Maximum Extraction Yield Research Articles

From Waste to Value: Optimization of Ultrasound-Assisted Extraction of Anthocyanins and Flavonols from Pistacia lentiscus L. Oilcakes.

Pistacia lentiscus L., commonly known as the mastic tree or lentisk, is a woody Mediterranean plant revered for its ecological relevance as well as for its extensive ethnobotanical heritage. Historically, the fruits and the resin of P. lentiscus have been widely utilized in traditional medicine, underscoring its important role in local healing practices. Given these properties, this study explored an innovative approach to efficiently extract anthocyanins and flavonols from P. lentiscus oilcakes utilizing ultrasound-assisted extraction (UAE) as an alternative to conventional solvent extraction. Liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography with diode-array detection (HPLC-DAD) were used to identify and quantify the anthocyanins and flavonols, revealing the successful extraction of eight distinct anthocyanins and twenty flavonols. A Fractional Factorial Design (FFD) followed by a Box-Behnken design (BBD) were applied to optimize the yield of anthocyanins and flavonols. The optimal extraction conditions found were to be an extraction time of 15 min with 70% ethanol as the solvent and a liquid-to-solid ratio of 0.012 L g-1, which resulted in a maximum extraction yield of 19.78 mg g-1 dry extract for the Total Flavonol Content and over 25.4 mg g-1 dry extract for the Total Flavonol and Anthocyanin Content. By elucidating the optimal conditions for extracting anthocyanins and flavonol glycosides, this study opens promising avenues for utilizing P. lentiscus oilcake by-products, supporting sustainable practices, and advancing the valorization of Mediterranean bio-resources for health-promoting applications.

Comparative Analysis of Supercritical Carbon Dioxide and Subcritical Water Extraction for Sabah Coffea Canephora

This work provides a thorough comparative analysis of the green extraction process, viz. supercritical carbon dioxide and subcritical water extraction methods for Sabah Coffea canephora. Rigorous experiments were conducted using supercritical carbon dioxide (temperature ranging from 40 °C to 80 °C and pressure from 10 to 30 MPa) and subcritical water (temperature ranging from 120 to 180 °C with extraction times from 5 to 15 min). The optimum conditions for supercritical carbon dioxide extraction were obtained at 79 °C and 30 MPa at the maximum extract yield (8.549%), total phenolic content (4.563 mg/g gallic acid equivalent), total flavonoid content (0.763 mg/g quercetin equivalent) and antioxidant activity (63.34%). Meanwhile, subcritical water extraction is the best extraction method for Coffea canephora, which was obtained optimum conditions at 180 °C and 15 min of extraction time with a maximum extract yield of 44.477%, total phenolic content of 6.481 mg/g gallic acid equivalent, total flavonoid content of 13.816 mg/g quercetin equivalent and 77.586% of antioxidant activity. In conclusion, this understanding contributes to developing optimized conditions for green extraction methods, expanding the potential applications of Sabah Coffea canephora in industries, including pharmaceuticals and functional foods.

Innovative CO2-NBs-assisted ultrasonication for the phytochemical extraction of peanut (Arachis hypoga) shells: Synthesis and characterization of CO2-nanobubbles.

This study was designed to obtain the maximum extraction yield of peanut shell (PS) polyphenols using a novel carbon dioxide nanobubbles (CO2-NBs) assisted ultrasonic extraction method. CO2-NBs were generated in distilled water with a self-developed high-pressure nano-jet homogenization method and characterized by size, zeta potential and transmission electron microscopy (TEM). The obtained nanobubble's mean size and zeta potential were 229.96±17.44nm and -15.9±1.27mV, respectively. Later, these CO2-NBs, combined with ultrasonic method, were used for the extraction of polyphenols, achieving the highest polyphenol content (3619.21±113.07 µg GAE/mL) as compared to ultrasonic extraction (2914.69±145.45µg GAE/mL) and conventional extraction (2340.11±80.02µg GAE/mL). Response surface methodology (RSM) provided optimization parameters, including ultrasonic power of 358.76W, surfactant concentration of 4.54%, and extraction time of 41.41min. HPLC analysis identified distinct peaks corresponding to polyphenolic compounds such as gallo-catechin, catechin gallate, resveratrol, and luteolin, confirming their presence and concentrations in the peanut shell extract (PSE). Scanning electron microscopy (SEM) revealed significant structural disruption and increased porosity in peanut shell powder, supporting the enhanced extraction of polyphenols through CO2-NBs-assisted ultrasonic extraction process. This research establishes theoretical and practical foundation for generation of CO2-NBs and CO2-NBs ultrasonic extraction technology to efficiently extract polyphenols from waste PS, thereby enhancing the extraction efficiency of valuable compounds for use in functional food products and promoting sustainable practices in food industry.

