Extraction of Tanshinone IIA and Cryptotanshinone from the Rhizome of Salvia miltiorrhiza Bunge: Kinetics and Modeling

Tanshinone IIA (TS) and cryptotanshinone (CT) are phenolic compounds which show significant biological potential. This study deals with the optimization and kinetics of TS and CT extraction from the rhizome of Salvia miltiorrhiza Bunge in a stirred batch extraction. The influence of various extraction parameters on the extraction yield has been studied. The optimum extraction conditions are 85% ethanol, solid to solvent ratio of 1:20, 333.15 K of temperature, agitation speed of 300 rpm, 0.09 to 0.125 mm of powder size and extraction time 30 min. 2.72 mg and 1.78 mg per gram of the rhizome powder of Salvia miltiorrhiza Bunge for TS and CT are obtained in the optimum extraction conditions, respectively. The extraction kinetics behavior of TS and CT from the rhizome powder of Salvia miltiorrhiz Bunge reveals that the extraction of TS and CT follows the first order kinetics. The kinetic expression developed by Spiro and Siddique is used and the model is in good agreement with the experimental results. The activation energy for the extraction of TS and CT is found to be 16.05 kJ/mol and 18.82 kJ/mol, respectively.     

香椿叶中总黄酮的提取工艺研究

研究了溶剂法提取香椿叶总黄酮的工艺条件。在单因素试验的基础上,用正交实验法对香椿叶总黄酮的提取工艺进行优选,考察乙醇体积分数、固液比、提取时间、浸提温度对香椿叶总黄酮提取率的影响。结果表明,在浸提3次条件下,得到叶片总黄酮最佳工艺条件为:乙醇浓度80%、固液比为1∶10(g/mL)、提取温度80℃、提取时间2 h,在此条件下香椿叶片总黄酮提取率为61.13%;叶轴总黄酮最佳提取条件为:乙醇浓度70%、固液比为1∶10(g/mL)、提取温度80℃、提取时间1 h,在此条件下香椿叶轴总黄酮提取率为71.71%。     

Extraction of phenolic compounds from spent blackberry pulp by enhanced-fluidity liquid extraction

This research describes an enhance-fluidity liquid extraction process for extracting total phenolic compounds (TPC) from spent blackberry pulp (SBP) using a modified solvent (CO₂–ethanol mixture). Effects of particle size (from 1,400 to 180 μm), pressure (150–300 bar), and cosolvent (ethanol)-to-solid ratio (64, 128, and 192 mL ethanol/32 g solid) on the extraction of TPC at 40°C were investigated. Experimental data was processed using the Sovova's model to obtain the solubility of TPC in the modified solvent. The Peng–Robinson equation of state was used to correlate the solubility of phenolic compounds at high pressures. Results indicated that particle sizes ranging from 600 to 850 μm and pressure of 300 bar allowed obtaining extracts with higher antioxidant activity (94.71% of inhibition) and TPC content (11.59 mg GA/g SBP). High pressure and the modified solvent increased the solubility up to 3.4 × 10⁻⁴ (mol fraction).     

Extraction of biologically active compounds from Sideritis ssp. L.

In this study extraction of polyphenols and flavonoids from cultivated hybrid Sideritis scardica × Sideritis syriaca, known for its rich content of phenolics and flavonoids with antioxidant activity, was investigated. Extractions have been done by ethanol and water-ethanol, respectively. High equilibrium values of the extracted species were obtained—17.55 mg/(g solid) total phenolics and 5.7 mg/(g solid) total flavonoids with ethanol as solvent. The influence of the solvent on the total yield and the content of biologically active compounds were studied. Maximum polyphenolics and flavonoids extraction was observed for water-ethanol solvent ratio 20/80. Increase of the content of ethanol in the solvents led to lower total yield of extracts but higher percentage of polyphenolics. The extraction kinetics showed that 90% of the phenolic compounds were extracted during the first 2.5 h. The experimental kinetics was described by a constant effective diffusion coefficient D_e = 1.5 × 10⁻¹² m²/s in the solid, accounting for the actual particle size distribution.     

