Extraction Temperature Research Articles

Microwave Irradiation as a Powerful Tool for Isolating Isoflavones from Soybean Flour

The use of microwave irradiation energy for isolating bioactive compounds from plant materials has gained popularity due to its ability to penetrate cells and facilitate extraction of intracellular materials, with the added benefits of minimal or no use of organic solvents. This is particularly significant due to the possibility of using extracts in the food and pharmaceutical industries. The aim of this work is to examine the effect of microwave irradiation on the extraction of three of the most important isoflavones from soybean flour, glycitin, genistin, and daidzin, as well as their aglycones, glycitein, genistein, and daidzein. By varying the extraction time, temperature, and microwave power, we have established the optimal parameters (irradiation power of 75 W for 5 min) for the most efficient extraction of individual isoflavones. Compared to conventional maceration and ultrasound-assisted extraction, the total phenol content of the extracts increased from 3.66 to 9.16 mg GAE/g dw and from 4.67 to 9.16 mg GAE/g dw, respectively. The total flavonoid content increased from 0.38 to 0.83 mg CE/g dw and from 0.48 to 0.83 mg CE/g dw, and the antioxidant activity increased from 96.54 to 185.04 µmol TE/g dw and from 158.57 to 185.04 µmol TE/g dw, but also from 21.97 to 37.16 µmol Fe2+/g dw and from 30.13 to 37.16 µmol Fe2+/g dw. The positive correlation between microwave extraction and increased levels of total phenols, flavonoids, and antioxidant activity demonstrates the method’s effectiveness in producing bioactive compounds. Considering the growing recognition of glycitein’s potential role in medical and pharmaceutical applications, microwave-assisted extraction under optimized conditions has proven highly efficient.

Hexafluoroisopropanol-based deep eutectic solvents for efficient aqueous two-phase extraction of flavonoids from Flos Sophorae Immaturus

Aqueous two-phase systems (ATPSs) based on deep eutectic solvents (DESs) are green extraction and separation media and have demonstrated remarkable potential for extracting bioactive substances from natural matrices. However, thus far, flavonoid extraction using DES-based ATPSs has rarely been reported. In this study, the state-of-the-art technique using DES-based ATPSs was employed for developing an effective method for extracting flavonoids from Flos Sophorae Immaturus (FSI). DESs prepared with hexafluoroisopropanol (HFIP) and five quaternary ammonium salts, N111xCl (x = 1, 4, 8, 12, and 16), were used as the hydrogen bond donor and hydrogen bond acceptors, respectively, for constructing ATPSs with K2HPO4 as a salting-out agent and utilized for extracting flavonoids from FSI. Fourier-transform infrared, 1H nuclear magnetic resonance, 1H–1H nuclear Overhauser effect spectroscopy analyses, and density functional theory calculations were implemented to demonstrate the successful preparation of DESs. The DES containing dodecyltrimethylammonium chloride and HFIP with a molar ratio of 1:2 was screened as the optimal DES, showing a higher extraction efficiency and yield of flavonoids compared to those of other DESs and the traditional solvent ethanol. Subsequently, various experimental parameters (amount of DES, salt concentration, liquid-to-solid ratio, extraction temperature, and ultrasonic time) for the extraction process were studied comprehensively and optimized using response surface methodology. The yield of flavonoids from FSI was 21.05 % under optimal extraction conditions (amount of DES = 2 g, salt concentration = 0.21 g/mL, liquid-to-solid ratio = 81 mL/g, and extraction temperature = 60 ℃), which is close to the predicted value of 20.82 %. Extraction mechanisms underlying the performance of DES-based ATPSs during the extraction of bioactive substances are yet to be fully understood. Therefore, molecular dynamics (MD) simulations were employed with rutin as the target compound to probe the extraction mechanism under DES-based ATPS conditions, and the results revealed that hydrogen-bonded frameworks are pivotal for the extraction process. Moreover, the existence of K2HPO4 was found to promote not only the increase in hydrogen bonding networks and π–π stacking interactions within rutin molecules but also the increase in solvent flexibility, facilitating the extraction process. The present work offers a promising approach for flavonoid extraction using DES-based ATPSs. Interpreting the extraction mechanism at the molecular level by adopting the MD simulation technique provides new insights that enable a deeper understanding and aid in the design of the extraction process for bioactive substances under DES-based ATPS circumstances.

