Search Results (3,345)

Five different biomass wastes—orange peel, coffee grounds, cork, almond shell, and peanut shell—were transformed into biochars (BCs) or activated carbons (ACs) to serve as adsorbents and/or ozone catalysts for the removal of recalcitrant water treatment products. Oxalic acid (OXL) was used as a model pollutant due to its known refractory character towards ozone. The obtained materials were characterized by different techniques, namely thermogravimetric analysis, specific surface area measurement by nitrogen adsorption, and elemental analysis. In adsorption experiments, BCs generally outperformed ACs, except for cork-derived materials. Orange peel BC revealed the highest adsorption capacity (Qe = 40 mg g⁻¹), while almond shell BC showed the best cost–benefit ratio at €0.0096 per mg of OXL adsorbed. In terms of catalytic ozonation, only ACs made from cork and coffee grounds presented significant catalytic activity, achieving pollutant removal rates of 72 and 64%, respectively. Among these materials, ACs made from coffee grounds reveal the best cost/benefit ratio with €0.02 per mg of OXL degraded. Despite the cost analysis showing that these materials are not the cheapest options, other aspects rather than the price alone must be considered in the decision-making process for implementation. This study highlights the promising role of biomass wastes as precursors for efficient and eco-friendly water treatment processes, whether as adsorbents following ozone water treatment or as catalysts in the ozonation reaction itself. Full article

This study explored the use of mandarin peels as an important source of health-promoting compounds by utilizing green methods (i.e., pulsed electric field and ultrasound-assisted extraction), along with conventional stirring. The impact of several extraction parameters, such as extraction duration, temperature, and solvent composition, on the recovery of bioactive compounds was evaluated through a response surface methodology. To identify the most effective conditions for all assays, a partial least-squares analysis was implemented. It was revealed that a combination of the above techniques was optimal at 80 °C for 30 min, with 75% v/v of ethanol in water as the extraction solvent. The concentration of bioactive compounds in the optimum extract had a total polyphenol content of 18.69 mg of gallic acid equivalents (GAE) per gram of dry weight (dw), and an ascorbic acid concentration of 18.25 mg/g dw. However, correlation analyses revealed a rather negative relationship between these bioactive compounds. The chromatographic analysis of optimum extracts supported this result by quantifying 20.53 mg/g dw of total individual polyphenols, with hesperidin being the dominant compound (13.98 mg/g dw). The antioxidant assays, including ferric-reducing antioxidant power and DPPH^• inhibition activity, were measured at 123.21 and 65.12 μmol of ascorbic acid equivalents (AAE) per gram of dw, respectively. This research enhances the valorization of mandarin peels as a renewable source of bioactive compounds, providing the opportunity to generate high-added-value products from food waste in the food and pharmaceutical sectors. Full article

This work aimed to assess the potential efficacy of a novel polysaccharides-based extract as a green consolidant for the pictorial layer on marble substrates. Understanding its properties could lead to determining whether it can ensure the correct conservation and transmission of the cultural heritage. Four different types of marble specimens were prepared with paint based on malachite (egg, tempera grassa, rabbit glue, and linseed oil as binders). Colorimetric analyses, peeling tests, SEM-EDS, and FTIR spectroscopy were used to test the properties of the consolidant. Results reveal that no aesthetic changes occur when using the extract on painted surfaces and that the cohesive properties of most pictorial films increase after its application, confirming the consolidating effect. In conclusion, the use of an innovative green product for the restoration of marble-painted surfaces can be considered a possible good solution for consolidating treatment. Through this initial explorative research, we suggest an innovative approach to the protection of cultural heritage that doesn’t cause harm to both the restorer’s health and the environment. Full article

