Study on Ultrasonic Extraction of Gastrodin from Gastrodia elata Bl.

Gastrodin, a pharmacologically active constituent, was ultrasonically extracted from gastrodia elata Bl. in the aqueous solution. The effects of six parameters including ethanol–water compositions, extraction time, extraction temperature, particle size, solvent volume, and ultrasonic power on the extraction yield of gastrodin were investigated. According to the orthogonal design, the optimal extraction conditions was explored as extraction temperature 60°C, extraction time 50 minutes, ultrasonic power 126 W, solvent volume 8 mL · g^?1, ethanol–water compositions 70%, and particle size 10–20 mesh. Though the yield of gastrodin via ultrasonic extraction was about 0.01% lower than that from the reflux extraction, the extraction time of the ultrasonic extraction was greatly shortened. Therefore, ultrasonic extraction has high efficiency and is proved to be very valuable in the extraction of gastrodin from gastrodia elata Bl.     

Optimization of Ethanol-Ultrasound-Assisted Destabilization of a Cream Recovered from Enzymatic Extraction of Soybean Oil

A novel method using ethanol and ultrasound to extract oil from cream obtained from enzyme-assisted aqueous extraction of soybean oil was developed. To evaluate the relationships between operating variables and free oil yield and to maximize the free oil yield, response surface methodology was introduced in this work. The developed regression model was fitted with R ² = 0.9591. Optimized variables were: ethanol concentration of 73 %, ethanol addition volume of 0.55 L/kg, ultrasound power of 427 W, ultrasound time of 47 s, and ultrasound temperature of 53 °C. The free oil yield from the cream under the above conditions was 92.6 ± 3.4 %. Scanning electron microscopy (SEM) was used to evaluate the effect of ultrasonic treatment on ethanol-treated cream, and the SEM images clearly showed that the ultrasound treatment affected dispersing and fracturing of the microstructure of ethanol-treated cream.     

Effect of ultrasound- and pulsed electric field-assisted enzymatic treatment on the recovery and quality of sunflower oil

The aim of this study was to evaluate the effect of cavitation and electroporation on enzymolysis extraction of sunflower oil. The optimum extraction conditions during 2 h under enzyme-assisted extraction (EAE) with a maximum oil yield of ≈23.70 ± 0.11% were as follows: cellulase/pectinase ratio 2:1, enzyme concentration 2%, pH 4.5, liquid/solid ratio 6:1 ml/g, and extraction temperature 40°C. Under the optimized enzymatic conditions, the application of ultrasound- (250 W) and pulsed electric field- (1.2 kV/cm; 52.4 kJ/kg) assisted enzymatic extraction for 30 min significantly increased the oil extraction yield by 91.1% and 18.6%, respectively, as compared with EAE.     

超声强化亚临界水萃取脱脂葡萄籽中原花青素的动力学研究

根据质量衡算微分模型和运用Fick第一定律,建立了超声强化亚临界水萃取(USWE)和亚临界水萃取(SWE)原花青素的动力学模型,并通过对比这2个模型说明了超声对亚临界水萃取的强化作用。结果表明,Y=5.3974×(1-e~(-0.001 4t))和Y=5.2019×(1-e~(-0.001 2t))分别是USWE和SWE原花青素的动力学模型,并且这2个动力学模型都能很好地模拟萃取的过程;对比这2个模型方程的参数可知,超声能够加快葡萄籽内部原花青素的扩散及促进其解吸,因此能够对SWE起到强化作用。     

超声波辅助提取五倍子单宁酸的响应面优化实验

以水为提取溶剂,在单因素试验的基础上,利用响应面分析法优化了五倍子中单宁酸的超声波辅助提取条件。利用中心组合(Box-Behnken)实验设计原理研究液固比、超声波作用时间、超声波功率3个自变量对响应值单宁酸提取得率的影响。结果表明,单宁酸最佳超声波辅助提取条件为: 5 g五倍子粉末,液固比38:1(mL:g),超声波提取时间32 min,超声波功率250 W,在此条件下单宁酸提取得率为66.0%。     

Ultrasonic Pretreatment Transesterification for Solid Basic-Catalyzed Synthesis of Fatty Acid Methyl Esters