Supercritical carbon dioxide extraction of Polygonum cuspidatum powders: Experiments and modelling

AbstractIn recent years, the natural anticancer components resveratrol and emodin have attracted significant attention. This study employs supercritical carbon dioxide (ScCO2) extraction, using ethanol as a cosolvent, to extract resveratrol and emodin from Polygonum cuspidatum powders. Experiments were conducted at temperatures ranging from 308 to 328 K, pressures from 15 to 30 MPa, ethanol contents of 60 to 160 mL/L, and extraction times between 1800 and 7200 s. The maximum extraction yields of resveratrol and emodin were 2.516 and 2.765 mg/g, respectively, under optimal conditions (temperature: 323 K, pressure: 25 MPa, ethanol content: 100 mL/L, extraction time: 3600 s), determined through one‐way experiments. Additionally, a mathematical model of the ScCO2 extraction process was developed. The mass transfer coefficient (Kf) was used as a fitting parameter and the kinetic model, based on mass conservation, was validated with experimental data. The model demonstrated good accuracy, with a low average absolute relative deviation (AARD) of 4.05%. This model provides theoretical support for industrial scaling and process optimization, achieving maximum extraction efficiency while minimizing CO₂ and ethanol consumption, thereby reducing costs and enhancing environmental benefits. Its establishment framework and methodology offer valuable references for optimizing similar ScCO2 extraction processes.

Optimization of ultrasound-assisted extraction of mango cotyledon starch: Physicochemical, structural, thermal and functional properties

Mango (Mangifera indica L.) seed, a byproduct of mango pulp and juice processing, is recognized for its abundant starch content. The advancement of the modern food industry has prompted a shift away from traditional starch extraction methods due to their environmental impact and low efficiency. The study aimed to optimize the ultrasound-assisted extraction process of starch from the cotyledons of mango seeds, employing response surface methodology with a customized optimal design and an optimal-I optimality criterion. We investigated the effects of cotyledon/water ratio, time, power, and sonication frequency on maximizing starch extraction yield. We explored the impact of ultrasound on structural, morphological, functional, and pasting properties. The maximum starch extraction yield was 50.74%. This yield was about 82.4% higher than that of conventional wet extraction. Ultrasound-assisted extraction increased starch purity and amylose content; it reduced granule size while enhancing all starch pasting properties without affecting starch's chemical structure and morphological, thermal, and functional properties. The mango cotyledon starch can be classified as medium to normal amylose content starches, exhibiting A-type polymorphs, fast-swelling, and capable of forming strong, firm, low-sticky gels. These results demonstrate the potential applications of mango residue and ultrasound technology in the food and pharmaceutical industry.

Mechanism of deep eutectic solvents based extraction of phenolic and flavonoid compounds from peony petals

Deep eutectic solvents (DES) have exhibited great potential in the extraction of active ingredients from flowers. In this study, ternary DESs were designed for the extraction of phenolic and flavonoid compounds from peony petals. When the molar ratio of ChCl:EG:U was 1:2:2, and the water content was 30 %, the maximum extraction yields of total phenolic content (TPC) and total flavonoid content (TFC) were achieved, reaching 109.30 mg GAE/g and 56.93 mg RE/g, respectively. Meanwhile, cellulose nanofibers were prepared. The relationship model with extraction yield as the target was established by multivariate analysis. The model indicated that the property parameters of the HBD had a significant impact on the extraction yields of TPC and TFC. At the molecular level, Density functional theory (DFT) was employed to explore the extraction mechanism. The analysis revealed that hydrogen bonding was the main interaction force. The maximum binding energy between DES and rutin was −89.03 kcal/mol. This study provides an efficient extraction solvent and insights into the mechanism of extracting the phenolic and flavonoid compounds from peony petals.