The tamarillo, or Solanum betaceum, recognized for its comprehensive nutritional profile, has long been valued for its diverse ethnobotanical uses. This study delves into the potential therapeutic applications of S. betaceum by analyzing its polyphenolic content (TPC), total flavonoid content (TFC), anti-skin aging activities against key enzymes like elastase, tyrosinase, and hyaluronidase, and its cytotoxic effects on oral carcinoma cells. Extracts from the seeds, pulp, and peel of red and yellow fruits were prepared using methanol, ethanol, and acetone. The highest TPC was found in the methanol extract from red fruit seeds (9.89 mg GAE/g), and the highest TFC was found in the methanol extract of yellow fruit peel (3.02 mg QUE/g). Some of these extracts significantly inhibited skin aging-associated enzymes with the red fruit seed extract (100 μg/mL) showing up to 50.4% inhibition of tyrosinase. Additionally, the red fruit seed extract obtained using methanol demonstrated potential anticancer effects against Ca9-22 oral carcinoma cells by inhibiting cell survival, migration, and proliferation as well as inducing apoptosis. These results underscore the potential of S. betaceum fruit extracts, especially from red fruit seeds, as promising agents for anti-skin aging and anticancer applications, meriting further exploration for therapeutic uses. Full article

The pharmacological effects of pomegranates have been described considering metabolic aspects such as hypoglycemic and hypolipidemic activities. The pomegranate extract has activity on the central nervous system (CNS) as a natural antidepressant and anxiolytic. The chemical composition of pomegranates is complex since the bioactive compounds are multiple secondary metabolites that have been identified in the extracts derived from the peel, seed, flowers, leaves, or in their combination; so, it has not been easy to identify an individual compound as responsible for its observed pharmacological properties. From this point of view, the present review analyzes the effects of crude extracts or fractions of pomegranates and their possible mechanisms of action concerning antidepressant- and anxiolytic-like effects in animal models. Serotonin receptors, estrogen receptors, the peroxisome proliferator-activated receptor gamma (PPARγ), or monoamine oxidase enzymes, as well as potent antioxidant and neuroplasticity properties, have been described as possible mediators involved in the antidepressant- and anxiolytic-like behaviors after pomegranate treatment. The pharmacological effects observed on the CNS in experimental models associated with a specific stress level suggest that pomegranates could simultaneously modulate the stress response by activating several targets. For the present review, scientific evidence was gathered to integrate it and suggest a possible pathway for mediators to be involved in the mechanisms of action of the pomegranate’s antidepressant- and anxiolytic-like effects. Furthermore, the potential benefits are discussed on comorbid conditions with anxiety and depression, such as perimenopause transition and pain. Full article

Citrus limon var. pompia Camarda var. nova, commonly known as pompia, is a distinctive citrus ecotype native to Sardinia, notable for its unique botanical, phytochemical, and potential health benefits. It holds cultural significance as a traditional food product of Sardinia, recognized by the Italian Ministry of Agricultural Food and Forestry Policies. This comprehensive review examines pompia’s traditional uses, taxonomic classification, pomological characteristics, phytochemical profile, and potential health benefits. Pompia phytochemical analyses reveal a rich composition of flavonoids and terpenoids, with notable concentrations of limonene, myrcene, and various oxygenated monoterpenes. Pompia essential oils are primarily extracted from its peel and leaves. Peel essential oils exhibit a high concentration of the monoterpene limonene (82%) and significantly lower quantities of myrcene (1.8%), geranial (1.7%), geraniol (1.5%), and neral (1.4%). In its rind extract, flavanones such as naringin (23.77 µg/mg), neoeriocitrin (46.53 µg/mg), and neohesperidin (44.57 µg/mg) have been found, along with gallic acid (128.3 µg/mg) and quinic acid (219.67 µg/mg). The main compounds detected in the essential oils from pompia leaves are oxygenated monoterpenes (53.5%), with limonene (28.64%), α-terpineol (41.18%), geranial (24.44%), (E)-β-ocimene (10.5%), linalool (0.56%), and neryl acetate (13.56%) being particularly prominent. In pompia juice, the presence of phenolic compounds has been discovered, with a composition more similar to lemon juice than orange juice. The primary flavonoid identified in pompia juice is chrysoeriol-6,8-di-C-glucoside (stellarin-2) (109.2 mg/L), which has not been found in other citrus juices. The compound rhoifolin-4-glucoside (17.5 mg/L) is unique to pompia juice, whereas its aglycone, rhoifolin, is found in lemon juice. Other flavonoids identified in pompia juice include diosmetin 6,8-C-diglucoside (54.5 mg/L) and isorhamnetin 3-O-rutinoside (79.4 mg/L). These findings support the potential of pompia in developing nutraceuticals and natural health products, further confirmed by its compounds’ antioxidant, anti-inflammatory and antibacterial properties. Future research should focus on optimizing extraction methods, conducting clinical trials to evaluate efficacy and safety, and exploring sustainable cultivation practices. The potential applications of pompia extracts in food preservation, functional foods, and cosmetic formulations also warrant further investigation. Addressing these areas could significantly enhance pompia’s contribution to natural medicine, food science, and biotechnology. Full article

