Optimization of ultrasound-assisted extraction of camptothecin from Camptotheca acuminata seeds

Naturally occurring camptothecin（CPT） is an important source of chemotherapeutic agents.The extraction from Camptotheca acuminata is still the main approach to obtain CPT compared with total synthesis.In the present study,ultrasound-assisted extractions（UAE） of CPT from C.acuminata seeds with alkaline solutions were investigated and CPT yield were determined by High Performance Liquid Chromatography.The conditions of alkaline species and concentrations,extraction time,extraction temperature and ultrasonic power were optimized.Results show that both Na3PO4 and Na2CO3 solutions gain good extraction yields,whereas Na3PO4 solution has stronger basicity and need higher concentration than Na2CO3 solution does,thus aqueous Na2CO3 is more beneficial for the extraction.The optimal condition was ultrasonically extracted with 0.5% aqueous Na2CO3 at 50°C and ultrasonic power of 400 W for 60 min.Comparing with UAE with ethanol,the extraction with 0.5% Na2CO3 solution achieves higher yield.Moreover,aqueous Na2CO3 as a solvent has various advantages including non-toxicity,inflammable,non-corrosive and low cost,which ensure this UAE method is a superior method with high utilizing prospect.

Determination of Five (5) Possible Contaminants in Recycled Cardboard Packages and Food Simulants Using Ultrasound Assisted Extraction Coupled to GC-MS

A modified analytical procedure has been developed to test for 5 organic pollutants [benzophenone, 2 diisopropylnaphthalenes (DIPNs) {2,6- and 2,7-diisopropylnapthalene} and 2 hydrogenated terphenyls (HTPs) {m-terphenyl and o-terphenyl}] that can be found as residues in recycled cardboards intended for use as food packaging materials and to test for migration levels of these compounds in a food simulant (Tenax). A main objective was to develop a modified rapid and reliable method for the identification and quantification of these compounds at low concentrations. The method was based on ultrasound-assisted solvent extraction (UAE) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The developed method was applied to analyze 3 commercially available recycled carton board food-packaging materials and also to study the potential migration of the 5 organic pollutants from these materials into Tenax to check if these recycled cardboards can be considered as suitable for use in direct contact with foodstuffs. The limits of detection (LODs) of standard solutions of the 5 compounds were determined at a signal-to-noise ratio of 3. The LODs and the limits of quantification (LOQs) of examined pollutants ranged between 0.005 to 0.5 mg/kg, and 0.1 to 1 mg/kg, respectively. The extremely low amounts of most contaminants that migrate from packaging materials to Tenax indicate that the recycled cardboards tested can be safely used for direct food contact applications.

Pectinmethylesterase extraction from orange solid wastes: Optimization and comparison between conventional and ultrasound-assisted treatments

During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is their treatment by addition of lime and a latter pressing, obtaining a press cake and a press liquor rich in sugars (10°Brix) and citric acid, protein, pectin and ethanol. For non-thermal concentration of press liquor to obtain citruss molasses (65°-70°Brix), the removal of pectin is necessary. Traditionally, depectinization of juices has been done by using pectinmethylesterase (PME) enzymes from external sources. In this work it performed the extraction of PME enzymes from orange peels to obtain the optimum extraction conditions. Two different methods of solventextraction were compared (conventional andultrasound-assisted methods). For the conventional extraction experiments, a central composite design with three variables ([NaCl], pH and time) and five replicates of the center point was used. For ultrasound-assisted extraction, experiments were done at pH = 5.5 and [NaCl] = 1.25M), varying extraction time (1-30 min). Response variables were PME activity, protein content and a ratio between them, named PME effectiveness (ηPME). At the same experimental conditions (pH =5.5, [NaCl] = 1.25 M, t = 15 min) it was found that conventional extractions led to slightly better results in terms of ηPME than ultrasound-assisted extraction method.

Effect of Ultrasound-Assisted Extraction of Phenolic Compounds on the Characteristics of Walnut Shells

Walnuts are one of nature’s more waste-heavy products. 67% of the nut is shell and husk, low value by-products that are rich in phenolic compounds. The phenolic compounds extracted from walnut shells are potentially good natural sources of antioxidants for the food and pharmaceutical industries. In this study, phenolic compounds were extracted using an ultrasonic bath, an ultrasonic probe and a standard shaking method. The extraction yield achieved with an ultrasonic probe was 51.2 mg GAE/g DW, two times higher than both the shaking method and the ultrasonic bath method which were 20.6 mg GAE/g DW and 25.8 mg GAE/g DW, respectively. Phenolic extraction was further improved by a size reduction of the walnut shells. The best extraction yield of 52.8 mg GAE/g DW was attained when the particle size was between 45 - 100 mesh. The ultrasonic probe treatment is the best method for extraction of phenolic compounds from walnut shells. Scanning electron microscopy (SEM) imaging indicated that the ultrasonic probe treatment could better rupture the hard structure of the cells, increasing the penetration of solvents and thus the extraction yield.