Generally, ultrasound irradiation is required throughout the reaction for fatty acid methyl esters (FAME, namely, biodiesel) production, which is energy-consuming and difficult to scale-up. In order to improve the industrial application of ultrasonic technology, a systematic study of ultrasonic pretreatment solid basic (Na₂SiO₃)-catalyzed transesterification for FAME production from cottonseed oil was carried out, and the effect of ultrasonic waves on the properties of Na₂SiO₃ catalyst was assessed by X-ray diffraction (XRD), Fourier transform Infrared (FTIR) and scanning electron microscopy (SEM) characterization of fresh and collected catalysts. An ultrasonic frequency of 30 kHz, ultrasonic power of 200 W and ultrasonic pretreatment irradiation time of 30 min was determined to guarantee a satisfactory degree of transesterification. The optimum production was achieved in the reaction system at 45 °C with methanol/cottonseed oil molar ratio 5:1, catalyst dosage 3% and stirring speed 350 rpm resulting in a FAME yield of above 97% after 60 min of reaction under mechanical stirring with the ultrasonic pretreatment process. The new process has a shorter reaction time, a more moderate reaction temperature, a less amount of methanol and catalyst than only the mechanical stirring process without essential damage to activity and the structure of catalyst. These results are of great significance for applying the ultrasonic pretreatment method to produce FAME.     

超临界CO_2和微波辅助萃取当归挥发油

考察当归挥发油的不同提取方法。文中用超临界CO2流体萃取法和微波辅助萃取法研究萃取当归挥发油。实验表明:超临界CO2萃取最佳工艺条件为萃取压力25 MPa、分离釜Ⅰ解析温度55℃、萃取温度45℃,提取率约1.9%;微波辅助萃取最佳工艺条件为无水乙醇为提取溶剂,微波功率800 W、微波辐射时间150 s、液料质量比为4.71∶1,提取率约11.2%。微波辅助萃取法取得当归油的收率高于超临界CO2萃取法。微波辅助萃取法萃取当归挥发油收率高,但外观品质较超临界萃取的当归挥发油差。     

Optimization of Ultrasound-Assisted Extraction of Artemisinin from Artemisia annua L. by Response Surface Methodology

Artemisinin is a compound extracted from Artemisia annua L. with a remarkable curative effect against malaria. It can be extracted using ultrasound-assisted extraction (UAE) and then detected via HPLC. In this study, response surface methodology (RSM) was used to optimize UAE conditions for obtaining the maximum yield of artemisinin. Three independent variables (ratio of solvent to material, extraction temperature, and ultrasonic power) were evaluated using the Box-Behnken experimental design, with the yield of artemisinin as a response variable. Experimental data were highly fitted to a mathematical-regression model using multiple linear regression (MLR). Based on response surface plots, the three independent variables exhibited interactive effects on the yield of artemisinin. The optimal extraction conditions were as follows: 42.71 mL/g ratio of solvent to material, 41.86°C extraction temperature and 120 W ultrasonic power. The predicted yield of artemisinin by model was 0.7848%, whereas the actual yield in the extracts was 0.7826% ± 0.0790% in adjusted optimal conditions, with a relative error of 0.28%. The results undoubtedly demonstrated that RSM could be used to explore the optimum conditions of artemisinin extraction.     

Solubility of fatty acids in subcritical water

A phase equilibrium apparatus was designed to determine the solubilities of stearic acid and palmitic acid in subcritical water at different temperatures and pressures. The dissolution equilibrium time was measured. The effect of an ultrasonic field on dissolution equilibrium was also studied. The results showed that the maximum solubilities of stearic acid and palmitic acid were 0.136 g/100 g and 0.178 g/100 g in subcritical water at temperatures of 180 °C and 160 °C, respectively, and a pressure of 15 MPa for 30 min. An ultrasonic field also clearly promoted the dissolution of fatty acids in subcritical water. The dissolution equilibrium time was shortened to 20 min using ultrasonic oscillation (250 W, 20 kHz).     

Effects of Operating Parameters on the Cinnamaldehyde Content of Extracted Essential Oil Using Various Methods

Supercritical fluid extraction (SFE) of essential oils from commercial cinnamon bark was compared with essential oils that were obtained by hydrodistillation. Effects of operating parameters (pressure, temperature and extraction time of SFE) on the extraction yield and the composition of the extracted volatile oil were studied. Moreover, in the hydrodistillation process, the effect of the pH of the solvent on the concentration of cinnamaldehyde in the extracted volatile oil was studied. The maximum yield of extract in the SFE process is about 7.8 % at 70 °C and 240 bar. The maximum concentration of cinnamaldehyde in the SFE process was obtained at 70 °C and 160 bar, and the maximum concentration of this component in hydrodistillation was achieved at pH = 4.1.     

