Ultrasound-assisted extraction of anthraquinones from roots of Morinda citrifolia

This study investigated the use of ultrasound-assisted extraction (UAE) to improve the extraction efficiency of the classical solvent extraction techniques such as maceration and soxhlet extraction to extract anti-oxidant activity compounds, anthraquinones, from the root of Morinda citrifolia. The effects of different extraction conditions were determined, i.e., temperature of (25, 45, 60 °C), ultrasonic power, solvent types, and compositions of ethanol in ethanol–water mixtures. The results show that the yield increases with increasing extraction times and extraction temperatures. The percent recovery of anthraquinones using ultrasound was found to be highly dependent on the type of solvents (acetone > acetonitrile > methanol > ethanol). Furthermore, the use of ethanol–water solution as extraction solvent increased the yield of anthraquinones due to the relative polarity, the swelling effect of plant tissue matrix by water, and increased sound absorption. To achieve the same recovery as that achieved by UAE, soxhlet extraction and maceration required much longer time.     

Ultrasound-assisted extraction of xyloglucan from apple pomace

Ultrasound-assisted extraction was evaluated as a simpler and more effective alternative to conventional extraction method for the isolation of xyloglucan from apple pomace. The apple pomace samples were extracted under indirect sonication in an ultrasound cleaning bath. The ultrasound extraction was compared with the conventional method, on the productions of xyloglucan. It was found that the ultrasound-assisted extraction of xyloglucan was about three times faster than the traditional extraction method. Response surface methodology was employed to study the effect of liquid:solid ratio, KOH concentration and ultrasound-assisted extraction time on the yield of xyloglucan from apple pomace. Regression analysis was performed on the data obtained. The most relevant variable was the quadratic of liquid:solid ratio. The coefficient determination (R²) was good for the second-order model. The optimum combination was determined as a liquid:solid ratio of 34.4:1 (v/w), a KOH concentration of 3.3 M and an ultrasound-assisted extraction time of 2.5 h.     

Ultrasound-assisted extraction of ginseng saponins from ginseng roots and cultured ginseng cells

Ultrasound-assisted extraction was evaluated as a simpler and more effective alternative to conventional extraction methods for the isolation of ginsenosides (saponins) from various types of ginseng. The ginseng samples were extracted with different solvents, under either direct sonication by an ultrasound probe horn or indirect sonication in an ultrasound cleaning bath. The ultrasonic extraction was compared with the conventional method of refluxing boiling solvents in a soxhlet extractor, on the yields of both the total saponin isolated by thin-layer chromatography and the individual ginsenosides by high performance liquid chromatography. It was found that the sonication-assisted extraction of ginseng saponins was about three times faster than the traditional extraction method. The ultrasonic extraction was not only more efficient but also convenient for the recovery and purification of the active ingredients of plant materials. In addition, the sonication-assisted extraction can be carried out at lower temperatures which are favorable for the thermally unstable compounds.     

Ultrasound-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum Ait

Oleanolic acid and ursolic acid are the main bioactive compounds in fruit of Ligustrum lucidum Ait, which possess anti-inflammatory, antioxidative, antiprotozoal, antimutagenic and anticancer properties. In this study, the ultrasound-assisted extraction of oleanolic acid and ursolic acid from L. lucidum Ait was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, extraction temperature and extraction time, on extraction efficiencies of oleanolic acid and ursolic acid from L. lucidum were evaluated. The influence of experimental parameters on extraction efficiency of ursolic acid was more significant than that of oleanolic acid. The optimal extraction conditions were 95% ethanol, the ratio of material to liquid at 1:20, and extraction for 10 min at 40 °C under ultrasonic irradiation. Under the optimal conditions, the yields of oleanolic acid and ursolic acid were 6.3 ± 0.25 and 9.8 ± 0.30 mg/g, respectively. The results indicated that the ultrasound-assisted extraction is a very useful method for the extraction of oleanolic acid and ursolic acid from L. lucidum.     

