A COMPARISON OF DIFFERENT TECHNIQUES FOR WATER-BASED EXTRACTION OF PECTIN FROM ORANGE PEELS

The extraction of pectin from orange peels has been studied using microwave and conventional extraction, with operating conditions including different extraction periods, different solvent pHs, and different types of solvent systems. The extracted pectin from orange peels was initially precipitated with concentrated ethanol and was quantified by the carbazole assay. For microwave extraction, the greatest total amount of pectin yield was found to be 5.27% on a dry basis for 15 minutes of extraction, although the greatest amount of material per unit time (%/min) was obtained after 5 minutes. This amount was the same as that extracted using Soxhlet extraction for three hours. The 15-minute microwave extraction period was further investigated at pH values of 1.5, 2.0, 5.5, and 10.0. The greatest amount of pectin was extracted from orange peels at the most strongly acidic condition of pH 1.5. The effect of a solvent system containing ethanol and EDTA (ethylenediamine tetraacetic acid) with a 15-minute extraction period and a pH of 1.5 was studied, giving approximately double the amount of pectin extracted using distilled water.     

A COMPARISON OF DIFFERENT TECHNIQUES FOR WATER-BASED EXTRACTION OF PECTIN FROM ORANGE PEELS

The extraction of pectin from orange peels has been studied using microwave and conventional extraction, with operating conditions including different extraction periods, different solvent pHs, and different types of solvent systems. The extracted pectin from orange peels was initially precipitated with concentrated ethanol and was quantified by the carbazole assay. For microwave extraction, the greatest total amount of pectin yield was found to be 5.27% on a dry basis for 15 minutes of extraction, although the greatest amount of material per unit time (%/min) was obtained after 5 minutes. This amount was the same as that extracted using Soxhlet extraction for three hours. The 15-minute microwave extraction period was further investigated at pH values of 1.5, 2.0, 5.5, and 10.0. The greatest amount of pectin was extracted from orange peels at the most strongly acidic condition of pH 1.5. The effect of a solvent system containing ethanol and EDTA (ethylenediamine tetraacetic acid) with a 15-minute extraction period and a pH of 1.5 was studied, giving approximately double the amount of pectin extracted using distilled water.     

微波协同提取柚子皮中果胶的工艺研究

以柚子皮为原料,微波协同提取柚皮中果胶。采用单因素试验和正交试验,对微波协同提取柚皮中果胶的提取工艺进行优化研究。探讨了液料比、pH值、辐射时间、微波强度等因素对柚皮中果胶提取率的影响。试验结果表明,微波协同提取lOg粒径为0．25mm的柚皮粉末中果胶的最佳工艺条件为：总液料质量比30：1,提取液pH2．0,微波功率450W,提取时间60s。提取液经硫酸铝盐析,析出沉淀用酸化醇处理脱盐,过滤,滤渣用乙醇反复洗涤干燥即得果胶,产率14．7％。与加热提取法比较,微波协同提取能大大缩短提取时间,并提高了果胶的产率。     

加勒比松树皮中原花青素的提取工艺研究

系统研究了以加勒比松树皮为原料提取原花青素的方法及工艺条件。研究对比了常规溶剂浸提、超声波提取及微波辅助提取等方法对原花青素提取得率的影响。实验结果表明,溶剂浸提采用 70% 乙醇溶液时原花青素的得率最高。在3种提取方法中,超声波提取法和微波辅助提取法提取效果较优。前者能在短时间内取得较高的提取得率,而后者需进一步延长微波辅助作用后溶剂浸提的时间才能达到较好的提取效果。超声波提取法的适宜提取条件为: 提取温度 50℃,功率 100 W,料液比1:11,提取时间 1.5 h;微波辅助提取法的适宜提取条件为: 功率 200 W,微波处理时间 30 s,料液比1:11,提取温度 50℃,提取时间 6 h。在上述条件下原花青素得率分别为 7.47% 和 7.69%。     

黑木耳多糖的微波法提取工艺研究

以黑木耳为原料研究了水浴提取法、回流提取法、微波辅助提取法、超声波提取法等提取效果,结果表明微波提取法效果较好。采用单因素和正交试验,探讨微波辅助法提取黑木耳多糖的最佳工艺条件。实验结果:微波处理前水浴浸泡时间30 min、提取溶剂为70%乙醇溶液、NaOH加入量1.0 g、提取时间2 min,微波提取功率为60 W。     

Optimization of microwave-assisted extraction of bioactive compounds from pistachio (Pistacia vera L.) hull

ABSTRACT

Phenolic compounds were extracted from pistachio hull using microwave-assisted solvent extraction (MASE). The effects of four parameters, microwave power, extraction time, solvent to sample ratio, and ethanol concentration were evaluated. The extraction conditions were optimized by response surface methodology to enhance the total phenolic content (TPC). Optimal conditions were found as 140 W microwave power, 4.5 min extraction time, 19:1 (v/w) solvent to sample ratio, and 56% ethanol concentration to get maximum TPC (62.24 mg GAE/g dry hull). Also, MASE was compared with conventional solvent extraction (CSE) and MASE gave higher TPC, yield, and antioxidant activity.     