Sorption kinetics and diffusion of alkanes into tetrafluoroethylene/propylene copolymer membranes

Sorption kinetics and diffusion of hexane, heptane, octane, nonane, decane, cyclohexane, and 2,2,4-trimethylpentane through tetrafluoroethylene/propylene copolymer membranes were studied using the gravimetric sorption method at 30, 45, and 60°C. Coefficients of diffusion were calculated from Fick's equation. From these data, the permeability coefficients were obtained. Analytical solutions of Fick's relations were used to estimate the liquid concentration profiles into the polymeric membranes at different times. The profiles of liquid concentrations were also simulated for the polymer–solvent systems using the numerical simulation method. Activation parameters for diffusion and sorption were evaluated and these results are discussed in terms of the molecular sizes and geometries of liquids (i.e., shape) as well as temperature. The diffusion coefficients follow a systematic decrease with increasing size of the penetrant molecules. The activation energies i.e., E_D values, increase with increasing size of n-alkanes. © 1996 John Wiley & Sons, Inc.     

Ultrasound-Assisted Extraction of Capsaicin from Red Peppers and Mathematical Modeling

A mathematical model based on Fick's first law was established to describe ultrasound-assisted extraction of capsaicin from red peppers. By considering the mechanism of ultrasound-assisted extraction and the experimental data, the effects of parameters (ultrasound power, extraction temperature and extraction time, solvent/sample ratio, ethanol volume fraction) on yield of capsaicin would be analyzed in detail. The model was very convenient for obtaining optimal parameters in the ultrasound-assisted extraction of capsaicin. The calculation result by the model was agreed with the experimental data very well, indicating that the mathematical model could provide valuable guidance for the ultrasound-assisted extraction of capsaicin from red peppers.     

响应面法优化螺旋藻中叶绿素的超声提取工艺

Chlorophylls were extracted by using ultrasonic from Spirulina platensis. Single factor examination and response surface analysis experiments were adopted to investigate the effects of extraction time, extraction solvent, solvent concentration, ratio of liquid to solid and extraction grade. The results showed that the optimal process parameters for this method were: extraction time of 56.5 min, ethanol concentration of 48.3% (vol) of ethanol/acetone solvent, and ratio of liquid to solid of 7. 9 ml·g^-1. The optimized chlorophylls extraction yield was 1.28%. The comparison experimental results indicated that the yield of chlorophylls by ultrasonic extraction was higher than that obtained from conventional solvent extraction.     

Ultrasound-assisted extraction of natural antioxidants from betel leaves (Piper betle): Extraction kinetics and modeling

Present study investigated the extraction kinetics of antioxidants from Piper betle by ultrasound-assisted extraction for three extraction variables: temperature, solute to solvent ratio and ethanol concentration. Based on the results of yield, total phenolic content and antioxidant activity, the optimum results were obtained at 50°C, 1:20 g/mL and 80% ethanol, respectively. Statistical coefficients of R² ≥ 0.961 and RMSE ≤ 0.508 for two-site kinetic model confirm the use of proposed models for simulation and prediction purpose. Comparison with ascorbic acid and butylated hydroxytoluene solidifies the use of Piper betle as feasible source of natural antioxidants. The presence of hydroxychavicol and eugenol was affirmed by high-performance liquid chromatography assay.     

乙醇提取-丙酮沉淀法提取分离茶皂素的工艺研究

以油茶饼粕为原料,采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标,对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明：体积分数95%的乙醇为提取溶剂,乙醇与预处理过的油茶饼粕液料比为9：1（mL：g）,提取温度为70℃,提取时间为4 h,提取次数为2次,提取液浓缩至刚好有固体析出,丙酮用量为4倍浓缩液体积量时提取分离效果较佳,得到的茶皂素纯度为85.17%,得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现：丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。     

油茶蒲总多酚回流提取工艺的研究

乙醇回流提取油茶蒲中的总多酚,考察了提取温度、提取时间、乙醇浓度和液料比对油茶蒲总多酚的提取效果的影响。结果表明,各因素对油茶蒲总多酚的提取效果的影响大小依次为:提取温度液料比乙醇浓度提取时间;油茶蒲总多酚的适宜提取工艺条件为:以50%的乙醇溶液为提取溶剂,液料比为20 mL/g,在70℃温度下回流提取3次,每次80 min。在此工艺条件下,总多酚提取量为71.13 mg/g。     

A Model of Drying Kinetics of Acacia mangium Wood at Different Temperatures

The objective of this study was to determine the isothermal drying kinetics of Acacia mangium wood blocks by employing a relative humidity-controlled drying chamber. A model was developed based on solution of Fick's second law and evaluated through the coefficient of determination (R ² ), sum of square error (SSE), root mean square error (RMSE), and reduced chi-square (χ ² ). This model was compared to semi-theoretical models which are commonly used to describe the drying behavior of biomass in previous studies. The porosity and shrinkage characteristics of dried specimens were also evaluated. Based on the findings in this work, it was determined that the proposed model resulted in an excellent fit with experimental data for all four drying temperature levels of 30, 35, 40, and 45 ^° C to describe the isothermal drying kinetics of Acacia mangium . It appears that volumetric shrinkage of the samples decreased quadratically with decreasing moisture ratio. The activation energy of the drying process was determined to be 41.07 kJ/mol.     