Evaluating the efficacy of ultrasound-assisted extraction of Plantago major L. leaves by response surface methodology through determination of aucubin levels

Plantago major L. (Plantaginaceae) contains bioactive phytochemicals supporting its wide array of pharmacological activities. Aucubin, a bioactive iridoid glycoside found in P. major, has been used as a marker substance for quality control. This study’s objective was to assess the efficacy of ultrasound-assisted extraction (UAE) on P. major leaf extracts based on the aucubin level. The response surface methodology (RSM) was employed to investigate the impact of process parameters on the UAE. The compound’s studies were developed and validated by the utilization of high-performance liquid chromatography coupled to photodiode array (HPLC-PDA). Four independent variables were studied: extraction temperature (°C), extraction time, ethanol concentration (%), and ratio of solute to solvent. The analytical method used HPLC-PDA to quantify the aucubin content as the dependent variable. The study’s findings indicate that the most favorable conditions for UAE were attained at a temperature of 20°C for 20 min, an ethanol concentration of 25%, and a ratio of 1:5 g/mL. The HPLC-PDA approach that has been verified demonstrates its efficacy as a technique for quantifying the concentration of aucubin in the extract of P. major leaves. The obtained experimental values (5.736% mg/g) for the aucubin content, under the optimal conditions of UAE, exhibited a satisfactory level of concurrence with the values predicted by the RSM (5.774% mg/g). This finding showed that UAE and RSM can be developed as an efficient extraction method for P. major leaves.

Recovery and detection of ignitable liquid residues from the substrates by solid phase microextraction – direct analysis in real time mass spectrometry

In this study, direct analysis in real time mass spectrometry (DART-MS) was coupled to the solid phase microextraction (SPME) to extract and analyze the ignitable liquid residues (ILR) present in the sample matrices. The SPME extraction parameters, such as extraction temperature and extraction time, were optimized using a two-factor central composite design. The SPME-DART-MS setup was utilized to analyze the substrates and fire debris matrices spiked with gasoline. The results indicate that the less volatile marker compounds from gasoline were recovered from the substrates and fire debris, and their profiles matched well with the gasoline liquid samples analyzed directly by DART-MS. As expected, the effective extraction of marker compounds in gasoline required a relatively high temperature, i.e., 150 ℃. In the presence of a matrix, a higher extraction temperature and longer extraction time could benefit the extraction efficiency. The desorption of ILR on SPME fiber was performed by inserting the fiber into the DART-MS helium gas stream at 300 ℃ for 1 min with no carry-over residues being observed between successive samples. The chemical information attained with this method is typically not observed in the current GC/MS-based practice. The SPME-DART-MS was also extended to reanalyze less volatile components of ILR on substrates after the ASTM E1412 activated charcoal method, which indicates its possible application subsequent to the traditional GC/MS ILR analysis. The SPME-DART-MS has shown promise in ILR detection as an important complementary tool.

Characterization of the influence of extraction factors on instant Pu-erh tea: Focusing on changes in sensory quality and aroma profile

The objective of this study is to explore the influence of extraction factors, including extraction temperatures, extraction time, and tea-water ratios, on the sensory quality and aroma characteristics of instant Pu-erh tea (IPET). Sensory evaluation, quantitative descriptive analysis (QDA) and HS-SPME-GC × GC-TOF/MS were utilized for analysis. The result showed that the optimal process condition of IPET was a tea-to-water ratio 1:8, an extraction temperature 75 °C, and an extraction time 60 min. A total of 235 volatile compounds were identified and 65 key odor-active compounds with ROAV>1 in all samples. Based VIP > 1, 19 key differential odor-active compounds were identified, including linalool oxide I, 1-dodecanol, linalool oxide II, etc. Further Pearson correlation analysis of key differential odor-active compounds and aroma characteristics showed that positive correlations between woody and ethyl nonanoate and 1-dodecanol, and between herbal and 1-methylnaphthalene. This research provides theoretical support for the production of high-quality IPET.