In order to prepare chitosan-coated pomelo peel flavonoid microcapsules with antibacterial properties, chitosan was used as the wall material for the purpose of coating the core material, pomelo peel flavonoids. The pH of the microcapsule crosslinking reaction was 7.5, the mass ratio of the microcapsule core material to the wall material was 1:1, and the concentration of the emulsifier was 1%. The microcapsules obtained under these preparation conditions exhibited superior performance, morphology, and dispersion. Additionally, the yield and coating rates were recorded at 22% and 50%, respectively. To prepare the paint film, the microcapsules were added into the coatings at varying concentrations of 0%, 3.0%, 6.0%, 9.0%, 12.0%, and 15.0%. The antibacterial efficacy of the paint film for both bacteria was progressively enhanced with the incorporation of microcapsules. The antibacterial efficacy against Staphylococcus aureus was observed to be higher than that against Escherichia coli. As the content of microcapsules increased, the color difference in the paint film increased, the gloss loss rate increased, and the light transmission rate reduced. The tensile property and elongation at break reduced, and the roughness increased. At a microcapsule content of 6.0%, the paint film exhibited superior overall performance, with an antibacterial efficacy against Escherichia coli and Staphylococcus aureus of 46.3% and 56.7%, respectively. The color difference was 38.58. The gloss loss rate was 41.0%, the light transmission rate was 90.4%, and the paint film exhibited a large elastic region, with an elongation at break of 21.5% and a roughness of 1.46 μm. Full article

CrN and diamond-like carbon (DLC) coatings are deposited on the surface of 431 stainless steel by the direct current magnetron sputtering technique. The surface morphology, micro-structure, hardness, friction, and wear properties of CrN, CrN/DLC and multi-layer composite DLC coatings are investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, nanoindentation tester, scratch tester, and friction and wear tester. The results show that the surface of the single CrN coating is very rough for the columnar crystal structure with preferred orientation. When it serves as inner transition layers to form the composite DLC coatings, the surface gets much smoother, with reduced defects. The friction and wear results indicate that the composite DLC coatings exhibit lower coefficients of friction, and better wear and corrosion resistance in dry friction, deionized water, and seawater. In the dry wear and friction process, the single CrN coating is easily worn out, and severe friction oxidation and furrow wear both appear with a friction coefficient of 0.48. But the friction coefficient of a CrN coating in seawater is reduced to 0.16, and friction oxidation and wear loss are further reduced with water lubrication. The CrN/DLC coating has excellent tribological performance in three test concoctions and has the lowest friction coefficient of 0.08 in seawater, which is related to the higher sp³ bond content, density (1.907 g/cm³) and high degree of amorphization, contributing to high hardness and a self-lubrication effect. However, due to the limited thickness of CrN/DLC (1.14 µm), it easily peels off and fails during friction and wear in different testing conditions. In multi-layer composite DLC coatings, there are more sp² bonds with decreased amorphization, high enough thickness (4.02 µm), and increased bonding strength for the formation of different carbides and nitrides of chromium as transition layers, which gives rise to the further decreased average friction coefficient and the lowest wear loss. Therefore, the CrN coating alone has good wear resistance, and, as with the inner transition layer with a DLC coating, it can effectively improve the overall thickness and the bonding strength of the multi-layer films by optimizing the chemical compounds of DLC coatings. These results provide experimental support and reference for the design and selection of surface coatings for 431 stainless steels in different working conditions. Full article