High-intensity ultrasound-assisted alkaline extraction of soy protein: Optimization, modeling, physicochemical and functional properties

This study examined the effect of high-intensity ultrasound-assisted alkaline extraction (HUAE) on the extraction yield and the physicochemical and functional properties of soy protein (SP) using the two-pot multivariate method for the first time. Plackett-Burman Design (PBD) coupled with Response Surface Methodology (RSM) was systematically utilized to select and subsequently optimize the HUAE parameters. Based on PBD results, the significant extraction factors were liquid to solid ratio (LSR), temperature, ultrasonic amplitude, and extraction time. The optimum conditions for the maximal extraction yield and minimal energy consumption were 50:1 mL/g LSR, 50 °C, 48 % ultrasonic amplitude, and 10 min extraction time. At optimum conditions, the extraction yield (35.28 %) was significantly improved compared to traditional extraction (26.39 %). Besides, HUAE resulted in modification of the protein secondary and tertiary structures due to the unfolding of protein molecules and the exposure of hydrophobic groups or regions as shown by FTIR spectroscopy, free sulfhydryl analysis, and scanning electron microscopy. These structural changes led to decreased solubility and emulsifying activity but improved emulsion stabilization and antioxidant properties. With future development, HUAE could potentially produce soy protein for targeted applications, broadening its utilization and meeting the need for more sustainable alternative processing.

Investigation of Chemical Composition and Biological Activity of Salix aegyptiaca L. Roots

The root of Salix aegyptiaca L. was extracted using their yield percentage, total condensed tannin concentration, antimicrobial, antioxidant activity and to determine chemical composition by LC-MS/MS. The root extraction was carried out together with water, ethanol and methanol. Accelerated solvent extraction (ASE), conventional extraction (CE), and microwave extraction (ME) were the extraction methods applied during the investigation. The LC-MS/MS methanol extract was used to detect phenolics. The antioxidant activities and total condensed tannin concentrations of root extracts have been done by UV-visible spectroscopy from 517 to 580 nm, severally. The disk diffusion method was used for antimicrobial activity. The maximum extraction yield (17.2%) was obtained in methanol by the ASE technique whereas, the conventional extraction technique obtained the minimum extraction efficiency (9.1%). By triplicate measurement, the total condensed tannin analysis result was found 35.14 mg/L. Using the ASE technique, the methanol extract was the maximum inhibitory zone (26 mm) against Candida albicans ATCC 10231. However, in water extract by conventional extraction, a minimum inhibitory zone (11 mm) was obtained against Staphylococcus aureus Cowan 1. The highest and lowest DPPH scavenging activity was determined in methanol (ASE) (98.8%) and ethanol (97.5%) extract respectively. The maximum amounts of quinic acid (63895 µg/g) were discovered using LC-MS/MS.

ANN modeling and RSM optimization of ultrasound-assisted extraction of protodioscin-rich extracts from Tribulus terrestris L.

Tribulus terrestris L. is a herb renowned for its abundance of saponins, flavonoids, and alkaloids, which are utilized in treating various health conditions. Protodioscin functions by enhancing the conversion of testosterone into potent dihydrotestosterone, stimulating an increase in libido, red blood cell production from the bone marrow, and muscle development. Contemporary ultrasound-assisted-extraction (UAE) process employing green extraction solvents was selected to design the required separation system. The experimental plan was developed based on the independent operating variables – extraction time, operating temperature and solvent system composition in order to determine the influence of defined parameters and their interactions on the extraction yield and the presence of protodioscin. The 3D-RSM approach was introduced to determine the optimal values of studied independent variables in the area of maximal extraction yield. UAE process performed at optimal operating conditions generated maximal extraction yield (31 %, w/w) and protodioscin content of 5.9 mg/g dry plant matrix. Experimental data was used to develop an ANN for the defined extraction system using the operating variables values as the input matrix and observed yield as target matrix. Successfully designed and trained ANN generated high correlation (r = 0.9992) between observed data and predictive model’ outputs, and MSE value of 0.29107.

