Extraction Of Phenolic Compounds Research Articles

Influence of temperature, solvent and extraction procedure on the content of phenolic compounds and antioxidant activity of <i>Aloysia citriodora</i> Palau leaves

Introduction: The leaves of Aloysia citriodora Palau are a source of phenolic compounds that have antioxidant properties. Objective: The objective of this study was to compare the effects of temperature, type of solvent, maceration, and ultrasound processes in the extraction of phenolic compounds from A. citriodora Palau leaves that allow for maintaining the highest antioxidant capacity. Methods: In this study, phenolic compounds were extracted from A. citriodora by two methods, maceration, and ultrasonic treatment, using water and 80% ethanol as solvents and extraction temperatures of 25 °C, 45 °C, and 65 °C. Total phenolic compounds (TPhen), total flavonoid compounds (TFlav), and antioxidant capacity, evaluated by DPPH and ABTS assay, were characterized and reported as inhibition concentration (IC50). Results: The highest CPhen content was obtained with ethanolic extract using the ultrasonic method at 65 °C, with a value of 15.32 mg EAG/mL at 65 °C. For TFlav, the highest value was obtained with the ultrasonic treatment at 45 °C using ethanol as solvent, obtaining a value of 6.52 mg EQ/mL. The best antioxidant capacity was shown by the sonication with ethanol at 65 and 45 °C, with IC50 values of 27.10 µg/mL and 20.40 µg/mL, respectively. Conclusion: Ultrasound extraction at higher temperatures (45°C and 65°C) proved more effective than maceration, yielding greater amounts of phenolic and flavonoid compounds and exhibiting better antioxidant capacity.”. Keywords: Aloysia citrodora, phenolic compounds, antioxidant activity, inhibitory concentration IC50.

Development of “water-lean” solvent-based air-assisted liquid–liquid microextraction; application in the extraction of some phenolic compounds from water and wastewater samples prior to GC-FID analysis

In the present study, an efficient, robust, and reliable air–assisted liquid–liquid microextraction procedure was introduced based on a “water-lean” solvents for the extraction and preconcentration of phenolic compounds from spring water and petrochemical, Songun mine, and municipal wastewater samples. For this purpose, various hydrophobic water-lean solvents composed of organic solvents consisting of carbon tetrachloride, dichloromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, and chloroform with amines including n-butylamine, di-n-butylamine, iso-propylamine, n-hexylamine, diethylamine, pyridine, aniline, toluidine, and benzylamine) were prepared and they were used as the new extraction media. The selected compounds (phenol, 1-naphthol, 2-naphthol, 4- chlorophenol, o-cresol, 2-nitrophenol, and 2-nitroso-1-naphthol) were extracted from sample solution containing sodium chloride (5 %, w/v) using 200 µL of a water-lean solvent composed of dichloromethane: butylamine (1:1) by performing the sucking/injection cycles for four times. The effect of several parameters on the extraction efficiency of the method, consisting of type and volume of water-lean solvent, extraction numbers, pH, and ionic strength, were examined and optimized by “one-variable-at-one-time” strategy. High enrichment factors (315–420), respectable extraction recoveries (63–84 %), low limits of detection (0.23–0.56 ng mL−1) and quantification (0.77–1.86 ng mL−1), and broad linearity of the calibration curve (1.86–500 ng mL−1) demonstrated satisfactory performance of the present approach. The relative standard deviation for the extraction of 50 and 100 ng mL−1 of each phenol (n = 6) were ≤ 6.3 % for intra- and inter-day precisions. Eventually, the proposed method was efficaciously performed for extraction and determination of the selected analytes in various water and wastewater samples and phenol and 4-chlorophenol were found in the samples at ng mL−1 level.