Ultrasound-assisted alkaline extraction of protein from Tenebrio molitor larvae: Extraction kinetics,physiochemical, and functional traits

Currently, as a promising alternative protein source, the interest of edible insect protein has been continuously increased. However, the extraction processing had distinct effects on the physicochemical properties and functionalities of this novel and sustainable protein. In this study, Tenebrio molitor larvae protein (TMLP) was extracted via ultrasound (US)-assisted alkaline extraction. The changes of extraction kinetics, physicochemical characteristics, and functional properties of TMLP as a function of US time (10, 20, 30, 40, 50 min) were investigated. The results showed that 30 min US treatment rendered the maximum protein yield (60.04 %) (P < 0.05). Meanwhile, Peleg's model was considered a suitable model to represent the extraction kinetics of TMLP, with a correlation coefficient of 0.9942. Moreover, the protein secondary structure, particle size, and amino acid profiles of TMLP were changed under the US-assisted alkaline extraction process. Additionally, a significant improvement of the functional properties of TMLP extracted with this method was observed compared to traditional alkaline extraction. In conclusion, the present work suggests that US-assisted alkaline extraction could be considered as a potential method to improve the protein yield, quality profiles, and functional properties of TMLP.     

Optimization of ultrasonic-assisted extraction of astaxanthin from green tiger (Penaeus semisulcatus) shrimp shell

This study was aimed at optimizing the astaxanthin extraction efficiency from shrimp shell (green tiger, Penaeus semisulcatus). Astaxanthin was extracted using selected nonpolar/polar solvents (petroleum ether, n-hexane, ethanol, acetone) individually and in ternary mixtures of petroleum ether, acetone, and water in ratios of 15:50:35, 50:45:5, and 15:75:10 for different times (2,4 and 6 h). The results showed that solvents with higher polarity were more suitable for the extraction of astaxanthin, and increasing the extraction time from 2 to 6 h improved the extraction yield. The conditions of extraction of astaxanthin with the desirable solvent were then optimized with the ultrasonic method using the Box-Behnken design [variables included: extraction temperature (25 to 45 °C), extraction time (5 to 15 min), and ultrasound amplitude (20 to 100%)]. Optimal extraction conditions were determined as the ultrasonic amplitude of 23.6%, extraction time of 13.9 min, and extraction temperature of 26.3 °C. Under this optimum condition, the amount of astaxanthin, ferric reducing antioxidant power, and free radical scavenging capacity of the extract were obtained as 51.5%, 1705 μmol of Fe²⁺/g, and 73.9%, respectively. Extraction and analysis of the extract at the optimum point were used to validate the results.     

Ultrasound-assisted extraction of phenolic acids,flavonols, and flavan-3-ols from muscadine grape skins and seeds using natural deep eutectic solvents and predictive modelling by artificial neural networking

The objective of this study was to investigate the extraction efficiency of 9 natural deep eutectic solvents (NDES) with the assistance of ultrasound for phenolic acids, flavonols, and flavan-3-ols in muscadine grape (Carlos) skins and seeds in comparison to 75% ethanol. Artificial neural networking (ANN) was applied to optimize NDES water content, ultrasonication time, solid-to-solvent ratio, and extraction temperature to achieve the highest extraction yields for ellagic acid, catechin and epicatechin. A newly formulated NDES (#1) consists of choline chloride: levulinic acid: ethylene glycol 1:1:2 and 20% water extracted the highest amount of ellagic acid in the skin at 22.1 mg/g. This yield was 1.73-fold of that by 75% ethanol. A modified NDES (#3) consisting of choline chloride: proline: malic acid 1:1:1 and 30% water extracted the highest amount of catechin (0.61 mg/g) and epicatechin (0.89 mg/g) in the skin, and 2.77 mg/g and 0.37 mg/g in the seed, respectively. The optimal yield of ellagic acid in the skin using NDES #1 was 25.3 mg/g (observed) and 25.3 mg/g (predicted). The optimal yield of (catechin + epicatechin) in seed using NDES #3 was 9.8 mg/g (observed) and 9.6 mg/g (predicted). This study showed the high extraction efficiency of selected NDES for polyphenols under optimized conditions.     