Efficient separation of methyl ethyl ketone and water azeotrope using hydrophobic amino acid ester ionic liquids

BackgroundMethyl ethyl ketone (MEK), an essential organic solvent, is commonly produced via the n-butene method, where water emerges as the principal impurity. The conventional distillation processes, which are necessitated by the azeotropic behavior between MEK and water, result in a substantial expenditure of energy. As a result, liquid-liquid extraction represents a promising alternative for energy-efficient separation. MethodsIn this work, three hydrophobic amino acid ester ionic liquids L-phenylalanine ethyl ester bis(trifluoromethylsulfonyl) imide ([Phe][NTf2]), L-leucine ethyl ester bis(trifluoromethylsulfonyl) imide ([Leu][NTf2]) and L-valine ethyl ester bis(trifluoromethylsulfonyl) imide ([Val][NTf2]) were utilized as extractants for separation of the binary azeotrope methyl ethyl ketone and water. The effects of extraction time, extraction temperature, mass ratio of MEK-water mixture to ionic liquid and initial concentration of MEK on extraction efficiency were investigated. Significant findingsThe results demonstrate that the ionic liquid [Phe][NTf2] exhibits superior extraction ability for the separation of the azeotrope methyl ethyl ketone and water. The maximum extraction yield of 99.86 % was achieved with the optimum extraction conditions of extraction time, 10 min, extraction temperature, 293.15 K, mass ratio of mixture to ionic liquid, 1:1 and initial concentration of MEK, 20 %. In addition, the relationship between the structure of ionic liquids and their extraction performance was revealed by quantum chemical calculations of ionic liquids with MEK and water. These ionic liquids were positioned as promising environmentally friendly alternatives to traditional organic solvents for the recovery of MEK from aqueous solutions, providing valuable insights for industrial applications.

Optimization of short-term dynamic and static maceration of Piper betle L. leaves to maximize extraction yield and anti-Candida albicans activity

This study aimed to optimize the extraction conditions of Piper betle leaves using a circumscribed central composite design, comparing dynamic and static maceration. Extraction temperatures were varied from 40°C to 80°C, while extraction times were varied from 15 to 45 minutes. Extraction yield, eugenol content in the raw material, and inhibition zone against Candita albicans were monitored. This study is notable for its comprehensive analysis of two maceration techniques under carefully controlled conditions and provides a novel comparison between dynamic and static maceration for this plant. The optimized conditions that maximized the extraction yield and inhibition zone were a temperature of 72.9°C for 19.4 minutes for dynamic maceration and 74°C for 19.4 minutes for static maceration. Under the optimal extraction conditions, static maceration resulted in superior extraction yield and eugenol content and a comparable inhibition zone compared to dynamic maceration. Specifically, static maceration produced an extraction yield of 27.50%±1.15%, eugenol content of 1.12%±0.05%, and an inhibition zone against C. albicans of 29.88±1.11 mm. Importantly, static maceration not only achieved comparable antifungal activity but also preserved the integrity of thermolabile compounds such as eugenol, which could contribute to a higher-quality extract. These findings have broader implications, particularly for industries prioritizing cost-effective and scalable extraction techniques for plant-based bioactives. In conclusion, static maceration was more suitable than dynamic maceration for extracting P. betle leaves. Moreover, the optimal conditions identified could serve as a guide for maximizing the extraction yield and anti-C. albicans of P. betle leaves.

Extraction and Nutritional Value of Soybean Meal Protein Isolate

The increasing protein demand driven by global population growth necessitates the search for an alternative protein source. Soybean meal (SM), with approximately 47–49% proteins, is a viable option. Soymeal protein isolate (SMPI) is a cost-efficient protein source with a well-balanced amino acid profile, making it suitable for addressing this demand. This study attempts to address the lack of information regarding the extractability and nutritional potential of SMPI obtained utilizing a weak base and recoverable solvent. In this work, the structural and compositional studies of SMPI, as well as the aqueous extractability of ammonium hydroxide (NH4OH), are investigated. Furthermore, we examined the effects of heat treatment during oil extraction, where a comparison between protein isolates from soymeal and whole soybeans was carried out. The maximum extraction yield of 24.1% was achieved by increasing the concentration of NH4OH from 0.25–1%. In comparison to the soy protein isolate from whole soybeans (SPI), the compositional analysis report revealed that SMPI had higher levels of crude protein, moisture, and ash content, but lower levels of fat and carbohydrates. Furthermore, the examination of the amino acid composition confirms the existence of vital amino acids in SMPI. The amino acid score indicates that methionine, lysine, and threonine are the limiting amino acids. SMPI and SPI share structural and functional group similarities, as demonstrated by Fourier-transform infrared spectroscopy. Gel electrophoresis using sodium dodecyl sulfate–polyacrylamide shows that the protein molecular weight distributions of SPI and SMPI are similar. This in-depth evaluation emphasizes the advantages of SM by advocating its application in other sectors beyond conventional animal feed, such as nutritional supplements and bio-based products, and by improving the environmental sustainability and global food chains.