Modeling, Simulation, and Optimization of Multi-Stage Equilibrium Extraction of Phenolic Compounds from Grape Pomace

The seasonal nature of wine production results in the accumulation of significant quantities of grape pomace (GP) during harvest, presenting management challenges for wineries that traditionally regard this solid byproduct as low-value waste. However, extracting phenolic compounds (PCs) from GP offers a promising avenue for creating bioactive extracts for use in the food, pharmaceutical, and cosmetic industries. This study develops a mathematical model for predicting the total phenolic content (TPC) and total dissolved solids (TDS) in liquids obtained from multi-equilibrium-stage extraction processes using a 50% aqueous ethanol solution to recover PCs from Tannat GP. The model is applicable across a wide range of TPC and TDS concentrations in the liquid (0.2-45.4 gGAE/L for TPC and 1 to 118 g/L for TDS) and extraction temperatures between 30 and 70 °C. It is used to determine the optimal operational conditions of a Shanks extraction system, either to minimize fresh solvent consumption or to maximize selectivity for PCs extraction, achieving a desired extraction yield with a specified number of extraction vessels.

Green synthesis of silver nanoparticles from supercritical CO2 mediated Lagerstroemia speciosa extract: Characterization, antimicrobial and antibiofilm activity

In the current study, optimal supercritical fluid extract (SFE) of Lagerstroemia speciosa (LS) leaves at pressure 29.59 megapascal (MPa), temperature 89.50 ºC and extraction time 53.85 min. was used to extract phenolic compounds for the synthesis of silver nanoparticles (AgNPs). The synthesis was studied for 0-20 hrs. Initially the synthesis of nanoparticles (SFELS-AgNPs) was confirmed using UV -spectroscopy. It demonstrated a maximum surface plasmon resonance at 430 nm. The crystallite dimension of nanoparticles was determined using X-ray diffraction (XRD) (13.47 nm), Transmission electron microscopy (TEM), zeta potential analysis and energy-dispersive X-ray analysis (EDAX) were used to analyze the morphology, surface charge and presence of differential elements in SFELS-AgNPs respectively. Developed nanoparticles revealed antimicrobial activity against two gram-positive viz. Staphylococcus aureus and Bacillus cereus, and three gram-negative bacteria viz. Klebsiella pneumonia, Pseudomonas aeruginosa and Escherichia coli. The nanoparticle showed a minimum inhibitory concentration (MIC) of 64 μg/ml whereas the minimum bactericidal concentration (MBC) 128 μg/ml against K. pneumonia. They significantly inhibited K. pneumonia biofilm formation which was confirmed using scanning electron microscopy (SEM). The results were encouraging compared to the standards drug Chloramphenicol and other controls. The generated nanoparticles have highly effective antimicrobial properties against pathogenic bacteria.

Machine learning-aided enhancement of white tea extraction efficiency using hybridized GMDH models in microwave-assisted extraction

White tea is valuable for having a high antioxidant content, which is considered to possess numerous beneficial effects on health. This study investigated the application of microwave-assisted extraction (MAE) for the extraction of total phenolic compounds from white tea. The experimental setup included four independent variables: microwave power (ranging from 100 to 300 W), extraction time (ranging from 10 to 40 min), temperature (ranging from 35 to 50 °C), and the ratio of food to solvent (ranging from 0.25 to 0.5 g/10 mL). The responses that were evaluated were IC50 (ppm) and total phenolic content (mg/g). The experimental design consisted of thirty runs conducted within the MAE system. The group method of data handling (GMDH) models were used to predict important efficiency measures (IC50 and total phenol content) in the extraction process. The models were assessed based on their ability to capture the relationships between input conditions and efficiency outputs. Three GMDH variants were compared: baseline GMDH, GMDH optimized with a genetic algorithm (GMDH-GA), and GMDH optimized with a harmony search algorithm (GMDH-HS). While all models achieved high predictive ability on a test set, GMDH-HS emerged as the superior performer. It achieved near-perfect agreement with observations (d-index > 0.998), minimal errors (NRMSE < 0.02), and effectively captured data variance (NSE > 0.99) for both outputs. Correlation diagrams and Taylor diagrams confirmed the superior performance of GMDH-HS in terms of linearity, correlation, and error minimization. This study demonstrates the effectiveness of hybridizing GMDH with a harmony search algorithm for complex modeling tasks, paving the way for improved efficiency and yield optimization in extraction processes.