Application of ionic liquids as co-solvent for oil extraction from desert date

The extraction of oil from Balanites seed (desert date) using ultrasound-assisted extraction was investigated using organic solvent (ethyl acetate) and ionic liquid as co-solvent. The study found that an optimum oil yield of 28.67 % was obtained using a seed to solvent ratio of 1:6, an extraction temperature of 50 °C and an extraction time of 30 min when ethyl acetate was used as the sole solvent in the extraction system. Different types of ionic liquids as co-solvents were screened in this study and an improvement of oil yield (3–6 %) was observed using 1-butyl-3-methylimidazolium acetate. Additionally, the presence of ionic liquid as a co-solvent during the extraction process could achieve a similar oil yield at a lower extraction temperature. This indicates the potential breakdown of the lignocellulosic cell wall of the seed using 1-butyl-3-methylimidazolium acetate. The presence of 1-butyl-3-methylimidazolium acetate as co-solvent can enhance the penetration of the organic solvent into the Balanites seed matrix for oil extraction and can reduce the energy required for the extraction process.

Effect of supercritical CO2 modified with ethanol on the extraction yield and antimicrobial activity of bioactive compounds from aerial parts of Berberis microphylla G. Fort

Calafate (Berberis microphylla G. Forts) is an endemic plant from the Patagonian area of Chile and Argentina, with a high content of bioactive compounds. In this study the effect of ethanol-modified supercritical extraction at temperatures of 40 and 60 °C, pressures of 30 and 35 MPa, and azeotropic ethanol contents in CO2 of 5 and 10% on the yield of total solids (gravimetric method), alkaloids (spectrophotometric analysis), berberine (HPLC-DAD analysis), phenolics (spectrophotometric analysis), and antimicrobial activity (disc diffusion method) of calafate aerial parts, was evaluated. The yield of total solids increased with extraction temperature, pressure, and the percentage of ethanol in CO2. Berberine yield reached a maximum of 0.0211 ± 0.46 g/kg substrate at 60 °C, 35 MPa, and using 10% ethanol. Extraction at 40 °C resulted in a higher phenolic content (1.69 ± 0.02 g GAE/kg substrate) than at 60 °C. Limited antibacterial activity was observed in all obtained extracts with ethanol-modified supercritical CO2 against Staphylococcus aureus, with no significant difference between treatments. Ethanol-modified CO2 demonstrated moderate efficiency for extracting bioactive compounds from calafate aerial parts compared with Soxhlet extraction with azeotropic ethanol.

Study of some active substances and biological activity of extracts of henna leaves collected from Umm al-Qandil area -Libya (Lawsonia inermis)

The study aims to detect the active ingredients in the plant and to know their biological effectiveness against bacteria. The pH and humidity of the plant were measured. Aqueous and alcoholic extracts were prepared to obtain the crude extract in order to estimate its effectiveness against bacteria. The study showed the effectiveness of henna leaves (Lawsonia inermis) and their inhibition of the growth of some types of tested bacteria, including Staphylococcus, Strep Pyogenes, Escherichia Coli, salmonella, and Shigella. The inhibition results of the extracts varied and depended on the extraction method, temperature, and solvent used. The results of the initial chemical examination also showed that these extracts contained some important active ingredients such as (tannins, saponins, flavonoids, glycosides, resins, alkaloids), which made this plant used as a treatment for infections. The pH was estimated, and thus the importance of this plant increases as it can be used as a natural antibiotic. Therefore, we recommend studying the quantity and quality of the active compounds and knowing their molecular structure with the aim of developing natural extracts and dispensing with manufactured compounds due to the harm they cause to the living organism. Keywords: henna plant, qualitative findings, aqueous and alcoholic plant extracts, some types of pathogenic bacteria