Antioxidant Activity of Banana Peel Waste, the Development and Stability Evaluation of Facial Toner Containing Banana Peel Extract

The banana processing industry produces many by-products, mainly banana peel. Banana peel waste, after banana processing, can be a good source of bioactive compounds. Extraction of phenolic compounds using optimum extraction conditions enhances the yield and quality of the products. This study evaluated optimizing the extraction time for the maximum extraction yield from banana peels, consequently lowering the overall process cost. In addition, the application of increasing the value of banana waste was also evaluated. The optimum conditions were achieved using 95% ethanol with a solid-to-liquid ratio of 1:5, 25 ± 5 oC under various extraction times (0-96 h). The responses, such as total phenol content (TPC), total flavonoid content (TFC), and DPPH inhibition activity, were measured by spectrophotometric analysis. The optimal incubation time at 72 h was found to be more effective compared to the others. The values of TPC, TFC, and DPPH inhibitory activity at optimized conditions were 8.23 ± 0.42 mg gallic acid equivalent (mg GAE)/g, 8.18 ± 0.08 mg quercetin equivalent (mg QE)/ g, and 93.96%, respectively. The ethanolic extract of banana peel had an inhibition concentration (IC50) of 48.35 ± 0.88 μg/mL. After that, banana peel extract was subjected to study the potential for cosmetic application. The extract was applied as an ingredient in facial toner. The toners were preliminarily characterized. Banana peel waste possesses reasonable antioxidant activity and shows high stability over time. The results showed high potential for cosmetic applications using banana peel extract. In addition, using banana peel waste reduces agricultural waste in the environment.

Electron beam irradiation coupled ultrasound-assisted natural deep eutectic solvents extraction: A green and efficient extraction strategy for proanthocyanidin from walnut green husk

Proanthocyanidin (PAC) is recognized as a potent natural antioxidant that prevents various diseases. As societal awareness increases, eco-friendly and efficient natural product extraction technologies are gaining more attention. In this study, an electron beam irradiation (EBI) coupled with ultrasound-assisted natural deep eutectic solvents (NADES) extraction method was developed to enable the green and highly efficient extraction of PAC from walnut green husk (WGH). NADES, prepared with choline chloride and ethylene glycol, demonstrated excellent extraction capacity and storage stability for PAC. Molecular dynamics simulations elucidated the high compatibility between NADES and PAC, attributed mainly to a higher SASA value (207.85 nm2), a greater number of hydrogen bonds (330.99), an extended hydrogen bonding lifetime (4.54 ps), and lower inter-molecular interaction energy. Based on these findings, the optimal conditions (13 kGy EBI, 42 mL/g liquid-solid ratio, 38 °C extraction temperature, 70 min extraction time) resulted in a maximum PAC extraction yield of 56.34 mg/g. Notably, this yield was 32.93 % higher than that observed in samples not treated with EBI and ultrasound-assisted extraction (UAE). Analysis of tissue morphology, extract functional groups and thermal behavior suggested a possible mechanism for the synergistically enhanced PAC extraction by the EBI-NADES-UAE method. Additionally, the PAC extracted using the NADES by the EBI coupled with ultrasound-assisted method exhibited outstanding antioxidant activity (comparable to Vc), digestive enzyme inhibition (IC50: 17–0.61 mg/mL), and anti-glycation capacity (IC50: 86.49 μg/mL). Overall, this work provided a green and efficient strategy for PAC extraction from WGH, elucidated the extraction mechanism and bioactivities, and offered valuable insights for potential industrial applications.