Bio-Guided Extraction of a Phenolic-Rich Extract from Industrial Peanut Skin with Antioxidant and Hypotensive Potential.

Peanut composition includes phenolic compounds, especially in the skins, which are often not consumed. High blood pressure affects more than one billion people worldwide and is considered a high-risk factor for cardiovascular diseases. Several studies have correlated antihypertensive activity with the total phenolic content present in the plants. This study evaluated the hydroethanolic extraction of phenolic compounds from the industrial residue of peanut skin and evaluated the antioxidant and antihypertensive capacity of these extracts using in vitro models. A rotational central composite design (DCCR) was proposed to study the influence of the variables: (1) the ethanol concentration on the hydroalcoholic extractor solution, and (2) the proportion of solid sample (waste) per liquid in the extraction (mass/volume) in a simple solid-a liquid extraction process. The optimal extraction conditions within this model were 50% ethanol in water, and the proportion of sample to extraction solution (m/v) equaled to 0.2. The extract obtained had significant antioxidant capacity, both in chemical (ORAC) and in cellular models, with potential for free radical scavenging. Significant levels of ACE inhibition were also found, indicating antihypertensive activity.

Comprehensive Study of Sustainable Pressurized Liquid Extractions to Obtain Bioavailable Antioxidant Phenolic Compounds from Grape Seed By-Products

Few investigations have been conducted to evaluate pressurized liquid extraction (PLE) technology as a sustainable method for the recovery of phenolic compounds of grape seed by-products. In this study, PLE combined with an experimental design was evaluated for optimizing the sustainable extraction of phenolic compounds from grape seed by-products. The solvent ethanol content (X1, 0–100%), temperature (X2, 20–100 °C) and time (X3, 1–11 min) were studied as independent experimental factors. Yield, TPC, antioxidant activity and phenolic composition were analyzed as optimized dependent variables. Two optimal extraction conditions at different temperatures (20 °C and 100 °C) were found, but thermal degradations at 100 °C allowed for selecting the optimal condition as 75% ethanol, 11 min and 20 °C. The optimal extracts showed high phenolic content (TPC = 350.80 ± 3.97 mg GAE/g extract) and antioxidant activity (ABTS, 9.31 ± 0.33 mmol Trolox/g extract), mainly composed of polymeric and mono-oligomeric flavan-3-ols. The digestion process reduced the TPC and antioxidant activity due to the low bioaccessibility of the flavan-3-ols, mainly as catechin, epicatechin and polymeric proanthocyanidin losses during the digestion process. However, increases in the antioxidant activity of the basolateral side (DDPH, 0.061 ± 0.000 mmol Trolox/g extract) were determined after in vitro transepithelial transport, which is a consequence of bioavailable catechin and epicatechin and reduced amounts of dimer B2, dimer B1, epicatechin gallate and gallic acid. Consequently, PLE combined with hydroalcoholic solvents at a low temperature resulted in a valuable methodology to obtain sustainable extracts from grape seed by-products (contributing to the circular economy), containing bioavailable phenolic compounds, which are able to increase the antioxidant status.

Optimization of green ultrasound-assisted extraction of phenolic compounds from Crataegus laciniata leaves and assessing for antioxidant activity, enzyme inhibition, and UPLC-ESI-MS-MS guided identification of metabolites

Optimization of green ultrasound-assisted extraction of phenolic compounds from Crataegus laciniata leaves and assessing for antioxidant activity, enzyme inhibition, and UPLC-ESI-MS-MS guided identification of metabolites

Ultrasound-assisted process to improve proteins recovery from industrial canola and soybean byproducts