Optimization of Ultrasonic-assisted Extraction of Polysaccharide from Hibiscus syriacus L.

The ultrasonic-assisted extraction of polysaccharides from Hibiscus syriacus L. at 180 W low power was optimized by the single factor tests and orthogonal test. Extraction temperature,ultrasonic treatment time,extraction times,and material-to-liquid ratio were considered as independent variables. The results suggested that the best extraction condition were determined as the extraction temperature at 80 ℃,the ultrasonic treatment time of 40 min,the material-to-liquid ratio at1∶ 20（ g/ml）,and the extraction times of 3. Under the optimal conditions,the extraction rate of polysaccharides from Hibiscus syriacus was 3. 114%.

酸化甘油-超声辅助提取杨梅花青素工艺优化及其抗氧化活性研究

目的 通过响应面实验确定酸化甘油-超声辅助提取杨梅花青素最佳提取参数,并探究其体外抗氧化活性。方法 研究了酸化甘油浓度、提取时间、超声功率和提取温度4个单因素对杨梅花青素得率的影响,并优化花青素提取工艺参数。此外,考察了最佳提取工艺下杨梅花青素对3种氧化自由基的清除率和还原力等指标,评估了其抗氧化活性。结果 优化后的酸化甘油-超声辅助提取杨梅花青素的工艺条件为:酸化甘油浓度16%、提取时间42 min、超声功率204 W、提取温度46℃,此条件下杨梅花青素的得率为(6.915±0.027) mg CGE/g DW,接近预测值(6.961 mg CGE/g DW)。提取的杨梅花青素质量浓度为100μg/mL时,对超氧阴离子自由基、羟基自由基、1,1-二苯基-2-三硝基苯肼自由基清除率分别为59.35%、46.77%和61.65%。该浓度下,杨梅花青素的还原力为维生素C的39.84%。结论 本研究成功地应用响应面法优化了酸化甘油-超声辅助提取杨梅花青素的提取参数,并且提取物展现出良好的抗氧化活性。

基于遗传算法-反向传播神经网络优化高压-超声-酶解法提取羊皮胶原蛋白工艺

采用高压-超声-酶解法提取羊皮胶原蛋白,对比遗传算法-反向传播(genetic algorithm-back propagation,GA-BP)神经网络模型和响应面模型的优化效果,确定最佳工艺参数。结果表明:GA-BP神经网络在模型拟合和预测方面表现优于响应面模型;最佳提取参数为高压时间23 min、超声时间22 min、酶添加量3.2%、酶解时间222 min,羊皮胶原蛋白提取率达到(80.5±1.6)%,较传统的木瓜蛋白酶法提高40%;紫外-可见吸收光谱和傅里叶变换红外光谱结果显示,此条件下提取的羊皮胶原蛋白结构完整,高压-超声-酶解法对胶原蛋白的破坏较小。

蛹虫草β-葡聚糖提取工艺优化及抗氧化活性

以β-葡聚糖得率得率为主要评价指标,通过单因素和响应面试验优化蛹虫草β-葡聚糖超声辅助水提工艺,采用红外扫描分析提取物的化学键及官能团信息,测定其中各组分含量及其体外抗氧化活性。结果表明,蛹虫草β-葡聚糖最优提取工艺为超声时间1 h、料液比1∶31(g/mL)、水浴温度90℃。最优条件下提取得率为(1.94±0.28)%,与预测值1.95%一致。经过纯化试验得出α-葡聚糖去除最优条件为α-淀粉酶添加量2%、孵育时间60 min、温度50℃,经过纯化处理后β-葡聚糖纯度由19.82%提高至33.93%;红外扫描结果表明,蛹虫草β-葡聚糖具有典型的多糖结构,并含有硫酸根基团。蛹虫草β-葡聚糖对DPPH自由基、ABTS+自由基和羟基自由基的清除能力与浓度呈正相关(2.00~10.00 mg/mL),IC_(50)值分别为1.17、2.17、4.35 mg/mL,清除率在浓度为8.34、9.88、9.97 mg/mL时,可达100%。综上,优化后的蛹虫草β-葡聚糖超声辅助水提工艺稳定可行,提取获得的β-葡聚糖具有较好的抗氧化活性。