Co-production of cellulose and lignin by Taguchi-optimized one-pot deep eutectic solvent-assisted ball milling pretreatment of raw oil palm leaves

This study explores an eco-friendly delignification technique for raw oil palm leaves (OPL), highlighting the optimized conditions of choline chloride-lactic acid deep eutectic solvent (DES)-mediated ball milling pretreatment to maximize the co-production yields of highly crystalline cellulose and lignin. Our five-level-four-factor Taguchi design identified the optimal reaction settings for cellulose production (85.83 % yield, 47.28 % crystallinity) as 90-minute milling, 1500 rpm, mill-ball size ratio of 30:10, ball-to-sample mass ratio of 20:1, DES-to-sample mass ratio of 3:1. Conversely, the maximal lignin extraction yield (35.23 %) occurred optimally at 120-minute milling, 600 rpm, mill-ball size ratio of 25:5, ball-to-sample mass ratio of 20:1 and DES-to-sample mass ratio of 9:1. Statistical results showed that milling frequency (p-value ≤ 0.0001) was highly significant in improving cellulose crystallinity and yield, while DES-to-sample mass ratio (p-value ≤ 0.0001) was the most impacting on lignin yield. The thermogravimetric method affirmed the elevated cellulose thermal stability, corroborating the enhanced cellulose content (40.14 % to 73.67 %) alongside elevated crystallinity and crystallite size (3.31 to 4.72 nm) shown by X-ray diffractograms. The increased surface roughness seen in micrographs mirrored the above-said post-treatment changes. In short, our optimized one-pot dual-action pretreatment effectively delignified the raw OPL to produce cellulose-rich material with enhanced crystallinity and lignin solidity.

Microwave-assisted extraction of phenolic compounds from Commiphora gileadensis leaf and their characterization

Commiphora gileadensis (C. gileadensis) is a plant traditionally used in many parts of the world for medicinal purposes. However, the benefits of this plant are yet to be uncovered due to the use of conventional extraction methods during its extraction. Hence, there is a need for more efficient and environment-friendly extraction methods for optimum recovery of the bioactive components of C. gileadensis. This study aims to evaluate the impact of microwave-assisted extraction (MAE) process parameters (individually and in combination) on the recovery of phenolic compounds from C. gileadensis leaf. One-Factor-At-a-Time (OFAT) optimization method was used in this work to study the impact of varying the MAE process parameters (sample: solvent ratio, microwave power, ethanol concentration, and extraction temperature) on the optimum yield of phenolic compounds. The obtained phenolic compounds were characterized using Gas chromatography-mass spectrometry (GC–MS) for tentative identification of the component phytochemicals of the extract. The results showed that the optimal process condition of microwave power at 300 W, solvent/sample ratio of 1:10 g/mL, solvent concentration of 40 % v/v, and extraction temperature of 40 °C gave the maximum extraction yield of 33.20 ± 0.42 % w/w, total phenolic content (TPC) of 114.65 ± 3.14 mg GAE/g d.w., and total flavonoids content (TFC) of 37.56 mg QE/g d.w.). Furthermore, the GC-MS analysis identified 25 phenolic compounds with good antioxidant activities from the extracts. Therefore, MAE is considered a non-conventional green method for improved extraction of phenolic compounds from C. gileadensis leaf compared to the existing conventional extraction methods.

Extraction of Centella asiatica herb using microwave-assisted solvent extraction: Optimization of crude extract using Box-Behnken design

Centella asiatica, is renowned in traditional medicine for its diverse applications, such as treating lupus, skin ailments, leprosy, fever, gastrointestinal issues, mental disorders, neurodegenerative conditions, and enhanced cognitive functions. Microwave-assisted solvent extraction (MASE) was chosen as a more effective, efficient, and environmentally friendly extraction method than the conventional method used to extract Centella asiatica. This study aims to optimize the extraction process for Centella asiatica using the Box-Behnken Design experimental approach. The experimental results showed that the highest yield, 62.25 %, was obtained at a microwave power of 450 W, feed-solvent (F/S) ratio of 0.05, and extraction time of 5 min. The lowest yield, 20.69 %, was obtained at a microwave power of 450 W, F/S ratio of 0.10, and extraction time of 10 min. The critical parameters under investigation include extraction time, microwave power, and F/S ratio. Employing Box-Behnken design (BBD) allows the identification of conditions that provide optimal results. The results showed the optimum conditions to achieve a maximum extraction yield of 62.4912 % were microwave power of 546.18 W, F/S ratio of 0.05 g/mL, and extraction time of 5.10 min.