AbstractAn ultrasound-assisted process is proposed to obtain protein isolates from canola and soybean byproducts. A laboratory-scale probe system (24 kHz, 400W) was used for protein extraction and six levels of energy density were analyzed. Different mixtures of solvents (water, ethanol, methanol, acetone) and temperatures were tested for removing phenolic compounds, and the best results were obtained with ethanol-water (8:2 v/v) and energy density of 104 kJ/L, which minimize protein losses at that step. After extraction of phenolic compounds, samples were alkalinized (pH 12 or 9.5), subjected to ultrasound treatment and the protein precipitated at the isoelectric pH. The highest yield on protein extraction was obtained with 1:20 meal: NaOH solution ratio, applying 150 kJ/L at constant temperature (30 °C), increasing the protein recovery, 72.5% for canola meal and 37.5% for soybean meal, compared to the conventional method. The solubility of both isolates obtained with ultrasound improved ~ 50% at a pH close to neutral and basic, with an increase in free sulfhydryl groups, without significant effects of ultrasound treatment on the subunit fractions of the proteins. These results provide alternatives to develop protein isolates from an undervalued by-product, with better techno-functional properties that can be employed in the food industry.

Comparative Evaluation of Conventional and Emerging Maceration Techniques for Enhancing Bioactive Compounds in Aronia Juice.

Ultrasound and microwave maceration techniques have been utilised to lower production costs and reduce processing time, while also preventing the degradation of nutrients like phenolics and vitamin C and preserving physical properties such as colour and viscosity. In this study, the effects of several traditional (cold, enzymatic, and thermal) and innovative (ultrasonic and microwave) maceration methods on some quality parameters of aronia juice were investigated. Microwave maceration significantly impacted the soluble solids content of the analysed juices and resulted in noticeably darker juice samples compared to the controls, with lower L*/lightness (20.1) and b*/blue-yellowness (-3.2) values and an increased a*/redness value (1.7). Different maceration methods also significantly impacted the rheological properties of the treated juices, among which MW treatment consistently showed a higher viscosity. Sorbitol and fructose were the main sugars identified, while malic acid and quinic acid accounted for 85% of the total acid content. Significant increases in the total sugar and acid concentrations were obtained in the juice samples from ultrasonic, microwave, and enzymatic maceration, while thermomaceration had no significant effect. The concentration of total phenolics ranged from 6.45 g/L in the thermomaceration samples to 9.86 and 14.07 g/L in the ultrasonic and microwave samples, respectively. The obtained results suggest that ultrasonic and microwave technologies were superior in terms of colour improvement and the extraction of sugars, acids, and phenolic compounds compared to traditional maceration methods. Ultrasound and microwave technologies present possible approaches to the improvement of aronia juice production in comparison to traditional methods.

Extraction of fermentable sugars and phenolic compounds from Colombian cashew (Anacardium occidentale) nut shells using subcritical water technology: Response surface methodology and chemical profiling

Subcritical water extraction (SCWE) is a novel technology that uses water at high pressure and temperature to recover bioactive compounds. While promising, further studies are needed to fully understand the potential of SCWE when applied to cashew nut shells (CNS), which are rich in phenolic compounds, carbohydrates, and other natural substances. This study aimed to evaluate SCWE applied to CNS from Vichada, Colombia, using a surface response methodology and to perform a comprehensive chemical profiling of the recovered extracts and the remaining solids. A Box-Behnken experimental design was employed to study the extraction process, focusing on variables such as temperature, pressure, and solid-to-solvent ratio. The liquid extracts were analyzed using ultra-high-performance liquid chromatography and gas chromatography coupled with mass spectrometry, while the extracted solids were characterized using Fourier-transform infrared spectroscopy and scanning electron microscopy. The liquid extracts revealed a variety of compounds, including xylose, glucose, arabinose, long-chain phenols, organic acids, and furans. Extraction conditions significantly influenced the distribution of these compounds, with the optimal conditions for extracting fermentable sugars and organic acids identified as 180 °C, 15 bar, and a 20:1 mL/g solid-to-solvent ratio. The resulting hydrochar comprised lignin (58.82 ± 3.44 %) and structural carbohydrates (approximately 40 %), showing thermal stability up to 200 °C, OH functional groups on its surface, and a textured morphology under microscopy. These by-products have potential applications in various fields. This study demonstrates that SCWE effectively recovers valuable compounds from CNS for use in fermentation processes, suggesting that the resulting hydrochar could be utilized in soil amendment, adsorption, or energy applications. SCWE is highlighted as an innovative and environmentally friendly technology for managing cashew residual biomass, promoting sustainability and circularity in this production chain.