Ultrasound-assisted extraction of rare-earth elements from carbonatite rocks

In view of the increasing demand for rare-earth elements (REE) in many areas of high technology, alternative methods for the extraction of these elements have been developed. In this work, a process based on the use of ultrasound for the extraction of REE from carbonatite (an igneous rock) is proposed to avoid the use of concentrated reagents, high temperature and excessive extraction time. In this pioneer work for REE extraction from carbonatite rocks in a preliminary investigation, ultrasonic baths, cup horn systems or ultrasound probes operating at different frequencies and power were evaluated. In addition, the power released to the extraction medium and the ultrasound amplitude were also investigated and the temperature and carbonatite mass/volume of extraction solution ratio were optimized to 70 °C and 20 mg/mL, respectively. Better extraction efficiencies (82%) were obtained employing an ultrasound probe operating at 20 kHz for 15 min, ultrasound amplitude of 40% (692 W dm⁻³) and using a diluted extraction solution (3% v/v HNO₃ + 2% v/v HCl). It is important to mention that high extraction efficiency was obtained even using a diluted acid mixture and relatively low temperature in comparison to conventional extraction methods for REE. A comparison of results with those obtained by mechanical stirring (500 rpm) using the same conditions (time, temperature and extraction solution) was carried out, showing that the use of ultrasound increased the extraction efficiency up to 35%. Therefore, the proposed ultrasound-assisted procedure can be considered as a suitable alternative for high efficiency extraction of REE from carbonatite rocks.     

Ultrasound-assisted cyanide extraction of gold from gold concentrate at low temperature

A sonochemical reactor was developed to study the ultrasound-assisted cyanide extraction of gold from gold ore at low temperature. The effects of ultrasound on gold leaching in low temperature and conventional conditions were investigated. At the low temperature of 10 °C, ultrasound-assisted extraction increased extraction rate of gold by 0.6%–0.8% and reduced the gold content of cyanide tailings to 0.28 g/t in the leaching of gold concentrate and cyanide tailings, respectively. At the conventional temperature of 25 °C, ultrasound-assisted extraction obtained a 0.1% higher extraction rate of gold compared with conventional extraction, with the unit consumption of NaCN reduction of 15%. The analysis of kinetic model also demonstrated that sonication indeed improved the reaction of gold leaching greatly. The mineralogy and morphology of ore were further analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and particle size analyzer to explore the strengthening mechanism of gold leaching. The results showed that the ore particles were smashed, the ore particle surface was peeled, the passive film was destroyed and the reaction resistance decreased under ultrasonic processing. Therefore, the extraction rate of gold was improved and the extraction time was shortened significantly in ultrasound-assisted cyanide extraction.     

响应面法优化超声提取熟地黄中5-羟甲基糠醛的工艺

采用响应面法优化了超声提取熟地黄中5-羟甲基糠醛的工艺.选取提取时间、溶剂浓度和温度3个因素为随机因子,在单因素的基础上进行3因素3水平Box-Behnken中心组合试验设计,以5-羟甲基糠醛得率为响应值进行响应面分析.优化后的超声提取熟地黄中5-羟甲基慷醛的条件为:在提取时间61.6min,溶剂体积分数90.5%,提...     

Ultrasound-assisted polysaccharide extraction from Cercis chinensis and properites,antioxidant activity of polysaccharide

The purpose of the study was to improve the extraction of polysaccharide from the leaves of Cercis chinensis Bunge using ultrasound, and compare the difference between boiling and ultrasound extraction in terms of polysaccharide content, monosaccharide compounds, and evaluate how the factors affected the bioactivity. The best conditions, according to the single factor experiments and the Box-Bohnken design (BBD), were an intensity of ultrasound of 180 W, duration of extraction of 40 min, proportion of water to material of 15:1 (g/g), and a higher polysaccharide yield of 20.02 ± 0.55 (mg/g) than in boiling extraction (16.09 ± 0.82 mg/g). The antioxidative experiment suggested the polysaccharide by ultrasound exhibited higher DPPH, hydroxyl radical scavenging capacities, and reducing power at 1.2–1.4 mg/mL, which was superior to the boiling polysaccharide. Further analysis showed that the ultrasonic purified polysaccharides like Gla, N-Glu, and GluA contained more total sugar and uronic acids than the boiling method did. This may indicate that the ultrasonic isolation of the polysaccharides increase the antioxidant activity of the polysaccharides.     