Impacts of microwaves on the pectin extraction from apple pomace: Technological properties in structuring of hydrogels

The valorization of by-products eliminates the risks of economic barriers and reduces the overall amount of pollution and the carbon footprint of the products. In this context, conventional heating extraction (CE) and microwave-assisted extraction (MAE) were compared to extract pectin from apple pomace. The effects of temperature on MAE were evaluated based on the resulting properties obtained in subsequent pectin hydrogels. A pectin yield of 10.6 ± 0.3% was obtained by MAE with 5 min extraction, while CE showed a yield of 9.5 ± 0.3% after 2 h. The pectin extracted by both methods had a low methoxyl content, indicating a low degree of esterification. The galacturonic acid content was greater than 60% for most samples. Zeta potential analysis indicated the ability of the pectin to form stable gels. According to the X-ray diffractograms, increasing the extraction temperature led to a decrease in the crystallinity of the pectin structure. Rheological tests showed increased storage modulus as the temperature increased by MAE from 80 to 100 °C for the pectin-based hydrogel. The water holding capacity was greater than 50% for all hydrogels. Furthermore, an analysis of electrical consumption and energy costs highlighted the economic advantage of using microwave heating technology to extract pectin.

Cloud point Extraction Of Methimazole By Direct (UV- Vis Spectrophotometer) And Indirect (Flame Atomic Absorption) methods

Abstract A new technique based on the formation of a chelate Methimazole-Fe(III) at 400 nm was used for the determination of Methimazole 114 as a surfactant in some pharmaceuticals using indirect flame atomic absorption spectroscopy (FAAS) and UV-visible methods based on Triton turbidity extraction. The optimal turbidity extraction temperature was 75.0°C after 25 min of extraction of the complex [MET-Fe(III)] with ethanol. The structure of the Methimazole-Fe(III) chelate was determined by the molar ratio method. A 1:1 L:M (ligand:metal) ratio was produced. The Beer law was employed in the concentration range of 2.5-30 and 2.5-32.5 g/mL for the UV and FAAS, respectively.. The limits of detection (LOD) and quantification (LOQ) were (0.3784) g/ml and (1.2612) g/ml, respectively, for these techniques. The technique has been approved and successfully used in the production of pharmaceutical preparations such as: B. Methimazole capsules sold in Iraq. The analytical results were validated by statistical and recycling studies with satisfactory results.

Optimization of Ultrasonic-Assisted Extraction, Characterization and Antioxidant and Immunoregulatory Activities of Arthrospira platensis Polysaccharides.

This study aimed to enhance the ultrasonic-assisted extraction (UAE) yield of seawater Arthrospira platensis polysaccharides (APPs) and investigate its structural characteristics and bioactivities. The optimization of UAE achieved a maximum crude polysaccharides yield of 14.78%. The optimal extraction conditions were a liquid-solid ratio of 30.00 mL/g, extraction temperature of 81 °C, ultrasonic power at 92 W and extraction time at 30 min. After purification through cellulose DEAE-52 and Sephadex G-100 columns, two polysaccharide elutions (APP-1 and APP-2) were obtained. APP-2 had stronger antioxidant and immunoregulatory activities than APP-1, thus the characterization of APP-2 was conducted. APP-2 was an acidic polysaccharide consisting of rhamnose, glucose, mannose and glucuronic acid at a ratio of 1.00:24.21:7.63:1.53. It possessed a molecular weight of 72.48 kDa. Additionally, APP-2 had linear and irregular spherical particles and amorphous structures, which contained pyranoid polysaccharides with alpha/beta glycosidic bonds. These findings offered the foundation for APP-2 as an antioxidant and immunomodulator applied in the food, pharmaceutical and cosmetic industries.