Valorization of Pineapple Core Waste for Sequential Extraction of Phenolic Compounds and Carotenoids: Optimization Through Ultrasound-Assisted Method and Box–Behnken Design

AbstractIn this study, a pioneering cascade method involving ultrasound-assisted extraction (UAE) and Box–Behnken Design (BBD) was optimized to valorize pineapple core waste by the sequential extraction of, firstly phenolic compounds and, secondly, carotenoids. The effectiveness of the extraction was evaluated based on total polyphenol content (TPC) and antioxidant activity using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Characterization of the carotenoids was performed using high-performance liquid chromatography with a diode array detector (HPLC–DAD). The initial characterization of dry pineapple core (DPC) samples revealed their nutritional composition, including protein, lipid, and carbohydrate weight percentages of 1.20 ± 0.05%, 5.3 ± 0.4%, and 88.6 ± 0.5%, respectively. The high extractives content (40.0 ± 4.5%) suggests a substantial presence of phenolic compounds, making the pineapple core a valuable source of natural antioxidants. The optimal UAE conditions for phenolic compound extraction were 70% amplitude, 5 min extraction time, and 2 cycles, yielding an antioxidant extract rich in phenolic compounds with a desirability value of 81.2%. Therefore, DPC was considered a valuable source of natural antioxidants. The extraction of β-carotene also showed promising results with optimal UAE conditions of 20% amplitude, 3 min extraction time, and 2 cycles. This research promotes the sustainable use of pineapple waste and demonstrates the potential to obtain valuable additives for the food, pharmaceutical, and cosmetic industries, encouraging a more circular and efficient use of resources in the pineapple processing industry.

Designing Natural Deep Eutectic Solvents for Extraction of Phenolic Compounds and Antioxidant Application: A Case Study with Diverse Thai Rice Bran Varieties

Designing Natural Deep Eutectic Solvents for Extraction of Phenolic Compounds and Antioxidant Application: A Case Study with Diverse Thai Rice Bran Varieties

Extraction of Phenolic Compounds from Tucuma (Astrocaryum vulgare Mat.) Postprocessing Cake Mediated by Rhamnolipids: Evaluation of Its Antifungal Potential against Common Fruit Pathogens

Extraction of Phenolic Compounds from Tucuma (<i>Astrocaryum vulgare</i> Mat.) Postprocessing Cake Mediated by Rhamnolipids: Evaluation of Its Antifungal Potential against Common Fruit Pathogens

An emulsion extraction system composed of hydrophobic deep eutectic solvent and water for synchronous extraction of oil and phenolic compounds from U.S. pecans [Carya illinoinensis (Wangenh.) K. Koch]

U.S. pecans nuts are rich in oils and phenolic compounds with important biological functions. At present, the reports about simultaneous extraction of oil and phenolic compounds are limited, and the traditional procedure is complicated and the yield is low. In this study, a new emulsion formed by hydrophobic deep eutectic solvent (DES) and water was used as extractant for synchronous extraction of oil and phenolic components from U.S. pecans, and subsequently the two were recovered from the upper and lower phases based on the incompatibility of DES and water, respectively. The oil and phenolic compounds obtained by the optimization of extraction conditions were 615.29 mg/g and 82.11 mg/g, respectively, which were higher than those obtained by conventional methods. At the same time, the extraction mechanism is discussed through the extraction kinetics and thermodynamics. The extraction process conformed to the Fick’s second law, and it was an endothermic process. After directional recovery by macroporous resin and back-extraction, the effectiveness of the method was proved by the analysis of fatty acid composition of oil, spectral characterization of phenolic compounds and antioxidant activities.

