neural network (ANN) models. The extraction methods included ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) with water as the extractant, as well as maceration (MAC) with natural deep eutectic solvents (NADES). Key parameters, such as total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities, including reducing power (EC₅₀) and free radical scavenging capacity (IC₅₀), were evaluated to compare the efficiency of each method. Among the techniques, UAE outperformed both MAE and MAC in extracting bioactive compounds, especially from onion skins and tangerine peels, as reflected in the highest TPC, TFC, and antioxidant activity. UAE of onion skins showed the best performance, yielding the highest TPC (5.735 ± 0.558 mg CAE/g) and TFC (1.973 ± 0.112 mg RE/g), along with the strongest antioxidant activity (EC₅₀ = 0.549 ± 0.076 mg/mL; IC₅₀ = 0.108 ± 0.049 mg/mL). Tangerine peel extracts obtained by UAE also exhibited high phenolic content (TPC up to 5.399 ± 0.325 mg CAE/g) and strong radical scavenging activity (IC₅₀ 0.118 ± 0.099 mg/mL). ANN models using multilayer perceptron architectures with high coefficients of determination (r² > 0.96) were developed to predict and optimize the extraction results. Sensitivity and error analyses confirmed the robustness of the models and emphasized the influence of the extraction technique and by-product type on the antioxidant parameters. Principal component and cluster analyses showed clear grouping patterns by extraction method, with UAE and MAE showing similar performance profiles. Overall, these results underline the potential of UAE- and ANN-based modeling for the optimal utilization of agricultural by-products. Full article

The juice industry generates substantial quantities of solid waste and wastewater. Consequently, efforts have focused on their treatment and valorization to obtain high-value-added products. Traditionally, these wastes are managed through landfill disposal and treatment in municipal wastewater facilities, respectively. In the present work, two alternative scenarios for the valorization of orange juice waste were developed and assessed in comparison to the conventional approach by performing a Life Cycle Assessment (LCA). Scenario 1 involved hydro-distillation of solid waste for essential oil recovery, followed by anaerobic digestion for biogas and fertilizer production, with wastewater treated via membrane filtration and chlorination. In Scenario 2, solvent-free microwave extraction (SFME) was employed for essential oil recovery, followed by anaerobic digestion. Wastewater was treated in a membrane bioreactor followed by ultraviolet treatment. According to the results, Scenario 1 achieved a 36% reduction in greenhouse gas emissions due to the beneficial effects of biogas and fertilizer production, despite its high energy demands. Scenario 2 exhibited the best environmental performance due to lower energy demands and higher extraction efficiency compared to Scenario 1, with reductions of 46% in greenhouse gas emissions and 48% in resource depletion. Overall, the findings highlight the potential of integrating innovative, energy-efficient technologies for the sustainable valorization of juice industry waste, offering measurable environmental advantages for industrial-scale implementation. Full article

Solvent-free microwave extraction (SFME) is a clean and advanced method of extracting essential oils. In this study, it was compared to conventional hydrodistillation (HD) and steam-water distillation (SD), which are commonly used to extract essential oils from fresh ylang-ylang flowers. The yield and density of essential oils extracted via SFME within 40 min after the appearance of the first oil drop were higher than those obtained via conventional HD and SD within 3 h after the appearance of the first drop. Analysis of chemical compounds in the essential oils showed a high degree of variability in volatile compounds between the three extraction methods. Light oxygenated compounds are odor-active constituents. They comprised 81.23% of the SFME extract, whereas their levels were lower in the HD (69.94%) and SD extracts (57.98%). Total aromatic compounds were also higher in the essential oils obtained via SFME than in those obtained via HD and SD. These results support the use of SFME for ylang-ylang essential oil extraction, as it offers promising energy-/time-saving characteristics, along with higher quality. Full article

Buckwheat, a gluten-free pseudocereal, is rich in dietary fiber, minerals, high-quality proteins, vitamins, and essential amino acids. Buckwheat husk, a by-product of dehulling, contains high levels of bioactive compounds such as polyphenols and dietary fibers. This study compares green extraction methods (ultrasound-assisted extraction, UAE; and microwave-assisted extraction, MAE) for recovering polyphenols from buckwheat husk. MAE improved polyphenol yield by 43.6% compared to conventional acidified methanol extraction. Structural and chemical analyses of the residual husk material using SEM, FTIR, and fiber analysis revealed that MAE alters husk properties, enhancing polyphenol accessibility. Thus, MAE appears an efficient and sustainable alternative to acid- and solvent-based extraction techniques. Extracts obtained via “green” methods retained strong antioxidant activity and showed significant modulation of inflammatory markers in human Caco-2 cells, highlighting the potential use of “green” buckwheat husk extracts for food and pharma applications. This work supports the valorization of buckwheat husk within a circular economy framework, promoting buckwheat husk as a valuable raw material for bioactive compound recovery in diverse applications. Full article