Extraction of Total Phenolics of Sour Cherry Pomace by High Pressure Solvent and Subcritical Fluid and Determination of the Antioxidant Activities of the Extracts

Abstract

High pressure liquid extraction (HPE) and subcritical fluid (CO₂+ethanol) extraction (SCE) were used for the extraction of total phenolic compounds (TPC) from sour cherry pomace. Antiradical efficiency (AE) of the extracts was also determined. Ethanol was the solvent for HPE and co‐solvent for SCE. Combinations of pressure (50, 125, 200 MPa), temperature (20, 40, 60°C), solid/solvent ratio (0.05, 0.15, 0.25 g/ml) and extraction time (10, 25, 40 min) were variables for HPE according to the Box‐Behnken experimental design. The variables used for SCE were pressure (20, 40, 60 MPa), temperature (40, 50, 60°C), ethanol concentration (14, 17, 20 wt%) and extraction time (10, 25, 40 min). For HPE, TPC, and AE at the optimum conditions (176–193 MPa, 60°C, 0.06–0.07 g solid/ml solvent, 25 min) were found as 3.80 mg gae/g sample and 22 mg DPPH^?/g sample, respectively. TPC and AE at the optimum conditions (54.8–59 MPa, 50.6–54.4°C, 20 wt% ethanol, 40 min) for SCE were determined as 0.60 mg gae/g sample and 2.30 mg DPPH^?/g sample for sour cherry pomace, respectively.     

Parametric optimization and modeling of batch extraction process for extraction of betulinic acid from leaves of Vitex Negundo Linn

Extraction of betulinic acid from leaves of Vitex Negundo Linn was carried out in a series of solvents (methanol, ethanol, isopropyl alcohol, and water). Methanol gave maximum yield of extraction and therefore was used to investigate influence of particle size, speed of agitation, solid loading, and temperature, etc., on the rate and recovery in a stirred batch reactor. Effective intra-particle diffusivity of the acid in each solvent at different temperatures was estimated using an unsteady state mass diffusion model. The diffusivity of betulinic acid through the cellulose matrix of leaves is in the range 1.7 x 10^?13 to 9.23 x 10^?11 m²/sec and is strongly influenced by the temperature of the extraction. The Response Surface Methodology was used to estimate optimal conditions for betulinic acid extraction.     

从虎杖中提取白藜芦醇的工艺研究

采用溶剂从虎杖中提取白藜芦醇,用紫外分光光度法测定含量。研究了不同溶剂、温度、料液比等各种因素对提取率的影响。结果表明,较优的提取条件为:60%乙醇为提取剂,提取温度为50℃,料液比1∶40,提取时间2.5 h,一次提取率达2.38%。按此工艺提取,粗品中白藜芦醇含量高。     

Production of pure phosphoric acid from El-Sebaeya low-grade phosphate ore

The extraction of phosphoric acid by tributyl phosphate (TBP) in kerosene from hydrochloric acid leach liquor of El-Sebaeya low-grade phosphate ore was carried out. The influence of various factors affecting the leaching process such as particle size, reaction time, acid concentration, liquid/solid mass ratio, reaction temperature and stirring speed were thoroughly studied to estimate the favor phosphate ore dissolution in relation to impurity. Thereafter, the effects controlling the extraction step, including shaking time, solvent concentration, aqueous/organic phase ratio, and reaction temperature, have been studied in terms of the maximum P₂O₅ extraction efficiency and the minimum impurities extraction efficiency. The obtained loaded organic solvent was subjected to the stripping stage using double-distilled water. The outlet stripping liquor was concentrated by evaporation up to 62% P₂O₅.     