Ultrasound assisted extraction of pectin from waste Artocarpus heterophyllus fruit peel

Four factors three level face centered central composite response surface design was employed in this study to investigate and optimize the effect of process variables (liquid-solid (LS) ratio (10:1–20:1 ml/g), pH (1−2), sonication time (15–30 min) and extraction temperature (50–70 °C)) on the maximum extraction yield of pectin from waste Artocarpus heterophyllus (Jackfruit) peel by ultrasound assisted extraction method. Numerical optimization method was adapted in this study and the following optimal condition was obtained as follows: Liquid-solid ratio of 15:1 ml/g, pH of 1.6, sonication time of 24 min and temperature of 60 °C. The optimal condition was validated through experiments and the observed value was interrelated with predicted value.     

Ultrasonic extraction of steroidal alkaloids from potato peel waste

Potato processors produce large volumes of waste in the form of potato peel which is either discarded or sold at a low price. Potato peel waste is a potential source of steroidal alkaloids which are biologically active secondary metabolites which could serve as precursors to agents with apoptotic, chemopreventive and anti-inflammatory properties. The present study investigated the relative efficacy of ultrasound assisted extraction (UAE) and solid liquid extraction (SLE) both using methanol, to extract steroidal alkaloids from potato peel waste and identified optimal conditions for UAE of α-solanine, α-chaconine, solanidine and demissidine. Using response surface methodology optimal UAE conditions were identified as an amplitude of 61 μm and an extraction time of 17 min which resulted the recovery of 1102 μg steroidal alkaloids/g dried potato peel (DPP). In contrast, SLE yielded 710.51 glycoalkaloid μg/g DPP. Recoveries of individual glycoalkoids using UAE yielded 273, 542.7, 231 and 55.3 μg/g DPP for α-solanine, α-chaconine, solanidine and demissidine respectively. Whereas for SLE yields were 180.3, 337.6, 160.2 and 32.4 μg/g DPP for α-solanine, α-chaconine, solanidine and demissidine respectively. The predicted values from the developed second order quadratic polynomial equation were in close agreement with the experimental values with low average mean deviation (E < 5%) values. Predicted models were highly significant (p < 0.05) for all parameters studied. This study indicates that UAE has strong potential as an extraction method for steroidal alkaloids from potato peel waste.     

Influence of ultrasonic amplitude,temperature, time and solvent concentration on bioactive compounds extraction from propolis

An ultrasound assisted method was investigated to extract bioactive compounds from propolis. This method was based on a simple ultrasound treatment using ethanol as an extraction medium to facilitate the disruption of the propolis cells. Four different variables were chosen for determining the influence on the extraction efficiency: ultrasonic amplitude, ethanol concentration, temperature and time; the variables were selected by Box-Behnken design experiments. These parameters were optimised in order to obtain the highest yield, and the results exhibited the optimum conditions for achieving the goal as 100% amplitude of ultrasonic treatment, 70% solvent concentration, 58 °C and 30 min. The extraction yield under modified optimum extraction conditions was, as follows: 459.92 mg GAE/g of TPC, 220.62 mg QE/g of TFC and 1.95% of balsam content. The results showed that the ultrasound assisted extraction was suitable for bioactive compounds extraction from propolis. The most abundant phenolic compound was kaempferol (228.8 mg/g propolis) followed by myricetin (115.5 mg/g propolis), luteolin (27.2 mg/g propolis) and quercetin (25.2 mg/g propolis).     

Ultrasound-assisted extraction of phenolic compounds from Laurus nobilis L. and their antioxidant activity

Bay leaves (BL) (Laurus nobilis L., Family: Laureceae) are traditionally used to treat some symptoms of gastrointestinal problems, such as epigastric bloating, impaired digestion, eructing and flatulence. These biological properties are mainly attributed to its phenolic compounds. In this paper, ultrasound-assisted extraction of phenolic compounds from Laurus nobilis L. (Laureceae) was studied.Effects of several experimental factors, such as sonication time, solid/liquid ratio and concentration of solvent on extraction of phenolic compounds were evaluated through a randomized complete block design with factorial treatment arrangement (3³). The best extraction conditions were: 1 g plant sample with 12 mL of 35% ethanol, for 40 min, obtaining a yield of phenolic compounds of 17.32 ± 1.52 mg g^?1 of plant. In addition, free radical-scavenging potential of DPPH and lipid oxidation inhibition, by linoleic acid peroxidation of the selected extract was measured in order to evidence their antioxidant properties. Results indicated that high amounts of phenolic compounds can be extracted from L. nobilis by ultrasound-assisted extraction technology.     