In this study, using 70% anhydrous ethanol as the extraction solvent, Moringa oleifera Lam. seed powder was extracted with the microwave-assisted extraction method, followed by purification using macroporous adsorbent resin NKA-9. The purified glucosinolate was subsequently hydrolyzed with myrosinase. The glucosinolate and its enzymatic product were identified as 4-(α-L-rhamnopyranosyloxy) benzyl glucosinolate (4-RBMG) and benzyl isothiocyanate (BITC) by UV–Vis, FT-IR, NMR, and MS. The bioactivities, including anti-oxidation, anti-inflammation, and anti-tumor activities of 4-RBMG and BITC, were systematically evaluated and compared. The results show that at 5–20 mg/mL, the anti-oxidation effects of 4-RBMG on DPPH and ABTS free radicals are superior to those of BITC. However, at the same concentrations, BITC has stronger anti-inflammatory and anti-tumor activities compared to 4-RBMG. Notably, at a concentration of 6.25 μmol/L, BITC significantly inhibited NO production with an inhibitory rate of 96.67% without cytotoxicity. Additionally, at a concentration of 40 μmol/L, BITC exhibited excellent inhibitory effects on five tumor cell lines, with the cell inhibitory rates of leukemia HL-60, lung cancer A549, and hepatocellular carcinoma HepG2 exceeding 90%. This study provides some evidence that the enzymatic product, BITC, shows promise as a therapeutic agent for tumor suppression and inflammation reduction. Full article

In the context of pollution-free waste treatment, anaerobic fermentation liquid (AFL), a prominent by-product of biogas engineering, has emerged as a focal point in contemporary research. Concurrently, vitamin C, an active compound abundant in fruits and vegetables, possesses extensive application potential. The development of efficient extraction processes and the utilization of its biological activities have garnered significant attention from researchers. This study investigated the impact of AFL on the growth and vitamin C content of Bok choy through field trials of varying concentrations of AFL. The results indicated that the growth characteristics of Bok choy exhibited a concentration-dependent trend with increasing AFL dosage, with the highest yield observed in the AFL-2 group (8.43 kg/m²). Additionally, with the increase in the concentration of the AFL application, the vitamin C content in Bok choy exhibited a trend of initially increasing and then decreasing, reaching its highest value (70.83 mg/100 g) in the AFL-1 group. Furthermore, response surface methodology was employed to optimize the microwave-assisted organic solvent extraction process of vitamin C, revealing that the optimal conditions for microwave-assisted extraction using a 2% citric acid solution were as follows: a microwave power of 313 W, a microwave time of 1.3 min, and a liquid-to-solid ratio of 16.4:1 v/w, achieving a vitamin C extraction rate of 90.77%. Subsequent mechanistic studies on colitis repair demonstrated that the combination of vitamin C and allicin significantly enhanced the ability of intestinal microorganisms to ferment and degrade complex carbohydrates in colitis-afflicted mice, thereby alleviating intestinal inflammation, markedly reducing bacterial invasion signals on intestinal epithelial cells, and decreasing the risk of intestinal infection. This study provides a valuable perspective for the harmless utilization of agricultural waste, and provides a theoretical basis and technical support for the high-value utilization of natural active ingredients. Full article

To determine the optimal conditions of pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE) of polyphenols from black chokeberry leaves (BCL), temperature, time and sample-to-solvent ratio (SSR) were varied to obtain maximum polyphenols yield. The extracts were analyzed for total polyphenols (TP) as well as individual ones (UPLC ESI MS²) and antioxidant capacity (FRAP, DPPH and ORAC). Moreover, the biological activity of the selected extracts was additionally determined. The optimal PLE and MAE conditions were 150 °C, 5 min extraction time and SSR 1:30 g/mL (TP 80.0 mg GAE/g dm), and 70 °C, extraction time 5 min and SSR 1:30 g/mL (TP 36.4 mg GAE/g dm), respectively. Both methods yielded similar polyphenol profiles (43 compounds) but differed quantitatively. MAE extracts contained more flavonols and phenolic acids, while PLE extracts had higher procyanidins and flavan-3-ols. Furthermore, the PLE extract exhibited a superior antioxidant capacity. This BCL extract also showed that it can protect against oxidative and DNA damage and can induce free radical formation and DNA damage, albeit at different doses. Moreover, it had a moderate antimicrobial activity against S. aureus and B. subtilis, while no antimicrobial activity was observed against Gram-negative bacteria as well as yeasts, lactic acid bacteria and molds. Full article