基于超声辅助液相萃取-电感耦合等离子体质谱法测定海水中痕量镉

该文建立基于超声辅助液相萃取(ultrasound-assisted liquid phase extraction,UALPE)电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP MS)的海水样品中镉分析新方法。镉与螯合剂吡咯烷二硫代氨基甲酸铵(ammonium pyrrolidine dithiocarbamate,APDC)反应,在超声辅助下利用四氯化碳萃取生成的螯合物。萃取相经加热烘干后用加入20%HNO3(v/v)和60%H2O2(v/v)反应5 min后,去离子水定容后上机测定。本文考察了影响液相萃取的影响因素和共存离子的干扰情况。在选择的实验条件下,方法的检出限为6.4 ng·L^(-1)。该方法应用于海水样品中痕量Cd的测定,回收率大于90%。与传统的分析方法相比,该方法具有操作简单和成本低廉等优点,并有效消除了传统液液萃取中有机质对分析结果的影响,解决了传统液液萃取和ICP MS兼容性问题。该方法还可拓展至其他重金属元素的痕量分析。

基于超声辅助-液相色谱法的大米中氟环唑残留检测

通过超声辅助-液相色谱法快速检测大米中的氟环唑残留。试验首先对样品前处理条件进行优化,然后对方法重复性和加标回收率进行测试。试验结果表明,提取剂为丙酮,固液比(样品与丙酮比例)为1∶9,氯化钠用量为3 g,超声提取时间为8 min的条件下,对大米样品中的氟环唑提取效果最好。在0.01~1.2μg/mL的浓度范围内,氟环唑的质量浓度与色谱峰面积线性相关系数R 2=0.99,最低检测限为0.01 mg/mL,重复性实验的相对标准偏差RSD为1.77%,加标回收率范围为89.0%~90.1%。超声辅助-液相色谱法可以快速萃取大米样品中的氟环唑,提高萃取效果,节约实验时间,对大米中的氟环唑进行有效测定。

超声波-水浴提取-电感耦合等离子体质谱法测定土壤中有效硼

本文建立了一种超声波-水浴提取-电感耦合等离子体质谱法测定土壤中有效硼的方法。以超声波辅助沸水浴提取土壤中的有效硼,在6 min后达到提取平衡;采用聚四氟乙烯螺纹管代替玻璃烧杯可有效降低空白测试值,空白测试均值为0.003 4 mg/kg;在提取液中滴加适量硝酸可大幅度提高测试液的稳定性,在常温放置50 h其测试结果仅下降约3%;实际样品测试结果显示,本文方法具有更低检出限和更好的精密度,RSD仅为0.9%。

超声-微波协同提取富硒米糠蛋白的工艺优化及其抗氧化活性评价

为解决富硒米糠蛋白提取率低、提取时间长及提取后功能特性下降等问题,以脱脂富硒米糠粉为原料,通过单因素试验和正交试验对超声-微波协同提取富硒米糠蛋白的工艺进行优化,通过与超声辅助法、微波辅助法和碱提法比较,探究该提取方法对富硒米糠蛋白的提取效果、抗氧化活性以及提取后米糠颗粒表面形貌变化的影响。结果表明,超声-微波协同提取富硒米糠蛋白的最佳工艺条件为超声功率600 W、微波功率500 W、提取时间20 min、料液比1∶40,在此条件下富硒米糠蛋白的提取率为86.94%,与超声辅助法、微波辅助法、碱提法相比富硒米糠蛋白提取率分别提高了40.96%、48.00%、53.50%,并且提取的富硒米糠蛋白抗氧化能力和硒含量更高。扫描电镜结果显示,超声-微波协同提取后米糠颗粒表面疏松卷曲,完整皮层结构消失,说明超声-微波协同能通过强烈破坏米糠颗粒结构增加富硒米糠蛋白的提取率,并提高其抗氧化活性。综上,超声-微波协同提取技术能够促进富硒米糠蛋白的提取并提高其抗氧化活性。