Pengaruh Suhu Ekstraksi dan Kecepatan Pengadukan terhadap Karakteristik Crude Ekstrak Stevia

Stevia is a natural sweetener that is 250-300 times sweeter than sucrose and is low in calories. Stevia sweeteners are obtained from the extraction of stevia leaves. This study aims to determine the effects of temperature and stirring speed on the characteristics of crude stevia extract (yield, brix value, and IR spectrum). Maceration extraction was conducted with 70% ethanol for 1 hour, varying the temperature (28 ℃, 40 ℃, 55 ℃) and stirring speed (0 rpm, 50 rpm, 100 rpm, 150 rpm). The results showed that a temperature of 40 ℃ produced the highest yield at each stirring speed. The yield increased with the increase in stirring speed at each extraction temperature. The highest brix value was obtained at 55 ℃ and a stirring speed of 150 rpm. The IR spectrum results showed that the functional groups in the crude stevia extract were almost identical to those in commercial stevia.

Enhancing antioxidant yield from carob (Ceratonia siliqua L.): evaluating the efficacy of maceration and ultrasound-assisted methods

ABSTRACT Our study aimed to optimize carob antioxidant extraction for use in the food, cosmetic, and pharmaceutical industries. Maceration investigated ethanol concentration, extraction temperature, and time, while ultrasound-assisted extraction examined ethanol concentration, ultrasound power, and time. A central composite design with 19 experimental points assessed the influence of variables on total yield, total phenolic content, and antioxidant activity. The results were analyzed to optimize the extraction parameters and enhance the antioxidant extraction from carob. The results of the study show that the best maceration condition for extracting antioxidants from the plant material was found to have a time of 24.38 minutes, an ethanol content of 59.02%, and a temperature of 54.52°C. Similarly, the optimal conditions for ultrasound-assisted extraction were found to be 51.49 minutes, 79.78% sonication power, and 76.12% alcohol. The optimal conditions identified can be used as a starting point for further optimization and scaling up of the extraction process.

Quantitative Determination of the Cytotoxic Compounds in Different Organs of Arctium minus (Hill) Bernh. by LC-HRESIMS Using Respond Survey Methodology.

Arctium minus (Hill) Bernh., commonly known as "Burdock", is a species within the Arctium genus of the Asteraceae family. Determining the optimum extraction conditions to obtain a concentrated extract with targeted active ingredients guides the most efficient use of natural products. Herein, ultrasound-assisted extraction (UAE) was optimized by using response surface methodology (RSM) to extract bioactive compounds from different organs of A. minus. Furthermore, phytochemical composition of extracts of the A. minus was investigated by using liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS), antioxidant potential by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), diazanium;3-ethyl-2-[(3-ethyl-6-sulfonato-1,3-benzothiazol-2-ylidene)hydrazinylidene]-1,3-benzothiazole-6-sulfonate (ABTS), CUPRAC, and metal chelation assays, and cytotoxic activities by using human breast cancer cell line (MDA-MB-231) and hepatocellular carcinoma cancer cell line (HepG2), and compared against conventional methods; Soxhlet and maceration. The RSM was employed to investigate the influence of ultrasound power, extraction time, and extraction temperature on the antioxidant potential assessed by the DPPH free radical scavenging assay. In UAE of A. minus leaves, flowers, and branches, the conditions resulting in the minimum IC50 values: 20 °C for 6 min at 50 W for leaves, 20 °C for 3 min at 100 W for flowers, and 20 °C for 3 min at 100 W for branches. Chlorogenic acid was identified as the major phenolic compound in the extracts obtained by UAE, with concentrations of 24,666.96 μg/g in leaves, 1054.92 μg/g in flowers, and 3,501.24 μg/g in branches. Flowers of A. minus had significantly higher levels of arctiin and arctigenin than those of leaves and branches. Extracts from leaves and flowers were more effective against MDA-MB-231 and HepG2 cancer cell lines than arctiin and arctigenin.