Sodium alginate (SA)–purple sweet potato peel extracts (PPE) from industrial waste indicator films were developed at different drying temperatures (25, 30, 35, 40, 45, 50, and 55 °C). The effects of drying temperatures on the film’s structural, physical, and sensitive properties were investigated. On the structural properties, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction indicated that compactness, intermolecular interactions, and crystallinity of indicator films were improved at a lower drying temperature. On the physical properties, with the drying temperature increasing, elongation at the break increased significantly (p < 0.05); ΔE and water-vapor permeability decreased significantly (p < 0.05); and thickness and tensile strength initially increased significantly (90.46 → 98.46, 62.99 → 95.73) and subsequently decreased significantly (98.46 → 71.93, 95.73 → 55.44) (p < 0.05), with the maximum values obtained at 30 °C. On sensitivity, the corresponding colors of the films became lighter as the drying temperature increased, and the films exhibited relatively excellent pH and NH₃ sensitivity, with easily discernible color changes at lower temperatures. The results of this paper revealed that the overall film characteristics are improved at lower drying temperatures, which will provide valuable references for selecting the drying temperature for preparing indicator films as a guide for industrialized production. Full article

Ipomoea batatas (L.) Lam is a dicotyledonous plant originally from tropical regions, with China and Spain acting as the main producers from outside and within the EU, respectively. The root, including only flesh, is the edible part, and the peel, leaves, stems, or shoots are considered by-products, which are generated due to being discarded in the field and during processing. Therefore, this study aimed to perform a comprehensive review of the nutritional value, phytochemical composition, and health-promoting activities of purple-fleshed sweet potato and its by-products, which lead to its potential applications in bakery products for the development of functional foods. The methodology is applied to the selected topic and is used to conduct the search, review abstracts and full texts, and discuss the results using different general databases. The studies suggested that purple-fleshed sweet potato parts are characterized by a high content of essential minerals and bioactive compounds, including anthocyanins belonging to the cyanidin or the peonidin type. The flesh and leaves are also high in phenolic compounds and carotenoids such as lutein and β-carotene. The high content of phenolic compounds and anthocyanins provides the purple-fleshed sweet potato with high antioxidant and anti-inflammatory power due to the modulation effect of the transcription factor Nrf2 and NF-kB translocation, which may lead to protection against hepatic and neurological disorders, among others. Furthermore, purple-fleshed sweet potato and its by-products can play a dual role in food applications due to its attractive color and wide range of biological activities which enhance its nutritional profile. As a result, it is essential to harness the potential of the purple-fleshed sweet potato and its by-products that are generated during its processing through an appropriate agro-industrial valorization system. Full article

In ultrasonic metal welding, low specific resistances and large joining surface cross-sections require the use of mechanical testing to quantify the joint quality. In this study, different quality features of ultrasonically welded joints made of pure copper sheet are investigated during the successive phases of joint formation. Two test series with different workpiece geometries are examined. It is shown that mechanical quality features such as shear and peel forces behave differently over the formation of the joint and are not transferable. As an alternative to these, laser scanning microscopy is used to record images of the fracture surface that describe the growth of the joint area during formation. The study finds that shear tensile force growth and joint area growth are non-linear and comparable, with optimized welds achieving joint areas of 30 mm² out of 64 mm² and 6 mm² out of 16 mm². Although overall quality increases with increasing welding time, the material strength in the joint zone decreases. Depending on the original rolling condition, between 43% and 59% of the original material strength can be identified as the joint strength. The automatic analysis of fracture images is a suitable alternative to mechanical testing for similar joints. Full article

