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The industries are searching for greener alternatives for their productions due to the rising concern about the environment and creation of waste and by-products without industrial utility for that specific line of products. This investigation describes the development of two stable nanostructured lipid carriers (NLCs): one is the formulation of a standard NLC, and the other one is the same NLC formulation associated with a natural deep eutectic solvent (NaDES). The research presents the formulation paths of the NLCs through completeness, which encompass dynamic light scattering (DLS), zeta potential tests, and pH. Transmission electron microscopy (TEM) and confocal microscopy were performed to clarify the morphology. Cytotoxicity tests with zebrafish were realized, and the results are complementary to the in vitro outcomes reached with fibroblast L132 tests by the MTT technique and the zymography test. Infrared spectroscopy and X-ray diffractometry tests elucidated the link between the physicochemical characteristics of the formulation and its behavior and properties. Different cooling techniques were explored to prove the tailorable properties of the NLCs for any industrial applications. In conclusion, the compiled results show the successful formulation of new nanocarriers based on a sustainable, eco-friendly, and highly tailorable technology, which presents low cytotoxic potential.

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The recovery of bioactive compounds is a promising approach for obtaining rich extracts from fruit by-products. This study investigated the influence of Natural Deep Eutectic Solvents (NADES) and Ultrasound-Assisted Extraction (UAE) on the phenolic content, antioxidant capacity, and in vitro antidiabetic activity of Psidium myrtoides by-product. Among eight NADES evaluated based on choline chloride, NADES ChCl:Gly (1:2) was selected for its efficiency in extracting total phenolic compounds (TPC) with high antioxidant capacity. The optimized conditions were 61 °C, a solid-liquid ratio of 100 mg 5 mL-1, and a 60-minute extraction time. ChCl:Gly exhibited superior TPC recovery (2.6-fold greater effectiveness) compared to the 60 % hydroethanolic solution. Twenty-six phenolic compounds were identified, including significant levels of catechin (336.48 mg g-1) and isoquercetin (26.09 mg g-1). Phenolic acids, such as p-anisic acid (5.47 mg g-1) and methoxyphenylacetic acid (0.23 mg g-1), were identified for the first time in the purple araçá by-product. The ChCl:Gly extract demonstrated the highest bioactivity, showcasing antioxidant and antidiabetic capacities. This study introduces an innovative and sustainable alternative for recovering phenolic compounds from fruit by-products, offering enhanced recovery efficiency and/or selectivity compared to organic solvents.

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The development of technologies to capture greenhouse gases (GHGs) like carbon dioxide (CO2) and nitrous oxide (N2O) is vital for climate change mitigation. Ionic liquids (ILs), deep eutectic solvents (DES), and natural deep eutectic solvents (NADES) are promising absorbents to abate GHGs emissions. However, their high viscosity limits the gas-liquid contact, as consequence of the mass transfer. To overcome this, their impregnation onto porous silica gel has been carried out, increasing the gas-liquid contact area. The present study analyzes the effect of size particle of silica gel impregnated with ILs, DES, and NADES over the CO2 and N2O capture at atmospheric conditions. The degree of impregnation of silica particles was determined by thermogravimetric analysis (TGA). The identification of functional groups present on the surface of silica, ILs, DES, and NADES was performed using Fourier-transform infrared spectroscopy (FTIR), and their crystalline structure was determined by X-ray diffraction (XRD). The partition coefficient of CO2 and N2O between gas and ILs, DES, and NADES was determined by a static headspace method. Results show that the degree of solvent impregnation on silica gel ranged from 36.8 to 43.0% w/w, the partition coefficient of CO2 in the impregnated silica varied from 0.005 to 0.067, and for N2O, from 0.005 to 0.032. This suggests that impregnated particles have a greater affinity for N2O compared to CO2. Using impregnated particles requires only 40% of the bulk solvent to achieve a similar GHG capture capacity compared to using bulk solvents.