H_(2)O_(2)协同超声辅助提取绿豆可溶性膳食纤维及其体外α-葡萄糖苷酶抑制活性研究

以绿豆为原料,采用H_(2)O_(2)协同超声辅助提取绿豆可溶性膳食纤维(SDF)。以SDF得率为指标,在单因素试验的基础上通过响应面试验优化绿豆SDF的提取条件,并研究绿豆SDF对α-葡萄糖苷酶活性的抑制作用。结果表明:最佳提取条件为超声功率200 W、超声时间40 min、H_(2)O_(2)体积分数2%、pH 11,在此条件下绿豆SDF得率为38.2%±0.1%,绿豆SDF对α-葡萄糖苷酶具有较强的抑制作用,IC_(50)为4.653 mg/mL。

Ultrasound-assisted Low Density Solvent Based Dispersive Liquid-liquid Microextraction for Determination of Phthalate Esters in Bottled Water Samples

A technique of ultrasound-assisted low density solvent based dispersive liquid-liquid microextraction was developed for the determination of four phthalate esters, including dimethyl phthalate（DMP）, diethyl phthalate（DEP）, di-n-butyl phthalate（DnBP） and di（2-ethylhexyl） phthalate（DEHP） in bottled water samples. A low density solvent, toluene, was selected as extraction solvent. In the extraction process, a mixture of 15 μL of toluene（extraction solvent） and 100 μL of methanol（disperser solvent） was rapidly injected into 1.0 mL of water samples. A cloudy solution was formed after ultrasounded for 5 min, and then centrifuged at 5000 r/min for 5 min. The enriched analytes in the floa- ting phase were determined by means of gas chromatograph. Under the optimum conditions, the enrichment factors were found to be in a range of 29--67, and the recoveries were ranged from 81.2% to 103.9%. The limits of the detection were in a range of 3.8--5.6 μg/L. The proposed method was applied to the extraction and determination of phthalate esters in bottled water samples, and the concentrations of phthalate esters found in the water samples were below the allowable levels.

油茶籽饼中茶皂苷的超声-微波辅助法提取工艺优化

为提高茶皂苷的提取率,扩大茶皂苷的应用范围,以脱脂油茶籽饼为原料,采用超声-微波辅助法提取茶皂苷。以油茶皂苷提取率为考察指标,在单因素试验的基础上,采用Plackett-Burman试验设计筛选出具有显著影响的试验因素,再通过响应面法对茶皂苷提取工艺进行优化。另外,将超声-微波辅助法提取茶皂苷的工艺与超声辅助法和微波辅助法提取工艺进行了对比。结果表明:超声-微波辅助法提取茶皂苷的最佳工艺条件为乙醇体积分数59%、料液比1∶12、提取液pH 7、超声功率475 W、超声时间4 min、超声工作2 s间隔2 s、微波功率480 W、提取温度59℃、微波提取时间8 min,在此条件下茶皂苷提取率为98.40%,产品纯度为64.7%;超声辅助法和微波辅助法茶皂苷的提取率分别为69.06%和71.40%。与超声辅助法和微波辅助法相比,超声-微波辅助法能够显著提高茶皂苷提取率。

超声-微波协同辅助优化酸枣果肉多糖提取工艺及抗氧化活性研究

目的:采用超声-微波协同提取的方法对酸枣果肉中多糖的提取工艺进行优化,并对所提酸枣果肉多糖进行抗氧化作用研究。方法:以单因素试验为基础,选取超声温度、料液比、微波-超声联用超声时间进行响应面分析,优化的酸枣果肉提取工艺的最佳条件为超声提取温度60℃、液料比1∶40(g/mL)、协同处理方式为微波2 min、超声16 min。结果:在此工艺条件下,酸枣果肉的总多糖最优得率为(42.61±0.78)%,对不同提取溶剂而言,pH=7的柠檬酸-柠檬酸钠缓冲溶液较去离子水有较好的多糖提取率。结论:酸枣多糖具有较强的1,1-二苯基-2-苦基肼自由基(DPPH·)清除能力和羟自由基(·OH)清除能力,且具有剂量依赖性,为酸枣保健食品的开发提供科学依据。

Evaluation of Oil Yield of Oil Shale by Infrared Spectrometry Coupled with Ultrasound-assisted Extraction