Ultrasound-Assisted Enzyme Extraction, Physicochemical Properties and Antioxidant Activity of Polysaccharides from Cordyceps militaris Solid Medium.

Cordyceps militaris solid medium polysaccharides (CMMPs) were extracted using an ultrasound-assisted enzyme method, and the process conditions were optimized via response surface methodology (RSM). The CMMPs were separated into four components named CMMP-1, CMMP-2, CMMP-3 and CMMP-4 using ethanol fractional precipitation, and their monosaccharide composition and structural properties were analyzed by molecular weight analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Congo red test, ultraviolet-visible spectroscopy (UV-vis), atomic force microscopy (AFM), and thermogravimetric analysis (TGA). RSM could predict the yield of the CMMP (R2 = 0.9928), and the polysaccharide yield was 15.43% under the selected conditions of 3.1% cellulase enzyme addition, a liquid-solid ratio of 42:1, an extraction temperature of 61 °C, and an extraction time of 60 min. Glucose and galactose were the main constituents of the four fractional precipitated polysaccharides. Furthermore, four components exhibited antioxidant activity, and CMMP-1 demonstrated stronger antioxidant activity in vitro. This study demonstrates the possibility of developing a natural antioxidant food from Cordyceps militaris solid medium.

Ultrasound-assisted optimized extraction and analysis of polysaccharides of Tricholoma matsutake

The ultrasound-assisted extraction technique was used for extracting polysaccharides of Tricholoma matsutake (PTM) in this work. The effects of different parameters, i.e., solid-to-liquid ratio, ultrasonic power, extraction time, and extraction temperature on the PTM yield were optimized using a rotatable, orthogonal central composite design. In the derived optimal conditions, the PTM yield was 16.97 ± 0.06%, which corresponded well with the regression model predicted value of 16.85%. The extracted PTM was purified, and the structural characteristics and antioxidant activities were investigated. The PTM was found to be composed mainly of fructose, mannose, glucose, and galactose with a molar molecular ratio of 1:2.25:9.35:5, and an average molecular weight of 90,100 Da. High antioxidant effects of PTM were seen in the tests of DPPH, hydroxyl, and ABTS radical scavenging, along with a moderate superoxide radical scavenging rate.

Ultrasound-assisted extraction, optimization, and purification of total flavonoids from [formula omitted] and analysis of their antioxidant, anti-inflammatory, and analgesic activities

Daphne genkwa (D. genkwa) is the dried flower buds of a Chinese medicinal plant with multiple biological activities. Response surface methodology (RSM) combined with artificial neural network (ANN) techniques were utilized to optimize ultrasound-assisted extraction conditions for D. genkwa. Antioxidant activity and anti-inflammatory and analgesic properties of total flavonoids from D. genkwa (TFDG) were assessed. Optimal conditions involving ultrasonic power of 225 W, 30 min extraction time, 30 mL/g liquid–solid ratio, 60 °C extraction temperature, and 70% ethanol concentration yielded a maximum total flavonoids content (TFC) of 5.41 mg/g. After microporous resin purification, four specific flavonoids in D. genkwa were identified and quantified using high-performance liquid chromatography (HPLC). The TFDG demonstrated potent antioxidant activity, with a 94% rate of scavenging the 2, 2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, TFDG exhibited pain-alleviating properties in hot plate and acetic acid-induced writhing tests and noteworthy inhibitory effects on xylene-induced ear swelling in mice. The total flavonoids extracted by ultrasound had excellent biological activity. This establishes a foundation for further investigation into the potential medical value of D. genkwa.