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The production of smokeable tobacco for use in cigarettes is characterized by the production of pre-harvest and post-harvest waste, with ensuing undesirable effects on the environment. The inflorescences of tobacco after blunting, deflowering, or topping are considered pre-harvest waste and left in the field. Using green and ecofriendly solvents such as Natural deep eutectic solvents (NaDESs), these wastes could be used to obtain antioxidant molecules of interest in cosmetics. Taking into account its potential as plant matrix to obtain metabolites of commercial interest, tobacco inflorescences and inflorescence powders of different particle sizes were characterized by optic and electronic microscopy. Thus, the powdered inflorescences were extracted with four conventional solvents, i.e., distilled water (DW), acetone: distilled water (AW), ethanol 70° (EW), methanol (Me), and five NaDESs, i.e., lactic acid: sucrose (LAS), lactic acid: sucrose: distilled water (SALA), fructose: glucose: sucrose: distilled water (FGS), choline chloride: urea: distilled water (CU), and citric acid: propylene glycol (CAP). Among the tested NADESs, SALA was the most promising solvent; higher extraction yields of total phenolic compound (3420.0 ± 9.4 µg GAE/mL) than conventional solvents were attained and it was the only selective solvent to phenolics. CU was the best solvent for flavonoids and alkaloids extraction (215.3 ± 3.2 µg QE/mL and 392.3 ± 8.0 µg ACE/mL, respectively). All extracts showed antioxidant activity. A heatmap with dendrogram and main component analysis showed that acid-based NaDESs are grouped together, this group being the one with the best performance in H2O2 scavenging. The extracts obtained with green solvents could be used directly in cosmetic formulations as antioxidant ingredients because both tobacco flower oil and flower extracts are listed in the cosmetic ingredients database as non-toxic products. Additionally, the demand for sustainable ecological cosmetics is growing. In this sense, NaDESs represent an opportunity to develop innovative extracts with unique phytochemical fingerprints and biological activities.

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Tobacco cultivation and industrialization are characterized by the production of trillions of pre-harvest and post-harvest waste biomasses each year with the resulting negative effects on the environment. The leaves of blunt, pre-harvest waste, could be further used to obtain bioactive metabolites, i.e., polyphenols and alkaloids, for its potential cosmetic use. This study was conducted to obtain bio-compounds from pre-harvest tobacco leaf waste (var. Virginia) by applying conventional and green solvents (NaDES). Leaves and ground leaf waste were characterized based on their microscopic features. Conventional solvents, such as water, acetone, ethanol, and non-conventional solvents, such as Natural Deep Eutectic Solvents (NaDES), i.e., sucrose:lactic acid (LAS), frutose:glucose:sucrose (FGS), lactic acid:sucrose:water (SALA), choline chloride:urea (CU), and citric acid: propylene glycol (CAP) were used for bioactive extraction from tobacco waste powder. CU, FGS, and acetone/ethanol had similar behavior for the best extraction of alkaloids (6.37-11.23 mg ACE/g tobacco powder). LAS, FGS, SALA, and CU were more effective in phenolic compound extraction than conventional solvents (18.13-21.98 mg AGE/g tobacco powder). Because of this, LAS and SALA could be used to obtain phenolic-enriched extracts with lower alkaloid content rather than CU and FGS. Extracts of the powder obtained with conventional solvent or CU showed a high level of sugars (47 mg/g tobacco powder) The ABTS antioxidant capacity of tobacco leaf powder was higher in the extracts obtained with CU, FGS, and acetone (SC50 1.6-5 µg GAE/mL) while H2O2 scavenging activity was better in the extracts obtained with LAS, CAP and SALA (SC50 3.8-8.7 µg GAE/mL). Due to the biocompatibility of the NaDES with the components of tobacco leaf waste, the opportunity to apply these extracts directly in antioxidant formulations, such as cosmetics, phytotherapic, and other formulations of topic use seems promising. Furthermore, NaDES constituents, i.e., urea and organic acid can also have beneficial effects on the skin.

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Bioactive functional coatings constitute a trendy topic due to they reduce postharvest fruit losses worldwide. Also, they could be carriers of biocompounds providing health benefits to the consumer. In this work, an innovative natural bioactive coating based on Natural Deep Eutectic Solvents (NADES) and Larrea divaricata extract was optimized by mixture-mixture design for the management of postharvest diseases caused by Monilinia fructicola. A NADES composed of lactic acid-glucose-water (LGH) for phenolic extraction from L. divaricata was optimized by a Simplex Lattice design and response surface methodology (RSM).Then, a d-optimal mixture-mixture design was carried out in order to optimize the bioactive coating composition, being the optimal proportion of 0.7 L. divaricata-LGH extract and 0.3 NADES plasticizer (composed by glycerol, citric acid and water). The optimal biocoating achieved an in vitro antimicrobial activity of 72 % against M. fructicola. Interestingly, NADES plasticizer improves the biocoating functionality, creating a smooth and uniform surface.