Phytochemical Screening, Nutritional Properties and Biological Activities of Sweet and Conventional Potato Planted in Morocco

This study aimed at studying phytochemical composition, nutritional properties and biological activities (antioxidant and anti-inflammatory) of two potato varieties (sweet potato (SP): Ipomoea batatas L. and conventional potato (CP): Solanum tuberosum L.) planted and consumed in Morocco. For this, potato samples (SP and CP) were firstly subjected to phytochemical and nutritional analysis, including water content, total and reducing sugars, proteins, lipids, vitamin C, carotenoids, phenolic compounds and flavonoids. Secondly, phenolic compounds extracts were subjected to biological activities namely antioxidant and invitro anti-inflammatory. Potato extracts antioxidant activity was tested by DPPH and total antioxidant capacity (TAC) methods. Proteins and lipids contents were found much higher in SP (5.21 ± 0.26 and 0.29 ± 0.02 g/100g DW) respectively than in CP (2.93 ± 0.15 and 0.11 ± 0.01 g/100g DW) respectively. Besides, total and reducing sugars contents were 16.65 and 2.53 g/100g DW in the CP, and 12.47 and 2.13 g/100g DW in the SP, respectively. The antioxidant activity of different SP extracts was found to be higher than those of CP, by using DPPH and TAC methods. These findings could be explained by SP richness in carotenoids (212 ± 10.60 mg/100g DW), phenolic compounds (130.11 ± 6.51 mg GAE/100g DW), flavonoids (85.03 ± 4.2 5mg QE/100g DW) and vitamin C (471.33 ± 23.57 mg/100g DW). Exclusion chromatography done by Sephadex G50 showed that polymeric phenolic compounds in SP were more abundant when compared to monomeric ones. This difference was consistent with the anti-inflammatory activity assessed in vitro.

Eco-friendly technologies for obtaining antioxidant compounds and protein hydrolysates from edible insect Tenebrio molitor beetles

The functional properties of edible insects can be explored by a joint use of novel technologies. This work applied varied pre-treatments (ultra-sound-assisted extraction, UAE; microwave-assisted extraction, MAE; temperature-assisted extraction, TAE; CO2-assisted extraction) and solvents (water, ethanol, water:ethanol) in Tenebrio molitor beetles to enhance the extraction of phenolic compounds with antioxidant activity. An enzymatic hydrolysis (EH) was performed in wet and treated biomasses to determine the protein hydrolysis. Higher phenolic compounds and antioxidant activity was released after MAE using water as solvent compared to the other treatments and solvents. Treatments decreased 32 %, 19 % and 30 % the protein, chitin and lipids content. EH improved protein and amino acids hydrolysis in the MAE-treated insects, followed by UAE and TAE treatments. In conclusion, MAE was the most effective to release phenolics and antioxidant activity from T. molitor beetles, while using MAE followed by EH improved protein and amino acids hydrolysis, envisioning valuable applications for this insect biomass.

Impact of pre-fermentative maceration techniques on the chemical characteristics, phenolic composition, in vitro bioaccessibility, and biological activities of alcoholic and acetic fermented products from jaboticaba (Plinia trunciflora)