The tailings from gold beneficiation can cause various negative impacts, necessitating measures to prevent their transport and environmental contamination. Geomembranes serve as hydraulic barriers in mining tailings reservoirs, thereby supporting the Sustainable Development Goals (SDGs). To ensure that the geomembrane effectively mitigates environmental impact, it is essential to study its durability when applied in the field. This article examines the long-term performance of an HDPE geomembrane exposed for 7 and 11 years at a gold mining tailing site in Brazil. Samples were exhumed from different locations at the dam, and their properties were evaluated. Non-parametric statistics were employed using the Kernel Density Estimator (KDE). For the 11-year-old geomembranes, the probability of the geomembrane reaching nominal failure in terms of tensile strength was 0.4%. The peel separation values exceeded the maximum allowable by the GRI GM13 standard. Although the geomembranes showed significant antioxidant depletion, suggesting they were close to or had already reached their residual stages, they approached nominal failure based on their stress crack resistance but did not rupture. The environmental analysis indicated no significant contamination in the area, corroborating that the geomembrane is fulfilling its function. The non-parametric methodology proved promising for durability analysis and could be applied to other engineering projects with geosynthetics, thereby adding reliability to decision-making in alignment with sustainable development. Full article

In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas. Full article

The objective of this study was to analyze the chemical profile of extracts from different fruit parts of the perennial arborescent cactus Opuntia leucotricha by applying ultra-high-performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS) and to evaluate their biological properties (antioxidant and enzyme inhibitory capacities). Extracts were obtained from the fruit pulp (without or with seeds), seeds, and peel by ultrasound-assisted extraction (UAE) using the conventional solvent methanol 50% and two Natural Deep Eutectic Solvents (NADESs) (glycerol:urea, 1:1 and citric acid:sorbitol, 1:2). A total of 33 compounds were identified, including phenolics, fatty acids, and others. Phenolic acids were the most abundant class of phenolics identified in all fruit parts, with the highest concentration observed in the methanol extracts from peel (593.02 µg/g_DW), followed by seed-containing pulp (69.03 µg/g_DW), pulp (57.83 µg/g_DW), and seeds (39.97 µg/g_DW). The second most effective extractant was NADES 1 (glycerol:urea, 1:1), which was also successful in extracting compounds with antioxidant capacity. Overall, the extracts demonstrated considerable enzyme inhibitory activities, with the greatest effects observed against α-amylase and α-glucosidase. The results indicate that O. leucotricha fruits could be a promising source of bioactive compounds, and NADES a viable alternative to organic solvents for their industrial exploitation. Full article

Mechanical peeling is more efficient and environmentally friendly compared to manual peeling. However, comparative studies on the quality of mechanically peeled pepper and manually peeled pepper are limited. This study utilized GC-MS to investigate the effects of immersion, steaming, and peeling machinery speed on the volatile composition of white pepper. A total of thirteen monoterpenes and seven sesquiterpenes were detected, with 3-carene, D-limonene, and sabinene being the most abundant monoterpenoids and β-caryophyllene, δ-elemene, and α-copaene being the most abundant sesquiterpenes. The total volatiles increased with longer steaming times and higher peeling machinery speeds. Compared to manual peeling or steaming followed by mechanical peeling, the volatile content of pepper was higher when using mechanical peeling alone. Additionally, relative odor activity values showed that 3-carene and D-limonene were the main contributors to flavor, with 3-carene, β-caryophyllene, and α-copaene being key volatiles responsible for flavor distinctions. This research aims to provide theoretical support for developing a superior and environmentally friendly mechanical method to replace manual labor. Full article