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Soybeans are mainly used for food and biodiesel production. It is estimated that soy crops worldwide will leave about 651 million metric tons of branches, leaves, pods, and roots on the ground post-harvesting in 2022/23. These by-products might serve as largely available and cheap source of high added-value metabolites, such as flavonoids, isoflavonoids, and other phenolic compounds. This work aimed to explore green approaches based on the use of pressurized and gas expanded-liquid extraction combined with natural deep eutectic solvents (NADESs) to achieve phenolic-rich extracts from soy by-products. The total phenolic and flavonoid contents of the generated extracts were quantified and compared with conventional solvents and techniques. Pressurized liquid extraction (PLE) with choline chloride/citric acid/water (1:1:11 - molar ratio) at 120°C, 100 bar, and 20 min, resulted in an optimized condition to generate phenolic and flavonoid-rich fractions of soy by-products. The individual parts of soy were extracted under these conditions, with their metabolic profile obtained by UHPLC-ESI-QToF-MS/MS and potential antioxidant properties by ROS scavenging capacity. Extracts of soy roots presented the highest antioxidant capacity (207.48 ± 40.23 mg AA/g), three times higher than soybean extracts (68.96 ± 12.30). Furthermore, Hansen solubility parameters (HSPs) were applied to select natural hydrophobic deep eutectic solvents (NaHDES) as substituents for n-heptane to defat soybeans. Extractions applying NaHDES candidates achieved a similar yield and chromatography profile (GC-QToF-MS) to n-heptane extracts.

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Habanero pepper leaves and stems (by-products) have been traditionally considered waste; however, bioactive compounds such as polyphenols, vitamin C and carotenoids have been identified that can be used for formulation of nutraceuticals or functional foods. Furthermore, the extraction of these bioactive compounds by using environmentally friendly methods and solvents is desirable. Thus, the aim of this study was to assess the antioxidant capacity, total polyphenol content (TPC), the phenolic profile and vitamin C content in extracts obtained from by-products (stems and leaves) of two varieties (Mayapan and Jaguar) of habanero pepper by ultrasound-assisted extraction (UAE) using natural deep eutectic solvents (NADES). The results showed that NADES leads to extracts with significantly higher TPC, higher concentrations of individual polyphenols (gallic acid, protocatechuic acid, chlorogenic acid, cinnamic acid, coumaric acid), vitamin C and, finally, higher antioxidant capacity (9.55 ± 0.02 eq mg Trolox/g DM) than UAE extraction performed with methanol as the solvent. The association of individual polyphenols with NADES was confirmed by principal component analysis (PCA). Overall, NADES is an innovative and promising "green" extraction technique that can be applied successfully for the extraction of phenolic compounds from habanero pepper by-products.

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This work reports for the first time the analytical performance of glassy carbon electrodes (GCE) modified with a dispersion of multi-wall carboxylated carbon nanotubes (MWCNTs-COOH) using a mixture of a natural deep eutectic solvent (NADES - LGH/lactic acid-glucose-water), ethylene glycol (EG) and water (GCE/MWCNT-LGH-EG) for the determination and N-(4-hydroxyphenyl) acetamide (paracetamol) (APAP) in urine samples. The optimization of both dispersion and measurement conditions was carried out using experimental design. The modified electrode exhibited enhanced current responses, demonstrating excellent electrochemical response towards APAP oxidation compared to MWCNTs-LGH, MWCNTs-EG, MWCNTs-H2O-EtOH and MWCNTs-H2O. The linear dependence between the anodic peak currents and the square root of scan rates over the range of 0.010-0.300 Vs-1 demonstrates that the electro oxidation of APAP occurs under diffusional control. The MWCNT-LGH-EG modified GCE displayed an analytical sensitivity of 10.72 mL µg-1 (r = 0.9994) and a detection limit of 100 ng mL-1 for the selective determination of APAP in urine samples. The proposed electrochemical sensor was successfully applied for quantifying APAP in urine samples in the presence of uric acid. In addition, the accuracy and precision of the method was contrasted against a HPLC reference method.

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Natural Deep Eutectic Solvents (NADES) are highly important for Green Chemistry principles and can be used instead of harmful organic solvents. Indeed, nowadays smartphone-based analytical devices can replace some traditional laboratory equipment. In the present work, a smartphone based dual spectrophotometer and spectrofluorometer device was designed, 3D manufactured, and validated. A resolution of 0.241 ± 0.010 pixel.nm-1 and a stability comparable with commercial instruments were obtained. Using the proposed device it was possible, for the first time, to study the role of water in NADES (fructose:urea:water) preparation, by testing the influence of structural and dilution water. In this sense, it was observed that when water was added before NADES preparation (integrated into the superstructure of the solvent), fluorescence and absorbance intensities sharply decayed (up to 90% and 95%, respectively). In contrast, dilution water had minor effects on spectroscopic features of the eutectic system, which was expressed as 29% and 23% of diminution of signal intensities for both techniques. The obtained results suggest that the moment the water is added plays a significant role in NADES properties.

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