Background/Objectives: Essential oils (EOs) have been exploited by humans for centuries, but many sources remain poorly investigated, mainly due to the low yields associated with conventional extraction. Recently, new techniques have been developed, like solvent-free microwave extraction (SFME), able to enhance efficiency and sustainability. The use of Papaver rhoeas L. in traditional medicine has led researchers to investigate non-volatile fractions, but there are little data available on EOs. Methods: In the present work, we prepared EOs from the petals and leaves of P. rhoeas by SFME. GC/MS analysis of EOs revealed the presence of 106 compounds belonging to 13 different classes. Isomers of the different alkenes were identified thanks to an alkylthiolation reaction. Results: The results highlighted a predominance of saturated and unsaturated hydrocarbons, alcohols, and esters that might suggest a specific relationship with pollinators. Each population has been compared using PCA, heatmap, and barplot tools, highlighting differences in terms of composition by both comparing leaves and flowers and hill and lowland samples. Furthermore, cantharidin, a metabolite usually produced by insects, was detected in the flowers, possible present for attractiveness purposes. Conclusions: These results could contribute to ensuring a better understanding of the pollination process and of the biological activities of EOs from P. rhoeas. Full article

Efflorescence, a time-dependent and water-driven phenomenon, is a major concern in alkali-activated materials (AAMs), impacting their practical use and preservation in a time-frozen state for post-characterisation. Although a method for stopping chemical reactions in conventional cements exists, it is time-consuming and not chemical-free. Therefore, this study explored the effects of low-power microwave-induced dehydration on efflorescence, mechanical performance, and structural integrity in AAMs, to create an alternative and more “user-friendly” dehydration method. For this purpose, several mixtures based on secondary raw (slag, fly ash, glass wool, and rock wool) and non-waste (metakaolin) materials were activated with a commercial Na-silicate solution in ratios that promoted or prevented efflorescence. Characterisation techniques, including Fourier-transform infrared spectroscopy and X-ray diffraction, showed that microwave dehydration effectively removed water without altering crystallinity, while mercury intrusion porosimetry and compressive strength tests confirmed increased porosity. In addition to being an efficient, time-saving, and solvent-free manner of stopping the reactions in AAMs, microwave irradiation emerged as an innovative, chemical-free method for evaluating curing finalisation and engineering foams in a stage when all other existing methods fail. However, the artificially provoked efflorescence in aged dehydrated AAMs connected the slipperiness of AAM with the instant extraction of Na, which raised the need for further research into alternative alkali replacements to evaluate the practical use of AAM. Full article

The guishe is a by-product of the fiber extraction from Agave lechuguilla. This material has no commercial value, although it contains metabolites that could be used as a resource for producing high-value products. This study optimized the DPPH^• (2,2-diphenyl-1-picrylhydrazyl) antioxidant activity through microwave-assisted extraction (MAE) of polyphenolic compounds from Agave lechuguilla residues. The MAE process was optimized using a Box-Behnken design, with extraction time (5–15 min), temperature (40–50 °C), and solvent: sample ratio (1:20–1:30 m/v) as independent variables. In contrast, the dependent variable was DPPH^• free radical scavenging activity. As a result, the highest antioxidant activity was at 8 min of irradiation, extraction temperature of 45 °C, and solvent: sample ratio 1:30 w/v, obtaining a total flavonoid content of 19.25 ± 0.60 mg QE/g DW, a total polyphenol content of 6.59 ± 0.31 mg GAE/g DW, a DPPH^• free radical scavenging activity of 73.35 ± 1.90%, and an ABTS^+• ([2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate)]) free radical scavenging activity of 91.93 ± 0.68%. Full article