荔枝核黄酮类化合物的提取工艺研究

采用回流、热浸提、微波提取等工艺提取荔枝核黄酮类化合物,采用正交实验考察了提取溶剂浓度、提取时间、微波功率、提取温度、料液比等因素对提取率的影响,优选出不同工艺的提取条件。回流提取工艺的优化条件是:50%乙醇溶液,提取温度80℃,提取时间1h,料液比1∶10,提取3次,总黄酮得率为6.76%。热浸提工艺的优化条件是:50%乙醇溶液,提取温度70℃,提取时间1.5h,料液比1∶12,提取2次,总黄酮得率达到6.37%。微波提取工艺的优化条件是:60%乙醇溶液,微波功率700W,提取时间2.5h,料液比1∶25,总黄酮得率达到6.86%。     

超声-微波交替法提取落叶松二氢槲皮素

以二氢槲皮素的得率为指标,采用超声-微波交替法从落叶松中提取二氢槲皮素。以体积分数60%乙醇作为提取溶剂,料液比1∶12,浸润3h,强档功率提取1次,微波提取10min,超声提取40min,超声-微波交替提取的条件为超声提取40min后再微波提取10min。二氢槲皮素单独超声和微波提取时得率分别为0.034%和0.074%,超声-微波交替提取时得率可达0.12%,明显优于单独超声或微波提取。通过扫描电子显微镜观察超声提取、微波提取和超声-微波交替提取所得的物料,超声-微波交替提取的抽提效果最为明显。     

Preparation and functional properties of soy hull pectin

Soy hulls (400 g), a co-product of the soybean processing industry, were used as a source of pectin which was extracted by0.05 N hydrochloric acid and precipitated with alcohol. The effect of various ratios of hull to extraction solvent (1∶10, 1∶15, 1∶20, and 1∶25) on the yield and purity of soy hull pectin was measured. The soy hull pectin extracts contained 63.07 to 68.72% galacturonic acid at various hull/solvent ratios. The pectin yield increased from 7.68 to 13.73% as the hull/solvent ratio increased from 1∶10 to 1∶15. Changes in pectin yield for higher hull/solvent ratio were insignificant (16.31–13.28% for 1∶20–1∶25 ratio, respectively). The hull/extraction solvent ratio did not significantly affect the pectin content and degree of esterification. Diffuse reflectance Fourier transform infrared spectroscopy of soy hull pectin revealed a similar surface structure to commercial-and analytical-grade pectins. The solubility of soy hull pectins was independent of solvent extraction ratios and pH. Rheology studies showed that pectin solution viscosity increased as the ratio of extraction solvent to hull decreased.     

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。     

微波辅助提取南瓜皮中果胶的研究

讨论了利用微波辐射萃取法从南瓜皮中提取果胶的不同因素的影响,通过实验确立了微波条件下提取果胶的最佳工艺条件为:用盐酸调pH值为1.8,用水作为溶剂,料液比为1∶20,微波辐射功率为600W,辐射时间为4min,乙醇(体积分数)为60%,提取率可达到16.9%。     

微波协同萃取射干异黄酮的研究

Microwave-assisted extraction （MAE） of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8：1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction （DHE）, MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.     

八角茴香中莽草酸提取工艺及抗氧化性研究

通过回流提取法、超声提取法、微波提取法对八角茴香中莽草酸的提取工艺进行优化。经过单因素与正交试验获得最佳提取工艺为微波提取方法下提取时间4 min、微波功率400 W、料液比1：20（g/mL）,莽草酸得率4.92％。用DPPH自由基捕获分光光度法对提取液莽草酸进行了研究,发现其对自由基清除率可达到12.71％,具有一定的抗氧化性。     

微波法提取毛泡桐花总黄酮的工艺研究

通过单因素实验和正交实验,研究乙醇浓度、料液比、微波作用时间、微波功率对毛泡桐花总黄酮提取得率的影响。单因素实验结果表明:微波提取毛泡桐花总黄酮的最佳工艺条件为,料液比1∶15,微波功率500 W,微波作用时间150 s,乙醇浓度70%,此条件下总黄酮得率为7.71%。正交实验结果表明:影响因素的显著性顺序为乙醇浓度>微波功率>料液比>微波作用时间。最佳工艺条件为A2B3C2D3,即料液比1∶20,微波功率500 W,微波作用时间150 s,乙醇浓度70%。     