A salt/salt aqueous two-phase system based on pH-switchable deep eutectic solvent for the extraction and separation of mulberry polysaccharides

With the aim of expanding the potential application scope of mulberries, eleven pH-switchable deep eutectic solvents were screened for the ultrasonic-assisted extraction of mulberry polysaccharides, and a salt/salt aqueous two-phase system was constructed for the efficient separation of mulberry polysaccharides by regulating the system pH. DES-9 (tetraethylammonium chloride: octanoic acid molar ratio = 1: 2) with a critical response pH value of approximately 6.1 was concluded to be the best extraction solvent for extracting mulberry polysaccharides. A maximum polysaccharide extraction yield of 270.71 mg/g was obtained under the optimal conditions. The maximum polysaccharide extraction efficiency was 78.09 % for the pH-driven tetraethylammonium chloride/K2HPO4 aqueous two-phase system. An acidic β-pyran mulberry polysaccharide with a low-molecular weight of 9.26 kDa and a confirmed monosaccharide composition were obtained. This efficient and environmentally friendly polysaccharide separation method offers a new approach for the efficient extraction and utilization of other plant polysaccharides.

Leaching of Rare Earths from End-of-Life NdFeB Magnets with Citric Acid Using Full Factorial Design, Response Surface Methodology, and Artificial Neural Network Analysis

In recent years, the increasing demand and rising prices of rare earth elements (REEs), along with their attendant supply risk (about 95% of these elements are supplied by China), have led the European Commission to consider REEs as critical raw materials. Developing and optimizing processes for recovering REEs from secondary sources such as NdFeB magnets is fundamental in this context. A novel method to recover REEs by leaching with citric acid and subsequently separating these elements using the solvent extraction method has been introduced. Therefore, this research investigates the leaching efficiency of REEs, Fe, and B from NdFeB magnets. A full factorial design, with 18 experimental setups, was conducted to optimize the citric acid concentration (1–3 mol/L), leaching time (1–3 h), and solid–liquid ratio (5–10%wt./vol.). All tests were carried out at room temperature and 150 rpm. Different optimizations (response surface methodology (RSM) and artificial neural network (ANN) analysis) are used to maximize the REEs’ leaching efficiency. RSM resulted in a maximum extraction yield of total rare earth elements (TREEs) of about 89% in the investigated experimental plan. This result is similar to that for ANN analysis (about 86%), but more accurate than that for RSM. In fact, for the ANN, an overall R-value higher than 0.99 was obtained. This result indicates that the developed ANN can be used as an accurate model for estimating the leaching efficiencies of REEs from NdFeB magnets.

Extraction of phenolic compounds from Juglans regia L. leaves using aqueous solutions of eutectic solvents

The leaves of Juglans regia L. (walnut tree) are a rich source of bioactive phenolic compounds, particularly flavonoids and phenolic acids, which can be used in cosmetic applications due to their antioxidant properties. Conventionally, these compounds are extracted using volatile organic solvents. This study focuses on a more sustainable approach by designing a heat-assisted extraction process using aqueous solutions of eutectic solvents (ES) composed of cosmetic-compatible ingredients aiming for direct incorporation into cream formulations. In this context, aqueous solutions of the ES betaine + urea and betaine + 1,3-propanediol (PPD) were selected, considering their potential as cosmetic ingredients. The screening process targeted the maximum extraction yield of phenolic compounds (phenolic acids and flavonoids), quantified by HPLC-DAD. The selected variables were water content (25, 50 and 75 % in weight) and the molar proportion of the ES components. For comparison purposes, pure water was used as a reference solvent.The total phenolic content ranged between 5.5 and 14.6 mg/g of dry plant. Betaine:urea (2:1), betaine:PPD (1:2), betaine, and PPD, all with 50 % water mass percentage, were among those resulting in higher extraction yields and were further selected for bioactivity analysis. The system containing betaine presented the best antioxidant capacity, analysed through ferric reducing power, DPPH radical scavenging, and TBARS assays. The extracts obtained with PPD presented the highest antimicrobial activity against gram-positive and gram-negative bacteria, and yeast. The results show the potential of using binary aqueous mixtures of betaine, or 1,3-propanediol, which are simple ingredients in cosmetics formulations, to efficiently extract phenolic compounds from a natural matrix. Moreover, the bioactivity results, particularly in the antioxidant dimension, support using J. regia leaves as a source of natural antioxidants.