Ultrasound-assisted rapid extraction and kinetic modelling of influential factors: Extraction of camptothecin from Nothapodytes nimmoniana plant

Ultrasound-assisted extraction (UAE) of commercially important natural product camptothecin (CPT) from Nothapodytes nimmoniana plant has been investigated. The influences of process factors such as electric acoustic intensity, solid to liquid ratio, duty cycle, temperature and particle size on the maximum extraction yield and kinetic mechanisms of the entire extraction process have been investigated. The kinetics results showed that increasing the intensity, duty cycle, solid to liquid ratio and decreasing the particle size lead to substantial increase in extraction yields compared to classical stirring extraction. Different kinetic models were applied to fit the experimental data. The second order rate model appears to be the best. The extraction rate constant, initial extraction rate and the equilibrium concentration for all experimental conditions have been calculated. SEM analysis of spent plant material clearly showed hollow openings on cell structure, which could be directly correlated to explosive disruption by the action of ultrasound waves. Overall 1.7-fold increase in extraction yields of CPT (0.32% w/w) and decrease in time from 6 h to 18 min was observed over the stirring method.     

响应曲面法提取水松总黄酮的工艺研究

采用响应曲面法,优化了提取水松总黄酮的提取工艺条件为:微波时间3.8min,乙醇浓度69%,固液比1∶31,在此条件下,水松总黄酮的产率为1.88%。     

Green ultrasound-assisted extraction of chlorogenic acids from sweet potato peels and sonochemical hydrolysis of caffeoylquinic acids derivatives

Sweet potato peels are rich in chlorogenic acids. In this work, we applied ultrasound technology to extract the main compounds from sweet potato peel and used multivariate analysis and principal component analysis (PCA) to evaluate the effects of different extraction conditions on the extraction of chlorogenic acids. The extraction was studied varying ultrasonic power density (20, 35 and 50 W/L) and processing time (5, 10, 20 and 40 min) using an ultrasonic bath operating at 25 kHz. The chemical analysis was carried out by UPLC-qTOF-MS, and the results were evaluated by PCA and PLS-DA chemometric analysis. Results show that both ultrasonic power density and processing time influences in the extraction of different chlorogenic acid, and that different extraction conditions can be used to selectively extract specific caffeoylquinic acids and feruloylquinic acids in higher amounts. Ultrasound promoted the hydrolysis of tricaffeoylquinic acid when subjected to ultrasonic waves (20–50 W/L), and of 3,4-caffeyolquinic acid at high ultrasonic power density (50 W/L).     

Ultrasound induced green solvent extraction of oil from oleaginous seeds

Ultrasound-assisted extraction of rapeseed oil was investigated and compared with conventional extraction for energy efficiency, throughput time, extraction yield, cleanness, processing cost and product quality. A multivariate study enabled us to define optimal parameters (7.7 W/cm² for ultrasonic power intensity, 40 °C for processing temperature, and a solid/liquid ratio of 1/15) for ultrasound-assisted extraction of oil from oilseeds to maximize lipid yield while reducing solvent consumption and extraction time using response surface methodology (RSM) with a three-variable central composite design (CCD). A significant difference in oil quality was noted under the conditions of the initial ultrasound extraction, which was later avoided using ultrasound in the absence of oxygen. Three concepts of multistage cross-current extraction were investigated and compared: conventional multistage maceration, ultrasound-assisted maceration and a combination, to assess the positive impact of using ultrasound on the seed oil extraction process. The study concludes that ultrasound-assisted extraction of oil is likely to reduce both economic and ecological impacts of the process in the fat and oil industry.