The jaboticaba is a fruit with a highly promising chemical profile for producing fermented products with biological activity. In this context, evaluating pre-fermentative maceration techniques in jaboticaba fermentations is essential to optimize the extraction of phenolic compounds and other metabolites of interest, imparting antioxidant characteristics to the product and offering potential health benefits. This study evaluated the impact of two pre-fermentative maceration techniques on the phenolic composition, bioaccessibility, and biological activities (α-amylase, α-glucosidase, and ACE inhibition) of alcoholic and acetic fermented products from jaboticaba. Three treatments were performed: one without pre-fermentative maceration and two with maceration, one cold (4 °C for 24 h) and the other thermal maceration (50 °C until 16 °Brix). The resulting musts were subjected to alcoholic and acetic fermentation. The results showed that the fermented products obtained after thermal maceration had higher concentrations of phenolic compounds, with ellagic acid (5,393.78 µg/L) standing out for thealcoholic beverage and 2.5-DHBA (1,552.33 µg/L) and 3.4-DHB (863.15 µg/L) acids for the vinegar. Regarding bioaccessibility, both pre-fermentative maceration techniques contributed to more bioaccessible compounds (with indices above 20 %) compared to the samples without maceration. A more significant inhibition of α-amylase and α-glucosidase was observed in the samples subjected to thermal maceration, along with notable ACE inhibition. Additionally, the sensitivity of E. coli, S. aureus, L. monocytogenes, and S. Enteritidis to the fermented jaboticaba products was verified, with distinct sensitivity patterns for each type of bacteria. In summary, this study offers a new perspective for valorizing fermented jaboticaba products through pre-fermentative techniques, enriching the understanding of this technique and its potential nutritional and bioactive contributions.

High-performance dicationic ionic liquids based on imidazolium and quaternary ammonium for phenol extraction

Phenolic compounds serve as crucial chemical raw materials abundant in coal tar, so it is of great economic value to extract phenolic compounds from coal tar. Ionic liquids (ILs) are regarded as desirable extractants in this separation field due to considerable advantages over traditional methods. Compared to traditional mono-cationic ILs, dicationic ionic liquids (DILs) exhibit outstanding thermal stability and a wider operating temperature range. Our research focused on developing DILs based on typical imidazolium and quaternary ammonium structures for phenol separation, examining the impact of the methylene chain length between the cations on the extraction efficiency. Hydrogen bonding and π-π interactions between DILs and phenol were also investigated as driving forces in the extraction process. 1-methyl-3-(3-(trimethylammonio)propyl)-1H-imidazol-3-ium bromide ([MIMC3N111][Br]2) with a moderate chain length was selected as the optimal extractant due to its weaker coulomb force inside the DIL, facilitating stronger hydrogen bonding with phenol compared to the other two DILs. Under optimized conditions, [MIMC3N111][Br]2 exhibited the highest extraction efficiency of 96.03 % in model oil (toluene and phenol) with a phenol content of 200 g dm−3 and the DIL to phenol mole ratio was only around 0.3. [MIMC3N111][Br]2 also featured excellent recyclability, maintaining high extraction efficiency through multiple cycles. Importantly, its lower solubility in oil-phenol mixtures compared to mono-cationic ILs significantly reduced contamination of the oil phase. The DILs in this work can exhibit significant potential for separating phenolic compounds with certain advantages.

Isoflavone-rich extracts from okara using supercritical fluid extraction: Kinetic modeling and characterization

The lipid fraction and bioactive compounds from okara, a by-product of soybean processing, have been extracted by supercritical fluid extraction. The effect of operating parameters, pressure (20–40 MPa), temperature (40–80 ºC), and cosolvent usage (0–10 %wt. ethanol), on the extraction kinetics has been investigated, satisfactorily correlating the experimental data to the Sovová’s model. Extraction yield by SFE ranged from 0.1014 g extract/g insoluble solid (IS) at 20 MPa and 80 ºC to 0.1081 g extract/g IS at 30 MPa and 60 ºC (from 9.2 to 9.8 g extract/100 g okara, respectively), similar to Soxhlet extraction with n-hexane (9.2 ± 0.2 g extract/100 g). Pressure positively affected the initial extraction rate, which also increased with temperature except for the lowest pressure of 20 MPa, exhibiting a typical cross-over behavior. The use of ethanol as cosolvent promoted the extraction of phenolic compounds and isoflavones, and was less important in the extraction of tocopherols. Extraction yield using ethanol increased up to 0.1100 g extract/g IS at 40 MPa and 40 ºC. As expected, the higher content of bioactive compounds in the sc-CO2 + ethanol extracts positively affected the antioxidant capacity, with the maximum found at 20 MPa, 40 ºC and 10 %wt. ethanol.