Encapsulation of Mentha aquatica methanol extract in alginate hydrogel promotes wound healing in a murine model of Pseudomonas aeruginosa burn infection

Burn injuries are the fourth most prevalent devastating form of trauma worldwide. Among the most extensively explored materials, composite dressings with alginate loaded with herbal extract can be mentioned. This research aimed to develop a sodium alginate (SA)-based hydrogel encapsulated with Mentha aquatica (MA) methanol extract and investigate its therapeutic efficacy in the infected burn mouse model. SEM, FTIR, in vitro extract release, HPLC, mechanical test, contact angle, swelling, degradability, and temperature response properties were used to analyze the hydrogel scaffold's physicochemical structure. Additionally, the antibacterial activity and MIC level of the extract, cell cytotoxicity, and macroscopic and microscopic analysis of the wound healing process were done using Masson's trichrome and hematoxylin-eosin staining. The physicochemical properties of the SA hydrogel encapsulated with MA extract were verified. The lowest inhibitory dose of the extract was determined to be 12.5 mg/ml. Application of SA/MA hydrogel to localized wounds of deep third-degree burns demonstrated faster tissue regeneration, collagen recovery, and eradication of bacterial infection. This research focused on the design and the preparation of a novel and effective biomaterials-based medical product, which has the potential to rehabilitate infected and injured skin tissue; therefore, it can be a promising candidate for wound dressing applications.

Valorisation of white wine lees: optimisation of subcritical water extraction of antioxidant compounds

This study explored the extraction of antioxidant compounds from white wine lees using subcritical water extraction (SWE). First, SWE was compared to extraction using conventional solvents mixed with water: 50 % methanol, 50 % ethanol and 50 % acetonitrile. The antiradical activity of the extract increased to 12.8 mg TE/g of extract dry matter (DM) using conventional solvents and to 29.2 mg TE/g DM with SWE, compared to the antiradical activity of dried lees, which was 5.7 mg Trolox Equivalent/g of dry matter (mg TE/g DM). Second, SWE conditions were optimised to obtain lees extracts with a high antioxidant activity by applying a Doehlert design and response surface methodology (RSM). The extraction parameters modulated during RSM optimisation were extraction time (t, 15 – 60 min), temperature (T, 100 – 250 °C) and stirring speed (S, 100 – 1000 RPM). Antioxidant activity was assessed using DPPH and FRAP tests, as well as by measuring the Oxygen Consumption Rate (OCR) of lees extracts. Temperature was found to be the main parameter that had a significant effect on antioxidant activity. The results of the RSM showed the optimal conditions (temperature, duration and speed) for attaining maximum antioxidant activity to be: 240 °C, 15 min and 550 RPM respectively. The best-known antioxidant compounds in white wine lees, Total Polyphenol Content (TPC), Glutathione (GSH) and Total Sulfhydryl groups (TSH) were also quantified. Extracts with the highest antioxidant capacity had the highest TPC and TSH concentrations. In conclusion, this study showed (i) that subcritical water extraction is a green process that has potential as an alternative to using conventional solvents for extracting white wine lees, (ii) the chemical components involved in their antioxidant capacity, and (iii) the potential of the lees for oenological and other industrial applications.

Investigating the impact of solvent extraction parameters on oil yield and oil properties: a review

Oilseeds are rich in fatty acids, proteins, fibers, minerals, and vitamins that are necessary for human health. It mainly comprises triglycerides and other minor components, including phytosterols, phenols, carotenoids, tocopherols, and phospholipids. Oils can be extracted using a variety of extraction methods including but not limited to the conventional mechanical and solvent method, and novel methods like supercritical fluid extraction. However, the quality and quantity of extracted oil depends on the process parameters. Among many process parameters temperature is the main parameter which controls the yield and its quality. Temperature range depends upon the nature and type of oilseed. High temperature leads to increased yield while relatively low temperature results in low oil yield and longer extraction time. Large particle size of the solid creates a temperature gradient between the inner and outer surface of the seeds which in turn lowers oil yield. Based on this review, an extraction temperature slightly below the boiling point of the solvent is recommended.