Pilot-Scale Multi-Stage Countercurrent Extraction of Scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz

Abstract

A low-temperature, timesaving, lower solvent consumption, and energy cost and multi-stage countercurrent extraction (MCCE) technique was developed for pilot-scale production of scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz. The optimum conditions of MCCE process were obtained using the orthogonal array design method, i.e., 70% (v/v) of ethanol water solution, 16 L/kg of solvent to herbal sample ratio, 45°C of extraction temperature and 30 min of extraction time. A comparison between the MCCE technique and single pot extraction (SPE) under respective optimized operation conditions was made and time courses of scutellarein of MCCE and SPE processes were plotted, indicating that the MCCE technique can lower the extraction temperature and decrease five-sixth of the extraction time and two-thirds of the solvent consumption at the equivalent extraction yield of scutellarein.     

Optimization of Microwave‐Assisted Extraction of Flavonoid from Radix Astragali using Response Surface Methodology

Abstract

Response surface methodology (RSM) was applied to predict optimum conditions for microwave‐assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent‐to‐material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent‐to‐material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods.     

Ultrasonic extraction of ferulic acid from Angelica sinensis

In this paper, the extraction of ferulic acid, a pharmacologically active ingredient from the root of Angelica sinensis with ultrasonic extraction was investigated. Percolation and supercritical fluid extraction (SFE) were also employed to make comparisons with ultrasonic extraction. Three variables, which including the concentration of solvent, the ratio of solvent volume to sample (mL/g), and extraction time, were found to have great influence on ultrasonic extraction. The optimum extraction conditions were using pure ethanol with a ratio of solvent volume to sample 8:1 (mL/g) and extraction time of 30 min. Under the optimum extraction conditions, the extraction yield could reach 6.5% mass fraction, which was higher than that of SFE process with ethanol as co‐solvent and nearly a content of ferulic acid 1.0%; both the yield and the content of ferulic acid were higher than those obtained by percolation. Moreover, the time of ultrasonic extraction was significantly shortened. Overall, Ultrasonic extraction was shown to be highly efficient in the extraction of ferulic acid from Angelica sinensis.     

Molecular transport of n‐alkanes through diol chain‐extended polyurethane membranes

Molecular transport of n‐alkanes was investigated by calculating sorption, diffusion, and permeation of liquids through the diol chain‐extended polyurethane (PU) membranes in the temperature interval 25–60°C. Sorption experiments were performed gravimetrically. Diffusion coefficients were calculated from Fick's equation. These results showed a dependency on the nature and size of interacting n‐alkane molecules as well as morphology of the chain‐extended PUs. Transport kinetics followed an anomalous trend. Using the temperature‐dependent transport parameters, activation energies were calculated for diffusion and permeation processes using an Arrhenius equation. The van't Hoff relationship was used to obtain enthalpy and entropy of sorption. Concentration profiles of liquids through PU membranes were computed using Fick's equation, solved under appropriate initial and boundary conditions. A correlation was attempted between transport properties of liquids and physicomechanical properties of PU membranes. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 874–882, 2005     

Fatty Acid Profile and Bioactive Compound Extraction in Purple Viper's Bugloss Seed Oil Extracted with Green Solvents

Oil extraction from seeds of purple viper's bugloss (Echium plantagineum) was carried out using different solvents (chloroform:methanol, n-hexane, ethanol, 2-propanol and ethyl acetate) at room temperature and also using Randall extraction. Extraction yields were calculated and oils were analyzed in terms of fatty acid profiles and distribution among lipid classes, total polyphenol content, oxygen radical absorbance capacity (ORAC) and phytosterol content. No considerable differences were found on fatty acid profiles and distribution in oils regardless of the solvent and temperature used for the extraction. However, ethanol combined with Randall extraction (85 °C for 1 hour) offered the best results in terms of total polyphenol content (20.9 mg GAE/100 g oil), ORAC (468.0 μmol TE/100 g oil), and phytosterol amount (437.2 mg identified phytosterols/100 g oil) among all assayed extraction methods. A higher extraction temperature led to significantly higher concentrations of bioactive compounds and ORAC values in the oil when ethanol or 2-propanol were used as extracting solvent, but that was not the case using n-hexane except for the concentrations of β-sitosterol and stigmasterol, which were significantly higher using Randall extraction than room temperature extraction with n-hexane. Ethanol is classified as a “green solvent,” and it could be considered a suitable option to produce oil from E. plantagineum seeds with a higher antioxidant capacity and bioactive compound concentration than the current commercial oil, which is usually extracted with n-hexane.