Ultrasonic Initiation of the Alkaline Hydrolysis of Triglycerides (Saponification) Without Phase Catalysis

A study into the ultrasonic initiated alkaline hydrolysis of triglycerides (also known as the saponification reaction) is described. Sunflower oil is used as a source of triglycerides. The reaction is driven by the ultrasound from either an ultrasonic water bath (35 kHz–85 W) or a probe (40 kHz–50 W) in the presence of potassium hydroxide (KOH). It will be shown that ultrasound is effective as a power source to initiate and drive the reaction, that a high reaction yield is achievable in only 15 min of total power application while working at ambient temperature, and that no detectable by-products are generated during the reaction. Comparison of the two methods shows the ultrasonic probe to be the superior technique. Our method demonstrates reasonable yields can be obtained without the need for excess alkali or phase transfer catalysis. Curing the soap for several weeks allowed the saponification reaction to proceed to completion. Suggestions for a practical application have also been given.     

Development of the ultrasonic conditions as an advanced technique for extraction of phenolic compounds from Eucalyptus robusta

This study is designed to develop ultrasonic conditions as an advanced technique for optimal recovery of phenolics and antioxidants from Eucalyptus robusta leaf and to evaluate the impact of solvents, temperature, sonication time and power on ultrasound-assisted extraction of these compounds. Temperature has the greatest impact on the total phenolic content (TPC) yield followed by time and power. A yield of 163.68 ± 2.13 mg GAE/g of TPC is observed using 250 W ultrasonic power for 90 min at 60°C with water. This study validates UAE as an efficient, green, and sustainable technique for extracting phenolics from E. robusta.     

均匀设计法优选辅酶Q10的超声提取工艺

用均匀设计法优化了以新鲜烟叶为原料,超声提取辅酶Q10的工艺。考察了超声时间、温度、液料比和超声功率4个因素对辅酶Q10提取率的影响,并对提取过程用多元回归方程进行了数值模拟。实验得到优化的辅酶Q10超声提取工艺条件为:提取溶剂体积分数85%乙醇,液料体积质量比18 mL/g,超声温度45℃,超声时间45 m in,超声功率250 W。结果表明,超声法提取对烟叶中辅酶Q10的提取质量分率为7.12×10-6,其提取率是索氏提取的1.34倍,实验结果与回归方程的拟合值吻合良好,说明应用超声法提取烟叶中的辅酶Q10是可行的。     

Extraction of bioactive components from Centella asiatica using subcritical water

Bioactive components, asiatic acid and asiaticoside, were extracted from Centella asiatica using subcritical water as an extraction solvent. Extraction yields of asiatic acid and asiaticoside were measured using high-performance liquid chromatography (HPLC) at temperatures from 100 to 250 °C and pressures from 10 to 40 MPa. As temperature or pressure increased, the extraction yield of asiatic acid and asiaticoside increased. At the optimal extraction conditions of 40 MPa and 250 °C, the extraction yield of asiatic acid was 7.8 mg/g and the extraction yield of asiaticoside was 10.0 mg/g. Extracted asiatic acid and asiaticoside could be collected from water as particles with a simple filtering process. Dynamic light scattering (DLS) was used to characterize particle size. Particles containing asiatic acid were larger (1.21 μm) than particles containing asiaticoside (0.76 μm). The extraction yields of asiatic acid and asiaticoside using subcritical water at 40 MPa and 250 °C were higher than extraction yields using conventional liquid solvent extraction with methanol or ethanol at room temperature while the subcritical water extraction yields were lower than extraction yields with methanol or ethanol at its boiling point temperature.     

Liquid–liquid two‐phase flow in ultrasonic microreactors: Cavitation,emulsification, and mass transfer enhancement

The effects of ultrasound on the hydrodynamic and mass transfer behaviors of immiscible liquid–liquid two‐phase flow was investigated in a domestic ultrasonic microreactor. Under ultrasonic irradiation, cavitation bubble was generated and underwent violent oscillation. Emulsification of immiscible phases was initiated by virtue of oscillating bubbles shuttling through the water/oil interface. The pressure drop was found to decrease with increasing ultrasound power, with a maximum decrement ratio of 12% obtained at power 30 W. The mass transfer behavior was characterized by extraction of Rhodamine B from water to 1‐octanol. An enhancement factor of 1.3–2.2 on the overall mass‐transfer coefficient was achieved under sonication. The mass transfer performance was comparable to passive microreactor at similar energy dissipation rate (61–184 W/kg). The extraction equilibrium was reached under a total flow velocity 0.01 m/s and input power 20 and 30 W, exhibiting its potential use in liquid‐liquid extraction process. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1412–1423, 2018     