微波萃取鸢尾香根的研究

本研究使用经改造的家用微波炉作为主要设备 ,对微波萃取鸢尾香根做了L9( 34 )正交实验。考察了四个因素 :微波辐射时间、微波功率、溶剂用量、洗涤干燥剂的溶剂量对三个指标 :提取率、溶剂回收率、鸢尾酮总含量的影响。实验结果表明 :综合考虑提取率、溶剂回收率和鸢尾酮总含量 ,最佳组合为辐射时间 12 0s、微波功率 850w、溶剂用量 160ml、洗涤干燥剂的溶剂量 2 0ml。本方法与索氏提取鸢尾、超临界二氧化碳萃取鸢尾相比 ,具有萃取时间短 (大约 12 0s) ,提取率高 (大约 10 % ) ,溶剂用量少 (大约 160ml/ 4 0 g原料 ) ,产品香气纯正等优点     

微波辅助提取枸杞中的总黄酮工艺研究

目的:探寻枸杞中总黄酮提取的最佳工艺。方法:设计正交试验,采用微波辅助有机溶剂法对枸杞中总黄酮提取方法进行了研究。结果:微波辅助提取枸杞中总黄酮的最佳工艺条件为:96%工业乙醇,固液比1:12,微波功率400W,微波辅助回流40min。实现枸杞黄酮浸膏得率62.72%,浸膏中总黄酮含量达2.69%的优化提取工艺。结论:以该工艺提取枸杞中总黄酮,保证了较高的黄酮含量,优化了枸杞中总黄酮的提取工艺。     

微波辅助提取麦冬多糖工艺研究

应用微波辅助技术提取麦冬多糖,考察了微波功率、辐射时间、溶剂用量等因素对提取率的影响。以微波辅助提取麦冬多糖的提取率为指标,筛选了工艺条件。由正交实验结果表明：最佳的工艺条件为提取时间20min,微波功率800W,水与麦冬液固比为50：1,提取率为14．002％。优化后的微波辅助提取工艺与传统提取方法相比,提取时间短,提取率高。     

Extraction of jojoba oil by pressing and leaching

Jojoba oil extraction by pressing alone, pressing followed by leaching, and leaching alone were investigated. The extraction process by first and second pressing followed by leaching gave about 50% by weight oil with reference to total seed, which is in agreement with what has been reported previously. The extraction by leaching process was carried out using different solvents. These solvents were; hexane, benzene, toluene, petroleum ether, chloroform, and isopropanol. Hexane, benzene, and petroleum ether gave the highest yield (all about 50% by weight oil with reference to total seed), but when cost is considered, petroleum ether is recommended as the best solvent to leach jojoba oil. The yield obtained in this work for leaching by hexane and benzene are 3–5% and about 10% for isopropanol more than those reported in the literature. Traces of solvent remained with the extracted oil after simple distillation followed by a second stage distillation via a Rotavapour apparatus. These traces slightly affected some of the oil properties such as pour point and flash point.     

从西瓜皮中提取果胶的工艺研究

果胶以其良好的稳定、增稠、乳化和胶凝效用,在食品、冶金、纺织、医药等领域有着广泛的应用。近年来一些关于瓜果皮类中果胶提取的研究较多,主要以橘类果皮为主。利用西瓜皮提取果胶,将果皮中含有的有益物质,进行收集再利用,将带来巨大的经济效益。以新鲜西瓜皮为原料,利用无机酸与有机酸混合作为酸提剂,乙醇作为沉淀剂,从西瓜皮中提取果胶,混合酸为冰乙酸与10%盐酸。试验考察了混合酸pH值、固液比、酸解温度、酸解时间、沉淀剂用量等因素对果胶提取的影响。以单因素实验为基础,通过正交试验优化果胶提取的实验条件,进而得到最佳的反应工艺,并对果胶样品进行检测。当提取温度保持80℃附近,pH值为2.0,提取时间持续70 min,瓜皮中果胶的浸提率接近10%。     

超声波辅助从菠萝皮中提取果胶的研究

以盐酸作为提取溶剂,采甩乙醇沉淀和超声波辅助处理方法从菠萝皮中提取果胶,研究了提取工艺条件对果胶收率的影响。结果表明,提取溶剂的pH为2、料液比为1：25,反应温度70℃、反应时间3h,超声功率100W,果胶的收率最高可达9.47％。