Exhausted olive pomace (EOP) represents the principal residue of olive pomace. Several studies have optimized the extraction of specialized metabolites from the EOP of Olea europaea L., but a comparison between different extractive methods has not been made. For this reason, the present investigation aims to compare four different extractive methods by using water and 15% ethanol/water as extractive solvents. Specifically, based on extract antioxidant activity, the methods compared were maceration (MAC), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and Accelerated Solvent Extraction (ASE). Between these, the UAE and ASE hydroalcoholic EOP extracts were demonstrated to have the highest antioxidant activity. Subsequently, these extracts were investigated for their hypoglycemic and antiradical activity using in vitro cell-free and cell-based assays, respectively. ASE hydroalcoholic EOP extract demonstrated the greatest ability to inhibit the α-amylase enzyme and an in vitro antioxidant activity comparable to N-acetyl cysteine in HepG2 cells. UAE and ASE extracts’ phytochemical characterization was also performed, identifying seven phenolic compounds, including 3-hydroxytyrosol, tyrosol, and, for the first time, salidroside. The ASE hydroalcoholic EOP extract was the richest from a phytochemical point of view, thus confirming its major biological activity. Therefore, ASE and 15% ethanol/water may represent the best extractive method for EOP nutraceutical valorization. Full article

Solidago virgaurea L., or European goldenrod, has a long tradition in folk medicine due to the wide range of its biological activity. This paper aimed to investigate the antimicrobial and antioxidative potential of S. virgaurea essential oil and hydrolates obtained by traditional and novel extraction techniques. For that purpose, hydrodistillation, microwave-assisted hydrodistillation and solvent-free extraction were performed. Analysis of the composition of essential oils indicated the presence of 59 different compounds with cyclocolorenone, germacrene D and spathulenol being the dominant in all essential oil samples. Antimicrobial activity was detected in all the analyzed samples, with higher effect on Gram-positive microorganisms compared to Gram-negative. Regarding the type of performed extraction process, the introduction of microwaves induced higher antimicrobial and antioxidative potential in both essential oils and hydrolates. Hydrolates obtained in microwave-assisted processes had pronounced antioxidative activity, which creates a good basis for further investigation of this side product’s potential use in the food, cosmetic and pharmaceutical industries. Full article

The utilization of bioactive compounds from fresh produce waste, which is gaining attention in the agri-food and cosmetics industries, focuses on employing green extraction over conventional extraction methods. This emerging field addresses environmental concerns about food waste and the uses of bioactive phytochemicals for skin health. Modern green extraction methods aim to minimize the energy-intensive process and the use of harmful solvents. These techniques include ultrasound, microwave, and supercritical fluid extraction, pulsed electric field extraction, pressurized liquid extraction, and subcritical water extraction methods, which provide high efficacy in recovering bioactive phytochemicals from vegetable and root crops. The phytochemicals, such as carotenoids, polyphenols, glucosinolates, and betalains of fresh produce waste, exhibit various therapeutic properties for applications in skin health. These dietary antioxidants help to neutralize free radicals generated by UV radiation, thus preventing oxidative stress, DNA damage, and inflammation. The skin care formulations with these phytochemicals can serve as natural alternatives to synthetic antioxidants that may have toxic and carcinogenic effects. Therefore, this review aims to discuss different green extraction technologies, consumer-friendly solvents, and the beneficial skin health properties of selected phytochemicals. The review highlights recent research on major phytochemicals extracted from vegetables and root crops in relation to skin health. Full article

A renewed understanding of eco-friendly principles is moving the industrial sector toward a shift in the utilization of less harmful solvents as a main strategy to improve manufacturing. Green analytical chemistry (GAC) has definitely paved the way for this transition by presenting green solvents to a larger audience. Among the most promising, surely DESs (deep eutectic solvents), NaDESs (natural deep eutectic solvents), HDESs (hydrophobic deep eutectic solvents), and HNaDESs (hydrophobic natural deep eutectic solvents), with their unique features, manifest a wide-range of applications, including their use as a means for the extraction of small bioactive compounds. In examining recent advancements, in this review, we want to focus our attention on some of the most interesting and novel ‘solvent-free‘ extraction techniques, such as microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) in relation to the possibility of better exploiting DESs and NaDESs as plausible extracting solvents of the phenolic compounds (PCs) present in different matrices from olive oil components, such as virgin olive pomace, olive leaves and twigs, virgin and extra virgin olive oil (VOO and EVOO, respectively), and olive cake and olive mill wastewaters (OMWW). Therefore, the status of DESs and NaDESs is shown in terms of their nature, efficacy and selectivity in the extraction of bioactive phytochemicals such as secoiridoids, lignans, phenolic acids and alcohols. Related studies on experimental design and processes’ optimization of the most promising DESs/NaDESs are also reviewed. In this framework, an extensive list of relevant works found in the literature is described to consider DESs/NaDESs as a suitable alternative to petrochemicals in cosmetics, pharmaceutical, or food applications. Full article