SOLUBILITY OF HIPPOPHAE RHAMNOIDES L. SEED OIL IN SC CO2 AND SCFE PROCESS ENHANCEMENT BY ULTRASOUND

Dynamic method was applied to measure the solubility of oil from Hippophae rhamnoides L. seed in supercritical CO₂. The experiments were carried out at pressures and temperatures ranging from 10 to 30 MPa and 303 to 323 K, respectively. No marked changes in composition of extracted oil in the course of extraction were observed. The solubility was correlated with CO₂ density and temperature by adjusting the constants of the del Valle-Aguilera equation. In order to enhance the extraction efficiency of supercritical fluid extraction (SCFE) for natural products, the SCFE process coupled with power ultrasound (20 kHz, 150 W) was investigated. The reactor with a power ultrasound transducer was specially designed and set up. For Hippophae rhamnoides L. seed oil, soybean seed oil, and licorice root oil extraction, the extraction rate and the oil yield were increased by 16.9–33.2% and 30% respectively, with the coupling of SCFE and power ultrasound.     

Response Surface Methodology to Supercritical Carbon Dioxide Extraction of Essential Oil from Amormum krevanh Pierre

Abstract

Response surface methodology was employed to investigate the effects of operating conditions and predict the optimal conditions for supercritical carbon dioxide extraction of essential oil from Amomum krevanh Pierre. The factors investigated were operating temperature (33–67°C), the operating pressure (91–259 bar), and the extraction time (20–70 min). The main effect of the operating pressure and the interaction effect between the operating temperature and the extraction time were found to be significant factors. From the response surface model, an optimal condition for essential oil content within the range of experimental study was found to be at 33°C, 175 bar, and 70 min, which gave the oil yield of 17.3 mg/g dry wt. The essential oil yield obtained at all conditions were higher than that obtained by organic solvent extraction (9.74 mg/g dry wt.) while the composition of the extract was similar, which were 1,8-cineole (70.87%), β-pinene (8.89%), and limonene (4.81%).     

The Effect of Pulsed Microwave Power on Transesterification of Chlorella sp. for Biodiesel Production

Pulsed microwave technique was employed for the production of biodiesel from Chlorellasp. via transesterification. Real-time microwave power and temperature profiles were used for the evaluation of efficiency of biodiesel production. The effect of power setting was determined in the range of 100–1000 W at the fixed reaction time (10 min) and temperature (60°C). In this work, the highest yield of biodiesel per unit energy consumption observed was 0.53% by weight of crude lipid per kilo joule at 250 W. From the results in this study, the efficiency of biodiesel production was correlated to the uniform pulse intensity and pulse frequency during the reaction process provided at the power setting of 250 W.     

An Improved Ultrasound-Assisted Alkali Extraction Process of Perilla Seed Meal Polysaccharide

The quantitative effects of extraction time, extraction temperature, concentration of alkali solution, and ratio of solid to liquid on yield of perilla seed meal polysaccharides were investigated using response surface methodology (RSM). The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods. By solving the regression equation and also by analyzing the response surface contour plots, the optimal ultrasound-assisted (ultrasonic power was 70 W) extraction conditions of polysaccharides were determined: Extraction time of 29.4 min, extraction temperature of 42.8°C, concentration of NaOH of 4.5 mol/L, and ratio of liquid to solid of 22 g/mL. These predicted values were also verified by validation experiments.     

油砂沥青超声波减粘工艺研究

油砂沥青粘度较大,自然状态下不易流动,严重影响了管道输送及加工,针对目前油砂沥青研究中存在的问题,采用超声波进行了减粘的实验研究。实验综合考察了超声波作用时间、温度、超声波频率、超声波功率等因素对减粘效果的影响。实验结果表明,在适当的超声作用时间(20 min)、适宜的温度(30℃)、适宜的超声波频率(20 kHz)和超声波功率(250 W)的条件下,油砂沥青的减粘率可达80%以上。经超声波处理后的油砂沥青粘度略有恢复,但仍远低于处理前的粘度,超声波减粘效果良好。