The oil yield of oil shale was evaluated by Fourier transform infrared（FTIR） spectrometry coupled with ultrasound-assisted extraction. The extraction conditions, including the amount of sample, extraction time and extrac- tion temperature, were examined and optimized. Twenty-four oil shale samples were collected and divided into calibration set and prediction set randomly with a ratio of 2：1. The oil yields of all the samples were determined by the routine method（low-temperature retorting） for reference. The linear regression（LR） equations of oil yield vs. the total area of the spectrum peaks in a wavenumber range of 3100--2800 cm-1 as well as the sum of absorbance of three absorption peaks（2855, 2927 and 2955 cm-l）, and the multiple linear regression（MLR） model of oil yield vs. the absorbances of the three absorption peaks were constructed with the samples in calibration set and applied to the evaluation of the oil yields of the samples in prediction set, respectively. The results show that the MLR model provides more accurate predictions than the other LR two equations. The determination coefficient（P2p ）, the root- mean-square error of prediction（RMSEP） and the residual prediction deviation（RPD） of the MLR model are 0.9616, 0.6458 and 3.6, respectively. The present method is a rapid and effective alternative to the routine low-temperature retorting method.

Optimization of ultrasound assisted extraction of six major compounds from Cimicifugae Rhizome

Cimicifugae Rhizome （RC） is one of many commonly used traditional Chinese medicines. This study used Box-Behnken Design （BBD）, a widely used form of response surface methodology （RSM）, to optimize the conditions of the ultrasound-assisted extraction （UAE） for the extraction of phenolic compounds from CimicifugaeRhizome. The influence of three independent variables, including ethanol concentration （%）, extraction time （min） and solvent-to-material ratio （mL/g）, on the extraction yields of phenolic compounds were examined. The results demonstrated that the optimal ultrasound-assisted extraction （UAE） conditions were as follows： ethanol concentration of 68%, an extraction time of 19 min, and solvent-to-material ratio of 30 mL/g for the extraction of caffeic acid, cimicifugoside, ferulic acid, isoferulicacid, cimifugin, 4′-O-β-glucopyranosyl-5-O-methylvisamminol. These results demonstrated the suitability of UAE for the extraction of phenolic compounds from CimicifugaeRhizome.

Extraction of Carotenoids and Fatty Acids from Microalgae Using Supercritical Technology

The work described here is based on a comparative study of carotenoids and fatty acids extracted from Synechococcus sp. with (1) pure supercritical CO2, (2) CO2 with 5% (v/v) ethanol as cosolvent and (3) ultrasound-assisted extraction using N, N-dimethylformamide (DMF). The effects of extraction conditions on supercritical CO2 extraction with and within cosolvent were analyzed at different temperatures (40℃, 50℃ and 60℃) and pressures (200, 300 and 400 bars). SFE with CO2 proved to be the most selective method for the extraction of β-carotene, but under these conditions the contents of zeaxanthin and fatty acids were only comparable to or lower than those obtained with techniques that use SFE cosolvent. The SFE technique with CO2 and ethanol simultaneously extracted β-carotene and zeaxanthin and not only increased the concentrations of fatty acids obtained, but also helped to remove fatty acids (palmitoleic and linolenic acid) that were not obtained with pure CO2. Comparison of the supercritical technology with the ultrasound-assisted extraction (UAE) shows that the former technique is the most appropriate due to the fact that ethanol is generally regarded as a safe solvent in comparison to DMF.

超声波辅助碱提类PSE鸡肉分离蛋白-EGCG复合体系的理化特性

为了提高类PSE(Pale, Soft and Exudative)鸡肉分离蛋白的加工利用,防止表没食子儿茶素没食子酸酯(EGCG)的氧化降解,分析了碱溶酸沉法和超声波(20 kHz, 450 W,10 min)辅助碱提法(UAE)对类PSE鸡肉分离蛋白结构的影响及其对EGCG的保护作用。结果表明:与碱溶酸沉处理相比,经UAE提取的类PSE鸡肉分离蛋白的平均粒径和浊度减小、Zeta电位绝对值增加,添加EGCG后,复合体系的平均粒径明显减小(P<0.05);经UAE提取的类PSE鸡肉分离蛋白的α-螺旋与β-折叠相对含量分别下降至12.84%和11.96%,β-转角相对含量上升至63.17%(P<0.05),添加EGCG后α-螺旋相对含量下降至9.07%,β-折叠相对含量上升至19.08%(P<0.05);经UAE提取的类PSE鸡肉分离蛋白与EGCG之间具有更强的结合能力,结合位点较大(1.265),对EGCG的保护效果更好。UAE改变了类PSE鸡肉分离蛋白的结构,增强了类PSE鸡肉分离蛋白与EGCG的相互作用,减缓了EGCG被氧化降解。